Commonwealth Edison 8-K30 Jun 22Other EventsFinancial data

Company Profile

Cover Page

Cover Page	Jun. 30, 2022
Document Type	8-K
Amendment Flag	false
Document Period End Date	Jun. 30, 2022
Entity File Number	001-16169
Entity Registrant Name	EXELON CORPORATION
Entity Tax Identification Number	23-2990190
Entity Incorporation, State or Country Code	PA
Entity Address, Address Line One	10 South Dearborn Street
Entity Address, Address Line Two	P.O. Box 805379
Entity Address, City or Town	Chicago
Entity Address, State or Province	IL
Entity Address, Postal Zip Code	60680-5379
City Area Code	(800)
Local Phone Number	483-3220
Title of 12(b) Security	Common Stock, without par value
Trading Symbol	EXC
Security Exchange Name	NASDAQ
Entity Emerging Growth Company	false
Entity Central Index Key	0001109357
Written Communications	false
Soliciting Material	false
Pre-commencement Tender Offer	false
Pre-commencement Issuer Tender Offer	false
Commonwealth Edison Co [Member]
Entity File Number	001-01839
Entity Registrant Name	COMMONWEALTH EDISON COMPANY
Entity Tax Identification Number	36-0938600
Entity Incorporation, State or Country Code	IL
Entity Address, Address Line One	10 South Dearborn Street
Entity Address, City or Town	Chicago
Entity Address, State or Province	IL
Entity Address, Postal Zip Code	60603-2300
City Area Code	(312)
Local Phone Number	394-4321
Entity Central Index Key	0000022606
PECO Energy Co [Member]
Entity File Number	000-16844
Entity Registrant Name	PECO ENERGY COMPANY
Entity Tax Identification Number	23-0970240
Entity Incorporation, State or Country Code	PA
Entity Address, Address Line One	P.O. Box 8699
Entity Address, Address Line Two	2301 Market Street
Entity Address, City or Town	Philadelphia
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	19101-8699
City Area Code	(215)
Local Phone Number	841-4000
Title of 12(b) Security	Cumulative Preferred Security, Series D
Trading Symbol	EXC/28
Security Exchange Name	NYSE
Entity Central Index Key	0000078100
Baltimore Gas and Electric Company [Member]
Entity File Number	001-01910
Entity Registrant Name	BALTIMORE GAS AND ELECTRIC COMPANY
Entity Tax Identification Number	52-0280210
Entity Incorporation, State or Country Code	MD
Entity Address, Address Line One	2 Center Plaza
Entity Address, Address Line Two	110 West Fayette Street
Entity Address, City or Town	Baltimore
Entity Address, State or Province	MD
Entity Address, Postal Zip Code	21201-3708
City Area Code	(410)
Local Phone Number	234-5000
Entity Central Index Key	0000009466
Pepco Holdings LLC [Member]
Entity File Number	001-31403
Entity Registrant Name	PEPCO HOLDINGS LLC
Entity Tax Identification Number	52-2297449
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	701 Ninth Street, N.W.
Entity Address, City or Town	Washington
Entity Address, State or Province	DC
Entity Address, Postal Zip Code	20068-0001
City Area Code	(202)
Local Phone Number	872-2000
Entity Central Index Key	0001135971
Potomac Electric Power Company [Member]
Entity File Number	001-01072
Entity Registrant Name	POTOMAC ELECTRIC POWER COMPANY
Entity Tax Identification Number	53-0127880
Entity Address, Address Line One	701 Ninth Street, N.W.
Entity Address, City or Town	Washington
Entity Address, State or Province	DC
Entity Address, Postal Zip Code	20068-0001
City Area Code	(202)
Local Phone Number	872-2000
Entity Central Index Key	0000079732
Delmarva Power & Light Company [Member]
Entity File Number	001-01405
Entity Registrant Name	DELMARVA POWER & LIGHT COMPANY
Entity Tax Identification Number	51-0084283
Entity Address, Address Line One	500 North Wakefield Drive
Entity Address, City or Town	Newark
Entity Address, State or Province	DE
Entity Address, Postal Zip Code	19702-5440
City Area Code	(202)
Local Phone Number	872-2000
Entity Central Index Key	0000027879
Atlantic City Electric Company [Member]
Entity File Number	001-03559
Entity Registrant Name	ATLANTIC CITY ELECTRIC COMPANY
Entity Tax Identification Number	21-0398280
Entity Incorporation, State or Country Code	NJ
Entity Address, Address Line One	500 North Wakefield Drive
Entity Address, City or Town	Newark
Entity Address, State or Province	DE
Entity Address, Postal Zip Code	19702-5440
City Area Code	(202)
Local Phone Number	872-2000
Entity Central Index Key	0000008192
VIRGINIA \| Potomac Electric Power Company [Member]
Entity Incorporation, State or Country Code	VA
VIRGINIA \| Delmarva Power & Light Company [Member]
Entity Incorporation, State or Country Code	VA
DELAWARE \| Delmarva Power & Light Company [Member]
Entity Incorporation, State or Country Code	DE
DISTRICT OF COLUMBIA \| Potomac Electric Power Company [Member]
Entity Incorporation, State or Country Code	DC

Auditor Information

Auditor Information	12 Months Ended
Auditor Information	Dec. 31, 2021
Auditor [Line Items]
Auditor Name	PricewaterhouseCoopers LLP
Auditor Location	Chicago, Illinois
Auditor Firm ID	238

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Income - USD ($) shares in Millions, $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating revenues
Revenues from alternative revenue programs		$ 171	$ 6	$ (155)
Total operating revenues		17,938	16,663	16,725
Operating expenses
Purchased power and/or fuel from affiliates		1,178	1,209	1,171
Operating and maintenance		4,547	4,641	4,324
Depreciation and Amortization		3,033	2,891	2,717
Taxes other than income		1,291	1,232	1,213
Total operating expenses		15,256	14,485	14,073
Gain on sales of assets and businesses		0	13	4
Operating income (loss)		2,682	2,191	2,656
Other income and (deductions)
Interest Expense, net		(1,264)	(1,282)	(1,197)
Interest expense to affiliates		(25)	(25)	(25)
Other, net		261	208	204
Total other income and (deductions)		(1,028)	(1,099)	(1,018)
Income (loss) before income taxes		1,654	1,092	1,638
Income taxes		38	(7)	153
Equity in losses of unconsolidated affiliates		0	0	1
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest		1,616	1,099	1,486
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest		213	855	1,542
Net income (loss)		1,829	1,954	3,028
Net income (loss) attributable to noncontrolling interests		123	(9)	92
Net income (loss) attributable to common shareholders		1,706	1,963	2,936
Net Income (Loss) from Continuing Operations Available to Common Shareholders, Basic		1,616	1,099	1,486
Net Income (Loss) from Discontinued Operations Available to Common Shareholders, Basic		90	864	1,450
Other comprehensive income (loss), net of income taxes
Prior service benefit reclassified to periodic benefit cost		(4)	(40)	(65)
Actuarial loss reclassified to periodic cost		223	190	149
Pension and non-pension postretirement benefit plan valuation adjustment		432	(357)	(289)
Unrealized (loss) gain on cash flow hedges		(1)	(3)	0
Unrealized gain (loss) on investments in unconsolidated affiliates		0	0	1
Unrealized (loss) gain on foreign currency translation		0	4	6
Other comprehensive income (loss)		650	(206)	(198)
Comprehensive income (loss)		2,479	1,748	2,830
Comprehensive income attributable to noncontrolling interests		123	(9)	93
Comprehensive income (loss) attributable to common shareholders		$ 2,356	$ 1,757	$ 2,737
Average shares of common stock outstanding:
Basic Average Number of Shares Outstanding		979	976	973
Assumed Exercise and/or Distributions of Stock-Based Awards		1	1	1
Diluted Average Number of Shares Outstanding	[1]	980	977	974
Income (Loss) from Continuing Operations, Per Basic Share		$ 1.65	$ 1.13	$ 1.53
Income (Loss) from Continuing Operations, Per Diluted Share		1.65	1.13	1.52
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Basic Share		0.09	0.88	1.49
Income (Loss) from Discontinued Operations and Disposal of Discontinued Operations, Net of Tax, Per Diluted Share		$ 0.09	$ 0.88	$ 1.49
Earnings per average common share from discontinued operations
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount		0	0	0
Commonwealth Edison Co [Member]
Operating revenues
Revenues from alternative revenue programs		$ 42	$ (47)	$ (133)
Operating revenues from affiliates		41	37	30
Total operating revenues		6,406	5,904	5,747
Operating expenses
Purchased power and/or fuel from affiliates		383	345	376
Operating and maintenance		1,048	1,231	1,041
Operating and maintenance from affiliates		307	289	264
Depreciation and Amortization		1,205	1,133	1,033
Taxes other than income		320	299	301
Total operating expenses		5,151	4,950	4,580
Gain on sales of assets and businesses		0	0	4
Operating income (loss)		1,255	954	1,171
Other income and (deductions)
Interest Expense, net		(376)	(369)	(346)
Interest expense to affiliates		(13)	(13)	(13)
Other, net		48	43	39
Total other income and (deductions)		(341)	(339)	(320)
Income (loss) before income taxes		914	615	851
Income taxes		172	177	163
Net income (loss)		742	438	688
Other comprehensive income (loss), net of income taxes
Comprehensive income (loss)		742	438	688
PECO Energy Co [Member]
Operating revenues
Revenues from alternative revenue programs		26	16	(21)
Operating revenues from affiliates		21	9	6
Total operating revenues		3,198	3,058	3,100
Operating expenses
Purchased power and/or fuel from affiliates		194	188	157
Operating and maintenance		757	816	707
Operating and maintenance from affiliates		177	159	154
Depreciation and Amortization		348	347	333
Taxes other than income		184	172	165
Total operating expenses		2,547	2,512	2,388
Gain on sales of assets and businesses		0	0	1
Operating income (loss)		651	546	713
Other income and (deductions)
Interest Expense, net		(149)	(136)	(124)
Interest expense to affiliates		(12)	(11)	(12)
Other, net		26	18	16
Total other income and (deductions)		(135)	(129)	(120)
Income (loss) before income taxes		516	417	593
Income taxes		12	(30)	65
Net income (loss)		504	447	528
Other comprehensive income (loss), net of income taxes
Comprehensive income (loss)		504	447	528
Baltimore Gas and Electric Company [Member]
Operating revenues
Revenues from alternative revenue programs		12	16	12
Operating revenues from affiliates		31	20	26
Total operating revenues		3,341	3,098	3,106
Operating expenses
Purchased power and/or fuel from affiliates		233	311	286
Operating and maintenance		618	617	600
Operating and maintenance from affiliates		193	172	160
Depreciation and Amortization		591	550	502
Taxes other than income		283	268	260
Total operating expenses		2,860	2,598	2,574
Operating income (loss)		481	500	532
Other income and (deductions)
Interest Expense, net		(138)	(133)	(121)
Other, net		30	23	28
Total other income and (deductions)		(108)	(110)	(93)
Income (loss) before income taxes		373	390	439
Income taxes		(35)	41	79
Net income (loss)		408	349	360
Other comprehensive income (loss), net of income taxes
Comprehensive income (loss)		408	349	360
Pepco Holdings LLC [Member]
Operating revenues
Revenues from alternative revenue programs		91	21	(14)
Operating revenues from affiliates		13	17	14
Total operating revenues		5,041	4,663	4,806
Operating expenses
Purchased power and/or fuel from affiliates		367	366	352
Operating and maintenance		925	940	939
Operating and maintenance from affiliates		179	159	143
Depreciation and Amortization		821	782	754
Taxes other than income		458	450	450
Total operating expenses		4,240	4,045	4,084
Gain on sales of assets and businesses		0	11	0
Operating income (loss)		801	629	722
Other income and (deductions)
Interest Expense, net		(267)	(268)	(263)
Other, net		69	57	55
Total other income and (deductions)		(198)	(211)	(208)
Income (loss) before income taxes		603	418	514
Income taxes		42	(77)	38
Equity in losses of unconsolidated affiliates		0	0	1
Net income (loss)		561	495	477
Other comprehensive income (loss), net of income taxes
Comprehensive income (loss) attributable to common shareholders		561	495	477
Potomac Electric Power Company [Member]
Operating revenues
Revenues from alternative revenue programs		53	40	(3)
Operating revenues from affiliates		5	7	5
Total operating revenues		2,274	2,149	2,260
Operating expenses
Purchased power and/or fuel from affiliates		271	278	264
Operating and maintenance		258	248	273
Operating and maintenance from affiliates		213	205	209
Depreciation and Amortization		403	377	374
Taxes other than income		373	367	378
Total operating expenses		1,871	1,799	1,899
Gain on sales of assets and businesses		0	9	0
Operating income (loss)		403	359	361
Other income and (deductions)
Interest Expense, net		(140)	(138)	(133)
Other, net		48	38	31
Total other income and (deductions)		(92)	(100)	(102)
Income (loss) before income taxes		311	259	259
Income taxes		15	(7)	16
Net income (loss)		296	266	243
Other comprehensive income (loss), net of income taxes
Comprehensive income (loss)		296	266	243
Delmarva Power & Light Company [Member]
Operating revenues
Revenues from alternative revenue programs		14	(7)	(11)
Operating revenues from affiliates		7	9	7
Total operating revenues		1,380	1,271	1,306
Operating expenses
Purchased power and/or fuel from affiliates		79	75	70
Operating and maintenance		183	208	171
Operating and maintenance from affiliates		162	153	152
Depreciation and Amortization		210	191	184
Taxes other than income		67	65	56
Total operating expenses		1,161	1,120	1,089
Operating income (loss)		219	151	217
Other income and (deductions)
Interest Expense, net		(61)	(61)	(61)
Other, net		12	10	13
Total other income and (deductions)		(49)	(51)	(48)
Income (loss) before income taxes		170	100	169
Income taxes		42	(25)	22
Net income (loss)		128	125	147
Other comprehensive income (loss), net of income taxes
Comprehensive income (loss)		128	125	147
Atlantic City Electric Company [Member]
Operating revenues
Revenues from alternative revenue programs		24	(12)	0
Operating revenues from affiliates		2	4	3
Total operating revenues		1,388	1,245	1,240
Operating expenses
Purchased power and/or fuel from affiliates		17	13	19
Operating and maintenance		179	192	187
Operating and maintenance from affiliates		141	134	133
Depreciation and Amortization		179	180	157
Taxes other than income		8	8	4
Total operating expenses		1,201	1,123	1,089
Gain on sales of assets and businesses		0	2	0
Operating income (loss)		187	124	151
Other income and (deductions)
Interest Expense, net		(58)	(59)	(58)
Other, net		4	6	6
Total other income and (deductions)		(54)	(53)	(52)
Income (loss) before income taxes		133	71	99
Income taxes		(13)	(41)	0
Net income (loss)		146	112	99
Other comprehensive income (loss), net of income taxes
Comprehensive income (loss)		146	112	99
Generation commodities and services [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		17,767	16,657	16,880
Operating expenses
Purchased power and/or fuel		5,207	4,512	4,648
Electricity, US Regulated [Member] \| Commonwealth Edison Co [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		6,323	5,914	5,850
Operating expenses
Purchased power and/or fuel		1,888	1,653	1,565
Electricity, US Regulated [Member] \| PECO Energy Co [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		2,613	2,519	2,505
Operating expenses
Purchased power and/or fuel		699	645	610
Electricity, US Regulated [Member] \| Baltimore Gas and Electric Company [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		2,497	2,323	2,368
Operating expenses
Purchased power and/or fuel		699	509	585
Electricity, US Regulated [Member] \| Pepco Holdings LLC [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		4,769	4,463	4,639
Operating expenses
Purchased power and/or fuel		1,417	1,279	1,371
Electricity, US Regulated [Member] \| Potomac Electric Power Company [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		2,216	2,102	2,258
Operating expenses
Purchased power and/or fuel		353	324	401
Electricity, US Regulated [Member] \| Delmarva Power & Light Company [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		1,191	1,107	1,143
Operating expenses
Purchased power and/or fuel		387	359	381
Electricity, US Regulated [Member] \| Atlantic City Electric Company [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		1,362	1,253	1,237
Operating expenses
Purchased power and/or fuel		677	596	589
Natural Gas, US Regulated [Member] \| PECO Energy Co [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		538	514	610
Operating expenses
Purchased power and/or fuel		188	185	262
Natural Gas, US Regulated [Member] \| Baltimore Gas and Electric Company [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		801	739	700
Operating expenses
Purchased power and/or fuel		243	171	181
Natural Gas, US Regulated [Member] \| Pepco Holdings LLC [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		168	162	167
Operating expenses
Purchased power and/or fuel		73	69	75
Natural Gas, US Regulated [Member] \| Delmarva Power & Light Company [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		168	162	167
Operating expenses
Purchased power and/or fuel		$ 73	$ 69	$ 75

[1]The number of stock options not included in the calculation of diluted common shares outstanding due to their antidilutive effect was zero for the year ended December 31, 2021 and less than 1 million for the years ended December 31, 2020 and 2019

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities
Net income (loss)	$ 1,829	$ 1,954	$ 3,028
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization and accretion, including nuclear fuel and energy contract amortization	7,573	6,527	5,780
Asset impairments	552	591	201
Gain on sales of assets and businesses	(201)	(24)	(27)
Deferred income taxes and amortization of investment tax credits	18	309	681
Net fair value changes related to derivatives	(568)	(268)	222
Net realized and unrealized gains on NDT fund investments	(586)	(461)	(663)
Net unrealized losses (gains) on equity investments	160	(186)	0
Other non-cash operating activities	(200)	592	613
Changes in assets and liabilities:
Accounts receivable	(703)	697	(243)
Inventories	(141)	(85)	(87)
Accounts payable and accrued expenses	440	(129)	(425)
Option premiums paid, net	(338)	(139)	(29)
Collateral received (posted), net	(74)	494	(438)
Income taxes	327	140	(64)
Pension and non-pension postretirement benefit contributions	(665)	(601)	(408)
Other assets and liabilities	(4,411)	(5,176)	(1,482)
Net cash flows provided by operating activities	3,012	4,235	6,659
Cash flows from investing activities
Capital expenditures	(7,981)	(8,048)	(7,248)
Proceeds from NDT fund sales	6,532	3,341	10,051
Investment in NDT funds	(6,673)	(3,464)	(10,087)
Collection of deferred purchase price	3,902	3,771	0
Acquisitions of assets and businesses, net	0	0	(41)
Proceeds from sales of assets and businesses	877	46	53
Other investing activities	26	18	12
Net cash flows used in investing activities	(3,317)	(4,336)	(7,260)
Cash flows from financing activities
Changes in short-term borrowings	269	161	781
Proceeds from short-term borrowings with maturities greater than 90 days	1,380	500	0
Repayments on short-term borrowings with maturities greater than 90 days	(350)	0	(125)
Issuance of long-term debt	3,481	7,507	1,951
Retirement of long-term debt	(1,640)	(6,440)	(1,287)
Dividends paid on common stock	(1,497)	(1,492)	(1,408)
Acquisition of CENG noncontrolling interest	(885)	0	0
Proceeds from employee stock plans	80	45	112
Other financing activities	(80)	(136)	(82)
Net cash flows provided by (used in) financing activities	758	145	(58)
Increase (decrease) in cash, restricted cash, and cash equivalents	453	44	(659)
Cash, restricted cash, and cash equivalents at beginning of period	1,166	1,122	1,781
Cash, restricted cash, and cash equivalents at end of period	1,619	1,166	1,122
Increase (decrease) in capital expenditures not paid	16	194	(7)
Increase in Deferred Purchase Price	3,652	4,441	0
Increase (decrease) in PPE related to ARO update	642	850	968
Commonwealth Edison Co [Member]
Cash flows from operating activities
Net income (loss)	742	438	688
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization and accretion, including nuclear fuel and energy contract amortization	1,205	1,133	1,033
Deferred income taxes and amortization of investment tax credits	244	228	109
Other non-cash operating activities	126	202	265
Changes in assets and liabilities:
Accounts receivable	(25)	(10)	(34)
Receivables from and payables to affiliates, net	32	(1)	(12)
Inventories	(2)	(13)	(16)
Accounts payable and accrued expenses	0	63	(51)
Collateral received (posted), net	0	14	48
Income taxes	0	8	95
Pension and non-pension postretirement benefit contributions	(196)	(148)	(77)
Other assets and liabilities	(531)	(590)	(345)
Net cash flows provided by operating activities	1,595	1,324	1,703
Cash flows from investing activities
Capital expenditures	(2,387)	(2,217)	(1,915)
Other investing activities	26	2	29
Net cash flows used in investing activities	(2,361)	(2,215)	(1,886)
Cash flows from financing activities
Changes in short-term borrowings	(323)	193	130
Issuance of long-term debt	1,150	1,000	700
Retirement of long-term debt	(350)	(500)	(300)
Dividends paid on common stock	(507)	(499)	(508)
Contributions from parent	791	712	250
Other financing activities	(16)	(13)	(16)
Net cash flows provided by (used in) financing activities	745	893	256
Increase (decrease) in cash, restricted cash, and cash equivalents	(21)	2	73
Cash, restricted cash, and cash equivalents at beginning of period	405	403	330
Cash, restricted cash, and cash equivalents at end of period	384	405	403
Increase (decrease) in capital expenditures not paid	(46)	109	(37)
PECO Energy Co [Member]
Cash flows from operating activities
Net income (loss)	504	447	528
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization and accretion, including nuclear fuel and energy contract amortization	348	347	333
Deferred income taxes and amortization of investment tax credits	11	(23)	20
Other non-cash operating activities	0	24	38
Changes in assets and liabilities:
Accounts receivable	(35)	(88)	(29)
Receivables from and payables to affiliates, net	21	(6)	(5)
Inventories	(26)	(1)	4
Accounts payable and accrued expenses	15	63	(11)
Income taxes	5	31	(34)
Pension and non-pension postretirement benefit contributions	(18)	(18)	(28)
Other assets and liabilities	(52)	1	(65)
Net cash flows provided by operating activities	773	777	751
Cash flows from investing activities
Capital expenditures	(1,240)	(1,147)	(939)
Changes in Exelon/PHI intercompany money pool	0	68	(68)
Other investing activities	9	7	(1)
Net cash flows used in investing activities	(1,231)	(1,072)	(1,008)
Cash flows from financing activities
Issuance of long-term debt	750	350	325
Retirement of long-term debt	(300)	0	0
Changes in Exelon/PHI intercompany money pool	(40)	40	0
Dividends paid on common stock	(339)	(340)	(358)
Contributions from parent	414	248	188
Other financing activities	(9)	(4)	(6)
Net cash flows provided by (used in) financing activities	476	294	149
Increase (decrease) in cash, restricted cash, and cash equivalents	18	(1)	(108)
Cash, restricted cash, and cash equivalents at beginning of period	26	27	135
Cash, restricted cash, and cash equivalents at end of period	44	26	27
Increase (decrease) in capital expenditures not paid	26	55	40
Baltimore Gas and Electric Company [Member]
Cash flows from operating activities
Net income (loss)	408	349	360
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization and accretion, including nuclear fuel and energy contract amortization	591	550	502
Deferred income taxes and amortization of investment tax credits	(17)	37	130
Other non-cash operating activities	75	97	85
Changes in assets and liabilities:
Accounts receivable	30	(165)	25
Receivables from and payables to affiliates, net	(13)	(8)	1
Inventories	(29)	10	(1)
Accounts payable and accrued expenses	14	102	(43)
Income taxes	20	60	(67)
Pension and non-pension postretirement benefit contributions	(81)	(78)	(48)
Other assets and liabilities	(269)	(70)	(196)
Net cash flows provided by operating activities	729	884	748
Cash flows from investing activities
Capital expenditures	(1,226)	(1,247)	(1,145)
Other investing activities	18	2	8
Net cash flows used in investing activities	(1,208)	(1,245)	(1,137)
Cash flows from financing activities
Changes in short-term borrowings	130	(76)	40
Issuance of long-term debt	600	400	400
Retirement of long-term debt	(300)	0	0
Dividends paid on common stock	(292)	(246)	(224)
Contributions from parent	257	411	193
Other financing activities	(6)	(8)	(8)
Net cash flows provided by (used in) financing activities	389	481	401
Increase (decrease) in cash, restricted cash, and cash equivalents	(90)	120	12
Cash, restricted cash, and cash equivalents at beginning of period	145	25	13
Cash, restricted cash, and cash equivalents at end of period	55	145	25
Increase (decrease) in capital expenditures not paid	(59)	53	6
Pepco Holdings LLC [Member]
Cash flows from operating activities
Net income (loss)	561	495	477
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization and accretion, including nuclear fuel and energy contract amortization	821	782	754
Deferred income taxes and amortization of investment tax credits	24	(97)	(7)
Other non-cash operating activities	(12)	103	161
Changes in assets and liabilities:
Accounts receivable	(48)	(159)	(39)
Receivables from and payables to affiliates, net	6	3	3
Inventories	(16)	(6)	(27)
Accounts payable and accrued expenses	34	49	(17)
Income taxes	17	(25)	16
Pension and non-pension postretirement benefit contributions	(48)	(39)	(25)
Other assets and liabilities	(182)	(104)	(179)
Net cash flows provided by operating activities	1,157	1,002	1,117
Cash flows from investing activities
Capital expenditures	(1,720)	(1,604)	(1,355)
Other investing activities	2	7	(3)
Net cash flows used in investing activities	(1,718)	(1,597)	(1,358)
Cash flows from financing activities
Changes in short-term borrowings	100	160	154
Repayments on short-term borrowings with maturities greater than 90 days	0	0	(125)
Issuance of long-term debt	825	602	485
Retirement of long-term debt	(260)	(128)	(157)
Changes in Exelon/PHI intercompany money pool	(14)	9	12
Distributions to member	(703)	(553)	(526)
Contributions from member	683	494	398
Other financing activities	(17)	(10)	(5)
Net cash flows provided by (used in) financing activities	614	574	236
Increase (decrease) in cash, restricted cash, and cash equivalents	53	(21)	(5)
Cash, restricted cash, and cash equivalents at beginning of period	160	181	186
Cash, restricted cash, and cash equivalents at end of period	213	160	181
Increase (decrease) in capital expenditures not paid	(6)	54	2
Potomac Electric Power Company [Member]
Cash flows from operating activities
Net income (loss)	296	266	243
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization and accretion, including nuclear fuel and energy contract amortization	403	377	374
Deferred income taxes and amortization of investment tax credits	(8)	(46)	1
Other non-cash operating activities	(52)	(23)	56
Changes in assets and liabilities:
Accounts receivable	(28)	(67)	(22)
Receivables from and payables to affiliates, net	6	(12)	5
Inventories	(8)	1	(19)
Accounts payable and accrued expenses	16	41	(39)
Income taxes	11	(1)	9
Pension and non-pension postretirement benefit contributions	(11)	(11)	(14)
Other assets and liabilities	(163)	(24)	(82)
Net cash flows provided by operating activities	462	501	512
Cash flows from investing activities
Capital expenditures	(843)	(773)	(626)
Other investing activities	(1)	0	3
Net cash flows used in investing activities	(844)	(773)	(623)
Cash flows from financing activities
Changes in short-term borrowings	140	(47)	42
Issuance of long-term debt	275	300	260
Retirement of long-term debt	0	(3)	(125)
Dividends paid on common stock	(268)	(232)	(213)
Contributions from parent	244	262	160
Other financing activities	(6)	(6)	(3)
Net cash flows provided by (used in) financing activities	385	274	121
Increase (decrease) in cash, restricted cash, and cash equivalents	3	2	10
Cash, restricted cash, and cash equivalents at beginning of period	65	63	53
Cash, restricted cash, and cash equivalents at end of period	68	65	63
Increase (decrease) in capital expenditures not paid	30	1	39
Delmarva Power & Light Company [Member]
Cash flows from operating activities
Net income (loss)	128	125	147
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization and accretion, including nuclear fuel and energy contract amortization	210	191	184
Deferred income taxes and amortization of investment tax credits	39	(13)	(7)
Other non-cash operating activities	3	51	27
Changes in assets and liabilities:
Accounts receivable	15	(34)	(5)
Receivables from and payables to affiliates, net	(3)	8	(5)
Inventories	(8)	(5)	(6)
Accounts payable and accrued expenses	16	4	3
Income taxes	13	(25)	12
Pension and non-pension postretirement benefit contributions	(1)	0	(1)
Other assets and liabilities	(27)	(30)	(55)
Net cash flows provided by operating activities	385	272	294
Cash flows from investing activities
Capital expenditures	(429)	(424)	(348)
Other investing activities	4	(3)	1
Net cash flows used in investing activities	(425)	(427)	(347)
Cash flows from financing activities
Changes in short-term borrowings	3	90	56
Issuance of long-term debt	125	178	75
Retirement of long-term debt	0	(80)	(12)
Dividends paid on common stock	(147)	(141)	(139)
Contributions from parent	120	112	63
Other financing activities	(5)	(2)	(1)
Net cash flows provided by (used in) financing activities	96	157	42
Increase (decrease) in cash, restricted cash, and cash equivalents	56	2	(11)
Cash, restricted cash, and cash equivalents at beginning of period	15	13	24
Cash, restricted cash, and cash equivalents at end of period	71	15	13
Increase (decrease) in capital expenditures not paid	(18)	20	(4)
Atlantic City Electric Company [Member]
Cash flows from operating activities
Net income (loss)	146	112	99
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization and accretion, including nuclear fuel and energy contract amortization	179	180	157
Deferred income taxes and amortization of investment tax credits	(15)	(37)	3
Other non-cash operating activities	0	36	22
Changes in assets and liabilities:
Accounts receivable	(37)	(55)	(13)
Receivables from and payables to affiliates, net	4	6	(6)
Inventories	1	(3)	(1)
Accounts payable and accrued expenses	3	5	26
Income taxes	0	(1)	2
Pension and non-pension postretirement benefit contributions	(3)	(2)	(1)
Other assets and liabilities	17	(42)	(27)
Net cash flows provided by operating activities	295	199	261
Cash flows from investing activities
Capital expenditures	(445)	(401)	(375)
Other investing activities	1	6	(1)
Net cash flows used in investing activities	(444)	(395)	(376)
Cash flows from financing activities
Changes in short-term borrowings	(43)	117	56
Repayments on short-term borrowings with maturities greater than 90 days	0	0	(125)
Issuance of long-term debt	425	123	150
Retirement of long-term debt	(260)	(44)	(18)
Dividends paid on common stock	(288)	(114)	(124)
Contributions from parent	319	117	175
Other financing activities	(5)	(1)	(1)
Net cash flows provided by (used in) financing activities	148	198	113
Increase (decrease) in cash, restricted cash, and cash equivalents	(1)	2	(2)
Cash, restricted cash, and cash equivalents at beginning of period	30	28	30
Cash, restricted cash, and cash equivalents at end of period	29	30	28
Increase (decrease) in capital expenditures not paid	$ (18)	$ 33	$ (29)

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions		Dec. 31, 2021	Dec. 31, 2020
Current assets
Cash and cash equivalents		$ 672	$ 432
Restricted cash and cash equivalents		321	349
Accounts receivable
Customer accounts receivable		2,189	2,266
Customer allowance for credit losses		(320)	(334)
Customer accounts receivable, net		1,869	1,932
Other accounts receivable		1,068	1,117
Other allowance for credit losses		(72)	(71)
Other accounts receivable, net		996	1,046
Inventories, net
Fossil fuel and emission allowances		105	64
Materials and supplies		476	447
Regulatory assets, current		1,296	1,228
Currents assets of discontinued operations		7,835	6,841
Other		387	223
Total current assets		13,957	12,562
Accumulated depreciation and amortization		14,430	13,346
Property, plant and equipment, net		64,558	60,332
Deferred debits and other assets
Regulatory assets, noncurrent		8,224	8,759
Investments		250	238
Goodwill		6,630	6,630
Other		885	1,143
Disposal Group, Including Discontinued Operation, Other Assets, Noncurrent		38,509	39,653
Total deferred debits and other assets		54,498	56,423
Total assets	[1]	133,013	129,317
Current liabilities
Short-term borrowings		1,248	1,191
Long-term debt due within one year		2,153	1,622
Accounts payable		2,379	2,309
Accrued expenses		1,137	1,230
Payables to affiliates, current		5	5
Regulatory liabilities, current		376	581
Mark-to-market derivative liabilities, current		18	33
Unamortized energy contract liabilities, current		89	93
Liabilities held for sale		7,940	4,923
Other		766	784
Total current liabilities		16,111	12,771
Long-term debt		30,749	29,527
Long-term debt to financing trusts		390	390
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		10,611	9,592
Asset retirement obligations, noncurrent		271	246
Pension obligations		2,051	2,946
Non-pension postretirement benefits obligations		811	1,002
Regulatory liabilities, noncurrent		9,628	9,485
Mark-to-market derivative liabilities, noncurrent		201	268
Unamortized energy contract liabilities, noncurrent		146	235
Other		1,573	1,642
Disposal Group, Including Discontinued Operation, Other Liabilities, Noncurrent		25,676	26,345
Total deferred credits and other liabilities		50,968	51,761
Total liabilities	[1]	98,218	94,449
Commitments and contingencies
Shareholders’ equity
Common Stock, No Par Value		$ 0	$ 0
Common Stock, Shares Authorized		2,000,000,000	2,000,000,000
Common Stock, Shares, Outstanding		979,000,000	976,000,000
Common stock		$ 20,324	$ 19,373
Treasury Stock, Shares		2,000,000	2,000,000
Treasury stock, at cost		$ (123)	$ (123)
Retained earnings/Undistributed earnings (losses)		16,942	16,735
Accumulated other comprehensive loss, net		(2,750)	(3,400)
Total shareholders’ equity		34,393	32,585
Member’s equity
Noncontrolling interests		402	2,283
Total equity		34,795	34,868
Total liabilities and equity		133,013	129,317
Variable Interest Entity, Primary Beneficiary [Member] \| Asset Pledged as Collateral [Member]
Deferred debits and other assets
Total assets			18
Variable Interest Entity, Primary Beneficiary [Member] \| Nonrecourse [Member]
Deferred credits and other liabilities
Total liabilities			26
Commonwealth Edison Co [Member]
Current assets
Cash and cash equivalents		131	83
Restricted cash and cash equivalents		210	279
Accounts receivable
Customer accounts receivable		647	656
Customer allowance for credit losses		(73)	(97)
Customer accounts receivable, net		574	559
Other accounts receivable		227	239
Other allowance for credit losses		(17)	(21)
Other accounts receivable, net		210	218
Receivables from affiliates, current		16	22
Inventories, net
Inventories, net		170	170
Regulatory assets, current		335	279
Other		76	49
Total current assets		1,722	1,659
Accumulated depreciation and amortization		6,099	5,672
Property, plant and equipment, net		25,995	24,557
Deferred debits and other assets
Regulatory assets, noncurrent		1,870	1,749
Investments		6	6
Goodwill		2,625	2,625
Receivable from affiliates, noncurrent		2,761	2,541
Prepaid pension asset		1,086	1,022
Other		405	307
Total deferred debits and other assets		8,753	8,250
Total assets		36,470	34,466
Current liabilities
Short-term borrowings		0	323
Long-term debt due within one year		0	350
Accounts payable		647	683
Accrued expenses		384	390
Payables to affiliates, current		121	96
Customer deposits		99	86
Regulatory liabilities, current		185	289
Mark-to-market derivative liabilities, current		18	33
Other		133	143
Total current liabilities		1,587	2,393
Long-term debt		9,773	8,633
Long-term debt to financing trusts		205	205
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		4,685	4,341
Asset retirement obligations, noncurrent		144	126
Non-pension postretirement benefits obligations		169	173
Regulatory liabilities, noncurrent		6,759	6,403
Mark-to-market derivative liabilities, noncurrent		201	268
Other		592	595
Total deferred credits and other liabilities		12,550	11,906
Total liabilities		24,115	23,137
Commitments and contingencies
Shareholders’ equity
Common Stock, Par or Stated Value Per Share		$ 12.50	$ 12.50
Common Stock, Shares Authorized		250,000,000	250,000,000
Common Stock, Shares, Outstanding		127,000,000	127,000,000
Common stock		$ 1,588	$ 1,588
Other paid-in capital		9,076	8,285
Retained deficit unappropriated		(1,639)	(1,639)
Retained earnings appropriated		3,330	3,095
Total shareholders’ equity		12,355	11,329
Member’s equity
Total liabilities and equity		36,470	34,466
PECO Energy Co [Member]
Current assets
Cash and cash equivalents		36	19
Restricted cash and cash equivalents		8	7
Accounts receivable
Customer accounts receivable		489	511
Customer allowance for credit losses		(105)	(116)
Customer accounts receivable, net		384	395
Other accounts receivable		116	130
Other allowance for credit losses		(7)	(8)
Other accounts receivable, net		109	122
Receivables from affiliates, current		1	2
Inventories, net
Fossil fuel and emission allowances		51	33
Materials and supplies		45	38
Regulatory assets, current		48	25
Other		29	21
Total current assets		711	662
Accumulated depreciation and amortization		3,964	3,843
Property, plant and equipment, net		11,117	10,181
Deferred debits and other assets
Regulatory assets, noncurrent		943	776
Investments		34	30
Receivable from affiliates, noncurrent		597	475
Prepaid pension asset		386	375
Other		36	32
Total deferred debits and other assets		1,996	1,688
Total assets		13,824	12,531
Current liabilities
Long-term debt due within one year		350	300
Accounts payable		494	479
Accrued expenses		136	129
Payables to affiliates, current		70	50
Borrowings from Exelon/PHI intercompany money pool		0	40
Customer deposits		48	59
Regulatory liabilities, current		94	121
Other		35	30
Total current liabilities		1,227	1,208
Long-term debt		3,847	3,453
Long-term debt to financing trusts		184	184
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		2,421	2,242
Asset retirement obligations, noncurrent		29	29
Non-pension postretirement benefits obligations		286	286
Regulatory liabilities, noncurrent		635	503
Other		83	93
Total deferred credits and other liabilities		3,454	3,153
Total liabilities		8,712	7,998
Commitments and contingencies
Shareholders’ equity
Common Stock, No Par Value		$ 0	$ 0
Common Stock, Shares Authorized		500,000,000	500,000,000
Common Stock, Shares, Outstanding		170,000,000	170,000,000
Common stock		$ 3,428	$ 3,014
Retained earnings/Undistributed earnings (losses)		1,684	1,519
Total shareholders’ equity		5,112	4,533
Member’s equity
Total liabilities and equity		13,824	12,531
Baltimore Gas and Electric Company [Member]
Current assets
Cash and cash equivalents		51	144
Restricted cash and cash equivalents		4	1
Accounts receivable
Customer accounts receivable		436	487
Customer allowance for credit losses		(38)	(35)
Customer accounts receivable, net		398	452
Other accounts receivable		124	117
Other allowance for credit losses		(9)	(9)
Other accounts receivable, net		115	108
Receivables from affiliates, current		1	3
Inventories, net
Fossil fuel and emission allowances		42	25
Materials and supplies		53	41
Prepaid utility taxes		49	0
Regulatory assets, current		215	168
Other		8	6
Total current assets		936	948
Accumulated depreciation and amortization		4,299	4,034
Property, plant and equipment, net		10,577	9,872
Deferred debits and other assets
Regulatory assets, noncurrent		477	481
Investments		14	10
Prepaid pension asset		276	270
Other		44	69
Total deferred debits and other assets		811	830
Total assets		12,324	11,650
Current liabilities
Short-term borrowings		130	0
Long-term debt due within one year		250	300
Accounts payable		349	346
Accrued expenses		176	205
Payables to affiliates, current		48	61
Customer deposits		97	110
Regulatory liabilities, current		26	30
Other		48	91
Total current liabilities		1,124	1,143
Long-term debt		3,711	3,364
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		1,686	1,521
Asset retirement obligations, noncurrent		26	23
Non-pension postretirement benefits obligations		175	189
Regulatory liabilities, noncurrent		934	1,109
Other		98	104
Total deferred credits and other liabilities		2,919	2,946
Total liabilities		7,754	7,453
Commitments and contingencies
Shareholders’ equity
Common Stock, No Par Value		$ 0	$ 0
Common Stock, Shares Authorized		1,500	1,500
Common Stock, Shares, Outstanding		1,000	1,000
Common stock	[2]	$ 2,575	$ 2,318
Retained earnings/Undistributed earnings (losses)		1,995	1,879
Total shareholders’ equity		4,570	4,197
Member’s equity
Total liabilities and equity		12,324	11,650
Pepco Holdings LLC [Member]
Current assets
Cash and cash equivalents		136	111
Restricted cash and cash equivalents		77	39
Accounts receivable
Customer accounts receivable		616	611
Customer allowance for credit losses		(104)	(86)
Customer accounts receivable, net		512	525
Other accounts receivable		283	260
Other allowance for credit losses		(39)	(33)
Other accounts receivable, net		244	227
Receivables from affiliates, current		2	8
Inventories, net
Fossil fuel and emission allowances		11	6
Materials and supplies		209	198
Regulatory assets, current		432	440
Other		69	45
Total current assets		1,692	1,599
Accumulated depreciation and amortization		2,108	1,811
Property, plant and equipment, net		16,498	15,377
Deferred debits and other assets
Regulatory assets, noncurrent		1,794	1,933
Investments		145	140
Goodwill		4,005	4,005
Prepaid pension asset		344	365
Deferred income taxes		8	10
Other		258	307
Total deferred debits and other assets		6,554	6,760
Total assets	[3]	24,744	23,736
Current liabilities
Short-term borrowings		468	368
Long-term debt due within one year		399	347
Accounts payable		578	539
Accrued expenses		281	299
Payables to affiliates, current		104	104
Borrowings from Exelon/PHI intercompany money pool		7	21
Customer deposits		81	106
Regulatory liabilities, current		68	137
Unamortized energy contract liabilities, current		89	92
Other		171	141
Total current liabilities		2,246	2,154
Long-term debt		7,148	6,659
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		2,675	2,439
Asset retirement obligations, noncurrent		70	59
Non-pension postretirement benefits obligations		66	86
Regulatory liabilities, noncurrent		1,238	1,438
Unamortized energy contract liabilities, noncurrent		146	235
Other		570	622
Total deferred credits and other liabilities		4,765	4,879
Total liabilities	[3]	14,159	13,692
Commitments and contingencies
Shareholders’ equity
Retained earnings/Undistributed earnings (losses)		(210)	(68)
Member’s equity
Membership interest		10,795	10,112
Total member’s equity		10,585	10,044
Total equity		10,585	10,044
Total liabilities and equity		24,744	23,736
Pepco Holdings LLC [Member] \| Variable Interest Entity, Primary Beneficiary [Member]
Current assets
Restricted cash and cash equivalents			3
Inventories, net
Other			5
Total current assets			8
Deferred debits and other assets
Other			10
Total assets			18
Current liabilities
Long-term debt due within one year			26
Total current liabilities			26
Deferred credits and other liabilities
Total liabilities			26
Pepco Holdings LLC [Member] \| Variable Interest Entity, Primary Beneficiary [Member] \| Asset Pledged as Collateral [Member]
Deferred debits and other assets
Total assets		0	18
Pepco Holdings LLC [Member] \| Variable Interest Entity, Primary Beneficiary [Member] \| Nonrecourse [Member]
Deferred credits and other liabilities
Total liabilities		0	26
Potomac Electric Power Company [Member]
Current assets
Cash and cash equivalents		34	30
Restricted cash and cash equivalents		34	35
Accounts receivable
Customer accounts receivable		277	279
Customer allowance for credit losses		(37)	(32)
Customer accounts receivable, net		240	247
Other accounts receivable		160	131
Other allowance for credit losses		(16)	(13)
Other accounts receivable, net		144	118
Receivables from affiliates, current		0	2
Inventories, net
Inventories, net		119	111
Regulatory assets, current		213	214
Other		25	13
Total current assets		809	770
Accumulated depreciation and amortization		3,875	3,697
Property, plant and equipment, net		8,104	7,456
Deferred debits and other assets
Regulatory assets, noncurrent		532	570
Investments		120	115
Prepaid pension asset		279	284
Other		59	69
Total deferred debits and other assets		990	1,038
Total assets		9,903	9,264
Current liabilities
Short-term borrowings		175	35
Long-term debt due within one year		313	3
Accounts payable		272	226
Accrued expenses		160	164
Payables to affiliates, current		59	55
Customer deposits		35	51
Regulatory liabilities, current		14	46
Merger related obligation		27	33
Other		55	61
Total current liabilities		1,110	674
Long-term debt		3,132	3,162
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		1,275	1,189
Asset retirement obligations, noncurrent		45	39
Non-pension postretirement benefits obligations		3	13
Regulatory liabilities, noncurrent		549	644
Other		314	340
Total deferred credits and other liabilities		2,186	2,225
Total liabilities		6,428	6,061
Commitments and contingencies
Shareholders’ equity
Common Stock, Par or Stated Value Per Share		$ 0.01	$ 0.01
Common Stock, Shares Authorized		200,000,000	200,000,000
Common Stock, Shares, Outstanding		100	100
Common stock	[4]	$ 2,302	$ 2,058
Retained earnings/Undistributed earnings (losses)		1,173	1,145
Total shareholders’ equity		3,475	3,203
Member’s equity
Total liabilities and equity		9,903	9,264
Delmarva Power & Light Company [Member]
Current assets
Cash and cash equivalents		28	15
Restricted cash and cash equivalents		43	0
Accounts receivable
Customer accounts receivable		149	176
Customer allowance for credit losses		(18)	(22)
Customer accounts receivable, net		131	154
Other accounts receivable		58	68
Other allowance for credit losses		(8)	(9)
Other accounts receivable, net		50	59
Receivables from affiliates, current		1	1
Inventories, net
Fossil fuel and emission allowances		11	6
Materials and supplies		54	51
Prepaid utility taxes		20	11
Regulatory assets, current		68	58
Other		16	13
Total current assets		422	368
Accumulated depreciation and amortization		1,635	1,533
Property, plant and equipment, net		4,560	4,314
Deferred debits and other assets
Regulatory assets, noncurrent		212	222
Prepaid pension asset		157	162
Other		61	74
Total deferred debits and other assets		430	458
Total assets		5,412	5,140
Current liabilities
Short-term borrowings		149	146
Long-term debt due within one year		83	82
Accounts payable		131	126
Accrued expenses		40	46
Payables to affiliates, current		33	36
Customer deposits		28	32
Regulatory liabilities, current		25	47
Other		59	20
Total current liabilities		548	535
Long-term debt		1,727	1,595
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		803	715
Asset retirement obligations, noncurrent		16	14
Non-pension postretirement benefits obligations		11	15
Regulatory liabilities, noncurrent		441	493
Other		89	97
Total deferred credits and other liabilities		1,360	1,334
Total liabilities		3,635	3,464
Commitments and contingencies
Shareholders’ equity
Common Stock, Par or Stated Value Per Share		$ 2.25	$ 2.25
Common Stock, Shares Authorized		1,000	1,000
Common Stock, Shares, Outstanding		1,000	1,000
Common stock	[5]	$ 1,209	$ 1,089
Retained earnings/Undistributed earnings (losses)		568	587
Total shareholders’ equity		1,777	1,676
Member’s equity
Total liabilities and equity		5,412	5,140
Atlantic City Electric Company [Member]
Current assets
Cash and cash equivalents		29	17
Restricted cash and cash equivalents		0	3
Accounts receivable
Customer accounts receivable		190	156
Customer allowance for credit losses		(49)	(32)
Customer accounts receivable, net		141	124
Other accounts receivable		76	72
Other allowance for credit losses		(15)	(11)
Other accounts receivable, net		61	61
Receivables from affiliates, current		2	6
Inventories, net
Inventories, net		36	37
Regulatory assets, current		61	75
Other		3	3
Total current assets		333	326
Accumulated depreciation and amortization		1,420	1,303
Property, plant and equipment, net		3,729	3,475
Deferred debits and other assets
Regulatory assets, noncurrent		430	395
Prepaid pension asset		27	40
Other		37	50
Total deferred debits and other assets		494	485
Total assets	[6]	4,556	4,286
Current liabilities
Short-term borrowings		144	187
Long-term debt due within one year		3	261
Accounts payable		165	177
Accrued expenses		44	46
Payables to affiliates, current		31	31
Customer deposits		18	23
Regulatory liabilities, current		28	44
Other		12	11
Total current liabilities		445	780
Long-term debt		1,579	1,152
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits		679	624
Non-pension postretirement benefits obligations		12	17
Regulatory liabilities, noncurrent		224	274
Other		49	48
Total deferred credits and other liabilities		964	963
Total liabilities	[6]	2,988	2,895
Commitments and contingencies
Shareholders’ equity
Common Stock, Par or Stated Value Per Share		$ 3	$ 3
Common Stock, Shares Authorized		25,000,000	25,000,000
Common Stock, Shares, Outstanding		9,000,000	9,000,000
Common stock		$ 1,590	$ 1,271
Retained earnings/Undistributed earnings (losses)		(22)	120
Total shareholders’ equity		1,568	1,391
Member’s equity
Total liabilities and equity		4,556	4,286
Atlantic City Electric Company [Member] \| Variable Interest Entity, Primary Beneficiary [Member]
Current assets
Restricted cash and cash equivalents			3
Inventories, net
Other			0
Total current assets			3
Deferred debits and other assets
Other			10
Total assets			13
Current liabilities
Long-term debt due within one year			21
Total current liabilities			21
Deferred credits and other liabilities
Total liabilities			21
Atlantic City Electric Company [Member] \| Variable Interest Entity, Primary Beneficiary [Member] \| Asset Pledged as Collateral [Member]
Deferred debits and other assets
Total assets		0	13
Atlantic City Electric Company [Member] \| Variable Interest Entity, Primary Beneficiary [Member] \| Nonrecourse [Member]
Deferred credits and other liabilities
Total liabilities		$ 0	$ 21

[1]Exelon’s consolidated assets include $18 million as of December 31, 2020, of certain VIEs that can only be used to settle the liabilities of the VIE. Exelon’s consolidated liabilities include $26 million as of December 31, 2020, of certain VIEs for which the VIE creditors do not have recourse to Exelon. See Note 21–Variable Interest Entities for additional information.[2]In millions, shares round to zero. Number of shares is 1,500 authorized and 1,000 outstanding as of December 31, 2021 and 2020.[3]PHI’s consolidated total assets include $0 million and $18 million as of December 31, 2021 and 2020, respectively, of PHI's consolidated VIE that can only be used to settle the liabilities of the VIE. PHI’s consolidated total liabilities include $0 million and $26 million as of December 31, 2021 and 2020, respectively, of PHI's consolidated VIE for which the VIE creditors do not have recourse to PHI. See Note 21 - Variable Interest Entities for additional information.[4]In millions, shares round to zero. Number of shares is 100 outstanding as of December 31, 2021 and 2020.[5]In millions, shares round to zero. Number of shares is 1,000 authorized and 1,000 outstanding as of December 31, 2021 and 2020.[6] ACE’s consolidated assets include $0 million and $13 million as of December 31, 2021 and 2020, respectively, of ACE’s consolidated VIE that can only be used to settle the liabilities of the VIE. ACE’s consolidated liabilities include $0 million and $21 million as of December 31, 2021 and 2020, respectively, of ACE’s consolidated VIE for which the VIE creditors do not have recourse to ACE. See Note 21 - Variable Interest Entities for additional information.

Consolidated Statement of Chang

Consolidated Statement of Changes in Shareholders Equity - USD ($) shares in Thousands, $ in Millions	Total	Common Stock [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss), net	Noncontrolling Interest [Member]	Other Comprehensive Income (Loss) [Member]	Commonwealth Edison Co [Member]	Commonwealth Edison Co [Member] Common Stock [Member]	Commonwealth Edison Co [Member] Retained Earnings [Member]	Commonwealth Edison Co [Member] Other Additional Capital [Member]	Commonwealth Edison Co [Member] Retained Earnings, Unappropriated [Member]	Commonwealth Edison Co [Member] Retained Earnings Appropriated [Member]	PECO Energy Co [Member]	PECO Energy Co [Member] Common Stock [Member]	PECO Energy Co [Member] Retained Earnings [Member]	Baltimore Gas and Electric Company [Member]	Baltimore Gas and Electric Company [Member] Common Stock [Member]	Baltimore Gas and Electric Company [Member] Retained Earnings [Member]	Pepco Holdings LLC [Member]	Pepco Holdings LLC [Member] Membership Interest [Member]	Pepco Holdings LLC [Member] Retained Earnings [Member]	Potomac Electric Power Company [Member]	Potomac Electric Power Company [Member] Common Stock [Member]	Potomac Electric Power Company [Member] Retained Earnings [Member]	Delmarva Power & Light Company [Member]	Delmarva Power & Light Company [Member] Common Stock [Member]	Delmarva Power & Light Company [Member] Retained Earnings [Member]	Atlantic City Electric Company [Member]	Atlantic City Electric Company [Member] Common Stock [Member]	Atlantic City Electric Company [Member] Retained Earnings [Member]
Beginning Balance (in shares) at Dec. 31, 2018	970,020
Beginning Balance at Dec. 31, 2018	$ 33,047	$ 19,116	$ (123)	$ 14,743	$ (2,995)	$ 2,306
Beginning Balance at Dec. 31, 2018																				$ 9,259	$ 9,220	$ 39
Beginning Balance at Dec. 31, 2018								$ 10,247	$ 1,588		$ 7,322	$ (1,639)	$ 2,976	$ 3,820	$ 2,578	$ 1,242	$ 3,354	$ 1,714	$ 1,640				$ 2,717	$ 1,636	$ 1,081	$ 1,509	$ 914	$ 595	$ 1,126	$ 979	$ 147
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 3,028			2,936		92		688				688		528		528	360		360	477		477	243		243	147		147	99		99
Appropriation of retained earnings for future dividends										$ 0		(688)	688
Long-Term Incentive Plan Activity (shares)	3,111
Long-Term Incentive Plan Activity	$ 40	40
Employee stock purchase plan issuances, shares	1,285
Employee stock purchase plan issuances	$ 112	112
Sale of noncontrolling interests	6	6
Changes in equity of noncontrolling interests	(48)					(48)
Acquisition of CENG noncontrolling interest	$ 0
Common Stock, Dividends, Per Share, Declared	$ 1.45
Common stock dividends	$ (1,412)			(1,412)				(508)					(508)	(358)		(358)	(224)		(224)				(213)		(213)	(139)		(139)	(124)		(124)
Other Comprehensive Income (Loss), Net of Tax	$ (198)				(199)	(1)	$ (200)
Distributions to member																				(526)		(526)
Contributions from parent								250			250			188	188		193	193		398	398		160	160		63	63		175	175
Ending Balance (in shares) at Dec. 31, 2019	974,416
Ending Balance at Dec. 31, 2019	$ 34,573	19,274	(123)	16,267	(3,194)	2,349
Ending Balance at Dec. 31, 2019								10,677	1,588		7,572	(1,639)	3,156	4,178	2,766	1,412	3,683	1,907	1,776				2,907	1,796	1,111	1,580	977	603	1,276	1,154	122
Ending Balance at Dec. 31, 2019																				9,608	9,618	(10)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 1,954			1,963		(9)		438				438		447		447	349		349	495		495	266		266	125		125	112		112
Appropriation of retained earnings for future dividends										0		(438)	438
Long-Term Incentive Plan Activity (shares)	1,570
Long-Term Incentive Plan Activity	$ 40	40
Employee stock purchase plan issuances, shares	1,480
Employee stock purchase plan issuances	$ 56	56
Sale of noncontrolling interests	3	3				(57)
Changes in equity of noncontrolling interests	(57)
Acquisition of CENG noncontrolling interest	$ 0
Common Stock, Dividends, Per Share, Declared	$ 1.53
Common stock dividends	$ (1,495)			(1,495)				(499)					(499)	(340)		(340)	(246)		(246)				(232)		(232)	(141)		(141)	(114)		(114)
Other Comprehensive Income (Loss), Net of Tax	$ (206)				(206)
Distributions to member																				(553)		(553)
Contributions from parent								713			713			248	248		411	411		494	494		262	262		112	112		117	117
Ending Balance (in shares) at Dec. 31, 2020	977,466
Ending Balance at Dec. 31, 2020	$ 34,868	19,373	(123)	16,735	(3,400)	2,283
Ending Balance at Dec. 31, 2020	32,585							11,329	1,588		8,285	(1,639)	3,095	4,533	3,014	1,519	4,197	2,318	1,879				3,203	2,058	1,145	1,676	1,089	587	1,391	1,271	120
Ending Balance at Dec. 31, 2020																				10,044	10,112	(68)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Retained earnings appropriated								3,095
Net income (loss)	$ 1,829			1,706		123		742				742		504		504	408		408	561		561	296		296	128		128	146		146
Appropriation of retained earnings for future dividends										$ 0		(742)	742
Long-Term Incentive Plan Activity (shares)	1,734
Long-Term Incentive Plan Activity	$ 69	69
Employee stock purchase plan issuances, shares	2,091
Employee stock purchase plan issuances	$ 90	90
Changes in equity of noncontrolling interests	(37)					(37)
Acquisition of CENG noncontrolling interest	(885)	1,080				(1,965)
Deferred Tax Liability Adjustment - Noncontrolling Interest	$ (290)	(290)
Common Stock, Dividends, Per Share, Declared	$ 1.53
Common stock dividends	$ (1,499)			(1,499)				(507)					(507)	(339)		(339)	(292)		(292)				(268)		(268)	(147)		(147)	(288)		(288)
Payments to Noncontrolling Interests	0	2				(2)
Other Comprehensive Income (Loss), Net of Tax	$ 650				650
Distributions to member																				(703)		(703)
Contributions from parent								791			791			414	414		257	257		683	683		244	244		120	120		319	319
Ending Balance (in shares) at Dec. 31, 2021	981,291
Ending Balance at Dec. 31, 2021	$ 34,795	$ 20,324	$ (123)	$ 16,942	$ (2,750)	$ 402
Ending Balance at Dec. 31, 2021	$ 34,393							12,355	$ 1,588		$ 9,076	$ (1,639)	$ 3,330	$ 5,112	$ 3,428	$ 1,684	$ 4,570	$ 2,575	$ 1,995				$ 3,475	$ 2,302	$ 1,173	$ 1,777	$ 1,209	$ 568	$ 1,568	$ 1,590	$ (22)
Ending Balance at Dec. 31, 2021																				$ 10,585	$ 10,795	$ (210)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Retained earnings appropriated								$ 3,330

Significant Accounting Policies

Significant Accounting Policies (All Registrants)	12 Months Ended
Significant Accounting Policies (All Registrants)	Dec. 31, 2021
Accounting Policies [Abstract]
Significant Accounting Policies (All Registrants)	Significant Accounting Policies (All Registrants) Description of Business (All Registrants) As of December 31, 2021, Exelon was a utility services holding company engaged in the generation, delivery and marketing of energy through Generation and the energy distribution and transmission businesses through ComEd, PECO, BGE, Pepco, DPL, and ACE. On February 21, 2021, Exelon’s Board of Directors approved a plan to separate the Utility Registrants and Generation, creating two publicly traded companies. The separation was completed on February 1, 2022. See Note 2 — Discontinued Operations for additional information. Name of Registrant Business Service Territories Commonwealth Edison Company Purchase and regulated retail sale of electricity Northern Illinois, including the City of Chicago Transmission and distribution of electricity to retail customers PECO Energy Company Purchase and regulated retail sale of electricity and natural gas Southeastern Pennsylvania, including the City of Philadelphia (electricity) Transmission and distribution of electricity and distribution of natural gas to retail customers Pennsylvania counties surrounding the City of Philadelphia (natural gas) Baltimore Gas and Electric Company Purchase and regulated retail sale of electricity and natural gas Central Maryland, including the City of Baltimore (electricity and natural gas) Transmission and distribution of electricity and distribution of natural gas to retail customers Pepco Holdings LLC Utility services holding company engaged, through its reportable segments Pepco, DPL, and ACE Service Territories of Pepco, DPL, and ACE Potomac Electric Power Company Purchase and regulated retail sale of electricity District of Columbia, and major portions of Montgomery and Prince George’s Counties, Maryland. Transmission and distribution of electricity to retail customers Delmarva Power & Light Company Purchase and regulated retail sale of electricity and natural gas Portions of Delaware and Maryland (electricity) Transmission and distribution of electricity and distribution of natural gas to retail customers Portions of New Castle County, Delaware (natural gas) Atlantic City Electric Company Purchase and regulated retail sale of electricity Portions of Southern New Jersey Transmission and distribution of electricity to retail customers Basis of Presentation (All Registrants) This is a combined annual report of all Registrants. The Notes to the Consolidated Financial Statements apply to the Registrants as indicated parenthetically next to each corresponding disclosure. When appropriate, the Registrants are named specifically for their related activities and disclosures. Each of the Registrant’s Consolidated Financial Statements includes the accounts of its subsidiaries. All intercompany transactions have been eliminated, except for the historical transactions between the Utility Registrants and Generation for the purposes of presenting discontinued operations in all periods presented in the Consolidated Statements of Operations and Comprehensive Income. Through its business services subsidiary, BSC, Exelon provides its subsidiaries with a variety of support services at cost, including legal, human resources, financial, information technology, and supply management services. PHI also has a business services subsidiary, PHISCO, which provides a variety of support services at cost, including legal, accounting, engineering, customer operations, distribution and transmission planning, asset management, system operations, and power procurement, to PHI operating companies. The costs of BSC and PHISCO are directly charged or allocated to the applicable subsidiaries. The results of Exelon’s corporate operations are presented as “Other” within the consolidated financial statements and include intercompany eliminations unless otherwise disclosed. As of December 31, 2021 and 2020, Exelon owned 100% of Generation, PECO, BGE, and PHI and more than 99% of ComEd. PHI owns 100% of Pepco, DPL, and ACE. As of February 1, 2022, as a result of the completion of the separation, Exelon no longer owns any interest in Generation. The separation of Constellation Energy Corporation, including Generation and its subsidiaries, meets the criteria for discontinued operations and as such, its results of operations are presented as discontinued operations and have been excluded from continuing operations for all periods presented. Accounting rules require that certain BSC costs previously allocated to Generation be presented as part of Exelon’s continuing operations as these costs do not qualify as expenses of the discontinued operations. Comprehensive income, shareholders' equity, and cash flows related to Generation have not been segregated and are included in the Consolidated Statements of Operations and Comprehensive Income, Consolidated Statements of Changes in Shareholders’ Equity, and Consolidated Statements of Cash Flows, respectively, for all periods presented. See Note 2 — Discontinued Operations for additional information. The accompanying consolidated financial statements have been prepared in accordance with GAAP for annual financial statements and in accordance with the instructions to Form 10-K and Regulation S-X promulgated by the SEC. COVID-19 (All Registrants) The Registrants have taken steps to mitigate the potential risks posed by the global outbreak (pandemic) of the 2019 novel coronavirus (COVID-19). The Registrants provide a critical service to their customers and have taken measures to keep employees who operate the business safe and minimize unnecessary risk of exposure to the virus, including extra precautions for employees who work in the field. The Registrants have implemented work from home policies where appropriate and imposed travel limitations on employees. Management makes estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities as of the date of the financial statements and accompanying notes, and the amounts of revenues and expenses reported during the periods covered by those financial statements and accompanying notes. As of December 31, 2021 and 2020, and through the date of this report, management assessed certain accounting matters that require consideration of forecasted financial information, including, but not limited to, allowance for credit losses and the carrying value of goodwill and other long-lived assets, in context with the information reasonably available and the unknown future impacts of COVID-19. The Registrants' future assessment of the magnitude and duration of COVID-19, as well as other factors, could result in material impacts to their consolidated financial statements in future reporting periods. Use of Estimates (All Registrants) The preparation of financial statements of each of the Registrants in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Areas in which significant estimates have been made include, but are not limited to, the accounting for AROs, pension and OPEB, inventory reserves, allowance for credit losses, goodwill and long-lived asset impairment assessments, derivative instruments, unamortized energy contracts, fixed asset depreciation, environmental costs and other loss contingencies, taxes, and unbilled energy revenues. Actual results could differ from those estimates. Accounting for the Effects of Regulation (All Registrants) For their regulated electric and gas operations, the Registrants reflect the effects of cost-based rate regulation in their financial statements, which is required for entities with regulated operations that meet the following criteria: 1) rates are established or approved by a third-party regulator; (2) rates are designed to recover the entities’ cost of providing services or products; and (3) there is a reasonable expectation that rates designed to recover costs can be charged to and collected from customers. The Registrants account for their regulated operations in accordance with regulatory and legislative guidance from the regulatory authorities having jurisdiction, principally the ICC, PAPUC, MDPSC, DCPSC, DEPSC, and NJBPU, under state public utility laws and the FERC under various Federal laws. Regulatory assets and liabilities are amortized and the related expense or revenue is recognized in the Consolidated Statements of Operations consistent with the recovery or refund included in customer rates. The Registrants' regulatory assets and liabilities as of the balance sheet date are probable of being recovered or settled in future rates. If a separable portion of the Registrants' business was no longer able to meet the criteria discussed above, the affected entities would be required to eliminate from their consolidated financial statements the effects of regulation for that portion, which could have a material impact on their financial statements. See Note 3 — Regulatory Matters for additional information. With the exception of income tax-related regulatory assets and liabilities, the Registrants classify regulatory assets and liabilities with a recovery or settlement period greater than one year as both current and non-current in their Consolidated Balance Sheets, with the current portion representing the amount expected to be recovered from or refunded to customers over the next twelve-month period as of the balance sheet date. Income tax-related regulatory assets and liabilities are classified entirely as non-current in the Registrants’ Consolidated Balance Sheets to align with the classification of the related deferred income tax balances. The Registrants treat the impacts of a final rate order received after the balance sheet date but prior to the issuance of the financial statements as a non-recognized subsequent event, as the receipt of a final rate order is a separate and distinct event that has future impacts on the parties affected by the order. Revenues (All Registrants) Operating Revenues. The Registrants’ operating revenues generally consist of revenues from contracts with customers involving the sale and delivery of power and natural gas and utility revenues from ARP. The Registrants recognize revenue from contracts with customers to depict the transfer of goods or services to customers in an amount that the entities expect to be entitled to in exchange for those goods or services. The primary sources of revenue include regulated electric and natural gas tariff sales, distribution, and transmission services. At the end of each month, the Registrants accrue an estimate for the unbilled amount of energy delivered or services provided to customers. ComEd records ARP revenue for its best estimate of the electric distribution, energy efficiency, and transmission revenue impacts resulting from future changes in rates that ComEd believes are probable of approval by the ICC and FERC in accordance with its formula rate mechanisms. BGE, Pepco, DPL, and ACE record ARP revenue for their best estimate of the electric and natural gas distribution revenue impacts resulting from future changes in rates that they believe are probable of approval by the MDPSC, DCPSC, and/or NJBPU in accordance with their revenue decoupling mechanisms. PECO, BGE, Pepco, DPL, and ACE record ARP revenue for their best estimate of the transmission revenue impacts resulting from future changes in rates that they believe are probable of approval by FERC in accordance with their formula rate mechanisms. See Note 3 — Regulatory Matters for additional information. Taxes Directly Imposed on Revenue-Producing Transactions. The Registrants collect certain taxes from customers such as sales and gross receipts taxes, along with other taxes, surcharges, and fees, that are levied by state or local governments on the sale or distribution of electricity and gas. Some of these taxes are imposed on the customer, but paid by the Registrants, while others are imposed on the Registrants. Where these taxes are imposed on the customer, such as sales taxes, they are reported on a net basis with no impact to the Consolidated Statements of Operations and Comprehensive Income. However, where these taxes are imposed on the Registrants, such as gross receipts taxes or other surcharges or fees, they are reported on a gross basis. Accordingly, revenues are recognized for the taxes collected from customers along with an offsetting expense. Se e Note 22 — Supplemental Financial Information for taxes that are presented on a gross basis. Leases (All Registrants) The Registrants recognize a ROU asset and lease liability for operating and finance leases with a term of greater than one year. Operating lease ROU assets are included in Other deferred debits and other assets and operating lease liabilities are included in Other current liabilities and Other deferred credits and other liabilities on the Consolidated Balance Sheets. Finance lease ROU assets are included in Plant, property, and equipment, net and finance lease liabilities are included in Long-term debt due within one year and Long-term debt on the Consolidated Balance Sheets. The ROU asset is measured as the sum of (1) the present value of all remaining fixed and in-substance fixed payments using t he rate implicit in the lease whenever that is readily determinable or each Registrant’s incremental borrowing rate, (2) any lease payments made at or before the commencement date (less any lease incentives received), and (3) any initial direct costs incurred. The lease liability is measured the same as the ROU asset, but excludes any payments made before the commencement date and initial direct costs incurred. Lease terms include options to extend or terminate the lease if it is reasonably certain they will be exercised. The Registrants include non-lease components for most asset classes, which are service-related costs that are not integral to the use of the asset, in the measurement of the ROU asset and lease liability. Expense for operating leases and leases with a term of one year or less is recognized on a straight-line basis over the term of the lease, unless another systematic and rational basis is more representative of the derivation of benefit from use of the leased property. Variable lease payments are recognized in the period in which the related obligation is incurred. Operating lease expense, finance lease expense, and variable lease payments are primarily recorded to Operating and maintenance expense on the Registrants’ Statements of Operations and Comprehensive Income. Income from operating leases, including subleases, is recognized on a straight-line basis over the term of the lease, unless another systematic and rational basis is more representative of the pattern in which income is earned over the term of the lease. Variable lease income is recognized in the period in which the related obligation is performed. Operating lease income and variable lease income are recorded to Operating revenues on the Registrants’ Statements of Operations and Comprehensive Income. The Registrants’ operating and finance leases consist primarily of real estate including office buildings and vehicles and equipment. The Registrants account for land right arrangements that provide for exclusive use as leases while shared use land arrangements are generally not leases. The Registrants do not account for secondary use pole attachments as leases. See Note 10 — Leases for additional information. Income Taxes (All Registrants) Deferred federal and state income taxes are recorded on significant temporary differences between the book and tax basis of assets and liabilities and for tax benefits carried forward. Investment tax credits have been deferred in the Registrants’ Consolidated Balance Sheets and are recognized in book income over the life of the related property. The Registrants account for uncertain income tax positions using a benefit recognition model with a two-step approach; a more-likely-than-not recognition criterion; and a measurement approach that measures the position as the largest amount of tax benefit that is greater than 50% likely of being realized upon ultimate settlement. If it is not more-likely-than-not that the benefit of the tax position will be sustained on its technical merits, no benefit is recorded. Uncertain tax positions that relate only to timing of when an item is included on a tax return are considered to have met the recognition threshold. The Registrants recognize accrued interest related to unrecognized tax benefits in Interest expense, net or Other, net (interest income) and recognize penalties related to unrecognized tax benefits in Other, net in their Consolidated Statements of Operations and Comprehensive Income. Cash and Cash Equivalents (All Registrants) The Registrants consider investments purchased with an original maturity of three months or less to be cash equivalents. Restricted Cash and Cash Equivalents (All Registrants) Restricted cash and cash equivalents represent funds that are restricted to satisfy designated current liabilities. As of December 31, 2021 and 2020, the Registrants' restricted cash and cash equivalents primarily represented the following items: Registrant Description Exelon Payment of medical, dental, vision, and long-term disability benefits, in addition to the items listed below for the Utility Registrants. ComEd Collateral held from suppliers associated with energy and REC procurement contracts, any over-recovered RPS costs and alternative compliance payments received from RES pursuant to FEJA, and costs for the remediation of an MGP site. PECO Proceeds from the sales of assets that were subject to PECO’s mortgage indenture. BGE Proceeds from the loan program for the completion of certain energy efficiency measures and collateral held from energy suppliers. PHI Payment of merger commitments, collateral held from its energy suppliers associated with procurement contracts, and repayment of Transition Bonds. Pepco Payment of merger commitments and collateral held from energy suppliers. DPL Collateral held from energy suppliers. ACE Repayment of Transition Bonds and collateral held from energy suppliers. Restricted cash and cash equivalents not available to satisfy current liabilities are classified as noncurrent assets. As of December 31, 2021 and 2020, the Registrants' noncurrent restricted cash and cash equivalents primarily represented ComEd’s over-recovered RPS costs and alternative compliance payments received from RES pursuant to FEJA and costs for the remediation of an MGP site, and ACE’s repayment of Transition Bonds. See Note 15 — Debt and Credit Agreements and Note 22 — Supplemental Financial Information for additional information. Allowance for Credit Losses on Accounts Receivables (All Registrants) The allowance for credit losses reflects the Registrants’ best estimates of losses on the customers' accounts receivable balances based on historical experience, current information, and reasonable and supportable forecasts. The allowance for credit losses is developed by applying loss rates for each Utility Registrant, based on historical loss experience, current conditions, and forward-looking risk factors, to the outstanding receivable balance by customer risk segment. Utility Registrants' customer accounts are written off consistent with approved regulatory requirements. Adjustments to the allowance for credit losses are primarily recorded to Operating and maintenance expense on the Registrants' Consolidated Statements of Operations and Comprehensive Income or Regulatory assets and liabilities on the Registrants' Consolidated Balance Sheets. See Note 3 - Regulatory Matters for additional information regarding the regulatory recovery of credit losses on customer accounts receivable. The Registrants have certain non-customer receivables in Other deferred debits and other assets which primarily are with governmental agencies and other high-quality counterparties with no history of default. As such, the allowance for credit losses related to these receivables is not material. The Registrants monitor these balances and will record an allowance if there are indicators of a decline in credit quality. Variable Interest Entities (Exelon, PHI, and ACE) Exelon accounts for its investments in and arrangements with VIEs based on the following specific requirements: • qualitative assessment of factors determinant in whether it has a controlling financial interest, • ongoing reconsideration of this assessment, and • where it consolidates a VIE (as primary beneficiary), disclosure of (1) the assets of the consolidated VIE, if they can be used to only settle specific obligations of the consolidated VIE, and (2) the liabilities of a consolidated VIE for which creditors do not have recourse to the general credit of the primary beneficiary. See Note 21 — Variable Interest Entities for additional information. Inventories (All Registrants) Inventory is recorded at the lower of weighted average cost or net realizable value. Provisions are recorded for excess and obsolete inventory. Fossil fuel and materials and supplies are generally included in inventory when purchased. Fossil fuel is expensed to Purchased power and fuel expense when used or sold. Materials and supplies generally includes transmission and distribution materials and are expensed to Operating and maintenance or capitalized to Property, plant, and equipment, as appropriate, when installed or used. Equity Security Investments with Readily Determinable Fair Values (Exelon, PECO, BGE, PHI, and Pepco) For investments in equity securities with readily determinable fair values, Exelon reports their investment values based on quoted prices in active markets and realized and unrealized gains and losses are included in earnings. See Note 16 — Fair Value of Financial Assets and Liabilities for additional information. Property, Plant, and Equipment (All Registrants) Property, plant, and equipment is recorded at original cost. Original cost includes construction-related direct labor and material costs and indirect construction costs including labor and related costs of departments associated with supporting construction activities. When appropriate, original cost also includes capitalized interest for Exelon Corporate and PHI and AFUDC for regulated property at the Utility Registrants. The cost of repairs and maintenance and minor replacements of property is charged to Operating and maintenance expense as incurred. Third parties reimburse the Utility Registrants for all or a portion of expenditures for certain capital projects. Such contributions in aid of construction costs (CIAC) are recorded as a reduction to Property, plant, and equipment, net. Upon retirement, the cost of property, net of salvage, is charged to accumulated depreciation consistent with the composite and group methods of depreciation. Depreciation expense at ComEd, BGE, Pepco, DPL, and ACE includes the estimated cost of dismantling and removing plant from service upon retirement. Actual incurred removal costs are applied against a related regulatory liability or recorded to a regulatory asset if in excess of previously collected removal costs. PECO’s removal costs are capitalized to accumulated depreciation when incurred and recorded to depreciation expense over the life of the new asset constructed consistent with PECO’s regulatory recovery method. Capitalized Software. Certain costs, such as design, coding, and testing incurred during the application development stage of software projects that are internally developed or purchased for operational use are capitalized within Property, plant, and equipment. Similar costs incurred for cloud-based solutions treated as service arrangements are capitalized within Other Current Assets and Deferred Debits and Other Assets. Such capitalized amounts are amortized ratably over the expected lives of the projects when they become operational, generally not to exceed five years. Certain other capitalized software costs are being amortized over longer lives based on the expected life or pursuant to prescribed regulatory requirements. Capitalized Interest and AFUDC. During construction, Exelon capitalizes the costs of debt funds used to finance non-regulated construction projects. Capitalization of debt funds is recorded as a charge to construction work in progress and as a non-cash credit to interest expense. AFUDC is the cost, during the period of construction, of debt and equity funds used to finance construction projects for regulated operations. AFUDC is recorded to construction work in progress and as a non-cash credit to an allowance that is included in interest expense for debt-related funds and other income and deductions for equity-related funds. The rates used for capitalizing AFUDC are computed under a method prescribed by regulatory authorities. See Note 7 — Property, Plant, and Equipment, Note 8 — Jointly Owned Electric Utility Plant and Note 22 — Supplemental Financial Information for additional information. Depreciation and Amortization (All Registrants) Depreciation is generally recorded over the estimated service lives of property, plant, and equipment on a straight-line basis using the group or composite methods of depreciation. The group approach is typically for groups of similar assets that have approximately the same useful lives and the composite approach is used for dissimilar assets that have different lives. Under both methods, a reporting entity depreciates the assets over the average life of the assets in the group. ComEd, BGE, Pepco, DPL, and ACE's depreciation expense includes the estimated cost of dismantling and removing plant from service upon retirement, which is consistent with each utility's regulatory recovery method. PECO's removal costs are capitalized to accumulated depreciation when incurred and recorded to depreciation expense over the life of the new asset constructed consistent with PECO's regulatory recovery method. The estimated service lives for the Registrants are based on a combination of depreciation studies and historical retirements. See Note 7 — Property, Plant, and Equipment for additional information regarding depreciation. Amortization of regulatory assets and liabilities are recorded over the recovery or refund period specified in the related legislation or regulatory order or agreement. When the recovery or refund period is less than one year, amortization is recorded to the line item in which the deferred cost or income would have originally been recorded in the Registrants’ Consolidated Statements of Operations and Comprehensive Income. Amortization of ComEd’s electric distribution and energy efficiency formula rate regulatory assets and the Utility Registrants' transmission formula rate regulatory assets is recorded to Operating revenues. Amortization of income tax related regulatory assets and liabilities is generally recorded to Income tax expense. Except for the regulatory assets and liabilities discussed above, amortization is generally recorded to Depreciation and amortization in the Registrants’ Consolidated Statements of Operations and Comprehensive Income when the recovery period is more than one year. See Note 3 — Regulatory Matters and Note 22 — Supplemental Financial Information for additional information regarding the amortization of the Registrants' regulatory assets. Asset Retirement Obligations (All Registrants) The Registrants estimate and recognize a liability for their legal obligation to perform asset retirement activities even though the timing and/or methods of settlement may be conditional on future events. The Registrants update their AROs either annually or on a rotational basis at least once every three years, based on a risk profile, unless circumstances warrant more frequent updates. The updates factor in new cost estimates, credit-adjusted, risk-free rates (CARFR) and escalation rates, and the timing of cash flows. AROs are accreted throughout each year to reflect the time value of money for these present value obligations through an increase to regulatory assets. See Note 9 — Asset Retirement Obligations for additional information. Guarantees (All Registrants) If necessary, the Registrants recognize a liability at the time of issuance of a guarantee for the fair value of the obligations they have undertaken by issuing the guarantee. The liability is reduced or eliminated as the Registrants are released from risk under the guarantee. Depending on the nature of the guarantee, the release from risk of the Registrant may be recognized only upon the expiration or settlement of the guarantee or by a systematic and rational amortization method over the term of the guarantee. See Note 17 — Commitments and Contingencies for additional information. Asset Impairments Long-Lived Assets (All Registrants). The Registrants evaluate the carrying value of long-lived assets for recoverability whenever events or changes in circumstances indicate that the carrying value of those assets may not be recoverable. Indicators of impairment may include specific regulatory disallowance, abandonment, or plans to dispose of a long-lived asset significantly before the end of its useful life. When the estimated undiscounted future cash flows attributable to the long-lived asset may not be recoverable, the amount of the impairment loss is determined by measuring the excess of the carrying amount of the long-lived asset over its fair value. Goodwill (Exelon, ComEd, and PHI). Goodwill represents the excess of the purchase price paid over the estimated fair value of the net assets acquired and liabilities assumed in the acquisition of a business. Goodwill is not amortized but is assessed for impairment at least annually or on an interim basis if an event occurs or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying value. See Note 11 — Intangible Assets for additional information. Derivative Financial Instruments (All Registrants) Derivatives are recognized on the balance sheet at their fair value unless they qualify for certain exceptions, including NPNS. For derivatives intended to serve as economic hedges, changes in fair value are recognized in earnings each period. Changes in fair value may be recorded as a regulatory asset or liability if there is an ability to recover or return the associated costs. Cash inflows and outflows related to derivative instruments are included as a component of operating, investing, or financing cash flows in the Consolidated Statements of Cash Flows, depending on the nature of each transaction. See Note 3 — Regulatory Matters and Note 14 — Derivative Financial Instruments for additional information. Retirement Benefits (All Registrants) Exelon sponsors defined benefit pension plans and OPEB plans for substantially all current employees. The plan obligations and costs of providing benefits under these plans are measured as of December 31. The measurement involves various factors, assumptions, and accounting elections. The impact of assumption changes or experience different from that assumed on pension and OPEB obligations is recognized over time rather than immediately recognized in the Consolidated Statements of Operations and Comprehensive Income. Gains or losses in excess of the greater of ten percent of the projected benefit obligation or the MRV of plan assets are amortized over the expected average remaining service period of plan participants. See Note 13 — Retirement Benefits for additional information.

Discontinued Operations (Exelon

Discontinued Operations (Exelon)	12 Months Ended
Discontinued Operations (Exelon)	Dec. 31, 2021
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations (Exelon)	Discontinued Operations (Exelon) On February 21, 2021, Exelon's Board of Directors approved a plan to separate the Utility Registrants and Generation, creating two publicly traded companies ("the separation"). On February 25, 2021, Exelon filed applications with FERC, NYPSC, and NRC seeking approvals for the separation of Generation. On March 25, 2021, Exelon filed a request for a private letter ruling with the IRS to confirm the tax-free treatment of the separation, which was received on September 23, 2021. Exelon received approval from FERC on August 24, 2021, NRC on November 16, 2021, and NYPSC on December 16, 2021 for the separation. The Form 10 registration statement was declared effective by the SEC on December 29, 2021. Exelon completed the separation on February 1, 2022, through the distribution of 326,663,937 common stock shares of Constellation Energy Corporation, the new publicly traded company, to Exelon shareholders. Under the separation plan, Exelon shareholders retained their current shares of Exelon stock and received one share of Constellation Energy Corporation common stock for every three shares of Exelon common stock held on January 20, 2022, the record date for the distribution, in a transaction that is tax-free to Exelon and its shareholders for U.S. federal income tax purposes. Constellation Energy Corporation was newly formed and incorporated in Pennsylvania on June 15, 2021 for the purposes of separation and holds Generation (including Generation's subsidiaries). Pursuant to the separation: • Exelon entered into four term loans consisting of a 364-day term loan for $1.15 billion and three 18-month term loans for $300 million, $300 million and $250 million, respectively. Exelon issued these term loans primarily to fund the cash payment described below to Constellation Energy Corporation and for general corporate purposes. See Note 15 — Debt and Credit Agreements for additional information. • Exelon made a cash payment of $1.75 billion to Constellation Energy Corporation on January 31, 2022. • Exelon contributed its equity ownership interest in Generation (including its subsidiaries) to Constellation Energy Corporation. Exelon no longer retains any equity ownership interest in Generation or Constellation Energy Corporation. • Exelon transferred certain corporate assets and employee-related obligations to Constellation Energy Corporation. • Exelon received cash from Generation of $258 million to settle the intercompany loan on January 31, 2022. See Note 15 — Debt and Credit Agreements for additional information. Continuing Involvement In order to govern the ongoing relationships between Exelon and Constellation Energy Corporation after the separation, and to facilitate an orderly transition, Exelon and Constellation Energy Corporation have entered into several agreements, including the following: • Separation Agreement – governs the rights and obligations between Exelon and Constellation Energy Corporation regarding certain actions to be taken in connection with the separation, among others, including the allocation of assets and liabilities between Exelon and Constellation Energy Corporation. • Transition Services Agreement (TSA) – governs the terms and conditions of the services that Exelon will provide to Constellation Energy Corporation and Constellation Energy Corporation will provide to Exelon for an expected period of two years, provided that certain services may be longer than the term and services may be extended with approval from both parties. The services include specified accounting, finance, information technology, human resources, employee benefits and other services that have historically been provided on a centralized basis by BSC. • Tax Matters Agreement (TMA) – governs the respective rights, responsibilities and obligations of Exelon and Constellation Energy Corporation with respect to all tax matters, including tax liabilities and benefits, tax attributes, tax returns, tax contests and other tax sharing regarding U.S. federal, state, local and foreign income taxes, other tax matters and related tax returns. In addition, the Utility Registrants will continue to incur expenses from transactions with Generation after the separation. Prior to the separation, such expenses were primarily recorded as Purchased power from affiliates and an immaterial amount recorded as Operating and maintenance expense from affiliates at the Utility Registrants. • ComEd had an ICC-approved RFP contract with Generation to provide a portion of ComEd’s electric supply requirements. ComEd also purchased RECs and ZECs from Generation. • PECO received electric supply from Generation under contracts executed through PECO’s competitive procurement process. In addition, PECO had a ten-year agreement with Generation to sell solar AECs. • BGE received a portion of its energy requirements from Generation under its MDPSC-approved market-based SOS and gas commodity programs. • Pepco received electric supply from Generation under contracts executed through Pepco’s competitive procurement process approved by the MDPSC and DCPSC. • DPL received a portion of its energy requirements from Generation under its MDPSC and DEPSC approved market-based SOS commodity programs. • ACE received electric supply from Generation under contracts executed through ACE’s competitive procurement process approved by the NJBPU. ComEd and PECO also have receivables with Generation as a result of the nuclear decommissioning contractual construct whereby, to the extent NDT funds are greater than the underlying ARO at the end of decommissioning, such amounts are due back to ComEd and PECO, as applicable, for payment to their respective customers. See Note 3 — Regulatory Matters for additional information. Discontinued Operations The separation represented a strategic shift that would have a major effect on Exelon’s operations and financial results. Accordingly, the separation meets the criteria for discontinued operations. The following table presents the results of Generation that have been reclassified from continuing operations and included in discontinued operations within Exelon’s Consolidated Statements of Operations and Comprehensive Income for the years ended December 31, 2021, 2020, and 2019. These results are primarily Generation, which is comprised of Exelon’s Mid-Atlantic, Midwest, New York, ERCOT, and Other Power Regions reportable segments, and include the impact of transaction costs, certain BSC costs, including any transition costs, that were historically allocated and directly attributable to Generation, transactions between Generation and the Utility Registrants, and tax-related adjustments. Transaction costs include costs for external bankers, accountants, appraisers, lawyers, external counsels and other advisors, among others, who are involved in the negotiation, appraisal, due diligence and regulatory approval of the separation. Transition costs are primarily employee-related costs such as recruitment expenses, costs to establish certain stand-alone functions and information technology systems, professional services fees and other separation-related costs during the transition to separate Generation. For the purposes of reporting discontinued operations, these results also include transactions between Generation and the Utility Registrants that were historically eliminated within Exelon’s Consolidated Statements of Operations as these transactions will be ongoing after the separation. Certain BSC costs that were historically allocated to Generation are presented as part of continuing operations in Exelon’s Consolidated Statements of Operations as these costs do not qualify as expenses of the discontinued operations per the accounting rules. Year Ended 2021 2020 2019 Operating revenues Competitive business revenues $ 18,466 $ 16,399 $ 17,754 Competitive business revenues from affiliates 1,189 1,206 1,171 Total operating revenues 19,655 17,605 18,925 Operating expenses Competitive businesses purchased power and fuel 12,163 9,585 10,856 Operating and maintenance (a) 4,174 4,794 4,324 Depreciation and amortization 3,003 2,123 1,535 Taxes other than income taxes 475 482 519 Total operating expenses 19,815 16,984 17,234 Gain on sales of assets and businesses 201 11 27 Operating income 41 632 1,718 Other income and (deductions) Interest expense, net (282) (328) (394) Other, net 795 937 1,023 Total other income 513 609 629 Income before income taxes 554 1,241 2,347 Income taxes 332 380 621 Equity in losses of unconsolidated affiliates (9) (6) (184) Net income 213 855 1,542 Net income (loss) attributable to noncontrolling interests 123 (9) 92 Net income from discontinued operations $ 90 $ 864 $ 1,450 __________ (a) Includes transaction and transition costs related to the separation of $24 million and $19 million for the year ended December 31, 2021. There were no separation related costs incurred in 2020 or 2019. See discussion above for additional information. The following table presents the assets and liabilities of discontinued operations in Exelon’s Consolidated Balance Sheets as of December 31, 2021 and 2020. December 31, 2021 December 31, 2020 ASSETS Current assets Cash and cash equivalents $ 510 $ 231 Restricted cash and cash equivalents 72 89 Accounts receivable Customer accounts receivable 1,724 1,331 Customer allowance for credit losses (55) (32) Customer accounts receivable, net 1,669 1,299 Other accounts receivable 596 352 Other allowance for credit losses (4) — Other accounts receivable, net 592 352 Mark-to-market derivative assets 2,169 644 Inventories, net Fossil fuel and emission allowances 284 233 Materials and supplies 1,004 978 Renewable energy credits 529 633 Assets held for sale 13 958 Other 993 1,424 Total current assets of discontinued operations 7,835 6,841 Property, plant, and equipment (net of accumulated depreciation and amortization of $15,888 and $13,381, respectively) 19,661 22,252 Deferred debits and other assets Nuclear decommissioning trust funds 15,938 14,464 Investments 193 202 Mark-to-market derivative assets 949 555 Other 1,768 2,180 Total property, plant, and equipment, deferred debits, and other assets of discontinued operations 38,509 39,653 Total assets of discontinued operations $ 46,344 $ 46,494 December 31, 2021 December 31, 2020 LIABILITIES AND SHAREHOLDERS’ EQUITY Current liabilities Short-term borrowings $ 2,082 $ 840 Long-term debt due within one year 1,220 197 Accounts payable 1,757 1,253 Accrued expenses 818 848 Mark-to-market derivative liabilities 981 262 Renewable energy credit obligation 779 661 Liabilities held for sale 3 375 Other 300 487 Total current liabilities of discontinued operations 7,940 4,923 Long-term debt 4,575 5,566 Deferred credits and other liabilities Deferred income taxes and unamortized investment tax credits 3,583 3,443 Asset retirement obligations 12,819 12,054 Pension obligations 939 1,557 Non-pension postretirement benefit obligations 876 1,009 Spent nuclear fuel obligation 1,210 1,208 Mark-to-market derivative liabilities 513 205 Other 1,161 1,303 Total long-term debt, deferred credits, and other liabilities of discontinued operations 25,676 26,345 Total liabilities of discontinued operations $ 33,616 $ 31,268 The following table presents selected financial information regarding cash flows of the discontinued operations that are included within Exelon’s Consolidated Statements of Cash Flows for the years ended December 31, 2021, 2020, and 2019. Year Ended 2021 2020 2019 Non-cash items included in net income (loss) from discontinued operations: Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization $ 4,540 $ 3,636 $ 3,063 Asset impairments 545 563 201 Gain on sales of assets and businesses (201) (11) (27) Deferred income taxes and amortization of investment tax credits (224) 94 376 Net fair value changes related to derivatives (568) (270) 228 Net realized and unrealized gains on NDT fund investments (586) (461) (663) Net unrealized losses (gains) on equity investments 160 (186) — Other decommissioning-related activity (946) (659) (506) Cash flows from investing activities: Capital expenditures (1,341) (1,759) (1,849) Collection of DPP 3,902 3,771 — Supplemental cash flow information: Increase (decrease) in capital expenditures not paid 96 (88) (34) Increase in DPP 3,652 4,441 — Increase in PP&E related to ARO update 618 850 959

Regulatory Matters (All Registr

Regulatory Matters (All Registrants)	12 Months Ended
Regulatory Matters (All Registrants)	Dec. 31, 2021
Regulated Operations [Abstract]
Regulatory Matters (All Registrants)	Regulatory Matters (All Registrants) The following matters below discuss the status of material regulatory and legislative proceedings of the Registrants. Distribution Base Rate Case Proceedings The following tables show the completed and pending distribution base rate case proceedings in 2021. Completed Distribution Base Rate Case Proceedings Registrant/Jurisdiction Filing Date Service Requested Revenue Requirement (Decrease) Increase Approved Revenue Requirement (Decrease) Increase Approved ROE Approval Date Rate Effective Date ComEd - Illinois (a) April 16, 2020 Electric $ (11) $ (14) 8.38 % December 9, 2020 January 1, 2021 April 16, 2021 Electric 51 46 7.36 % December 1, 2021 January 1, 2022 PECO - Pennsylvania September 30, 2020 Natural Gas 69 29 10.24 % June 22, 2021 July 1, 2021 March 30, 2021 Electric 246 132 N/A (b) November 18, 2021 January 1, 2022 BGE - Maryland (c) May 15, 2020 (amended September 11, 2020) Electric 203 140 9.50 % December 16, 2020 January 1, 2021 Natural Gas 108 74 9.65 % Pepco - District of Columbia (d) May 30, 2019 (amended June 1, 2020) Electric 136 109 9.275 % June 8, 2021 July 1, 2021 Pepco - Maryland (e) October 26, 2020 (amended March 31, 2021) Electric 104 52 9.55 % June 28, 2021 June 28, 2021 DPL - Delaware March 6, 2020 (amended February 2, 2021) Electric 23 14 9.60 % September 15, 2021 October 6, 2020 ACE - New Jersey (f) December 9, 2020 (amended February 26, 2021) Electric 67 41 9.60 % July 14, 2021 January 1, 2022 __________ (a) Pursuant to EIMA and FEJA, ComEd’s electric distribution rates are established through a performance-based formula, which sunsets at the end of 2022. See discussion of the Clean Energy Law below for details on the transition away from the electric distribution formula rate. The electric distribution formula rate includes decoupling provisions and, as a result, ComEd's electric distribution formula rate revenues are not impacted by abnormal weather, usage per customer, or number of customers. ComEd is required to file an annual update to its electric distribution formula rate on or before May 1 st , with resulting rates effective in January of the following year. ComEd’s annual electric distribution formula rate update is based on prior year actual costs and current year projected capital additions (initial year revenue requirement). The update also reconciles any differences between the revenue requirement in effect for the prior year and actual costs incurred from the year (annual reconciliation). ComEd’s 2021 approved revenue requirement reflects an increase of $50 million for the initial year revenue requirement for 2021 and a decrease of $64 million related to the annual reconciliation for 2019. The revenue requirement for 2021 and the revenue requirement for 2019 provide for a weighted average debt and equity return on distribution rate base of 6.28% inclusive of an allowed ROE of 8.38%, reflecting the monthly average yields for 30-year treasury bonds plus 580 basis points . ComEd’s 2022 approved revenue requirement above reflects an increase of $37 million for the initial year revenue requirement for 2022 and an increase of $9 million related to the annual reconciliation for 2020. The revenue requirement for 2022 provides for a weighted average debt and equity return on distribution rate base of 5.72% inclusive of an allowed ROE of 7.36%, reflecting the monthly average yields for 30-year treasury bonds plus 580 basis points. The reconciliation revenue requirement for 2020 provides for a weighted average debt and equity return on distribution rate base of 5.69%, inclusive of an allowed ROE of 7.29%, reflecting the monthly yields on 30-year treasury bonds plus 580 basis points less a performance metrics penalty of 7 basis points. (b) The PECO electric base rate case proceeding was resolved through a settlement agreement, which did not specify an approved ROE. (c) Reflects a three-year cumulative multi-year plan for 2021 through 2023. The MDPSC awarded BGE electric revenue requirement increases of $59 million, $39 million, and $42 million, before offsets, in 2021, 2022, and 2023, respectively, and natural gas revenue requirement increases of $53 million, $11 million, and $10 million, before offsets, in 2021, 2022, and 2023, respectively. BGE proposed to use certain tax benefits to fully offset the increases in 2021 and 2022 and partially offset the increase in 2023. However, the MDPSC utilized the tax benefits to fully offset the increases in 2021 and January 2022 such that customer rates remained unchanged. For the remainder of 2022, the MDPSC chose to offset only 25% of the cumulative 2021 and 2022 electric revenue requirement increases and 50% of the cumulative gas revenue requirement increases. Whether certain tax benefits will be used to offset the customer rate increases in 2023 has not been decided, and BGE cannot predict the outcome. (d) Reflects a cumulative multi-year plan with 18-months remaining in 2021 through 2022. The DCPSC awarded Pepco electric incremental revenue requirement increases of $42 million and $67 million, before offsets, for the remainder of 2021 and 2022, respectively. However, the DCPSC utilized the acceleration of refunds for certain tax benefits along with other rate relief to partially offset the customer rate increases by $22 million and $40 million for the remainder of 2021 and 2022, respectively. (e) Reflects a three-year cumulative multi-year plan for April 1, 2021 through March 31, 2024. The MDPSC awarded Pepco electric incremental revenue requirement increases of $21 million, $16 million, and $15 million, before offsets, for the 12-month periods ending March 31, 2022, 2023, and 2024, respectively. Pepco proposed to utilize certain tax benefits to fully offset the increase through 2023 and partially offset customer rate increases in 2024. However, the MDPSC only utilized the acceleration of refunds for certain tax benefits to fully offset the increases such that customer rates remain unchanged through March 31, 2022. On February 23, 2022, the MDPSC chose to offset 25% of the cumulative revenue requirement increase through March 31, 2023. Whether certain tax benefits will be used to offset the customer rate increases for the twelve months ended March 31, 2024 has not been decided, and Pepco cannot predict the outcome. (f) Requested and approved increases are before New Jersey sales and use tax. The order allows ACE to retain approximately $11 million of certain tax benefits which resulted in a decrease to income tax expense in Exelon's, PHI's, and ACE's Consolidated Statements of Operations and Comprehensive Income in the third quarter of 2021. Pending Distribution Base Rate Case Proceedings Registrant/Jurisdiction Filing Date Service Requested Revenue Requirement Increase Requested ROE Expected Approval Timing DPL - Delaware January 14, 2022 Natural Gas $ 14 10.30 % First quarter of 2023 DPL - Maryland (a) September 1, 2021 (amended December 23, 2021) Electric 27 10.10 % First quarter of 2022 __________ (a) On January 24, 2022, DPL filed a settlement agreement with the MDPSC. The settlement provides for a revenue requirement increase of $13 million. The 9.60% ROE in the agreement is solely for the purposes of calculating AFUDC and regulatory asset carrying costs. On February 15, 2021, the Chief Public Utility Law Judge issued a proposed order approving the settlement agreement without modification. The proposed order will become a final order of the MDPSC on March 2, 2022, subject to modification or reversal by the MDPSC. Transmission Formula Rates The Utility Registrants' transmission rates are each established based on a FERC-approved formula. ComEd, BGE, Pepco, DPL, and ACE are required to file an annual update to the FERC-approved formula on or before May 15, and PECO is required to file on or before May 31, with the resulting rates effective on June 1 of the same year. The annual update for ComEd is based on prior year actual costs and current year projected capital additions (initial year revenue requirement). The annual update for PECO is based on prior year actual costs and current year projected capital additions, accumulated depreciation, and accumulated deferred income taxes. The annual update for BGE, Pepco, DPL, and ACE is based on prior year actual costs and current year projected capital additions, accumulated depreciation, depreciation and amortization expense, and accumulated deferred income taxes. The update for ComEd also reconciles any differences between the revenue requirement in effect beginning June 1 of the prior year and actual costs incurred for that year (annual reconciliation). The update for PECO, BGE, Pepco, DPL, and ACE also reconciles any differences between the actual costs and actual revenues for the calendar year (annual reconciliation). For 2021, the following total increases/(decreases) were included in the Utility Registrants' electric transmission formula rate updates: Registrant (a) Initial Revenue Requirement Increase (Decrease) Annual Reconciliation Increase Total Revenue Requirement Increase (b) Allowed Return on Rate Base (c) Allowed ROE (d) ComEd $ 33 $ 12 $ 45 8.20 % 11.50 % PECO (2) 26 24 7.37 % 10.35 % BGE 38 27 65 7.35 % 10.50 % Pepco (9) 21 12 7.68 % 10.50 % DPL 19 33 52 7.20 % 10.50 % ACE 27 24 51 7.45 % 10.50 % __________ (a) All rates are effective June 1, 2021 - May 31, 2022, subject to review by interested parties pursuant to review protocols of each Utility Registrant's tariff. (b) In 2020, ComEd, BGE, Pepco, DPL, and ACE's transmission revenue requirement included a one-time decrease in accordance with the April 24, 2020 settlement agreement related to excess deferred income taxes which now completed has resulted in an increase to the 2021 transmission revenue requirement. In 2020, PECO's transmission revenue requirement included a one-time decrease in accordance with the December 5, 2019 settlement agreement related to refunds which now completed has resulted in an increase to the 2021 transmission revenue requirement. (c) Represents the weighted average debt and equity return on transmission rate bases. (d) As part of the FERC-approved settlements of ComEd’s 2007 and PECO's 2017 transmission rate cases, the rate of return on common equity is 11.50% and 10.35%, respectively, inclusive of a 50-basis-point incentive adder for being a member of a RTO, and the common equity component of the ratio used to calculate the weighted average debt and equity return for the transmission formula rate is currently capped at 55% and 55.75%, respectively. As part of the FERC-approved settlement of the ROE complaint against BGE, Pepco, DPL, and ACE, the rate of return on common equity is 10.50%, inclusive of a 50-basis-point incentive adder for being a member of a RTO. Other State Regulatory Matters Illinois Regulatory Matters Clean Energy Law (Exelon and ComEd). On September 15, 2021, the Illinois Public Act 102-0662 was signed into law by the Governor of Illinois (“Clean Energy Law”). The Clean Energy Law includes, among other features, (1) procurement of CMCs from qualifying nuclear-powered generating facilities, (2) a requirement to file a general rate case or a new four-year multi-year plan no later than January 20, 2023 to establish rates effective after ComEd’s existing performance-based distribution formula rate sunsets, (3) an extension of and certain adjustments to ComEd’s energy efficiency MWh savings goals, (4) revisions to the Illinois RPS requirements, including expanded charges for the procurement of RECs from wind and solar generation, (5) a requirement to accelerate amortization of ComEd’s unprotected excess deferred income taxes that ComEd was previously directed by the ICC to amortize using the average rate assumption method which equates to approximately 39.5 years, and (6) requirements that the ICC initiate and conduct various regulatory proceedings on subjects including ethics, spending, grid investments, and performance metrics. Regulatory or legal challenges regarding the validity or implementation of the Clean Energy Law are possible and Exelon and ComEd cannot reasonably predict the outcome of any such challenges. Carbon Mitigation Credit The Clean Energy Law establishes decarbonization requirements for Illinois as well as programs to support the retention and development of emissions-free sources of electricity. Among other things, the Clean Energy Law authorized the IPA to procure up to 54.5 million CMCs from qualifying nuclear plants for a five-year period beginning on June 1, 2022 through May 31, 2027. CMCs are credits for the carbon-free attributes of eligible nuclear power plants in PJM. ComEd will procure CMCs based upon the number of MWhs produced annually by each plant, subject to minimum performance requirements. The price to be paid for each CMC was established through a competitive bidding process that included consumer-protection measures that capped the maximum acceptable bid amount and a formula that reduces CMC prices by an energy price index, the base residual auction capacity price in the ComEd zone of PJM, and the monetized value of any federal tax credit or other subsidy if applicable. The consumer protection measures contained in the new law will result in net payments to ComEd ratepayers if the energy index, the capacity price and applicable federal tax credits or subsidy exceed the CMC contract price. ComEd is required to purchase CMCs and all its costs of doing so will be recovered through a new rider. That rider will provide for an annual reconciliation and true-up to actual costs incurred by ComEd to purchase CMCs, with any difference to be credited to or collected from ComEd’s retail customers in subsequent periods. The provisions do not impact ComEd’s consolidated financial statements until 2022. ComEd Electric Distribution Rates The Clean Energy Law contains requirements associated with ComEd’s transition away from the performance-based electric distribution formula rate. The law authorizing that rate setting process sunsets at the end of 2022. The Clean Energy Law, and tariffs adopted under it, governs both the remaining reconciliations of rates set under that formula process and requires ComEd to file in 2023 its choice of either a general rate case or a four-year multi-year plan to set rates that take effect in 2024. On February 3, 2022, the ICC approved a tariff that establishes the process under which ComEd will reconcile its 2022 and 2023 rate year revenue requirements with actual costs. Those reconciliation amounts will be determined using the same process as were used for prior reconciliations under the performance-based electric distribution formula rate. Using that process, for the years 2022 and 2023 ComEd will ultimately collect revenues from customers reflecting each year’s actual recoverable costs, year-end rate base, and a weighted average debt and equity return on distribution rate base, with the ROE component based on the annual average of the monthly yields of the 30-year United States Treasury bonds plus 580 basis points. If ComEd elects to file a multi-year plan, that plan would set rates for 2024 – 2027, based on forecasted revenue requirements and an ICC determined rate of return on rate base, including the cost of common equity. Each year of the multi-year plan is subject to after the fact ICC review and reconciliation of the plan’s revenue requirement for that year with the actual costs that the ICC determines are prudently and reasonably incurred for that year. That reconciliation is subject to adjustment for certain expenses and, unless the plan is modified, to a 5% cap on increases in certain costs over the costs in the previously approved multi-year rate plan revenue requirement. ComEd would make its initial reconciliation filing in 2025, and the rate adjustments necessary to reconcile 2024 revenues to ComEd’s actual 2024 costs incurred would take effect in January 2026 after the ICC’s review. The ICC must also approve certain annual performance metrics, which can impose symmetrical performance adjustments in the total range of 20 to 60 basis points to ComEd’s rate of return on common equity based on the extent to which ComEd achieved the annual performance goals. ComEd will recover from retail customers, subject to certain exceptions, the costs it incurs pursuant to the Clean Energy Law either through its electric distribution rate or other recovery mechanisms. The Clean Energy Law, among other things, also requires ComEd’s rates to include a decoupling mechanism to eliminate any impacts of weather or load from ComEd’s electric distribution rate revenues. The Clean Energy Law also requires the ICC to initiate a docket to accelerate and fully credit to customers unprotected property related TCJA excess deferred income taxes no later than December 31, 2025. Energy Efficiency The Clean Energy Law extends ComEd’s current cumulative annual energy efficiency MWh savings goals through 2040, adds expanded electrification measures to those goals, increases low-income commitments and adds a new performance adjustment to the energy efficiency formula rate. ComEd expects its annual spend to increase in 2022 through 2040 to achieve these energy efficiency MWh savings goals, which will be deferred as a separate regulatory asset that will be recovered through the energy efficiency formula rate over the weighted average useful life, as approved by the ICC, of the related energy efficiency measures. Energy Efficiency Formula Rate (Exelon and ComEd). FEJA allows ComEd to defer energy efficiency costs (except for any voltage optimization costs which are recovered through the electric distribution formula rate) as a separate regulatory asset that is recovered through the energy efficiency formula rate over the weighted average useful life, as approved by the ICC, of the related energy efficiency measures. ComEd earns a return on the energy efficiency regulatory asset at a rate equal to its weighted average cost of capital, which is based on a year-end capital structure and calculated using the same methodology applicable to ComEd’s electric distribution formula rate. Beginning January 1, 2018 through December 31, 2030, the ROE that ComEd earns on its energy efficiency regulatory asset is subject to a maximum downward or upward adjustment of 200 basis points if ComEd’s cumulative persisting annual MWh savings falls short of or exceeds specified percentage benchmarks of its annual incremental savings goal. ComEd is required to file an update to its energy efficiency formula rate on or before June 1 st each year, with resulting rates effective in January of the following year. The annual update is based on projected current year energy efficiency costs, PJM capacity revenues, and the projected year-end regulatory asset balance less any related deferred income taxes (initial year revenue requirement). The update also reconciles any differences between the revenue requirement in effect for the prior year and actual costs incurred from the year (annual reconciliation). The approved energy efficiency formula rate also provides for revenue decoupling provisions similar to those in ComEd’s electric distribution formula rate. During 2021, the ICC approved the following total increases in ComEd's requested energy efficiency revenue requirement: Filing Date Requested Revenue Requirement Increase Approved Revenue Requirement Increase (a) Approved ROE Approval Date Rate Effective Date June 1, 2021 $ 54 $ 54 7.36 % November 18, 2021 January 1, 2022 _________ (a) ComEd’s 2022 approved revenue requirement above reflects an increase of $55 million for the initial year revenue requirement for 2022 and a decrease of $1 million related to the annual reconciliation for 2020. The revenue requirement for 2022 provides for a weighted average debt and equity return on the energy efficiency regulatory asset and rate base of 5.72% inclusive of an allowed ROE of 7.36%, reflecting the monthly average yields for 30-year treasury bonds plus 580 basis points. The revenue requirement for the 2020 reconciliation year provides for a weighted average debt and equity return on the energy efficiency asset and rate base of 6.26% inclusive of an allowed ROE of 8.46%, which includes an upward performance adjustment that increased the ROE. The performance adjustment can either increase or decrease the ROE based upon the achievement of energy efficiency savings goals. See table below for ComEd's regulatory assets associated with its energy efficiency formula rate. Maryland Regulatory Matters Maryland Revenue Decoupling (Exelon, BGE, PHI, Pepco, and DPL). In 1998, the MDPSC approved natural gas monthly rate adjustments for BGE and in 2007, the MDPSC approved electric monthly rate adjustments for BGE and BSAs for Pepco and DPL, all of which are decoupling mechanisms. As a result of the decoupling mechanisms, certain Operating revenues from electric and natural gas distribution at BGE and Operating revenues from electric distribution at Pepco Maryland (see also District of Columbia Revenue Decoupling below for Pepco District of Columbia) and DPL are not impacted by abnormal weather or usage per customer. For BGE, Pepco, and DPL, the decoupling mechanism eliminates the impacts of abnormal weather or customer usage by recognizing revenues based on an authorized distribution amount per customer by customer class. Operating revenues from electric and natural gas distribution at BGE and Operating revenues from electric distribution at Pepco Maryland and DPL are, however, impacted by changes in the number of customers. Maryland Order Directing the Distribution of Energy Assistance Funds (Exelon, BGE, PHI, Pepco, and DPL). On June 15, 2021, the MDPSC issued an order authorizing the disbursal of funds to utilities in accordance with Maryland COVID-19 relief legislation. Under this order, BGE, Pepco, and DPL received funds of $50 million, $12 million, and $8 million, respectively, in July 2021. The funds have been used to reduce or eliminate certain qualifying past-due residential customer receivables. District of Columbia Regulatory Matters District of Columbia Revenue Decoupling (Exelon, PHI, and Pepco). In 2009, the DCPSC approved a BSA, which is a decoupling mechanism. As a result of the decoupling mechanism, Operating revenues from electric distribution at Pepco District of Columbia (see also Maryland Revenue Decoupling above for Pepco Maryland) are not impacted by abnormal weather or usage per customer. The decoupling mechanism eliminates the impacts of abnormal weather or customer usage by recognizing revenues based on an authorized distribution amount per customer by customer class. Operating revenues from electric distribution at Pepco District of Columbia are, however, impacted by changes in the number of customers. New Jersey Regulatory Matters Conservation Incentive Program (CIP) (Exelon, PHI, and ACE). On September 25, 2020, ACE filed an application with the NJBPU as was required seeking approval to implement a portfolio of energy efficiency programs pursuant to New Jersey’s clean energy legislation. The filing included a request to implement a CIP that would eliminate the favorable and unfavorable impacts of weather and customer usage patterns on distribution revenues for most customers. The CIP compares current distribution revenues by customer class to approved target revenues established in ACE’s most recent distribution base rate case. The CIP is calculated annually and recovery is subject to certain conditions, including an earnings test and ceilings on customer rate increases. On April 27, 2021, the NJBPU approved the settlement filed by ACE and the third parties to the proceeding. The approved settlement addresses all material aspects of ACE’s filing, including ACE’s ability to implement the CIP prospectively effective July 1, 2021. As a result of this decoupling mechanism, operating revenues will no longer be impacted by abnormal weather or usage for most customers. Starting in third quarter of 2021, ACE will record alternative revenue program revenues for its best estimate of the distribution revenue impacts resulting from future changes in CIP rates that it believes are probable of approval by the NJBPU in accordance with this mechanism. ACE Infrastructure Investment Program Filing (Exelon, PHI, and ACE). On February 28, 2018, ACE filed with the NJBPU the company’s IIP proposing to seek recovery of a series of investments through a new rider mechanism, totaling $338 million, between 2019-2022 to provide safe and reliable service for its customers. The IIP will allow for more timely recovery of investments made to modernize and enhance ACE’s electric system. On April 15, 2019, ACE entered into a settlement agreement with other parties, which allows for a recovery totaling $96 million of reliability related capital investments from July 1, 2019 through June 30, 2023. On April 18, 2019, the NJBPU approved the settlement agreement. Advanced Metering Infrastructure Filing (Exelon, PHI, and ACE). On August 26, 2020, ACE filed an application with the NJBPU as was required seeking approval to deploy a smart energy network in alignment with New Jersey’s Energy Master Plan and Clean Energy Act. The proposal consisted of estimated costs totaling $220 million with deployment taking place over a 3-year implementation period from approximately 2021 to 2024 that involves the installation of an integrated system of smart meters for all customers accompanied by the requisite communications facilities and data management systems. On July 14, 2021, the NJBPU approved the settlement filed by ACE and the third parties to the proceeding. The approved settlement addresses all material aspects of ACE's smart energy network deployment plan, including cost recovery of the investment costs, incremental O&M expenses, and the unrecovered balance of existing infrastructure through future distribution rates. New Jersey Clean Energy Legislation (Exelon, PHI, and ACE). On May 23, 2018, New Jersey enacted legislation that established and modified New Jersey’s clean energy and energy efficiency programs and solar and RPS. On the same day, New Jersey enacted legislation that established a ZEC program that provides compensation for nuclear plants that demonstrate to the NJBPU that they meet certain requirements. Under the legislation, the NJBPU will issue ZECs to the qualifying nuclear power plants and the electric distribution utilities in New Jersey, including ACE, will be required to purchase those ZECs. ACE began collecting from retail distribution customers, through a non-bypassable charge, all costs associated with the procurement of the ZECs effective April 18, 2019. Other Federal Regulatory Matters Transmission-Related Income Tax Regulatory Assets (Exelon, ComEd, BGE, PHI, Pepco, DPL, and ACE). On December 13, 2016 (and as amended on March 13, 2017), BGE filed with FERC to begin recovering certain existing and future transmission-related income tax regulatory assets through its transmission formula rate. BGE’s existing regulatory assets included (1) amounts that, if BGE’s transmission formula rate provided for recovery, would have been previously amortized and (2) amounts that would be amortized and recovered prospectively. On November 16, 2017, FERC issued an order rejecting BGE’s proposed revisions to its transmission formula rate to recover these transmission-related income tax regulatory assets. In the fourth quarter of 2017, ComEd, BGE, Pepco, DPL, and ACE fully impaired their associated transmission-related income tax regulatory assets for the portion of the income tax regulatory assets that would have been previously amortized. On February 23, 2018 (as amended on July 9, 2018), ComEd, Pepco, DPL, and ACE each filed with FERC to revise their transmission formula rate mechanisms to permit recovery of transmission-related income tax regulatory assets, including those amounts that would have been previously amortized and recovered through rates had the transmission formula rate provided for such recovery. On September 7, 2018, FERC issued orders rejecting 1) BGE’s rehearing request of FERC's November 16, 2017 order and 2) the February 23, 2018 (as amended on July 9, 2018) filing by ComEd, Pepco, DPL, and ACE for similar recovery. On November 2, 2018, BGE filed an appeal of FERC's September 7, 2018 order to the U.S. Court of Appeals for the D.C. Circuit. On March 27, 2020, the U.S. Court of Appeals for the D.C. Circuit Court denied BGE’s November 2, 2018 appeal. On October 1, 2018, ComEd, BGE, Pepco, DPL, and ACE submitted filings to recover ongoing non-TCJA amortization amounts and credit TCJA transmission-related income tax regulatory liabilities to customers for the prospective period starting on October 1, 2018. On April 26, 2019, FERC issued an order accepting ComEd's, BGE's, Pepco's, DPL's, and ACE's October 1, 2018 filings, effective October 1, 2018, subject to refund and established hearing and settlement judge procedures. On April 24, 2020, ComEd, BGE, Pepco, DPL, ACE, and other parties filed a settlement agreement with FERC, which FERC approved on September 24, 2020. The settlement agreement provides for the recovery of ongoing transmission-related income tax regulatory assets and establishes the amount and amortization period for excess deferred income taxes resulting from TCJA. The settlement resulted in a reduction to Operating revenues and an offsetting reduction to Income tax expense in the second quarter of 2020. Regulatory Assets and Liabilities Regulatory assets represent incurred costs that have been deferred because of their probable future recovery from customers through regulated rates. Regulatory liabilities represent the excess recovery of costs or accrued credits that have been deferred because it is probable such amounts will be returned to customers through future regulated rates or represent billings in advance of expenditures for approved regulatory programs. The following tables provide information about the regulatory assets and liabilities of the Registrants as of December 31, 2021 and 2020: December 31, 2021 Exelon ComEd PECO BGE PHI Pepco DPL ACE Regulatory assets Pension and OPEB $ 2,409 $ — $ — $ — $ — $ — $ — $ — Pension and OPEB - merger related 893 — — — — — — — Deferred income taxes 883 — 873 — 10 10 — — AMI programs - deployment costs 145 — — 89 56 30 26 — AMI programs - legacy meters 186 69 — 29 88 60 21 7 Electric distribution formula rate annual reconciliations 44 44 — — — — — — Electric distribution formula rate significant one-time events 104 104 — — — — — — Energy efficiency costs 1,181 1,181 — — — — — — Fair value of long-term debt 557 — — — 443 — — — Fair value of PHI's unamortized energy contracts 236 — — — 236 — — — Asset retirement obligations 145 99 21 19 6 5 — 1 MGP remediation costs 283 266 8 9 — — — — Renewable energy 219 219 — — — — — — Electric energy and natural gas costs 96 — — 49 47 29 13 5 Transmission formula rate annual reconciliations 43 — 14 1 28 — 8 20 Energy efficiency and demand response programs 564 — — 283 281 199 79 3 Under-recovered revenue decoupling 157 — — 32 125 125 — — Removal costs 758 — — 143 615 147 109 360 DC PLUG charge 70 — — — 70 70 — — Deferred storm costs 49 — — — 49 3 3 43 COVID-19 82 28 33 8 13 10 3 — Under-recovered credit loss expense 89 60 — — 29 — — 29 Other 327 135 42 30 130 57 18 23 Total regulatory assets 9,520 2,205 991 692 2,226 745 280 491 Less: current portion 1,296 335 48 215 432 213 68 61 Total noncurrent regulatory assets $ 8,224 $ 1,870 $ 943 $ 477 $ 1,794 $ 532 $ 212 $ 430 December 31, 2021 Exelon ComEd PECO BGE PHI Pepco DPL ACE Regulatory liabilities Deferred income taxes $ 4,005 $ 2,105 $ — $ 819 $ 1,081 $ 525 $ 354 $ 202 Decommissioning the Regulatory Agreement Units 3,357 2,760 597 — — — — — Removal costs 1,694 1,541 — 39 114 20 94 — Electric energy and natural gas costs 113 25 71 — 17 9 3 5 Transmission formula rate annual reconciliations 8 7 — — 1 1 — — Renewable portfolio standards costs 500 500 — — — — — — Stranded costs 35 — — — 35 — — 35 Other 292 6 61 102 58 8 15 10 Total regulatory liabilities 10,004 6,944 729 960 1,306 563 466 252 Less: current portion 376 185 94 26 68 14 25 28 Total noncurrent regulatory liabilities $ 9,628 $ 6,759 $ 635 $ 934 $ 1,238 $ 549 $ 441 $ 224 December 31, 2020 Exelon ComEd PECO BGE PHI Pepco DPL ACE Regulatory assets Pension and OPEB $ 3,010 $ — $ — $ — $ — $ — $ — $ — Pension and OPEB - merger related 1,014 — — — — — — — Deferred income taxes 715 — 705 — 10 10 — — AMI programs - deployment costs 174 — — 109 65 35 30 — AMI programs

Revenue from Contracts with Cus

Revenue from Contracts with Customers (All Registrants)	12 Months Ended
Revenue from Contracts with Customers (All Registrants)	Dec. 31, 2021
Revenue from Contract with Customer (All Registrants) [Abstract]
Revenue from Contracts with Customers [Text Block]	Revenue from Contracts with Customers (All Registrants) The Registrants recognize revenue from contracts with customers to depict the transfer of goods or services to customers at an amount that the entities expect to be entitled to in exchange for those goods or services. The primary sources of revenue include regulated electric and gas tariff sales, distribution, and transmission services. The performance obligations, revenue recognition, and payment terms associated with these sources of revenue are further discussed in the table below. There are no significant financing components for these sources of revenue and no variable consideration. Unless otherwise noted, for each of the significant revenue categories and related performance obligations described below, the Registrants have the right to consideration from the customer in an amount that corresponds directly with the value transferred to the customer for the performance completed to date. Therefore, the Registrants generally recognize revenue in the amount for which they have the right to invoice the customer. As a result, there are generally no significant judgments used in determining or allocating the transaction price. Revenue Source Description Performance Obligation Timing of Revenue Recognition Payment Terms Regulated Electric and Gas Tariff Sales Sales of electricity and electricity distribution services (the Utility Registrants) and natural gas and gas distribution services (PECO, BGE, and DPL) to residential, commercial, industrial, and governmental customers through regulated tariff rates approved by state regulatory commissions. Delivery of electricity and/or natural gas. Over time (each day) as the electricity and/or natural gas is delivered to customers. Tariff sales are generally considered daily contracts as customers can discontinue service at any time. (a) Within the month following delivery of the electricity or natural gas to the customer. Regulated Transmission Services The Utility Registrants provide open access to their transmission facilities to PJM, which directs and controls the operation of these transmission facilities and accordingly compensates the Utility Registrants pursuant to filed tariffs at cost-based rates approved by FERC. Various including (i) Network Integration Transmission Services (NITS), (ii) scheduling, system control and dispatch services, and (iii) access to the wholesale grid. Over time utilizing output methods to measure progress towards completion. (b) Paid weekly by PJM. __________ (a) Electric and natural gas utility customers have the choice to purchase electricity or natural gas from competitive electric generation and natural gas suppliers. While the Utility Registrants are required under state legislation to bill their customers for the supply and distribution of electricity and/or natural gas, they recognize revenue related only to the distribution services when customers purchase their electricity or natural gas from competitive suppliers. (b) Passage of time is used for NITS and access to the wholesale grid and MWHs of energy transported over the wholesale grid is used for scheduling, system control and dispatch services. The Utility Registrants do not incur any material costs to obtain or fulfill contracts with customers. Contract Liabilities The Registrants record contract liabilities when consideration is received or due prior to the satisfaction of the performance obligations. The Registrants record contract liabilities in Other current liabilities and Other noncurrent liabilities in the Registrants' Consolidated Balance Sheets. On July 1, 2020, Pepco, DPL, and ACE each entered into a collaborative arrangement with an unrelated owner and manager of communication infrastructure (the Buyer). Under this arrangement, Pepco, DPL, and ACE sold a 60% undivided interest in their respective portfolios of transmission tower attachment agreements with telecommunications companies to the Buyer, in addition to transitioning management of the day-to-day operations of the jointly-owned agreements to the Buyer for 35 years, while retaining the safe and reliable operation of its utility assets. In return, Pepco, DPL, and ACE will provide the Buyer limited access on the portion of the towers where the equipment resides for the purposes of managing the agreements for the benefit of Pepco, DPL, ACE, and the Buyer. In addition, for an initial period of three years and two, two-year extensions that are subject to certain conditions, the Buyer has the exclusive right to enter into new agreements with telecommunications companies and to receive a 30% undivided interest in those new agreements. PHI, Pepco, DPL, and ACE received cash and recorded contract liabilities as of July 1, 2020 as shown in the table below. The revenue attributable to this arrangement will be recognized as operating revenue over the 35 years under the collaborative arrangement. The following table provides a rollforward of the contract liabilities reflected in Exelon's, PHI's, Pepco's, DPL's, and ACE'S Consolidated Balance Sheets. As of December 31, 2021, 2020, and 2019, ComEd's, PECO's, and BGE's contract liabilities were not material. Exelon PHI Pepco DPL ACE Balance as of December 31, 2019 $ — $ — $ — $ — $ — Consideration received or due 122 122 98 12 12 Revenues recognized (4) (4) (4) — — Balance as of December 31, 2020 118 118 94 12 12 Revenues recognized (9) (9) (7) (1) (1) Balance as of December 31, 2021 $ 109 $ 109 $ 87 $ 11 $ 11 The following table reflects revenues recognized in the years ended December 31, 2021, 2020 and 2019, which were included in contract liabilities at December 31, 2020, 2019, and 2018, respectively: 2021 Exelon $ 9 PHI 9 Pepco 7 DPL 1 ACE 1 Transaction Price Allocated to Remaining Performance Obligations The following table shows the amounts of future revenues expected to be recorded in each year for performance obligations that are unsatisfied or partially unsatisfied as of December 31, 2021. This disclosure only includes contracts for which the total consideration is fixed and determinable at contract inception. The average contract term varies by customer type and commodity but ranges from one month to several years. This disclosure excludes the Utility Registrants' gas and electric tariff sales contracts and transmission revenue contracts as they generally have an original expected duration of one year or less and, therefore, do not contain any future, unsatisfied performance obligations to be included in this disclosure. 2022 2023 2024 2025 2026 and thereafter Total Exelon $ 8 $ 8 $ 6 $ 5 $ 82 $ 109 PHI 8 8 6 5 82 109 Pepco 6 6 5 5 65 87 DPL 1 1 — — 9 11 ACE 1 1 1 — 8 11 Revenue Disaggregation The Registrants disaggregate revenue recognized from contracts with customers into categories that depict how the nature, amount, timing, and uncertainty of revenue and cash flows are affected by economic factors. See Note 5 — Segment Information for the presentation of the Registrant's revenue disaggregation.

Segment Information (All Regist

Segment Information (All Registrants)	12 Months Ended
Segment Information (All Registrants)	Dec. 31, 2021
Segment Reporting [Abstract]
Segment Information (All Registrants)	Segment Information (All Registrants) Operating segments for each of the Registrants are determined based on information used by the CODMs in deciding how to evaluate performance and allocate resources at each of the Registrants. As of December 31, 2021, Exelon had eleven reportable segments, which included five reportable segments for Generation and ComEd, PECO, BGE, and PHI's three reportable segments consisting of Pepco, DPL, and ACE. ComEd, PECO, BGE, Pepco, DPL, and ACE each represent a single reportable segment, and as such, no separate segment information is provided for these Registrants. Exelon, ComEd, PECO, BGE, Pepco, DPL, and ACE's CODMs evaluate the performance of and allocate resources to ComEd, PECO, BGE, Pepco, DPL, and ACE based on net income. The separation of Constellation Energy Corporation, including Generation and its subsidiaries, meets the criteria for discontinued operations and as such, results of operations are presented as discontinued operations and have been excluded from continuing operations for all periods presented. Furthermore, the reportable segment information related to the discontinued operations has been excluded from the tables presented below. See Note 2 — Discontinued Operations for additional information. An analysis and reconciliation of the reportable segment information to the respective information in the Exelon consolidated financial statements for the years ended December 31, 2021, 2020, and 2019 is as follows: ComEd PECO BGE PHI Other (a) Intersegment Exelon Operating revenues (b) : 2021 Electric revenues $ 6,406 $ 2,659 $ 2,505 $ 4,860 $ — $ (35) $ 16,395 Natural gas revenues — 539 836 168 — — 1,543 Shared service and other revenues — — — 13 2,213 (2,226) — Total operating revenues $ 6,406 $ 3,198 $ 3,341 $ 5,041 $ 2,213 $ (2,261) $ 17,938 2020 Electric revenues $ 5,904 $ 2,543 $ 2,336 $ 4,485 $ — $ (44) $ 15,224 Natural gas revenues — 515 762 162 — — 1,439 Shared service and other revenues — — — 16 2,035 (2,051) — Total operating revenues $ 5,904 $ 3,058 $ 3,098 $ 4,663 $ 2,035 $ (2,095) $ 16,663 2019 Electric revenues $ 5,747 $ 2,490 $ 2,379 $ 4,626 $ — $ (21) $ 15,221 Natural gas revenues — 610 727 167 — — 1,504 Shared service and other revenues — — — 13 1,921 (1,934) — Total operating revenues $ 5,747 $ 3,100 $ 3,106 $ 4,806 $ 1,921 $ (1,955) $ 16,725 Intersegment revenues (c) : 2021 $ 41 $ 21 $ 31 $ 13 $ 2,203 $ (2,252) $ 57 2020 37 9 20 17 2,024 (2,084) 23 2019 30 6 26 14 1,913 (1,948) 41 Depreciation and amortization: 2021 $ 1,205 $ 348 $ 591 $ 821 $ 67 $ 1 $ 3,033 2020 1,133 347 550 782 79 — 2,891 2019 1,033 333 502 754 95 — 2,717 Operating expenses: 2021 $ 5,151 $ 2,547 $ 2,860 $ 4,240 $ 2,045 $ (1,587) $ 15,256 2020 4,950 2,512 2,598 4,045 1,882 (1,502) 14,485 2019 4,580 2,388 2,574 4,084 1,830 (1,383) 14,073 ComEd PECO BGE PHI Other (a) Intersegment Exelon Interest expense, net: 2021 $ 389 $ 161 $ 138 $ 267 $ 335 $ (1) $ 1,289 2020 382 147 133 268 380 (3) 1,307 2019 359 136 121 263 343 — 1,222 Income (loss) from continuing operations before income taxes: 2021 $ 914 $ 516 $ 373 $ 603 $ (149) $ (603) $ 1,654 2020 615 417 390 418 (151) (597) 1,092 2019 851 593 439 514 (127) (632) 1,638 Income taxes: 2021 $ 172 $ 12 $ (35) $ 42 $ 8 $ (161) $ 38 2020 177 (30) 41 (77) 35 (153) (7) 2019 163 65 79 38 (32) (160) 153 Net income (loss) from continuing operations: 2021 $ 742 $ 504 $ 408 $ 561 $ (156) $ (443) $ 1,616 2020 438 447 349 495 (184) (446) 1,099 2019 688 528 360 477 (95) (472) 1,486 Capital expenditures: 2021 $ 2,387 $ 1,240 $ 1,226 $ 1,720 $ 67 $ — $ 6,640 2020 2,217 1,147 1,247 1,604 74 — 6,289 2019 1,915 939 1,145 1,355 45 — 5,399 Total assets: 2021 $ 36,470 $ 13,824 $ 12,324 $ 24,744 $ 7,626 $ (8,319) $ 86,669 2020 34,466 12,531 11,650 23,736 8,894 (8,454) 82,823 __________ (a) Other primarily includes Exelon’s corporate operations, shared service entities, and other financing and investment activities. (b) Includes gross utility tax receipts from customers. The offsetting remittance of utility taxes to the governing bodies is recorded in expenses in the Registrants’ Consolidated Statements of Operations and Comprehensive Income. See Note 22 — Supplemental Financial Information for additional information on total utility taxes. (c) See Note 23 — Related Party Transactions for additional information on intersegment revenues. PHI: Pepco DPL ACE Other (a) Intersegment PHI Operating revenues (b) : 2021 Electric revenues $ 2,274 $ 1,212 $ 1,388 $ — $ (14) $ 4,860 Natural gas revenues — 168 — — — 168 Shared service and other revenues — — — 379 (366) 13 Total operating revenues $ 2,274 $ 1,380 $ 1,388 $ 379 $ (380) $ 5,041 2020 Electric revenues $ 2,149 $ 1,109 $ 1,245 $ — $ (18) $ 4,485 Natural gas revenues — 162 — — — 162 Shared service and other revenues — — — 372 (356) 16 Total operating revenues $ 2,149 $ 1,271 $ 1,245 $ 372 $ (374) $ 4,663 2019 Electric revenues $ 2,260 $ 1,139 $ 1,240 $ — $ (13) $ 4,626 Natural gas revenues — 167 — — — 167 Shared service and other revenues — — — 396 (383) 13 Total operating revenues $ 2,260 $ 1,306 $ 1,240 $ 396 $ (396) $ 4,806 Intersegment revenues (c) : 2021 $ 5 $ 7 $ 2 $ 380 $ (381) $ 13 2020 7 9 4 372 (375) 17 2019 5 7 3 396 (397) 14 Depreciation and amortization: 2021 $ 403 $ 210 $ 179 $ 29 $ — $ 821 2020 377 191 180 34 — 782 2019 374 184 157 39 — 754 Operating expenses: 2021 $ 1,871 $ 1,161 $ 1,201 $ 388 $ (381) $ 4,240 2020 1,799 1,120 1,123 378 (375) 4,045 2019 1,899 1,089 1,089 403 (396) 4,084 Interest expense, net: 2021 $ 140 $ 61 $ 58 $ 8 $ — $ 267 2020 138 61 59 10 — 268 2019 133 61 58 10 1 263 Income (loss) before income taxes: 2021 $ 311 $ 170 $ 133 $ (11) $ — $ 603 2020 259 100 71 (12) — 418 2019 259 169 99 (13) — 514 Income taxes: 2021 $ 15 $ 42 $ (13) $ (2) $ — $ 42 2020 (7) (25) (41) (4) — (77) 2019 16 22 — — — 38 Pepco DPL ACE Other (a) Intersegment PHI Net income (loss): 2021 $ 296 $ 128 $ 146 $ (9) $ — $ 561 2020 266 125 112 (8) — 495 2019 243 147 99 (12) — 477 Capital expenditures: 2021 $ 843 $ 429 $ 445 $ 3 $ — $ 1,720 2020 773 424 401 6 — 1,604 2019 626 348 375 6 — 1,355 Total assets: 2021 $ 9,903 $ 5,412 $ 4,556 $ 4,933 $ (60) $ 24,744 2020 9,264 5,140 4,286 5,079 (33) 23,736 __________ (a) Other primarily includes PHI’s corporate operations, shared service entities, and other financing and investment activities. (b) Includes gross utility tax receipts from customers. The offsetting remittance of utility taxes to the governing bodies is recorded in expenses in the Registrants’ Consolidated Statements of Operations and Comprehensive Income. See Note 22 — Supplemental Financial Information for additional information on total utility taxes. (c) Includes intersegment revenues with ComEd, BGE, and PECO, which are eliminated at Exelon. The following tables disaggregate the revenues recognized from contracts with customers into categories that depict how the nature, amount, timing, and uncertainty of revenue and cash flows are affected by economic factors. For the Utility Registrants, the disaggregation of revenues reflects the two primary utility services of electric sales and natural gas sales (where applicable), with further disaggregation of these tariff sales provided by major customer groups. Exelon's disaggregated revenues are consistent with the Utility Registrants, but exclude any intercompany revenues. 2021 Revenues from contracts with customers ComEd PECO BGE PHI Pepco DPL ACE Electric revenues Residential $ 3,233 $ 1,704 $ 1,375 $ 2,441 $ 1,003 $ 694 $ 744 Small commercial & industrial 1,571 422 267 521 135 193 193 Large commercial & industrial 559 243 459 1,123 844 94 185 Public authorities & electric railroads 45 31 27 58 31 14 13 Other (a) 926 229 371 634 205 201 229 Total electric revenues (b) $ 6,334 $ 2,629 $ 2,499 $ 4,777 $ 2,218 $ 1,196 $ 1,364 Natural gas revenues Residential $ — $ 372 $ 518 $ 97 $ — $ 97 $ — Small commercial & industrial — 136 83 42 — 42 — Large commercial & industrial — — 147 7 — 7 — Transportation — 24 — 14 — 14 — Other (c) — 7 68 8 — 8 — Total natural gas revenues (d) $ — $ 539 $ 816 $ 168 $ — $ 168 $ — Total revenues from contracts with customers $ 6,334 $ 3,168 $ 3,315 $ 4,945 $ 2,218 $ 1,364 $ 1,364 Other revenues Revenues from alternative revenue programs $ 42 $ 26 $ 12 $ 91 $ 53 $ 14 $ 24 Other electric revenues (e) 30 4 11 5 3 2 — Other natural gas revenues (e) — — 3 — — — — Total other revenues $ 72 $ 30 $ 26 $ 96 $ 56 $ 16 $ 24 Total revenues for reportable segments $ 6,406 $ 3,198 $ 3,341 $ 5,041 $ 2,274 $ 1,380 $ 1,388 2020 Revenues from contracts with customers ComEd PECO BGE PHI Pepco DPL ACE Electric revenues Residential $ 3,090 $ 1,656 $ 1,345 $ 2,332 $ 988 $ 652 $ 692 Small commercial & industrial 1,399 386 241 472 132 171 169 Large commercial & industrial 515 228 406 1,001 736 89 176 Public authorities & electric railroads 45 29 27 60 34 13 13 Other (a) 884 225 309 613 218 190 207 Total electric revenues (b) $ 5,933 $ 2,524 $ 2,328 $ 4,478 $ 2,108 $ 1,115 $ 1,257 Natural gas revenues Residential $ — $ 361 $ 504 $ 96 $ — $ 96 $ — Small commercial & industrial — 126 79 42 — 42 — Large commercial & industrial — — 135 4 — 4 — Transportation — 24 — 14 — 14 — Other (c) — 4 29 6 — 6 — Total natural gas revenues (d) $ — $ 515 $ 747 $ 162 $ — $ 162 $ — Total revenues from contracts with customers $ 5,933 $ 3,039 $ 3,075 $ 4,640 $ 2,108 $ 1,277 $ 1,257 Other revenues Revenues from alternative revenue programs $ (47) $ 16 $ 16 $ 21 $ 40 $ (7) $ (12) Other electric revenues (e) 18 3 5 2 1 1 — Other natural gas revenues (e) — — 2 — — — — Total other revenues $ (29) $ 19 $ 23 $ 23 $ 41 $ (6) $ (12) Total revenues for reportable segments $ 5,904 $ 3,058 $ 3,098 $ 4,663 $ 2,149 $ 1,271 $ 1,245 2019 Revenues from contracts with customers ComEd PECO BGE PHI Pepco DPL ACE Electric revenues Residential $ 2,916 $ 1,596 $ 1,326 $ 2,316 $ 1,012 $ 645 $ 659 Small commercial & industrial 1,463 404 254 505 149 186 170 Large commercial & industrial 540 219 436 1,112 833 99 180 Public authorities & electric railroads 47 29 27 61 34 14 13 Other (a) 888 249 321 650 227 204 218 Total electric revenues (b) $ 5,854 $ 2,497 $ 2,364 $ 4,644 $ 2,255 $ 1,148 $ 1,240 Natural gas revenues Residential $ — $ 409 $ 474 $ 96 $ — $ 96 $ — Small commercial & industrial — 169 77 44 — 45 — Large commercial & industrial — 1 132 5 — 5 — Transportation — 25 — 14 — 14 — Other (c) — 6 31 7 — 7 — Total natural gas revenues (d) $ — $ 610 $ 714 $ 166 $ — $ 167 $ — Total revenues from contracts with customers $ 5,854 $ 3,107 $ 3,078 $ 4,810 $ 2,255 $ 1,315 $ 1,240 Other revenues Revenues from alternative revenue programs $ (133) $ (21) $ 12 $ (14) $ (3) $ (11) $ — Other electric revenues (e) 26 13 12 10 8 2 — Other natural gas revenues (e) — 1 4 — — — — Total other revenues $ (107) $ (7) $ 28 $ (4) $ 5 $ (9) $ — Total revenues for reportable segments $ 5,747 $ 3,100 $ 3,106 $ 4,806 $ 2,260 $ 1,306 $ 1,240 __________ (a) Includes revenues from transmission revenue from PJM, wholesale electric revenue and mutual assistance revenue. (b) Includes operating revenues from affiliates in 2021, 2020, and 2019 respectively of: • $41 million, $37 million, and $30 million at ComEd • $20 million, $8 million, and $5 million at PECO • $13 million, $10 million, and $8 million at BGE • $13 million, $17 million, and $14 million at PHI • $5 million, $7 million, and $5 million at Pepco • $7 million, $9 million, and $7 million at DPL • $2 million, $4 million, and $3 million at ACE (c) Includes revenues from off-system natural gas sales. (d) Includes operating revenues from affiliates in 2021, 2020, and 2019 respectively of: • $1 million, $1 million, and $1 million at PECO • $18 million, $10 million, and $18 million at BGE (e) Includes late payment charge revenues.

Accounts Receivable (All Regist

Accounts Receivable (All Registrants)	12 Months Ended
Accounts Receivable (All Registrants)	Dec. 31, 2021
Credit Loss [Abstract]
Accounts Receivable (All Registrants)	Accounts Receivable (All Registrants) Allowance for Credit Losses on Accounts Receivable The following tables present the rollforward of Allowance for Credit Losses on Customer Accounts Receivable. Year Ended December 31, 2021 Exelon ComEd PECO BGE PHI Pepco DPL ACE Balance as of December 31, 2020 $ 334 $ 97 $ 116 $ 35 $ 86 $ 32 $ 22 $ 32 Plus: Current period provision for expected credit losses (a) 96 21 23 15 37 13 6 18 Less: Write-offs, net of recoveries (b)(c) 110 45 34 12 19 8 10 1 Balance as of December 31, 2021 $ 320 $ 73 $ 105 $ 38 $ 104 $ 37 $ 18 $ 49 Year Ended December 31, 2020 Exelon ComEd PECO BGE PHI Pepco DPL ACE Balance as of December 31, 2019 $ 163 $ 59 $ 55 $ 12 $ 37 $ 13 $ 11 $ 13 Plus: Current period provision for expected credit losses (d) 235 62 79 30 64 24 15 25 Less: Write-offs, net of recoveries (c) 64 24 18 7 15 5 4 6 Balance as of December 31, 2020 $ 334 $ 97 $ 116 $ 35 $ 86 $ 32 $ 22 $ 32 _________ (a) The increase is primarily a result of increased aging of receivables. (b) For ComEd, PECO and DPL, the increase in 2021 is primarily related to the termination of the moratorium which, beginning in March 2020, prevented customer disconnections for non-payment. With disconnection activities restarting in 2021, write-offs of aging accounts receivable increased throughout the year. (c) Recoveries were not material to the Registrants. (d) The increase is primarily as a result of increased aging of receivables, the temporary suspension of customer disconnections for non-payment, temporary cessation of new late payment fees, and reconnection of service to customers previously disconnected due to COVID-19. The following tables present the rollforward of Allowance for Credit Losses on Other Accounts Receivable. Year Ended December 31, 2021 Exelon ComEd PECO BGE PHI Pepco DPL ACE Balance as of December 31, 2020 $ 71 $ 21 $ 8 $ 9 $ 33 $ 13 $ 9 $ 11 Plus: Current period provision for expected credit losses 11 (2) 3 4 6 3 (1) 4 Less: Write-offs, net of recoveries (a) 10 2 4 4 — — — — Balance as of December 31, 2021 $ 72 $ 17 $ 7 $ 9 $ 39 $ 16 $ 8 $ 15 Year Ended December 31, 2020 Exelon ComEd PECO BGE PHI Pepco DPL ACE Balance as of December 31, 2019 $ 48 $ 20 $ 7 $ 5 $ 16 $ 7 $ 4 $ 5 Plus: Current period provision for expected credit losses 33 5 3 7 18 6 5 7 Less: Write-offs, net of recoveries (a) 10 4 2 3 1 — — 1 Balance as of December 31, 2020 $ 71 $ 21 $ 8 $ 9 $ 33 $ 13 $ 9 $ 11 _________ (a) Recoveries were not material to the Registrants. Unbilled Customer Revenue The following table provides additional information about unbilled customer revenues recorded in the Registrants' Consolidated Balance Sheets as of December 31, 2021 and 2020. Unbilled customer revenues (a) Exelon ComEd PECO BGE PHI Pepco DPL ACE December 31, 2021 $ 747 $ 240 $ 161 $ 171 $ 175 $ 82 $ 53 $ 40 December 31, 2020 740 218 147 197 178 87 62 29 _________ (a) Unbilled customer revenues are classified in Customer accounts receivables, net in the Registrants' Consolidated Balance Sheets. Other Purchases of Customer and Other Accounts Receivables The Utility Registrants are required, under separate legislation and regulations in Illinois, Pennsylvania, Maryland, District of Columbia, and New Jersey, to purchase certain receivables from alternative retail electric and, as applicable, natural gas suppliers that participate in the utilities' consolidated billing. The following tables present the total receivables purchased and sold. Year Ended December 31, 2021 Exelon ComEd PECO BGE PHI Pepco DPL ACE Total receivables purchased $ 3,840 $ 1,031 $ 1,041 $ 687 $ 1,081 $ 660 $ 217 $ 204 Related party transactions: Receivables purchased from Generation — 1 1 21 — — — — Year Ended December 31, 2020 Exelon ComEd PECO BGE PHI Pepco DPL ACE Total receivables purchased $ 3,781 $ 1,094 $ 1,020 $ 652 $ 1,015 $ 622 $ 207 $ 186 Related party transactions: Receivables purchased from Generation — 34 67 79 72 51 13 8

Property, Plant and Equipment (

Property, Plant and Equipment (All Registrants)	12 Months Ended
Property, Plant and Equipment (All Registrants)	Dec. 31, 2021
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment (All Registrants)	Property, Plant, and Equipment (All Registrants) The following tables present a summary of property, plant, and equipment by asset category as of December 31, 2021 and 2020: Asset Category Exelon ComEd PECO BGE PHI Pepco DPL ACE December 31, 2021 Electric—transmission and distribution $ 64,771 $ 31,077 $ 10,076 $ 9,352 $ 16,062 $ 10,798 $ 4,957 $ 4,882 Gas—transportation and distribution 7,429 — 3,339 3,712 646 — 806 — Common—electric and gas 2,335 — 1,005 1,224 201 — 180 — Construction work in progress 3,698 918 620 554 1,590 1,118 229 242 Other property, plant, and equipment (a) 755 99 41 34 107 63 23 25 Total property, plant, and equipment 78,988 32,094 15,081 14,876 18,606 11,979 6,195 5,149 Less: accumulated depreciation 14,430 6,099 3,964 4,299 2,108 3,875 1,635 1,420 Property, plant, and equipment, net $ 64,558 $ 25,995 $ 11,117 $ 10,577 $ 16,498 $ 8,104 $ 4,560 $ 3,729 December 31, 2020 Electric—transmission and distribution $ 60,946 $ 29,371 $ 9,462 $ 8,797 $ 15,137 $ 10,264 $ 4,730 $ 4,568 Gas—transportation and distribution 6,733 — 3,098 3,315 591 — 751 — Common—electric and gas 2,170 — 956 1,138 178 — 180 — Construction work in progress 3,107 799 474 627 1,174 824 163 182 Other property, plant and equipment (a) 722 59 34 29 108 65 23 28 Total property, plant and equipment 73,678 30,229 14,024 13,906 17,188 11,153 5,847 4,778 Less: accumulated depreciation 13,346 5,672 3,843 4,034 1,811 3,697 1,533 1,303 Property, plant, and equipment, net $ 60,332 $ 24,557 $ 10,181 $ 9,872 $ 15,377 $ 7,456 $ 4,314 $ 3,475 __________ (a) Primarily composed of land and non-utility property. The following table presents the average service life for each asset category in number of years: Average Service Life (years) Asset Category Exelon ComEd PECO BGE PHI Pepco DPL ACE Electric - transmission and distribution 5-80 5-80 5-70 5-80 5-75 5-75 5-70 5-65 Gas - transportation and distribution 5-80 N/A 5-70 5-80 5-75 N/A 5-75 N/A Common - electric and gas 4-75 N/A 5-55 4-50 5-75 N/A 5-75 N/A Other property, plant, and equipment 3-61 32-50 50 20-50 3-50 33-50 8-50 13-15 The following table presents the annual depreciation rates for each asset category. Annual Depreciation Rates Exelon ComEd PECO BGE PHI Pepco DPL ACE December 31, 2021 Electric—transmission and distribution 2.81 % 2.94 % 2.28 % 2.80 % 2.87 % 2.56 % 2.86 % 3.21 % Gas—transportation and distribution 2.13 % N/A 1.84 % 2.54 % 1.47 % N/A 1.47 % N/A Common—electric and gas 7.31 % N/A 6.34 % 7.88 % 8.33 % N/A 8.69 % N/A December 31, 2020 Electric—transmission and distribution 2.79 % 2.95 % 2.31 % 2.69 % 2.81 % 2.53 % 2.85 % 3.08 % Gas—transportation and distribution 2.14 % N/A 1.85 % 2.56 % 1.50 % N/A 1.50 % N/A Common—electric and gas 7.01 % N/A 6.39 % 7.45 % 7.36 % N/A 6.72 % N/A December 31, 2019 Electric—transmission and distribution 2.80 % 2.99 % 2.36 % 2.60 % 2.77 % 2.47 % 2.86 % 2.94 % Gas—transportation and distribution 2.04 % N/A 1.89 % 2.30 % 1.55 % N/A 1.55 % N/A Common—electric and gas 7.37 % N/A 6.06 % 8.30 % 8.25 % N/A 6.24 % N/A Capitalized Interest and AFUDC The following table summarizes capitalized interest and credits to AFUDC by year: Exelon ComEd PECO BGE PHI Pepco DPL ACE December 31, 2021 Capitalized interest $ — $ — $ — $ — $ — $ — $ — $ — AFUDC debt and equity 189 47 34 36 72 59 8 5 December 31, 2020 Capitalized interest $ — $ — $ — $ — $ — $ — $ — $ — AFUDC debt and equity 150 42 23 30 55 42 6 7 December 31, 2019 Capitalized interest $ — $ — $ — $ — $ — $ — $ — $ — AFUDC debt and equity 132 32 17 29 54 39 6 9 See Note 1 — Significant Accounting Policies for additional information regarding property, plant and equipment policies. See Note 15 — Debt and Credit Agreements for additional information regarding Exelon’s, ComEd’s, PECO's, Pepco's, DPL's, and ACE’s property, plant and equipment subject to mortgage liens.

Jointly Owned Electric Utility

Jointly Owned Electric Utility Plant (Exelon, PECO, DPL and ACE)	12 Months Ended
	Dec. 31, 2021
Public Utilities, Property, Plant and Equipment [Abstract]
Jointly Owned Electric Utility Plant (Exelon, PECO, DPL and ACE)	Jointly Owned Electric Utility Plant (Exelon, PECO, PHI, DPL, and ACE) PECO's, DPL's, and ACE's material undivided ownership interests in jointly owned electric plants and transmission facilities as of December 31, 2021 and 2020 were as follows: Transmission NJ/DE (a) Operator PSEG/DPL Ownership interest various Exelon’s share as of December 31, 2021: Plant in service $ 103 Accumulated depreciation 55 Exelon’s share as of December 31, 2020: Plant in service $ 103 Accumulated depreciation 54 __________ (a) PECO, DPL, and ACE own a 42.55%, 1%, and 13.9% share, respectively in 151.3 miles of 500kV lines located in New Jersey and of the Salem generating plant substation. PECO, DPL, and ACE also own a 42.55%, 7.45%, and 7.45% share, respectively, in 2.5 miles of 500kV line located over the Delaware River. ACE also has a 21.78% share in a 500kV New Freedom Switching substation. PECO's, DPL's, and ACE's undivided ownership interests are financed with their funds and all operations are accounted for as if such participating interests were wholly owned facilities. PECO's, DPL's, and ACE's share of direct expenses of the jointly owned plants are included in Operating and maintenance expenses in Exelon's, PECO's, PHI's, DPL's, and ACE's Consolidated Statements of Operations and Comprehensive Income.

Asset Retirement Obligations (A

Asset Retirement Obligations (All Registrants)	12 Months Ended
Asset Retirement Obligations (All Registrants)	Dec. 31, 2021
Asset Retirement Obligation Disclosure [Abstract]
Asset Retirement Obligations (All Registrants)	Asset Retirement Obligations (All Registrants) The Registrants have AROs primarily associated with the abatement and disposal of equipment and buildings contaminated with asbestos and PCBs. See Note 1 — Significant Accounting Policies for additional information on the Registrants’ accounting policy for AROs. The following table provides a rollforward of the AROs reflected in the Registrants’ Consolidated Balance Sheets from December 31, 2019 to December 31, 2021: Exelon ComEd PECO BGE PHI Pepco DPL ACE AROs as of December 31, 2019 $ 244 $ 129 $ 28 $ 23 $ 57 $ 41 $ 12 $ 4 Net increase (decrease) due to changes in, and timing of, estimated future cash flows 5 — 2 1 1 (3) 2 2 Accretion expense (a) 5 1 1 1 1 1 — — Payments (5) (1) (2) (2) — — — — AROs as of December 31, 2020 249 129 29 23 59 39 14 6 Net increase due to changes in, and timing of, estimated future cash flows 26 15 — 2 10 5 2 3 Accretion expense (a) 7 4 1 1 1 1 — — Payments (8) (2) (1) — — — — — AROs as of December 31, 2021 $ 274 $ 146 $ 29 $ 26 $ 70 $ 45 $ 16 $ 9 __________ (a) For ComEd, PECO, BGE, PHI, and Pepco, the majority of the accretion is recorded as an increase to a regulatory asset due to the associated regulatory treatment.

Leases (All Registrants)

Leases (All Registrants)	12 Months Ended
Leases (All Registrants)	Dec. 31, 2021
Leases [Abstract]
Leases of Lessee Disclosure [Text Block]	Lessee The Registrants have operating and finance leases for which they are the lessees. The following tables outline the significant types of leases at each registrant and other terms and conditions of the lease agreements as of December 31, 2021. Exelon, ComEd, PECO, and BGE did not have material finance leases in 2021, 2020, or in 2019. PHI, Pepco, DPL, and ACE also did not have material finance leases in 2019. Exelon ComEd PECO BGE PHI Pepco DPL ACE Real estate ● ● ● ● ● ● ● ● Vehicles and equipment ● ● ● ● ● ● ● ● (in years) Exelon ComEd PECO BGE PHI Pepco DPL ACE Remaining lease terms 1-84 1-3 1-12 1-84 1-10 1-10 1-10 1-7 Options to extend the term 3-30 5 N/A N/A 3-30 5 3-30 5 Options to terminate within 1-11 1 N/A 1 N/A N/A N/A N/A The components of operating lease costs were as follows: Exelon ComEd PECO BGE PHI Pepco DPL ACE For the year ended December 31, 2021 Operating lease costs $ 84 $ 3 $ — $ 30 $ 43 $ 10 $ 12 $ 6 Variable lease costs 7 1 — 1 1 — — — Total lease costs (a) $ 91 $ 4 $ — $ 31 $ 44 $ 10 $ 12 $ 6 For the year ended December 31, 2020 Operating lease costs $ 98 $ 3 $ 1 $ 33 $ 46 $ 11 $ 13 $ 6 Variable lease costs 7 1 — 1 2 1 1 — Total lease costs (a) $ 105 $ 4 $ 1 $ 34 $ 48 $ 12 $ 14 $ 6 For the year ended December 31, 2019 Operating lease costs $ 98 $ 3 $ 1 $ 33 $ 48 $ 12 $ 14 $ 7 Variable lease costs 18 2 — 2 6 2 2 1 Total lease costs (a) $ 116 $ 5 $ 1 $ 35 $ 54 $ 14 $ 16 $ 8 __________ (a) Excludes sublease income recorded at Exelon, PHI, and DPL of $4 million, $4 million, and $7 million for the years ended December 31, 2021, 2020, and 2019, respectively. PHI, Pepco, DPL, and ACE recorded finance lease costs of $13 million, $5 million, $5 million, and $3 million, respectively, for the year ended December 31, 2021 and $9 million, $3 million, $4 million, and $2 million, respectively, for the year ended December 31, 2020. The following tables provide additional information regarding the presentation of operating and finance lease ROU assets and lease liabilities within the Registrants’ Consolidated Balance Sheets: Operating Leases Exelon ComEd PECO BGE PHI Pepco DPL ACE As of December 31, 2021 Operating lease ROU assets Other deferred debits and other assets $ 271 $ 5 $ 1 $ 16 $ 209 $ 43 $ 46 $ 11 Operating lease liabilities Other current liabilities 52 2 — 15 31 6 8 3 Other deferred credits and other liabilities 263 3 1 4 195 40 49 9 Total operating lease liabilities $ 315 $ 5 $ 1 $ 19 $ 226 $ 46 $ 57 $ 12 As of December 31, 2020 Operating lease ROU assets Other deferred debits and other assets $ 338 $ 7 $ 1 $ 46 $ 241 $ 49 $ 54 $ 15 Operating lease liabilities Other current liabilities 81 3 — 45 31 6 9 4 Other deferred credits and other liabilities 314 5 1 19 224 46 56 11 Total operating lease liabilities $ 395 $ 8 $ 1 $ 64 $ 255 $ 52 $ 65 $ 15 Finance Leases PHI Pepco DPL ACE As of December 31, 2021 Finance lease ROU assets Plant, property and equipment, net $ 73 $ 25 $ 29 $ 19 Finance lease liabilities Long-term debt due within one year 10 3 4 3 Long-term debt 64 23 25 16 Total finance lease liabilities $ 74 $ 26 $ 29 $ 19 As of December 31, 2020 Finance lease ROU assets Plant, property and equipment, net $ 50 $ 17 $ 20 $ 13 Finance lease liabilities Long-term debt due within one year 7 2 3 2 Long-term debt 43 15 17 11 Total finance lease liabilities $ 50 $ 17 $ 20 $ 13 The weighted average remaining lease terms, in years, for operating and finance leases were as follows: Operating Leases Exelon ComEd PECO BGE PHI Pepco DPL ACE As of December 31, 2021 8.9 3.3 6.1 13.7 7.5 8.6 8.5 3.5 As of December 31, 2020 9.0 3.8 4.2 8.3 8.2 9.1 9.1 4.0 As of December 31, 2019 8.7 4.6 4.4 5.4 9.0 9.8 9.7 4.7 Finance Leases PHI Pepco DPL ACE As of December 31, 2021 6.1 5.9 6.1 6.3 As of December 31, 2020 6.5 6.3 6.5 6.5 The weighted average discount rates for operating and finance leases were as follows: Operating Leases Exelon ComEd PECO BGE PHI Pepco DPL ACE As of December 31, 2021 4.0 % 2.8 % 2.2 % 4.0 % 4.2 % 4.0 % 4.0 % 3.4 % As of December 31, 2020 4.0 % 3.0 % 2.9 % 3.8 % 4.2 % 4.0 % 4.0 % 3.5 % As of December 31, 2019 3.9 % 3.0 % 3.2 % 3.6 % 4.2 % 4.0 % 4.0 % 3.6 % Finance Leases PHI Pepco DPL ACE As of December 31, 2021 2.2 % 2.3 % 2.1 % 2.1 % As of December 31, 2020 2.5 % 2.6 % 2.4 % 2.4 % Future minimum lease payments for operating and finance leases as of December 31, 2021 were as follows: Operating Leases Year Exelon ComEd PECO BGE PHI Pepco DPL ACE 2022 $ 64 $ 2 $ — $ 16 $ 38 $ 8 $ 10 $ 4 2023 45 1 — 1 37 7 10 3 2024 43 1 — — 36 7 8 3 2025 41 1 — — 34 6 7 2 2026 35 — — — 29 5 5 1 Remaining years 162 — 1 18 94 22 30 — Total 390 5 1 35 268 55 70 13 Interest 75 — — 16 42 9 13 1 Total operating lease liabilities $ 315 $ 5 $ 1 $ 19 $ 226 $ 46 $ 57 $ 12 Finance Leases Year PHI Pepco DPL ACE 2022 $ 12 $ 4 $ 5 $ 3 2023 12 4 5 3 2024 13 5 5 3 2025 12 4 5 3 2026 12 4 5 3 Remaining years 18 6 7 5 Total 79 27 32 20 Interest 5 1 3 1 Total finance lease liabilities $ 74 $ 26 $ 29 $ 19 Cash paid for amounts included in the measurement of operating and finance lease liabilities were as follows: Operating cash flows from operating leases Exelon ComEd PECO BGE PHI Pepco DPL ACE For the year ended December 31, 2021 $ 93 $ 3 $ — $ 46 $ 39 $ 8 $ 9 $ 4 For the year ended December 31, 2020 67 3 1 20 39 8 9 4 For the year ended December 31, 2019 81 3 — 33 37 9 6 5 Financing cash flows from finance leases PHI Pepco DPL ACE For the year ended December 31, 2021 $ 10 $ 3 $ 4 $ 3 For the year ended December 31, 2020 6 2 3 1 ROU assets obtained in exchange for operating and finance lease obligations were as follows: Operating Leases Exelon ComEd PECO BGE PHI Pepco DPL ACE For the year ended December 31, 2021 $ 1 $ — $ — $ (1) $ 1 $ — $ 1 $ — For the year ended December 31, 2020 (2) — 1 — (1) — (1) — For the year ended December 31, 2019 38 6 — 2 (3) (1) (2) (1) Finance Leases PHI Pepco DPL ACE For the year ended December 31, 2021 $ 32 $ 12 $ 12 $ 8 For the year ended December 31, 2020 29 8 14 7
Leases of Lessor Disclosure [Text Block]	Lessor The Registrants have operating leases for which they are the lessors. The following tables outline the significant types of leases at each registrant and other terms and conditions of their lease agreements as of December 31, 2021. Exelon ComEd PECO BGE PHI Pepco DPL ACE Real estate ● ● ● ● ● ● ● (in years) Exelon ComEd PECO BGE PHI Pepco DPL ACE Remaining lease terms 1-81 1-15 1-81 21 1-11 1-4 10-11 N/A Options to extend the term 5-79 5-79 5-50 N/A 5 N/A N/A N/A The components of lease income were as follows: Exelon ComEd PECO BGE PHI Pepco DPL ACE For the year ended December 31, 2021 Operating lease income $ 5 $ — $ — $ — $ 4 $ — $ 3 $ — Variable lease income 1 — — — 1 — 1 — For the year ended December 31, 2020 Operating lease income $ 5 $ — $ — $ — $ 3 $ — $ 3 $ — Variable lease income 1 — — — 1 — 1 — For the year ended December 31, 2019 Operating lease income $ 7 $ — $ — $ — $ 5 $ — $ 4 $ — Variable lease income 3 — — — 3 — 3 — Future minimum lease payments to be recovered under operating leases as of December 31, 2021 were as follows: Year Exelon ComEd PECO BGE PHI Pepco DPL ACE 2022 $ 5 $ — $ — $ — $ 4 $ — $ 3 $ — 2023 4 — — — 3 — 3 — 2024 4 — — — 4 — 4 — 2025 4 — — — 4 — 4 — 2026 4 — — — 4 — 4 — Remaining years 32 1 4 1 26 — 26 — Total $ 53 $ 1 $ 4 $ 1 $ 45 $ — $ 44 $ —

Intangible Assets (Exelon, ComE

Intangible Assets (Exelon, ComEd, PHI, Pepco, DPL, and ACE)	12 Months Ended
Intangible Assets (Exelon, ComEd, PHI, Pepco, DPL, and ACE)	Dec. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets (Exelon, ComEd, PHI, Pepco, DPL, and ACE)	Intangible Assets Goodwill (Exelon, ComEd, PHI, Pepco, DPL, and ACE) The following table presents the gross amount, accumulated impairment loss, and carrying amount of goodwill at Exelon, ComEd, and PHI as of December 31, 2021 and 2020. There were no additions or impairments during the years ended December 31, 2021 and 2020. Gross Amount Accumulated Impairment Loss Carrying Amount Exelon $ 8,613 $ 1,983 $ 6,630 ComEd (a) 4,608 1,983 2,625 PHI (b) 4,005 — 4,005 __________ (a) Reflects goodwill recorded in 2000 from the PECO/Unicom merger (predecessor parent company of ComEd). (b) Reflects goodwill recorded in 2016 from the PHI merger. Goodwill is not amortized, but is subject to an assessment for impairment at least annually, or more frequently if events occur or circumstances change that would more likely than not reduce the fair value of ComEd's and PHI's reporting units below their carrying amounts. A reporting unit is an operating segment or one level below an operating segment (known as a component) and is the level at which goodwill is assessed for impairment. A component of an operating segment is a reporting unit if the component constitutes a business for which discrete financial information is available and its operating results are regularly reviewed by segment management. ComEd has a single operating segment. PHI's operating segments are Pepco, DPL, and ACE. See Note 5 — Segment Information for additional information. There is no level below these operating segments for which operating results are regularly reviewed by segment management. Therefore, the ComEd, Pepco, DPL, and ACE operating segments are also considered reporting units for goodwill impairment assessment purposes. Exelon's and ComEd's $2.6 billion of goodwill has been assigned entirely to the ComEd reporting unit, while Exelon's and PHI's $4.0 billion of goodwill has been assigned to the Pepco, DPL, and ACE reporting units in the amounts of $2.1 billion, $1.4 billion, and $0.5 billion, respectively. Entities assessing goodwill for impairment have the option of first performing a qualitative assessment to determine whether a quantitative assessment is necessary. As part of the qualitative assessments, Exelon, ComEd, and PHI evaluate, among other things, management's best estimate of projected operating and capital cash flows for their businesses, outcomes of recent regulatory proceedings, changes in certain market conditions, including the discount rate and regulated utility peer EBITDA multiples, and the passing margin from their last quantitative assessments performed. If an entity bypasses the qualitative assessment, a quantitative, fair value-based assessment is performed, which compares the fair value of the reporting unit to its carrying amount, including goodwill. If the carrying amount of the reporting unit exceeds its fair value, the entity recognizes an impairment charge, which is limited to the amount of goodwill allocated to the reporting unit. Application of the goodwill impairment assessment requires management judgment, including the identification of reporting units and determining the fair value of the reporting unit, which management estimates using a weighted combination of a discounted cash flow analysis and a market multiples analysis. Significant assumptions used in these fair value analyses include discount and growth rates, utility sector market performance and transactions, projected operating and capital cash flows for ComEd's, Pepco's, DPL's, and ACE's businesses, and the fair value of debt. 2021 and 2020 Goodwill Impairment Assessment. ComEd and PHI qualitatively determined that it was more likely than not that the fair values of their reporting units exceeded their carrying values and, therefore, did not perform quantitative assessments as of November 1, 2021 and 2020. The last quantitative assessments performed were as of November 1, 2016 for ComEd and November 1, 2018 for PHI. While the annual assessments indicated no impairments, certain assumptions used to estimate reporting unit fair values are highly sensitive to changes. Adverse regulatory actions or changes in significant assumptions could potentially result in future impairments of Exelon's, ComEd's, and PHI’s goodwill, which could be material. Other Intangible Assets and Liabilities (Exelon and PHI) Exelon’s other intangible assets, included in Other current assets and Other deferred debits and other assets in the Consolidated Balance Sheets, consisted of the following as of December 31, 2021 and 2020. Exelon's and PHI's other intangible liabilities, included in current and noncurrent Unamortized energy contract liabilities in their Consolidated Balance Sheets, consisted of the following as of December 31, 2021 and 2020. The intangible assets and liabilities shown below are amortized on a straight-line basis, except for unamortized energy contracts which are amortized in relation to the expected realization of the underlying cash flows: December 31, 2021 December 31, 2020 Gross Accumulated Amortization Net Gross Accumulated Amortization Net Exelon Unamortized Energy Contracts $ (1,515) $ 1,280 $ (235) $ (1,515) $ 1,188 $ (327) Software License 81 (53) 28 81 (44) 37 Exelon Total $ (1,434) $ 1,227 $ (207) $ (1,434) $ 1,144 $ (290) PHI Unamortized Energy Contracts $ (1,515) $ 1,280 $ (235) $ (1,515) $ 1,188 $ (327) The following table summarizes the amortization expense related to intangible assets and liabilities for each of the years ended December 31, 2021, 2020, and 2019: For the Years Ended December 31, Exelon (a) PHI (a) 2021 $ (83) $ (92) 2020 (98) (115) 2019 (102) (119) __________ (a) For PHI unamortized energy contracts, the amortization of the fair value adjustment amounts and the corresponding offsetting regulatory asset amounts are amortized through Purchased power and fuel expense in their Consolidated Statements of Operations and Comprehensive Income resulting in no effect to net income. The following table summarizes the estimated future amortization expense related to intangible assets and liabilities as of December 31, 2021: For the Years Ending December 31, Exelon PHI 2022 $ (80) $ (89) 2023 (72) (81) 2024 (29) (38) 2025 (2) (5) 2026 (5) (5)

Income Taxes (All Registrants)

Income Taxes (All Registrants)	12 Months Ended
Income Taxes (All Registrants)	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes (All Registrants)	Income Taxes (All Registrants) Components of Income Tax Expense or Benefit Income tax expense (benefit) from continuing operations is comprised of the following components: For the Year Ended December 31, 2021 Exelon ComEd PECO BGE PHI Pepco DPL ACE Included in operations: Federal Current $ (152) $ (30) $ 1 $ (18) $ 18 $ 22 $ 2 $ 1 Deferred 89 113 20 34 (52) (17) (14) (26) Investment tax credit amortization (2) (1) — — (1) — — — State Current (46) (41) — — — 1 1 — Deferred 149 131 (9) (51) 77 9 53 12 Total $ 38 $ 172 $ 12 $ (35) $ 42 $ 15 $ 42 $ (13) For the Year Ended December 31, 2020 Exelon ComEd PECO BGE PHI Pepco DPL ACE Included in operations: Federal Current $ (180) $ (24) $ (7) $ 4 $ 25 $ 40 $ (13) $ (4) Deferred 10 112 1 10 (129) (62) (20) (43) Investment tax credit amortization (3) (2) — — (1) — — — State Current (37) (27) — — (5) — — — Deferred 203 118 (24) 27 33 15 8 6 Total $ (7) $ 177 $ (30) $ 41 $ (77) $ (7) $ (25) $ (41) For the Year Ended December 31, 2019 Exelon ComEd PECO BGE PHI Pepco DPL ACE Included in operations: Federal Current $ (143) $ 59 $ 45 $ (51) $ 43 $ 16 $ 29 $ (3) Deferred 139 15 20 95 (34) (6) (21) (6) Investment tax credit amortization (3) (2) — — (1) — — — State Current (44) (5) — — 3 — — — Deferred 204 96 — 35 27 6 14 9 Total $ 153 $ 163 $ 65 $ 79 $ 38 $ 16 $ 22 $ — Rate Reconciliation The effective income tax rate from continuing operations varies from the U.S. federal statutory rate principally due to the following: For the Year Ended December 31, 2021 (a) Exelon ComEd PECO (b) BGE (b) PHI Pepco DPL (b) ACE (b) U.S. federal statutory rate 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % Increase (decrease) due to: State income taxes, net of federal income tax benefit 5.0 7.8 (1.4) (10.8) 10.1 2.7 25.0 7.4 Amortization of investment tax credit, including deferred taxes on basis differences (0.1) (0.1) — (0.1) (0.1) — (0.2) (0.2) Plant basis differences (5.4) (0.8) (13.6) (1.7) (1.1) (1.6) (0.8) (0.2) Tax credits (0.7) (0.5) — (0.9) (0.5) (0.5) (0.4) (0.5) Excess deferred tax amortization (17.2) (7.6) (3.8) (16.3) (22.4) (16.4) (20.0) (37.1) Other (0.3) (1.0) 0.1 (0.6) — (0.4) 0.1 (0.2) Effective income tax rate 2.3 % 18.8 % 2.3 % (9.4) % 7.0 % 4.8 % 24.7 % (9.8) % For the Year Ended December 31, 2020 (a) Exelon ComEd (c) PECO (c) BGE (d) PHI (d) Pepco (d) DPL (d) ACE (d) U.S. federal statutory rate 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % Increase (decrease) due to: State income taxes, net of federal income tax benefit 11.9 11.6 (4.5) 5.5 5.1 4.5 6.6 7.0 Deferred Prosecution Agreement payments 3.8 6.8 — — — — — — Amortization of investment tax credit, including deferred taxes on basis differences (0.3) (0.3) — (0.1) (0.2) (0.1) (0.3) (0.5) Plant basis differences (8.6) (0.6) (18.7) (1.5) (1.6) (1.7) (0.4) (3.0) Tax credits (0.5) (0.3) — (0.4) (0.3) (0.3) (0.3) (0.5) Excess deferred tax amortization (29.1) (11.2) (4.6) (13.9) (42.0) (25.4) (51.7) (82.1) Other 1.2 1.8 (0.4) (0.1) (0.4) (0.7) 0.1 0.4 Effective income tax rate (0.6) % 28.8 % (7.2) % 10.5 % (18.4) % (2.7) % (25.0) % (57.7) % For the Year Ended December 31, 2019 (a) Exelon ComEd PECO BGE PHI Pepco DPL ACE U.S. federal statutory rate 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % Increase (decrease) due to: State income taxes, net of federal income tax benefit 7.8 8.5 — 6.4 4.7 2.0 6.8 7.0 Amortization of investment tax credit, including deferred taxes on basis differences (0.2) (0.2) — (0.1) (0.2) (0.1) (0.2) (0.3) Plant basis differences (3.3) — (7.2) (1.2) (1.2) (1.8) (0.4) (0.7) Tax credits (1.9) (1.2) — (1.3) (0.2) (0.1) — (0.1) Excess deferred tax amortization (13.4) (9.7) (2.8) (6.8) (17.5) (15.1) (14.2) (27.0) Other (0.7) 0.8 — — 0.8 0.3 — 0.1 Effective income tax rate 9.3 % 19.2 % 11.0 % 18.0 % 7.4 % 6.2 % 13.0 % — % __________ (a) Positive percentages represent income tax expense. Negative percentages represent income tax benefit. (b) For PECO, the lower effective tax rate is primarily related to plant basis differences attributable to tax repair deductions. For BGE, the income tax benefit is primarily due to the Maryland multi-year plan which resulted in the acceleration of certain income tax benefits. For DPL, the higher effective tax rate is primarily related to a state income tax expense, net of federal income tax benefit, due to the recognition of a valuation allowance of approximately $31 million against a deferred tax asset associated with Delaware net operating loss carryforwards as a result of a change in Delaware tax law. For ACE, the income tax benefit is primarily due to a distribution rate case settlement which allows ACE to retain certain tax benefits. (c) At ComEd, the higher effective tax rate is primarily related to the nondeductible Deferred Prosecution Agreement payments. At PECO, the negative effective tax rate is primarily related to an increase in plant basis differences attributable to tax repair deductions related to an increase in storms and qualifying projects in 2021. (d) For BGE, PHI, Pepco, DPL, and ACE, the income tax benefit is primarily attributable to accelerated amortization of transmission related deferred income tax regulatory liabilities as a result of regulatory settlements. See Note 3 — Regulatory Matters for additional information. Tax Differences and Carryforwards The tax effects of temporary differences and carryforwards, which give rise to significant portions of the deferred tax assets (liabilities), as of December 31, 2021 and 2020 are presented below: As of December 31, 2021 Exelon ComEd PECO BGE PHI Pepco DPL ACE Plant basis differences $ (11,606) $ (4,648) $ (2,271) $ (1,826) $ (2,976) $ (1,321) $ (853) $ (777) Accrual based contracts 56 — — — 56 — — — Derivatives and other financial instruments 63 61 — — 2 — — — Deferred pension and postretirement obligation 641 (308) (32) (37) (90) (76) (40) (6) Deferred debt refinancing costs 146 (6) — (2) 123 (2) (1) (1) Regulatory assets and liabilities (1,130) 8 (280) 92 (53) 24 55 31 Tax loss carryforward, net of valuation allowances 242 — 65 68 64 2 18 42 Tax credit carryforward 584 — — — — — — — Investment in partnerships (21) — — — — — — — Other, net 449 216 97 21 212 99 19 34 Deferred income tax liabilities (net) $ (10,576) $ (4,677) $ (2,421) $ (1,684) $ (2,662) $ (1,274) $ (802) $ (677) Unamortized investment tax credits (15) (8) — (2) (5) (1) (1) (2) Total deferred income tax liabilities (net) and unamortized investment tax credits $ (10,591) $ (4,685) $ (2,421) $ (1,686) $ (2,667) $ (1,275) $ (803) $ (679) As of December 31, 2020 Exelon ComEd PECO BGE PHI Pepco DPL ACE Plant basis differences $ (11,272) $ (4,432) $ (2,131) $ (1,711) $ (2,822) $ (1,259) $ (806) $ (725) Accrual based contracts 77 — — — 77 — — — Derivatives and other financial instruments 82 84 — — 2 — — — Deferred pension and postretirement obligation 954 (288) (30) (33) (80) (74) (40) (7) Deferred debt refinancing costs 153 (6) — (2) 131 (3) (1) (1) Regulatory assets and liabilities (1,107) 87 (231) 142 (41) 38 67 46 Tax loss carryforward, net of valuation allowances 231 — 47 57 90 4 49 38 Tax credit carryforward 648 — — — — — — — Investment in partnerships (22) — — — — — — — Other, net 701 223 104 29 220 107 18 27 Deferred income tax liabilities (net) $ (9,555) $ (4,332) $ (2,241) $ (1,518) $ (2,423) $ (1,187) $ (713) $ (622) Unamortized investment tax credits (19) (9) (1) (3) (6) (2) (2) (3) Total deferred income tax liabilities (net) and $ (9,574) $ (4,341) $ (2,242) $ (1,521) $ (2,429) $ (1,189) $ (715) $ (625) The following table provides Exelon’s, PECO’s, BGE’s, PHI’s, Pepco’s, DPL’s, and ACE’s carryforwards, of which the state related items are presented on a post-apportioned basis, and any corresponding valuation allowances as of December 31, 2021. ComEd does not have net operating losses or credit carryforwards for the year ended December 31, 2021. Exelon PECO BGE PHI Pepco DPL ACE Federal Federal general business credits carryforwards and other carryforwards (a) $ 584 $ — $ — $ — $ — $ — $ — State State net operating losses and other carryforwards 4,616 890 1,098 1,512 42 736 605 Deferred taxes on state tax attributes (net of federal taxes) 291 70 72 104 3 50 43 Valuation allowance on state tax attributes (net of federal taxes) (b) 37 3 — 31 — 31 — Year in which net operating loss or credit carryforwards will begin to expire (c) 2035 2032 2033 2029 N/A 2032 2031 __________ (a) For Exelon, the federal general business credit carryforward will begin expiring in 2035. (b) At Exelon, a full valuation allowance has been recorded against certain separate company state net operating loss carryforwards that are expected to expire before realization. At PECO, a full valuation allowance has been recorded against Pennsylvania charitable contributions carryforwards that are expected to expire before realization. At DPL, a full valuation allowance has been recorded against Delaware net operating losses carryforwards due to a change in Delaware tax law. (c) A portion of Exelon's, BGE's, Pepco's, and DPL's Maryland state net operating loss carryforward have an indefinite carryforward period. Tabular Reconciliation of Unrecognized Tax Benefits The following table presents changes in unrecognized tax benefits, for Exelon, PHI, and ACE. ComEd's, PECO's, BGE's, Pepco's, and DPL's amounts are not material. Exelon PHI ACE Balance at January 1, 2019 $ 65 $ 45 $ 14 Change to positions that only affect timing 26 3 — Increases based on tax positions related to 2019 2 — — Increases based on tax positions prior to 2019 34 — — Decreases based on tax positions prior to 2019 (3) — — Decrease from settlements with taxing authorities (29) — — Balance at December 31, 2019 95 48 14 Change to positions that only affect timing 6 3 1 Increases based on tax positions related to 2020 3 — — Increases based on tax positions prior to 2020 26 1 — Decreases based on tax positions prior to 2020 (5) — — Balance at December 31, 2020 125 52 15 Change to positions that only affect timing 13 3 1 Increases based on tax positions related to 2021 4 1 — Increases based on tax positions prior to 2021 4 — — Decreases based on tax positions prior to 2021 (3) — — Balance at December 31, 2021 $ 143 $ 56 $ 16 Recognition of unrecognized tax benefits The following table presents Exelon's unrecognized tax benefits that, if recognized, would decrease the effe ctive tax rate. The Utility Registrants' amounts are not material. Exelon December 31, 2021 $ 77 December 31, 2020 73 December 31, 2019 51 Reasonably possible the total amount of unrecognized tax benefits could significantly increase or decrease within 12 months after the reporting date As of December 31, 2021, ACE has approximately $14 million of unrecognized state tax benefits that could significantly decrease within the 12 months after the reporting date based on the outcome of pending court cases involving other taxpayers. The unrecognized tax benefit, if recognized, may be included in future base rates and that portion would have no impact to the effective tax rate. Total amounts of interest and penalties recognized The following table represents the net interest and penalties receivable (payable) related to tax positions reflected in Exelon's Consolidated Balance Sheets. The Utility Registrants' amounts are not material. Net interest and penalties receivable as of Exelon December 31, 2021 (a) $ 43 December 31, 2020 314 __________ (a) As of December 31, 2021, the interest receivable balance is not expected to be settled in cash within the next twelve months and therefore classified as non-current receivable. In December of 2021, Exelon received a refund of approximately $272 million related to an interest netting refund claim. The Registrants did not record material interest and penalty expense related to tax positions reflected in their Consolidated Balance Sheets. Interest expense and penalty expense are recorded in Interest expense, net and Other, net, respect ively, in Other income and deductions in the Registrants' Consolidated Statements of Operations and Comprehensive Income. Description of tax years open to assessment by major jurisdiction Major Jurisdiction Open Years Registrants Impacted Federal consolidated income tax returns (a) 2010-2020 All Registrants Delaware separate corporate income tax returns Same as federal DPL District of Columbia combined corporate income tax returns 2018-2020 Exelon, PHI, Pepco Illinois unitary corporate income tax returns 2012-2020 Exelon, ComEd Maryland separate company corporate net income tax returns Same as federal BGE, Pepco, DPL New Jersey separate corporate income tax returns 2017-2018 Exelon New Jersey combined corporate income tax returns 2019-2020 Exelon New Jersey separate corporate income tax returns 2017-2020 ACE New York combined corporate income tax returns 2011-2020 Exelon Pennsylvania separate corporate income tax returns 2011-2016 Exelon Pennsylvania separate corporate income tax returns 2018-2020 Exelon Pennsylvania separate corporate income tax returns 2018-2020 PECO __________ (a) Certain registrants are only open to assessment for tax years since joining the Exelon federal consolidated group; BGE beginning in 2012 and PHI, Pepco, DPL, and ACE beginning in 2016. Other Tax Matters Long-Term Marginal State Income Tax Rate Quarterly, Exelon reviews and updates its marginal state income tax rates and updates for material changes in state tax laws and state apportionment. The Registrants remeasure their existing deferred income tax balances to reflect the changes in marginal rates, which results in either an increase or a decrease to their net deferred income tax liability balances. Utility Registrants record corresponding regulatory liabilities or assets to the extent such amounts are probable of settlement or recovery through customer rates and an adjustment to income tax expense for all other amounts. The impacts to the Utility Registrants for the years ended December 31, 2021, 2020, and 2019 were not material. December 31, 2021 Exelon Increase to Deferred Income Tax Liability and Income Tax Expense, Net of Federal Taxes $ 27 December 31, 2020 Increase to Deferred Income Tax Liability and Income Tax Expense, Net of Federal Taxes $ 66 December 31, 2019 Increase to Deferred Income Tax Liability and Income Tax Expense, Net of Federal Taxes $ 20 Allocation of Tax Benefits The Utility Registrants are party to an agreement with Exelon and other subsidiaries of Exelon that provides for the allocation of consolidated tax liabilities and benefits (Tax Sharing Agreement). The Tax Sharing Agreement provides that each party is allocated an amount of tax similar to that which would be owed had the party been separately subject to tax. In addition, any net federal and state benefits attributable to Exelon are reallocated to the other Registrants. That allocation is treated as a contribution from Exelon to the party receiving the benefit. The following table presents the allocation of tax benefits from Exelon under the Tax Sharing Agreement. ComEd PECO BGE PHI Pepco DPL ACE December 31, 2021 (a) $ 1 $ 19 $ — $ 17 $ 16 $ — $ — December 31, 2020 (b) 14 17 — 17 8 6 1 December 31, 2019 (c) — 14 3 7 6 1 — __________ (a) BGE, DPL, and ACE did not record an allocation of federal tax benefits from Exelon under the Tax Sharing Agreement as a result of a tax net operating loss. (b) BGE did not record an allocation of federal tax benefits from Exelon under the Tax Sharing Agreement as a result of a tax net operating loss. (c) ComEd and ACE did not record an allocation of federal tax benefits from Exelon under the Tax Sharing Agreement as a result of a tax net operating loss. Research and Development Activities In the fourth quarter of 2019, Exelon recognized additional tax benefits related to certain research and development activities that qualify for federal and state tax incentives for the 2010 through 2018 tax years, which resulted in an increase to Exelon’s net income of $47 million for the year ended December 31, 2019, reflecting a decrease to Exelon’s Income tax expense of $32 million.

Retirement Benefits (All Regist

Retirement Benefits (All Registrants)	12 Months Ended
Retirement Benefits (All Registrants)	Dec. 31, 2021
Retirement Benefits [Abstract]
Retirement Benefits (All Registrants)	Retirement Benefits (All Registrants) Exelon sponsors defined benefit pension plans and OPEB plans for essentially all current employees. Substantially all non-union employees and electing union employees hired on or after January 1, 2001 participate in cash balance pension plans. Effective January 1, 2009, substantially all newly-hired union-represented employees participate in cash balance pension plans. Effective February 1, 2018 for most newly-hired BSC non-represented, non-craft, employees, January 1, 2021 for most newly-hired utility management employees, and for certain newly-hired union employees pursuant to their collective bargaining agreements, these newly-hired employees are not eligible for pension benefits, and will instead be eligible to receive an enhanced non-discretionary employer contribution in an Exelon defined contribution savings plan. Effective January 1, 2018, most newly-hired non-represented, non-craft, employees are not eligible for OPEB benefits and employees represented by Local 614 are not eligible for retiree health care benefits. Effective January 1, 2021, most non-represented, non-craft, employees who are under the age of 40 are not eligible for retiree health care benefits. Effective January 1, 2022, management employees retiring on or after that date are no longer eligible for retiree life insurance benefits. Effective January 1, 2019, Exelon merged the Exelon Corporation Cash Balance Pension Plan (CBPP) into the Exelon Corporation Retirement Program (ECRP). The merging of the plans did not change the benefits offered to the plan participants and, thus, had no impact on Exelon's pension obligation. However, beginning in 2019, actuarial losses and gains related to the CBPP and ECRP are amortized over participants’ average remaining service period of the merged ECRP rather than each individual plan. Effective February 1, 2022, in connection with the separation, pension and OPEB obligations and assets for current and former Generation employees and shared service employees supporting Generation, were transferred to pension and OPEB plans and trusts established by Generation. The retirement benefits information below does not reflect these balances, except as otherwise disclosed. The tables below show the pension and OPEB plans in which employees of each operating company participated as of December 31, 2021: Operating Company (e) Name of Plan: ComEd PECO BGE PHI Pepco DPL ACE Qualified Pension Plans: Exelon Corporation Retirement Program (a) X X X X X X X Exelon Corporation Pension Plan for Bargaining Unit Employees (a) X Exelon Employee Pension Plan for Clinton, TMI, and Oyster Creek (a) X X X X X X Pension Plan of Constellation Energy Group, Inc. (b) X X X X X X Pension Plan of Constellation Energy Nuclear Group, LLC (c) X X X X Pepco Holdings LLC Retirement Plan (d) X X X X X X X Non-Qualified Pension Plans: Exelon Corporation Supplemental Pension Benefit Plan and 2000 Excess Benefit Plan (a) X X X Exelon Corporation Supplemental Management Retirement Plan (a) X X X X X X Constellation Energy Group, Inc. Senior Executive Supplemental Plan (b) X X Constellation Energy Group, Inc. Supplemental Pension Plan (b) X X Constellation Energy Group, Inc. Benefits Restoration Plan (b) X X X Constellation Energy Nuclear Plan, LLC Executive Retirement Plan (c) X Constellation Energy Nuclear Plan, LLC Benefits Restoration Plan (c) X Baltimore Gas & Electric Company Executive Benefit Plan (b) X Baltimore Gas & Electric Company Manager Benefit Plan (b) X X Pepco Holdings LLC 2011 Supplemental Executive Retirement Plan (d) X X X X Conectiv Supplemental Executive Retirement Plan (d) X X X Pepco Holdings LLC Combined Executive Retirement Plan (d) X X Atlantic City Electric Director Retirement Plan (d) X Operating Company (e) Name of Plan: ComEd PECO BGE PHI Pepco DPL ACE OPEB Plans: PECO Energy Company Retiree Medical Plan (a) X X X X X X X Exelon Corporation Health Care Program (a) X X X X X X X Exelon Corporation Employees’ Life Insurance Plan (a) X X X Exelon Corporation Health Reimbursement Arrangement Plan (a) X X X Constellation Energy Group, Inc. Retiree Medical Plan (b) X X X X X X Constellation Energy Group, Inc. Retiree Dental Plan (b) X Constellation Energy Group, Inc. Employee Life Insurance Plan and Family Life Insurance Plan (b) X X X X X Constellation Mystic Power, LLC Post-Employment Medical Account Savings Plan (b) X Retiree Medical Plan of Constellation Energy Nuclear Group, LLC (c) X X X Retiree Dental Plan of Constellation Energy Nuclear Group, LLC (c) X X X Pepco Holdings LLC Welfare Plan for Retirees (d) X X X X X X X __________ (a) These plans are collectively referred to as the legacy Exelon plans. (b) These plans are collectively referred to as the legacy Constellation Energy Group (CEG) Plans. (c) These plans are collectively referred to as the legacy CENG plans. (d) These plans are collectively referred to as the legacy PHI plans. (e) Employees generally remain in their legacy benefit plans when transferring between operating companies. Exelon’s traditional and cash balance pension plans are intended to be tax-qualified defined benefit plans. Exelon has elected that the trusts underlying these plans be treated as qualified trusts under the IRC. If certain conditions are met, Exelon can deduct payments made to the qualified trusts, subject to certain IRC limitations. Benefit Obligations, Plan Assets, and Funded Status During the first quarter of 2021, Exelon received an updated valuation of its pension and OPEB to reflect actual census data as of January 1, 2021. This valuation resulted in an increase to the pension obligations of $20 million and a decrease to the OPEB obligations of $5 million. Additionally, accumulated other comprehensive loss increased by $1 million (after-tax) and regulatory assets and liabilities increased by $21 million and $1 million, respectively. The following tables provide a rollforward of the changes in the benefit obligations and plan assets of Exelon for the most recent two years for all plans combined: Pension Benefits OPEB 2021 2020 2021 2020 Change in benefit obligation: Net benefit obligation as of the beginning of year $ 14,861 $ 13,652 $ 2,661 $ 2,692 Service cost 294 251 51 56 Interest cost 406 476 69 93 Plan participants’ contributions — — 32 31 Actuarial (gain) loss (a) (442) 1,252 (116) 38 Plan amendments — — — (64) Settlements (23) (19) (5) (5) Gross benefits paid (860) (751) (190) (180) Net benefit obligation as of the end of year $ 14,236 $ 14,861 $ 2,502 $ 2,661 Pension Benefits OPEB 2021 2020 2021 2020 Change in plan assets: Fair value of net plan assets as of the beginning of year $ 11,883 $ 10,859 $ 1,635 $ 1,627 Actual return on plan assets 822 1,488 130 122 Employer contributions 343 306 63 40 Plan participants’ contributions — — 32 31 Gross benefits paid (860) (751) (190) (180) Settlements (23) (19) (5) (5) Fair value of net plan assets as of the end of year $ 12,165 $ 11,883 $ 1,665 $ 1,635 __________ (a) The pension and OPEB gains in 2021 primarily reflect an increase in the discount rate. In 2020, the actuarial losses primarily reflect a decrease in the discount rate. OPEB losses in 2020 were offset by gains related to plan changes. Exelon presents its benefit obligations and plan assets net on its balance sheet within the following line items: Pension Benefits OPEB 2021 2020 2021 2020 Other current liabilities $ 20 $ 32 $ 26 $ 24 Pension obligations 2,051 2,946 — — Non-pension postretirement benefit obligations — — 811 1,002 Unfunded status (net benefit obligation less plan assets) $ 2,071 $ 2,978 $ 837 $ 1,026 The following table provides the ABO and fair value of plan assets for all pension plans with an ABO in excess of plan assets. Information for pension and OPEB plans with projected benefit obligations (PBO) and accumulated postretirement benefit obligation (APBO), respectively, in excess of plan assets has been disclosed in the Obligations and Plan Assets table above as all pension and OPEB plans are underfunded. Exelon ABO in Excess of Plan Assets 2021 2020 ABO $ 13,497 $ 14,037 Fair value of net plan assets 12,165 11,883 Components of Net Periodic Benefit Costs The majority of the 2021 pension benefit cost for the Exelon-sponsored plans is calculated using an expected long-term rate of return on plan assets of 7.00% and a discount rate of 2.58%. The majority of the 2021 OPEB cost is calculated using an expected long-term rate of return on plan assets of 6.46% for funded plans and a discount rate of 2.51%. A portion of the net periodic benefit cost for all plans is capitalized in the Consolidated Balance Sheets. The following table presents the components of Exelon’s net periodic benefit costs, prior to capitalization, for the years ended December 31, 2021, 2020, and 2019. Pension Benefits OPEB 2021 2020 2019 2021 2020 2019 Components of net periodic benefit cost: Service cost $ 294 $ 251 $ 218 $ 51 $ 56 $ 55 Interest cost 406 476 553 69 93 114 Expected return on assets (843) (796) (763) (99) (101) (95) Amortization of: Prior service cost (credit) 2 3 1 (25) (76) (104) Actuarial loss 399 349 289 27 34 32 Curtailment benefits — — — — (1) — Settlement and other charges 7 6 6 1 1 — Contractual termination benefits — — 1 — — — Net periodic benefit cost $ 265 $ 289 $ 305 $ 24 $ 6 $ 2 Cost Allocation to Exelon Subsidiaries All Registrants account for their participation in Exelon’s pension and OPEB plans by applying multi-employer accounting. Exelon allocates costs related to its pension and OPEB plans to its subsidiaries based on both active and retired employee participation in each plan. The amounts below represent the Registrants' allocated pension and OPEB costs. For Exelon, the service cost component is included in Operating and maintenance expense and Property, plant, and equipment, net while the non-service cost components are included in Other, net and Regulatory assets. For the Utility Registrants, the service cost and non-service cost components are included in Operating and maintenance expense and Property, plant, and equipment, net in their consolidated financial statements. For the Years Ended December 31, Exelon ComEd PECO BGE PHI Pepco DPL ACE 2021 $ 288 $ 129 $ 8 $ 64 $ 49 $ 6 $ 2 $ 11 2020 296 114 5 64 70 15 7 14 2019 307 96 12 61 95 25 15 16 Components of AOCI and Regulatory Assets Exelon recognizes the overfunded or underfunded status of defined benefit pension and OPEB plans as an asset or liability on its balance sheet, with offsetting entries to AOCI and regulatory assets (liabilities). A portion of current year actuarial (gains) losses and prior service costs (credits) is capitalized in Exelon’s Consolidated Balance Sheets to reflect the expected regulatory recovery of these amounts, which would otherwise be recorded to AOCI. The following tables provide the components of AOCI and regulatory assets (liabilities) for Exelon for the years ended December 31, 2021, 2020, and 2019 for all plans combined. The tables include amounts related to Generation prior to the separation. Pension Benefits OPEB 2021 2020 2019 2021 2020 2019 Changes in plan assets and benefit obligations recognized in AOCI and regulatory assets (liabilities): Current year actuarial (gain) loss $ (700) $ 941 $ 538 $ (270) $ 22 $ 80 Amortization of actuarial loss (598) (512) (414) (37) (49) (45) Current year prior service cost (credit) — — 68 — (111) — Amortization of prior service (cost) credit (3) (4) — 34 124 179 Curtailments — — (3) — 1 — Settlements (27) (14) (17) (1) (1) (1) Total recognized in AOCI and regulatory assets (liabilities) $ (1,328) $ 411 $ 172 $ (274) $ (14) $ 213 Total recognized in AOCI $ (747) $ 271 $ 169 $ (130) $ 6 $ 107 Total recognized in regulatory assets (liabilities) $ (581) $ 140 $ 3 $ (144) $ (20) $ 106 The following table provides the components of gross accumulated other comprehensive loss and regulatory assets (liabilities) for Exelon that have not been recognized as components of periodic benefit cost as of December 31, 2021 and 2020, respectively, for all plans combined: Pension Benefits OPEB 2021 2020 2021 2020 Prior service cost (credit) $ 32 $ 35 $ (111) $ (145) Actuarial loss 6,752 8,077 230 538 Total $ 6,784 $ 8,112 $ 119 $ 393 Total included in AOCI $ 3,592 $ 4,339 $ 53 $ 183 Total included in regulatory assets (liabilities) $ 3,192 $ 3,773 $ 66 $ 210 Average Remaining Service Period For pension benefits, Exelon amortizes its unrecognized prior service costs (credits) and certain actuarial (gains) losses, as applicable, based on participants’ average remaining service periods. For OPEB, Exelon amortizes its unrecognized prior service costs (credits) over participants’ average remaining service period to benefit eligibility age and amortizes certain actuarial (gains) losses over participants’ average remaining service period to expected retirement. The resulting average remaining service periods for pension and OPEB were as follows: 2021 2020 2019 Pension plans 12.4 12.3 11.7 OPEB plans: Benefit Eligibility Age 7.6 9.0 8.7 Expected Retirement 8.8 10.2 9.3 Assumptions The measurement of the plan obligations and costs of providing benefits under Exelon’s defined benefit and OPEB plans involves various factors, including the development of valuation assumptions and inputs and accounting policy elections. The measurement of benefit obligations and costs is impacted by several assumptions and inputs, as shown below, among other factors. When developing the required assumptions, Exelon considers historical information as well as future expectations. Expected Rate of Return. In determining the EROA, Exelon considers historical economic indicators (including inflation and GDP growth) that impact asset returns, as well as expectations regarding future long-term capital market performance, weighted by Exelon’s target asset class allocations. Mortality . The mortality assumption is composed of a base table that represents the current expectation of life expectancy of the population adjusted by an improvement scale that attempts to anticipate future improvements in life expectancy. For the year ended December 31, 2021, Exelon’s mortality assumption utilizes the SOA 2019 base table (Pri-2012) and MP-2021 improvement scale adjusted to use Proxy SSA ultimate improvement rates. For the year ended December 31, 2020, Exelon's mortality assumption utilizes the SOA 2019 base table (Pri-2012) and MP-2020 improvement scale adjusted to use Proxy SSA ultimate improvement rates. For Exelon, the following assumptions were used to determine the benefit obligations for the plans as of December 31, 2021 and 2020. Assumptions used to determine year-end benefit obligations are the assumptions used to estimate the subsequent year’s net periodic benefit costs. Pension Benefits OPEB 2021 2020 2021 2020 Discount rate 2.92 % (a) 2.58 % (a) 2.88 % (a) 2.51 % (a) Investment crediting rate 3.75 % (b) 3.72 % (b) N/A N/A Rate of compensation increase 3.75 % 3.75 % 3.75 % 3.75 % Mortality table Pri-2012 table with MP- 2021 improvement scale (adjusted) Pri-2012 table with MP- 2020 improvement scale (adjusted) Pri-2012 table with MP- 2021 improvement scale (adjusted) Pri-2012 table with MP- 2020 improvement scale (adjusted) Health care cost trend on covered charges N/A N/A Initial and ultimate rate of 5.00% Initial and ultimate trend of 5.00% __________ (a) The discount rates above represent the blended rates used to determine the majority of Exelon’s pension and OPEB obligations. Certain benefit plans used individual rates, which range from 2.55% - 3.02% and 2.84% - 2.92% for pension and OPEB plans, respectively, as of December 31, 2021 and 2.11% - 2.73% and 2.45% - 2.63% for pension and OPEB plans, respectively, as of December 31, 2020. (b) The investment crediting rate above represents a weighted average rate. The following assumptions were used to determine the net periodic benefit cost for Exelon for the years ended December 31, 2021, 2020 and 2019: Pension Benefits OPEB 2021 2020 2019 2021 2020 2019 Discount rate 2.58 % (a) 3.34 % (a) 4.31 % (a) 2.51 % (a) 3.31 % (a) 4.30 % (a) Investment crediting rate 3.72 % (b) 3.82 % (b) 4.46 % (b) N/A N/A N/A Expected return on plan assets 7.00 % (c) 7.00 % (c) 7.00 % (c) 6.46 % (c) 6.69 % (c) 6.67 % (c) Rate of compensation increase 3.75 % (d) 3.75 % (d) 3.25 % (d) 3.75 % (d) 3.75 % (d) 3.25 % (d) Mortality table Pri-2012 table with MP- 2020 improvement scale (adjusted) Pri-2012 table with MP - 2019 improvement scale (adjusted) RP-2000 table projected to 2012 with improvement scale AA, with Scale BB-2D improvements (adjusted) Pri-2012 table with MP- 2020 improvement scale (adjusted) Pri-2012 table with MP - 2019 improvement scale (adjusted) RP-2000 table projected to 2012 with improvement scale AA, with Scale BB-2D improvements (adjusted) Health care cost trend on covered charges N/A N/A N/A Initial and ultimate rate of 5.00% Initial and ultimate rate of 5.00% 5.00% with ultimate trend of 5.00% in 2017 __________ (a) The discount rates above represent the blended rates used to establish the majority of Exelon’s pension and OPEB costs. Certain benefit plans used individual rates, which range from 2.11%-2.73% and 2.45%-2.63% for pension and OPEB plans, respectively, for the year ended December 31, 2021; 3.02%-3.44% and 3.27%-3.40% for pension and OPEB plans; respectively, for the year ended December 31, 2020; and 4.13%-4.36% and 4.27%-4.38% for pension and OPEB plans, respectively, for the year ended December 31, 2019. (b) The investment crediting rate above represents a weighted average rate. (c) Not applicable to pension and OPEB plans that do not have plan assets. (d) 3.25% through 2019 and 3.75% thereafter. Contributions Exelon allocates contributions related to its legacy Exelon pension and OPEB plans to its subsidiaries based on accounting cost. For legacy CEG, CENG, FitzPatrick, and PHI plans, pension and OPEB contributions are allocated to the subsidiaries based on employee participation (both active and retired). The following tables provide contributions to the pension and OPEB plans: Pension Benefits OPEB 2021 2020 2019 2021 2020 2019 Exelon $ 343 $ 306 $ 196 $ 63 $ 40 $ 36 ComEd 174 143 72 22 5 5 PECO 17 18 27 1 — 1 BGE 57 56 34 24 22 14 PHI 39 30 10 9 9 15 Pepco 2 2 2 9 9 12 DPL 1 — 1 — — — ACE 3 2 — — — 1 Management considers various factors when making pension funding decisions, including actuarially determined minimum contribution requirements under ERISA, contributions required to avoid benefit restrictions and at-risk status as defined by the Pension Protection Act of 2006 (the Act), management of the pension obligation, and regulatory implications. The Act requires the attainment of certain funding levels to avoid benefit restrictions (such as an inability to pay lump sums or to accrue benefits prospectively), and at-risk status (which triggers higher minimum contribution requirements and participant notification). The projected contributions below reflect a funding strategy to make levelized annual contributions with the objective of achieving 100% funded status on an ABO basis over time. This level funding strategy helps minimize volatility of future period required pension contributions. Based on this funding strategy and current market conditions, which are subject to change, Exelon’s estimated annual qualified pension contributions will be approximately $313 million in 2022. In connection with the separation, an additional qualified pension contribution of $207 million was completed on February 1, 2022. Unlike the qualified pension plans, Exelon’s non-qualified pension plans are not funded, given that they are not subject to statutory minimum contribution requirements. While OPEB plans are also not subject to statutory minimum contribution requirements, Exelon does fund certain of its plans. For Exelon's funded OPEB plans, contributions generally equal accounting costs, however, Exelon’s management has historically considered several factors in determining the level of contributions to its OPEB plans, including liabilities management, levels of benefit claims paid, and regulatory implications (amounts deemed prudent to meet regulatory expectations and best assure continued rate recovery). The amounts below include benefit payments related to unfunded plans. The following table provides all Registrants' planned contributions to the qualified pension plans, planned benefit payments to non-qualified pension plans, and planned contributions to OPEB plans in 2022: Qualified Pension Plans Non-Qualified Pension Plans OPEB Exelon $ 313 $ 23 $ 39 ComEd 173 2 12 PECO 12 1 2 BGE 48 2 16 PHI 60 10 7 Pepco 2 1 6 DPL 1 1 — ACE 7 — — Estimated Future Benefit Payments Estimated future benefit payments to participants in all of the pension plans and postretirement benefit plans as of December 31, 2021 were: Pension Benefits OPEB 2022 $ 769 $ 146 2023 775 147 2024 792 147 2025 794 147 2026 792 149 2027 through 2031 4,021 742 Total estimated future benefits payments through 2031 $ 7,943 $ 1,478 Plan Assets Investment Strategy. On a regular basis, Exelon evaluates its investment strategy to ensure that plan assets will be sufficient to pay plan benefits when due. As part of this ongoing evaluation, Exelon may make changes to its targeted asset allocation and investment strategy. Exelon has developed and implemented a liability hedging investment strategy for its qualified pension plans that has reduced the volatility of its pension assets relative to its pension liabilities. Exelon is likely to continue to gradually increase the liability hedging portfolio as the funded status of its plans improves. The overall objective is to achieve attractive risk-adjusted returns that will balance the liquidity requirements of the plans’ liabilities while striving to minimize the risk of significant losses. Trust assets for Exelon’s OPEB plans are managed in a diversified investment strategy that prioritizes maximizing liquidity and returns while minimizing asset volatility. Actual asset returns have an impact on the costs reported for the Exelon-sponsored pension and OPEB plans. The actual asset returns across Exelon’s pension and OPEB plans for the year ended December 31, 2021 were 7.21% and 9.54%, respectively, compared to an expected long-term return assumption of 7.00% and 6.46%, respectively. Exelon used an EROA of 7.00% and 6.44% to estimate its 2022 pension and OPEB costs, respectively. Exelon’s pension and OPEB plan target asset allocations as of December 31, 2021 and 2020 were as follows: December 31, 2021 December 31, 2020 Asset Category Pension Benefits OPEB Pension Benefits OPEB Equity securities 35 % 44 % 34 % 45 % Fixed income securities 41 % 41 % 43 % 39 % Alternative investments (a) 24 % 15 % 23 % 16 % Total 100 % 100 % 100 % 100 % __________ (a) Alternative investments include private equity, hedge funds, real estate, and private credit. Concentrations of Credit Risk. Exelon evaluated its pension and OPEB plans’ asset portfolios for the existence of significant concentrations of credit risk as of December 31, 2021. Types of concentrations that were evaluated include, but are not limited to, investment concentrations in a single entity, type of industry, foreign country, and individual fund. As of December 31, 2021, there were no significant concentrations (defined as greater than 10% of plan assets) of risk in Exelon’s pension and OPEB plan assets. Fair Value Measurements The following tables present pension and OPEB plan assets measured and recorded at fair value in Exelon's Consolidated Balance Sheets on a recurring basis and their level within the fair value hierarchy as of December 31, 2021 and 2020: December 31, 2021 December 31, 2020 Level 1 Level 2 Level 3 Not subject to leveling Total Level 1 Level 2 Level 3 Not subject to leveling Total Pension plan assets (a) Cash equivalents $ 260 $ 91 $ — $ — $ 351 $ 238 $ 71 $ — $ — $ 309 Equities (b) 2,699 — 2 1,273 3,974 2,485 — 1 1,491 3,977 Fixed income: U.S. Treasury and agencies 1,002 176 — — 1,178 664 214 — — 878 State and municipal debt — 47 — — 47 — 50 — — 50 Corporate debt (c) — 2,523 325 — 2,848 — 2,846 336 — 3,182 Other (b) 43 161 12 301 517 — 140 12 314 466 Fixed income subtotal 1,045 2,907 337 301 4,590 664 3,250 348 314 4,576 Private equity — — — 1,124 1,124 — — — 953 953 Hedge funds — — — 774 774 — — — 768 768 Real estate — — — 760 760 — — — 631 631 Private credit — — 130 603 733 — — 136 611 747 Pension plan assets subtotal 4,004 2,998 469 4,835 12,306 3,387 3,321 485 4,768 11,961 OPEB plan assets (a) Cash equivalents 54 41 — — 95 32 33 — — 65 Equities 387 2 — 324 713 396 1 — 364 761 Fixed income: U.S. Treasury and agencies 14 44 — — 58 10 42 — — 52 State and municipal debt — 7 — — 7 — 57 — — 57 Corporate debt (c) — 74 — — 74 — 57 — — 57 Other 223 4 — 136 363 182 2 — 115 299 Fixed income subtotal 237 129 — 136 502 192 158 — 115 465 Hedge funds — — — 175 175 — — — 197 197 Real estate — — — 86 86 — — — 71 71 Private credit — — — 84 84 — — — 75 75 OPEB plan assets subtotal 678 172 — 805 1,655 620 192 — 822 1,634 Total pension and OPEB plan assets (d) $ 4,682 $ 3,170 $ 469 $ 5,640 $ 13,961 $ 4,007 $ 3,513 $ 485 $ 5,590 $ 13,595 __________ (a) See Note 16—Fair Value of Financial Assets and Liabilities for a description of levels within the fair value hierarchy. (b) Includes derivative instruments of $(2) million and $1 million for the years ended December 31, 2021 and 2020, respectively, which have total notional amounts of $3,481 million and $4,018 million as of December 31, 2021 and 2020, respectively. The notional principal amounts for these instruments provide one measure of the transaction volume outstanding as of the fiscal years ended and do not represent the amount of the company’s exposure to credit or market loss. (c) Includes investments in equities sold short held in investment vehicles primarily to hedge the equity option component of its convertible debt. Pension equities sold short totaled $(44) million and $(56) million as of December 31, 2021 and 2020, respectively. OPEB equities sold short totaled $(18) million and $(27) million as of December 31, 2021 and 2020, respectively. (d) Excludes net liabilities of $131 million and $77 million as of December 31, 2021 and 2020, respectively, which include certain derivative assets that have notional amounts of $127 million and $140 million as of December 31, 2021 and 2020, respectively. These items are required to reconcile to the fair value of net plan assets and consist primarily of receivables or payables related to pending securities sales and purchases, interest and dividends receivable, and repurchase agreement obligations. The repurchase agreements generally have maturities ranging from 3-6 months. The following table presents the reconciliation of Level 3 assets and liabilities for Exelon measured at fair value for pension and OPEB plans for the years ended December 31, 2021 and 2020: Fixed Income Equities Private Total Pension Assets Balance as of January 1, 2021 $ 348 $ 1 $ 136 $ 485 Actual return on plan assets: Relating to assets still held as of the (12) — 18 6 Purchases, sales and settlements: Purchases 10 — 5 15 Settlements (a) (13) — (29) (42) Transfers into Level 3 4 1 — 5 Balance as of December 31, 2021 $ 337 $ 2 $ 130 $ 469 Fixed Income Equities Private Total Pension Assets Balance as of January 1, 2020 $ 144 $ 3 $ 138 $ 285 Actual return on plan assets: Relating to assets still held as of the reporting date 11 (2) 9 18 Purchases, sales and settlements: Purchases 20 — 14 34 Settlements (a) (2) — (25) (27) Transfers into Level 3 (b) 175 — — 175 Balance as of December 31, 2020 $ 348 $ 1 $ 136 $ 485 __________ (a) Represents cash settlements only. (b) In 2020, a contract was terminated for a certain fixed income commingled fund resulting in the ownership of certain fixed income securities which led to a transfer into Level 3 from not subject to leveling of $175 million. Valuation Techniques Used to Determine Fair Value The techniques used to fair value the pension and OPEB assets invested in cash equivalents are the same as the valuation techniques used to determine the fair value of financial assets. See Cash Equivalents in Note 16 - Fair Value of Financial Assets and Liabilities for further information. Below outlines the techniques used to fair value the pension and OPEB assets invested in equities, fixed income, derivatives, private credit, private equity, and real estate investments. Equities. These investments consist of individually held equity securities, equity mutual funds, and equity commingled funds in domestic and foreign markets. With respect to individually held equity securities, the trustees obtain prices from pricing services, whose prices are generally obtained from direct feeds from market exchanges, which Exelon is able to independently corroborate. Equity securities held individually, including real estate investment trusts, rights, and warrants, are primarily traded on exchanges that contain only actively traded securities due to the volume trading requirements imposed by these exchanges. The equity securities that are held directly by the trust funds are valued based on quoted prices in active markets and categorized as Level 1. Certain equity securities have been categorized as Level 2 because they are based on evaluated prices that reflect observable market information, such as actual trade information or similar securities. Certain private placement equity securities are categorized as Level 3 because they are not publicly traded and are priced using significant unobservable inputs. Equity commingled funds and mutual funds are maintained by investment companies, and fund investments are held in accordance with a stated set of fund objectives. The values of some of these funds are publicly quoted. For mutual funds which are publicly quoted, the funds are valued based on quoted prices in active markets and have been categorized as Level 1. For equity commingled funds and mutual funds which are not publicly quoted, the fund administrators value the funds using the NAV per fund share, derived from the quoted prices in active markets on the underlying securities and are not classified within the fair value hierarchy. These investments can typically be redeemed monthly or more frequently, with 30 or less days of notice and without further restrictions. Fixed income. For fixed income securities, which consist primarily of corporate debt securities, U.S. government securities, foreign government securities, municipal bonds, asset and mortgage-backed securities, commingled funds, mutual funds, and derivative instruments, the trustees obtain multiple prices from pricing vendors whenever possible, which enables cross-provider validations in addition to checks for unusual daily movements. A primary price source is identified based on asset type, class, or issue for each security. With respect to individually held fixed income securities, the trustees monitor prices supplied by pricing services and may use a supplemental price source or change the primary price source of a given security if the portfolio managers challenge an assigned price and the trustees determine that another price source is considered to be preferable. Exelon has obtained an understanding of how these prices are derived, including the nature and observability of the inputs used in deriving such prices. Additionally, Exelon selectively corroborates the fair values of securities by comparison to other market-based price sources. Investments in U.S. Treasury securities have been categorized as Level 1 because they trade in highly-liquid and transparent markets. Certain private placement fixed income securities have been categorized as Level 3 because they are priced using certain significant unobservable inputs and are typically illiquid. The remaining fixed income securities, including certain other fixed income investments, are based on evaluated prices that reflect observable market information, such as actual trade information of similar securities, adjusted for observable differences and are categorized as Level 2. Other fixed income investments primarily consist of fixed income commingled funds and mutual funds, which are maintained by investment companies and hold fund investments in accordance with a stated set of fund objectives. The values of some of these funds are publicly quoted. For mutual funds which are publicly quoted, the funds are valued based on quoted prices in active markets and have been categorized as Level 1. For fixed income commingled funds and mutual funds

Derivative Financial Instrument

Derivative Financial Instruments (All Registrants)	12 Months Ended
Derivative Financial Instruments (All Registrants)	Dec. 31, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments (All Registrants)	Derivative Financial Instruments (All Registrants) The Registrants use derivative instruments to manage commodity price risk related to ongoing business operations. Authoritative guidance requires that derivative instruments be recognized as either assets or liabilities at fair value, with changes in fair value of the derivative recognized in earnings immediately. Other accounting treatments are available through special election and designation, provided they meet specific, restrictive criteria both at the time of designation and on an ongoing basis. These alternative permissible accounting treatments include NPNS, cash flow hedges, and fair value hedges. At ComEd, derivative economic hedges related to commodities are recorded at fair value and offset by a corresponding regulatory asset or liability. For all NPNS derivative instruments, accounts payable are recorded when derivatives settle and expense is recognized in earnings as the underlying physical commodity is consumed. ComEd’s use of cash collateral is generally unrestricted unless ComEd is downgraded below investment grade. Cash collateral held by PECO, BGE, Pepco, DPL, and ACE must be deposited in an unaffiliated major U.S. commercial bank or foreign bank with a U.S. branch office that meet certain qualifications. Commodity Price Risk The Registrants employ established policies and procedures to manage their risks associated with market fluctuations in commodity prices by entering into physical and financial derivative contracts, which are either determined to be non-derivative or classified as economic hedges. The Utility Registrants procure electric and natural gas supply through a competitive procurement process approved by each of the respective state utility commissions. The Utility Registrants’ hedging programs are intended to reduce exposure to energy and natural gas price volatility and have no direct earnings impact as the costs are fully recovered from customers through regulatory-approved recovery mechanisms. The following table provides a summary of the Utility Registrants’ primary derivative hedging instruments, listed by commodity and accounting treatment. Registrant Commodity Accounting Treatment Hedging Instrument ComEd Electricity NPNS Fixed price contracts based on all requirements in the IPA procurement plans. Electricity Changes in fair value of economic hedge recorded to an offsetting regulatory asset or liability (a) 20-year floating-to-fixed energy swap contracts beginning June 2012 based on the renewable energy resource procurement requirements in the Illinois Settlement Legislation of approximately 1.3 million MWhs per year. PECO Electricity NPNS Fixed price contracts for default supply requirements through full requirements contracts. Gas NPNS Fixed price contracts to cover about 10% of planned natural gas purchases in support of projected firm sales. BGE Electricity NPNS Fixed price contracts for all SOS requirements through full requirements contracts. Gas NPNS Fixed price contracts for between 10-20% of forecasted system supply requirements for flowing (i.e., non-storage) gas for the November through March period. Pepco Electricity NPNS Fixed price contracts for all SOS requirements through full requirements contracts. DPL Electricity NPNS Fixed price contracts for all SOS requirements through full requirements contracts. Gas NPNS Fixed and index priced contracts through full requirements contracts. Changes in fair value of economic hedge recorded to an offsetting regulatory asset or liability (b) Exchange traded future contracts for up to 50% of estimated monthly purchase requirements each month, including purchases for storage injections. ACE Electricity NPNS Fixed price contracts for all BGS requirements through full requirements contracts. _________ (a) See Note 3—Regulatory Matters for additional information. (b) The fair value of the DPL economic hedge is not material as of December 31, 2021 and 2020. The following tables provide a summary of the derivative fair value balances recorded by Exelon and ComEd as of December 31, 2021 and 2020: December 31, 2021 Mark-to-market derivative liabilities (current liabilities) $ (18) Mark-to-market derivative liabilities (noncurrent liabilities) (201) Total mark-to-market derivative liabilities $ (219) December 31, 2020 Mark-to-market derivative liabilities (current liabilities) $ (33) Mark-to-market derivative liabilities (noncurrent liabilities) (268) Total mark-to-market derivative liabilities $ (301) Credit Risk The Registrants would be exposed to credit-related losses in the event of non-performance by counterparties on executed derivative instruments. The credit exposure of derivative contracts, before collateral, is represented by the fair value of contracts at the reporting date. The Utility Registrants have contracts to procure electric and natural gas supply that provide suppliers with a certain amount of unsecured credit. If the exposure on the supply contract exceeds the amount of unsecured credit, the suppliers may be required to post collateral. The net credit exposure is mitigated primarily by the ability to recover procurement costs through customer rates. As of December 31, 2021, the amount of cash collateral held with external counterparties by ComEd and DPL was $41 million and $43 million, respectively, which is recorded in Other current liabilities in ComEd’s and DPL’s Consolidated Balance Sheets. The amounts for PECO, BGE, Pepco, and ACE as of December 31, 2021 and for the Utility Registrants as of December 31, 2020 are not material. The Utility Registrants’ electric supply procurement contracts do not contain provisions that would require them to post collateral. PECO’s, BGE’s, and DPL’s natural gas procurement contracts contain provisions that could require PECO, BGE, and DPL to post collateral in the form of cash or credit support, which vary by contract and counterparty, with thresholds contingent upon PECO’s, BGE's, and DPL’s credit rating. As of December 31, 2021, PECO, BGE, and DPL were not required to post collateral for any of these agreements. If PECO, BGE, or DPL lost their investment grade credit rating as of December 31, 2021, they could have been required to post collateral to their counterparties of $37 million, $78 million, and $14 million, respectively.

Debt and Credit Agreements (All

Debt and Credit Agreements (All Registrants)	12 Months Ended
Debt and Credit Agreements (All Registrants)	Dec. 31, 2021
Debt Disclosure [Abstract]
Debt and Credit Agreements (All Registrants)	Debt and Credit Agreements (All Registrants) Short-Term Borrowings Exelon Corporate, ComEd, and BGE meet their short-term liquidity requirements primarily through the issuance of commercial paper. PECO meets its short-term liquidity requirements primarily through the issuance of commercial paper and borrowings from the Exelon intercompany money pool. Pepco, DPL, and ACE meet their short-term liquidity requirements primarily through the issuance of commercial paper and borrowings from the PHI intercompany money pool. PHI Corporate meets its short-term liquidity requirements primarily through the issuance of short-term notes and borrowings from the Exelon intercompany money pool. The Registrants may use their respective credit facilities for general corporate purposes, including meeting short-term funding requirements and the issuance of letters of credit. Commercial Paper The following table reflects the Registrants' commercial paper programs supported by the revolving credit agreements and bilateral credit agreements as of December 31, 2021 and 2020: Maximum Outstanding Average Interest Rate on Commercial Paper Issuer 2021 (a)(b) 2020 (a)(b) 2021 2020 2021 2020 Exelon (c) $ 3,700 $ 3,700 $ 599 $ 691 0.35 % 0.24 % ComEd 1,000 1,000 — 323 — % 0.23 % PECO 600 600 — — — % — % BGE 600 600 130 — 0.37 % — % PHI (d) 900 900 469 368 0.35 % 0.24 % Pepco 300 300 175 35 0.33 % 0.22 % DPL 300 300 149 146 0.36 % 0.24 % ACE 300 300 145 187 0.35 % 0.25 % __________ (a) As of December 31, 2021, excludes $98 million of credit facility agreements arranged at minority and community banks, including $33 million, $33 million, $8 million, $8 million, $8 million, and $8 million, at ComEd, PECO, BGE, Pepco, DPL, and ACE, respectively. These facilities expire on October 7, 2022. These facilities are solely utilized to issue letters of credit. As of December 31, 2020, excludes $97 million of credit facility agreements arranged primarily at minority and community banks, including $32 million, $33 million, $8 million, $8 million, $8 million, and $8 million, at ComEd, PECO, BGE, Pepco, DPL, and ACE, respectively. (b) Pepco, DPL, and ACE's revolving credit facility has the ability to flex to $500 million, $500 million, and $350 million, respectively. The borrowing capacity may be increased or decreased during the term of the facility, except that (i) the sum of the borrowing capacity must equal the total amount of the facility, and (ii) the aggregate amount of credit used at any given time by each of Pepco, DPL, or ACE may not exceed $900 million or the maximum amount of short-term debt the company is permitted to have outstanding by its regulatory authorities. The total number of the borrowing reallocations may not exceed eight per year during the term of the facility. (c) Includes revolving credit agreement at Exelon Corporate with a maximum program size of $600 million as of December 31, 2021 and 2020. Exelon Corporate had no outstanding commercial paper as of December 31, 2021 and 2020. (d) Represents the consolidated amounts of Pepco, DPL, and ACE. In order to maintain their respective commercial paper programs in the amounts indicated above, each Registrant must have credit facilities in place, at least equal to the amount of its commercial paper program. A registrant does not issue commercial paper in an aggregate amount exceeding the then available capacity under its credit facility. As of December 31, 2021, the Registrants had the following aggregate bank commitments, credit facility borrowings, and available capacity under their respective credit facilities: Available Capacity as of December 31, 2021 Borrower (a) Facility Type Aggregate Bank (b) Facility Draws Outstanding Actual To Support Additional Commercial (c) Exelon (c) Syndicated Revolver $ 3,700 $ — $ 8 $ 3,692 $ 3,093 ComEd Syndicated Revolver 1,000 — 2 998 998 PECO Syndicated Revolver 600 — — 600 600 BGE Syndicated Revolver 600 — — 600 470 PHI (d) Syndicated Revolver 900 — — 900 431 Pepco Syndicated Revolver 300 — — 300 125 DPL Syndicated Revolver 300 — — 300 151 ACE Syndicated Revolver 300 — — 300 155 __________ (a) On February 1, 2022, Exelon Corporate and the Utility Registrants' respective syndicated revolving credit facilities were replaced with a new 5-year revolving credit facility. (b) As of December 31, 2021, excludes $98 million of credit facility agreements arranged at minority and community banks, including $33 million, $33 million, $8 million, $8 million, $8 million, and $8 million, at ComEd, PECO, BGE, Pepco, DPL, and ACE, respectively. These facilities expire on October 7, 2022. These facilities are solely utilized to issue letters of credit. As of December 31, 2021, letters of credit issued under these facilities totaled $5 million, $1 million, and $2 million for ComEd, PECO, and BGE, respectively. (c) Includes $600 million aggregate bank commitment related to Exelon Corporate. Exelon Corporate had $6 million outstanding letters of credit as of December 31, 2021. Exelon Corporate had $594 million in available capacity to support additional commercial paper as of December 31, 2021. (d) Represents the consolidated amounts of Pepco, DPL, and ACE. Revolving Credit Agreements On February 1, 2022, Exelon Corporate and the Utility Registrants each entered into a new 5-year revolving credit facility that replaced its existing syndicated revolving credit facility. The following table reflects the credit agreements: Borrower Aggregate Bank Commitment Interest Rate Exelon Corporate $ 900 SOFR plus 1.275 % ComEd 1,000 SOFR plus 1.000 % PECO 600 SOFR plus 0.900 % BGE 600 SOFR plus 0.900 % Pepco 300 SOFR plus 1.075 % DPL 300 SOFR plus 1.000 % ACE 300 SOFR plus 1.075 % Borrowings under Exelon’s, ComEd’s, PECO’s, BGE's, Pepco's, DPL's, and ACE's revolving credit agreements bear interest at a rate based upon either the prime rate or a LIBOR-based rate, plus an adder based upon the particular Registrant’s credit rating. The adders for the prime based borrowings and LIBOR-based borrowings are presented in the following table: Exelon (a) ComEd PECO BGE Pepco DPL ACE Prime based borrowings 0 - 27.5 — — — 7.5 — 7.5 LIBOR-based borrowings 90.0 - 127.5 100.0 90.0 90.0 107.5 100.0 107.5 __________ (a) Includes interest rate adders at Exelon Corporate of 27.5 basis points and 127.5 basis points for prime and LIBOR-based borrowings, respectively. If any registrant loses its investment grade rating, the maximum adders for prime rate borrowings and LIBOR-based rate borrowings would be 65 basis points and 165 basis points, respectively. The credit agreements also require the borrower to pay a facility fee based upon the aggregate commitments. The fee varies depending upon the respective credit ratings of the borrower. Short-Term Loan Agreements On March 23, 2017, Exelon Corporate entered into a term loan agreement for $500 million. The loan agreement was renewed on March 17, 2021 and will expire on March 16, 2022. Pursuant to the loan agreement, loans made thereunder bear interest at a variable rate equal to LIBOR plus 0.65% and all indebtedness thereunder is unsecured. The loan agreement is reflected in Short-term borrowings in Exelon's Consolidated Balance Sheet. On March 24, 2021, Exelon Corporate entered into a 9-month term loan agreement for $200 million. Pursuant to the loan agreement, loans made thereunder bear interest at a variable rate equal to LIBOR plus 0.65% and all indebtedness thereunder is unsecured. Exelon Corporate repaid the term loan on December 22, 2021. On March 31, 2021, Exelon Corporate entered into a 9-month and 364-day term loan agreement for $150 million each with variable interest rates of LIBOR plus 0.65% and expiration dates of December 31, 2021 and March 30, 2022, respectively. The 364-day loan agreement is reflected in Short-term borrowings in Exelon's Consolidated Balance Sheet. Exelon Corporate repaid the 9-month term loan on December 29, 2021. In connection with the separation, on January 24, 2022, Exelon Corporate entered into a 364-day term loan agreement for $1.15 billion. The loan agreement will expire on January 23, 2023. Pursuant to the loan agreement, loans made thereunder bear interest at a variable rate equal to SOFR plus 0.75% and all indebtedness thereunder is unsecured. On January 25, 2021, ComEd entered into two 90-day term loan agreements of $125 million each with variable interest rates of LIBOR plus 0.50% and LIBOR plus 0.75%, respectively. ComEd repaid the term loans on March 9, 2021. Variable Rate Demand Bonds DPL has outstanding obligations in respect of Variable Rate Demand Bonds (VRDB). VRDBs are subject to repayment on the demand of the holders and, for this reason, are accounted for as short-term debt in accordance with GAAP. However, these bonds may be converted to a fixed-rate, fixed-term option to establish a maturity which corresponds to the date of final maturity of the bonds. On this basis, PHI views VRDBs as a source of long-term financing. As of both December 31, 2021 and December 31, 2020, $79 million in variable rate demand bonds issued by DPL were outstanding and are included in the Long-term debt due within one year in Exelon's, PHI's, and DPL's Consolidated Balance Sheet. Long-Term Debt The following tables present the outstanding long-term debt at the Registrants as of December 31, 2021 and 2020: Exelon Maturity December 31, Rates 2021 2020 Long-term debt First mortgage bonds (a)(b)(c) 0.14 % - 7.90 % 2022 - 2051 $ 20,751 $ 18,915 Senior unsecured notes 3.40 % - 7.60 % 2025 - 2050 6,324 6,624 Unsecured notes 2.25 % - 6.35 % 2022 - 2050 4,000 3,700 Notes payable and other 1.64 % - 7.49 % 2022 - 2053 86 59 Junior subordinated notes 3.50 % 2022 1,150 1,150 Long-term software licensing agreement 3.62 % - 3.95 % 2024 - 2025 9 30 Unsecured tax-exempt bonds 0.12 % - 1.70 % 2022 - 2024 143 143 Medium-terms notes (unsecured) 7.72 % 2027 10 10 Transition bonds 5.55 % 2021 — 21 Loan agreement (d) 2.00 % 2023 50 50 Total long-term debt 32,523 30,702 Unamortized debt discount and premium, net (70) (72) Unamortized debt issuance costs (220) (202) Fair value adjustment 669 721 Long-term debt due within one year (2,153) (1,622) Long-term debt $ 30,749 $ 29,527 Long-term debt to financing trusts (e) Subordinated debentures to ComEd Financing III 6.35 % 2033 $ 206 $ 206 Subordinated debentures to PECO Trust III 5.25 % - 7.38 % 2028 81 81 Subordinated debentures to PECO Trust IV 5.75 % 2033 103 103 Total long-term debt to financing trusts $ 390 $ 390 __________ (a) Substantially all of ComEd’s assets other than expressly excepted property and substantially all of PECO’s, Pepco's, DPL's, and ACE's assets are subject to the liens of their respective mortgage indentures. (b) On November 16, 2021, DPL entered into a purchase agreement of First Mortgage Bonds of $125 million at 3.06% due on February 15, 2052. The closing date of the issuance occurred on February 15, 2022. (c) On November 16, 2021, ACE entered into a purchase agreement of First Mortgage Bonds of $25 million and $150 million at 2.27% and 3.06% due on February 15, 2032 and February 15, 2052, respectively. The closing date of the issuance occurred on February 15, 2022. (d) In connection with the separation, Exelon Corporate entered into three 18-month term loan agreements. On January 21, 2022, two of the loan agreements were issued for $300 million each with an expiration date of July 21, 2023. On January 24, 2022, the third loan agreement was issued for $250 million with an expiration date of July 24, 2023. Pursuant to the loan agreement, loans made thereunder bear interest at a variable rate equal to SOFR plus 0.65%. (e) Amounts owed to these financing trusts are recorded as Long-term debt to financing trusts within Exelon’s Consolidated Balance Sheet. ComEd Maturity December 31, Rates 2021 2020 Long-term debt First mortgage bonds (a) 2.20 % - 6.45 % 2024 - 2051 $ 9,879 $ 9,079 Other 7.49 % 2053 8 8 Total long-term debt 9,887 9,087 Unamortized debt discount and premium, net (27) (28) Unamortized debt issuance costs (87) (76) Long-term debt due within one year — (350) Long-term debt $ 9,773 $ 8,633 Long-term debt to financing trust (b) Subordinated debentures to ComEd Financing III 6.35 % 2033 $ 206 $ 206 Total long-term debt to financing trusts 206 206 Unamortized debt issuance costs (1) (1) Long-term debt to financing trusts $ 205 $ 205 __________ (a) Substantially all of ComEd’s assets, other than expressly excepted property, are subject to the lien of its mortgage indenture. (b) Amount owed to this financing trust is recorded as Long-term debt to financing trust within ComEd’s Consolidated Balance Sheet. PECO Maturity December 31, Rates 2021 2020 Long-term debt First mortgage bonds (a) 2.38 % - 5.95 % 2022 - 2051 $ 4,200 $ 3,750 Loan agreement 2.00 % 2023 50 50 Total long-term debt 4,250 3,800 Unamortized debt discount and premium, net (20) (20) Unamortized debt issuance costs (33) (27) Long-term debt due within one year (350) (300) Long-term debt $ 3,847 $ 3,453 Long-term debt to financing trusts (b) Subordinated debentures to PECO Trust III 5.25 % - 7.38 % 2028 $ 81 $ 81 Subordinated debentures to PECO Trust IV 5.75 % 2033 103 103 Long-term debt to financing trusts $ 184 $ 184 __________ (a) Substantially all of PECO’s assets are subject to the lien of its mortgage indenture. (b) Amounts owed to this financing trust are recorded as Long-term debt to financing trusts within PECO’s Consolidated Balance Sheet. BGE Maturity December 31, Rates 2021 2020 Long-term debt Unsecured notes 2.25 % - 6.35 % 2022 - 2050 $ 4,000 $ 3,700 Total long-term debt 4,000 3,700 Unamortized debt discount and premium, net (12) (12) Unamortized debt issuance costs (27) (24) Long-term debt due within one year (250) (300) Long-term debt $ 3,711 $ 3,364 PHI Maturity December 31, Rates 2021 2020 Long-term debt First mortgage bonds (a) 0.14 % - 7.90 % 2022 - 2051 $ 6,672 $ 6,086 Senior unsecured notes 7.45 % 2032 185 185 Unsecured tax-exempt bonds 0.12 % - 1.70 % 2022 - 2024 143 143 Medium-terms notes (unsecured) 7.72 % 2027 10 10 Transition bonds 5.55 % 2021 — 21 Finance leases 3.54 % 2022 - 2029 74 50 Other (b) 7.28 % - 7.49 % 2022 — 1 Total long-term debt 7,084 6,496 Unamortized debt discount and premium, net 4 4 Unamortized debt issuance costs (36) (28) Fair value adjustment 495 534 Long-term debt due within one year (399) (347) Long-term debt $ 7,148 $ 6,659 _________ (a) Substantially all of Pepco's, DPL's, and ACE's assets are subject to the liens of their respective mortgage indentures. (b) The amount in the Other category was less than 1 million as of December 31, 2021. Pepco Maturity December 31, Rates 2021 2020 Long-term debt First mortgage bonds (a) 2.32 % - 7.90 % 2022 - 2051 $ 3,350 $ 3,075 Unsecured tax-exempt bonds 1.70 % 2022 110 110 Finance leases 3.54 % 2025 - 2029 26 17 Other (b) 7.28 % - 7.49 % 2022 — 1 Total long-term debt 3,486 3,203 Unamortized debt discount and premium, net 2 2 Unamortized debt issuance costs (43) (40) Long-term debt due within one year (313) (3) Long-term debt $ 3,132 $ 3,162 ________ (a) Substantially all of Pepco's assets are subject to the lien of its mortgage indenture. (b) The amount in the Other category was less than 1 million as of December 31, 2021. DPL Maturity December 31, Rates 2021 2020 Long-term debt First mortgage bonds (a)(b) 0.14 % - 4.27 % 2023 - 2051 $ 1,749 $ 1,624 Unsecured tax-exempt bonds 0.12 % - 0.13 % 2024 33 33 Medium-terms notes (unsecured) 7.72 % 2027 10 10 Finance leases 3.54 % 2025 - 2029 29 20 Total long-term debt 1,821 1,687 Unamortized debt discount and premium, net — 1 Unamortized debt issuance costs (11) (11) Long-term debt due within one year (83) (82) Long-term debt $ 1,727 $ 1,595 __________ (a) Substantially all of DPL's assets are subject to the lien of its mortgage indenture. (b) On November 16, 2021, DPL entered into a purchase agreement of First Mortgage Bonds of $125 million at 3.06% due on February 15, 2052. The closing date of the issuance occurred on February 15, 2022. ACE Maturity December 31, Rates 2021 2020 Long-term debt First mortgage bonds (a)(b) 2.25 % - 5.80 % 2024 - 2050 $ 1,573 $ 1,387 Transition bonds 5.55 % 2021 — 21 Finance leases 3.54 % 2022 - 2029 19 13 Total long-term debt 1,592 1,421 Unamortized debt discount and premium, net (1) (1) Unamortized debt issuance costs (9) (7) Long-term debt due within one year (3) (261) Long-term debt $ 1,579 $ 1,152 __________ (a) Substantially all of ACE's assets are subject to the lien of its mortgage indenture. (b) On November 16, 2021, ACE entered into a purchase agreement of First Mortgage Bonds of $25 million and $150 million at 2.27% and 3.06% due on February 15, 2032 and February 15, 2052, respectively. The closing date of the issuance occurred on February 15, 2022. Long-term debt maturities at the Registrants in the periods 2022 through 2026 and thereafter are as follows: Year Exelon ComEd PECO BGE PHI Pepco DPL ACE 2022 $ 2,153 $ — $ 350 $ 250 $ 399 $ 313 $ 83 $ 3 2023 864 — 50 300 512 4 505 3 2024 817 250 — — 562 404 5 153 2025 1,322 — 350 — 162 4 5 153 2026 1,611 500 — 350 11 4 4 3 Thereafter 25,888 (a) 9,342 (b) 3,684 (c) 3,100 5,438 2,757 1,219 1,277 Total $ 32,655 $ 10,092 $ 4,434 $ 4,000 $ 7,084 $ 3,486 $ 1,821 $ 1,592 __________ (a) Includes $390 million due to ComEd and PECO financing trusts. (b) Includes $206 million due to ComEd financing trust. (c) Includes $184 million due to PECO financing trusts. Long-Term Debt to Affiliates In connection with the debt obligations assumed by Exelon as part of the Constellation merger, Exelon and subsidiaries of Generation (former Constellation subsidiaries) entered into intercompany loan agreements that mirror the terms and amounts of the third-party debt obligations of Exelon, resulting in intercompany notes receivable at Exelon Corporate from Generation. As of December 31, 2021 and 2020, Exelon Corporate had $319 million and $324 million, respectively, recorded to intercompany notes receivable from Generation. In connection with the separation, on January 31, 2022, Exelon Corporate received cash from Generation of $258 million to settle the intercompany loan. Debt Covenants As of December 31, 2021, the Registrants are in compliance with debt covenants.

Fair Value of Financial Assets

Fair Value of Financial Assets and Liabilities (All Registrants)	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value of Financial Assets and Liabilities (All Registrants)	Fair Value of Financial Assets and Liabilities (All Registrants) Exelon measures and classifies fair value measurements in accordance with the hierarchy as defined by GAAP. The hierarchy prioritizes the inputs to valuation techniques used to measure fair value into three levels as follows: • Level 1 — quoted prices (unadjusted) in active markets for identical assets or liabilities that the Registrants have the ability to liquidate as of the reporting date. • Level 2 — inputs other than quoted prices included within Level 1 that are directly observable for the asset or liability or indirectly observable through corroboration with observable market data. • Level 3 — unobservable inputs, such as internally developed pricing models or third-party valuations for the asset or liability due to little or no market activity for the asset or liability. Fair Value of Financial Liabilities Recorded at Amortized Cost The following tables present the carrying amounts and fair values of the Registrants’ short-term liabilities, long-term debt, and trust preferred securities (long-term debt to financing trusts or junior subordinated debentures) as of December 31, 2021 and 2020. The Registrants have no financial liabilities classified as Level 1. The carrying amounts of the Registrants’ short-term liabilities as presented in their Consolidated Balance Sheets are representative of their fair value (Level 2) because of the short-term nature of these instruments. December 31, 2021 December 31, 2020 Carrying Amount Fair Value Carrying Amount Fair Value Level 2 Level 3 Total Level 2 Level 3 Total Long-Term Debt, including amounts due within one year (a) Exelon $ 32,902 $ 34,897 $ 2,217 $ 37,114 $ 31,149 $ 35,416 $ 1,856 $ 37,272 ComEd 9,773 11,305 — 11,305 8,983 11,117 — 11,117 PECO 4,197 4,740 50 4,790 3,753 4,553 50 4,603 BGE 3,961 4,406 — 4,406 3,664 4,366 — 4,366 PHI 7,547 5,970 2,167 8,137 7,006 6,099 1,806 7,905 Pepco 3,445 3,201 975 4,176 3,165 3,336 748 4,084 DPL 1,810 1,426 552 1,978 1,677 1,484 455 1,939 ACE 1,582 1,091 641 1,732 1,413 1,018 602 1,620 Long-Term Debt to Financing Trusts Exelon $ 390 $ — $ 470 $ 470 $ 390 $ — $ 467 $ 467 ComEd 205 — 248 248 205 — 246 246 PECO 184 — 222 222 184 — 221 221 __________ (a) Includes unamortized debt issuance costs, unamortized debt discount and premium, net, purchase accounting fair value adjustments, and finance lease liabilities which are not fair valued. Refer to Note 15 — Debt and Credit Agreements for unamortized debt issuance costs, unamortized debt discount and premium, net, and purchase accounting fair value adjustments and Note 10 — Leases for finance lease liabilities . Exelon uses the following methods and assumptions to estimate fair value of financial liabilities recorded at carrying cost: Type Level Registrants Valuation Long-Term Debt, including amounts due within one year Taxable Debt Securities 2 All The fair value is determined by a valuation model that is based on a conventional discounted cash flow methodology and utilizes assumptions of current market pricing curves. Exelon obtains credit spreads based on trades of existing Exelon debt securities as well as other issuers in the utility sector with similar credit ratings. The yields are then converted into discount rates of various tenors that are used for discounting the respective cash flows of the same tenor for each bond or note. Variable Rate Financing Debt 2 Exelon, DPL Debt rates are reset on a regular basis and the carrying value approximates fair value. Taxable Private Placement Debt Securities 3 Exelon, Pepco, DPL, ACE Rates are obtained similar to the process for taxable debt securities. Due to low trading volume and qualitative factors such as market conditions, low volume of investors, and investor demand, these debt securities are Level 3. Non-Government Backed Fixed Rate Nonrecourse Debt 3 Exelon, Pepco Fair value is based on market and quoted prices for its own and other nonrecourse debt with similar risk profiles. Given the low trading volume in the nonrecourse debt market, the price quotes used to determine fair value will reflect certain qualitative factors, such as market conditions, investor demand, new developments that might significantly impact the project cash flows or off-taker credit, and other circumstances related to the project. Long-Term Debt to Financing Trusts Long Term Debt to Financing Trusts 3 Exelon, ComEd, PECO Fair value is based on publicly traded securities issued by the financing trusts. Due to low trading volume of these securities and qualitative factors, such as market conditions, investor demand, and circumstances related to each issue, this debt is classified as Level 3. Recurring Fair Value Measurements The following tables present assets and liabilities measured and recorded at fair value in the Registrants' Consolidated Balance Sheets on a recurring basis and their level within the fair value hierarchy as of December 31, 2021 and 2020: Exelon As of December 31, 2021 As of December 31, 2020 Level 1 Level 2 Level 3 Total (a) Level 1 Level 2 Level 3 Total (a) Assets Cash equivalents (b) $ 524 $ — $ — $ 524 $ 558 $ — $ — $ 558 Rabbi trust investments Cash equivalents 60 — — 60 59 — — 59 Mutual funds 60 — — 60 54 — — 54 Fixed income — 10 — 10 — 11 — 11 Life insurance contracts — 61 37 98 — 60 34 94 Rabbi trust investments subtotal 120 71 37 228 113 71 34 218 Total assets 644 71 37 752 671 71 34 776 Liabilities Mark-to-market derivative liabilities — — (219) (219) — — (301) (301) Deferred compensation obligation — (131) — (131) — (121) — (121) Total liabilities — (131) (219) (350) — (121) (301) (422) Total net assets $ 644 $ (60) $ (182) $ 402 $ 671 $ (50) $ (267) $ 354 __________ (a) There were no assets and liabilities that were not subject to leveling as of December 31, 2021 and 2020. (b) Excludes cash of $464 million and $237 million as of December 31, 2021 and 2020, respectively, and restricted cash of $49 million and $39 million as of December 31, 2021 and 2020, respectively, and includes long-term restricted cash of $44 million and $53 million as of December 31, 2021 and 2020, respectively, which is reported in Other deferred debits in the Consolidated Balance Sheets. ComEd, PECO, and BGE ComEd PECO BGE As of December 31, 2021 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets Cash equivalents (a) $ 237 $ — $ — $ 237 $ 9 $ — $ — $ 9 $ — $ — $ — $ — Rabbi trust investments Mutual funds — — — — 11 — — 11 14 — — 14 Life insurance contracts — — — — — 16 — 16 — — — — Rabbi trust investments subtotal — — — — 11 16 — 27 14 — — 14 Total assets 237 — — 237 20 16 — 36 14 — — 14 Liabilities Mark-to-market derivative liabilities (b) — — (219) (219) — — — — — — — — Deferred compensation obligation — (10) — (10) — (9) — (9) — (7) — (7) Total liabilities — (10) (219) (229) — (9) — (9) — (7) — (7) Total net assets (liabilities) $ 237 $ (10) $ (219) $ 8 $ 20 $ 7 $ — $ 27 $ 14 $ (7) $ — $ 7 ComEd PECO BGE As of December 31, 2020 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets Cash equivalents (a) $ 285 $ — $ — $ 285 $ 8 $ — $ — $ 8 $ 120 $ — $ — $ 120 Rabbi trust investments Mutual funds — — — — 9 — — 9 10 — — 10 Life insurance contracts — — — — — 13 — 13 — — — — Rabbi trust investments subtotal — — — — 9 13 — 22 10 — — 10 Total assets 285 — — 285 17 13 — 30 130 — — 130 Liabilities Mark-to-market derivative liabilities (b) — — (301) (301) — — — — — — — — Deferred compensation obligation — (8) — (8) — (9) — (9) — (5) — (5) Total liabilities — (8) (301) (309) — (9) — (9) — (5) — (5) Total net assets (liabilities) $ 285 $ (8) $ (301) $ (24) $ 17 $ 4 $ — $ 21 $ 130 $ (5) $ — $ 125 __________ (a) ComEd excludes cash of $105 million and $83 million as of December 31, 2021 and 2020, respectively, and restricted cash of $42 million and $37 million as of December 31, 2021 and 2020, respectively, and includes long-term restricted cash of $43 million as of both December 31, 2021 and 2020, which is reported in Other deferred debits in the Consolidated Balance Sheets. PECO excludes cash of $35 million and $18 million as of December 31, 2021 and 2020, respectively. BGE excludes cash of $51 million and $24 million as of December 31, 2021 and 2020, respectively, and restricted cash of $4 million and $1 million as of December 31, 2021 and 2020, respectively. (b) The Level 3 balance consists of the current and noncurrent liability of $18 million and $201 million, respectively, as of December 31, 2021 and $33 million and $268 million, respectively, as of December 31, 2020 related to floating-to-fixed energy swap contracts with unaffiliated suppliers. PHI, Pepco, DPL, and ACE As of December 31, 2021 As of December 31, 2020 PHI Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets Cash equivalents (a) $ 110 $ — $ — $ 110 $ 86 $ — $ — $ 86 Rabbi trust investments Cash equivalents 59 — — 59 55 — — 55 Mutual funds 14 — — 14 14 — — 14 Fixed income — 10 — 10 — 11 — 11 Life insurance contracts — 27 35 62 — 26 34 60 Rabbi trust investments subtotal 73 37 35 145 69 37 34 140 Total assets 183 37 35 255 155 37 34 226 Liabilities Deferred compensation obligation — (18) — (18) — (17) — (17) Total liabilities — (18) — (18) — (17) — (17) Total net assets $ 183 $ 19 $ 35 $ 237 $ 155 $ 20 $ 34 $ 209 Pepco DPL ACE As of December 31, 2021 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets Cash equivalents (a) $ 31 $ — $ — $ 31 $ 43 $ — $ — $ 43 $ — $ — $ — $ — Rabbi trust investments Cash equivalents 58 — — 58 — — — — — — — — Life insurance contracts — 27 35 62 — — — — — — — — Rabbi trust investments subtotal 58 27 35 120 — — — — — — — — Total assets 89 27 35 151 43 — — 43 — — — — Liabilities Deferred compensation obligation — (2) — (2) — — — — — — — — Total liabilities — (2) — (2) — — — — — — — — Total net assets $ 89 $ 25 $ 35 $ 149 $ 43 $ — $ — $ 43 $ — $ — $ — $ — Pepco DPL ACE As of December 31, 2020 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets Cash equivalents (a) $ 35 $ — $ — $ 35 $ — $ — $ — $ — $ 13 $ — $ — $ 13 Rabbi trust investments Cash equivalents 53 — — 53 — — — — — — — — Fixed income — 2 — 2 — — — — — — — — Life insurance contracts — 26 34 60 — — — — — — — — Rabbi trust investments subtotal 53 28 34 115 — — — — — — — — Total assets 88 28 34 150 — — — — 13 — — 13 Liabilities Deferred compensation obligation — (2) — (2) — — — — — — — — Total liabilities — (2) — (2) — — — — — — — — Total net assets $ 88 $ 26 $ 34 $ 148 $ — $ — $ — $ — $ 13 $ — $ — $ 13 __________ (a) PHI excludes cash of $100 million and $74 million as of December 31, 2021 and 2020, respectively, and restricted cash of $3 million and none as of December 31, 2021 and 2020, respectively, and includes long-term restricted cash of none and $10 million as of December 31, 2021 and 2020, respectively, which is reported in Other deferred debits in the Consolidated Balance Sheets. Pepco excludes cash of $34 million and $30 million as of December 31, 2021 and 2020, respectively, and restricted cash of $3 million and none as of December 31, 2021 and 2020, respectively. DPL excludes cash of $28 million and $15 million as of December 31, 2021 and 2020, respectively. ACE excludes cash of $29 million and $17 million as of December 31, 2021 and 2020, respectively, and includes long-term restricted cash of none and $10 million as of December 31, 2021 and 2020, respectively, which is reported in Other deferred debits in the Consolidated Balance Sheets. Reconciliation of Level 3 Assets and Liabilities The following tables present the fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis during the years ended December 31, 2021 and 2020: Exelon ComEd PHI and Pepco For the year ended December 31, 2021 Total Mark-to-Market Life Insurance Contracts Balance as of January 1, 2021 $ (267) $ (301) $ 34 Total realized / unrealized gains (losses) Included in net income (a) 3 — 3 Included in regulatory assets/liabilities 82 82 (b) — Purchases, sales, and settlements Settlements (2) — (2) Transfers into Level 3 2 — — Balance as of December 31, 2021 $ (182) $ (219) $ 35 The amount of total gains included in income attributed to the change in unrealized gains (losses) related to assets and liabilities as of December 31, 2021 3 $ — $ 3 Exelon ComEd PHI and Pepco For the year ended December 31, 2020 Total Mark-to-Market Life Insurance Contracts Balance as of January 1, 2020 $ (260) $ (301) $ 41 Total realized / unrealized gains (losses) Included in net income (a) 3 — 3 Included in regulatory assets/liabilities — — (b) — Purchases, sales, and settlements Settlements (10) — (10) Balance as of December 31, 2020 $ (267) $ (301) $ 34 The amount of total gains included in income attributed to the change in unrealized gains (losses) related to assets and liabilities as of December 31, 2020 $ 3 $ — $ 3 __________ (a) Classified in Operating and maintenance expense in the Consolidated Statements of Operations and Comprehensive Income. (b) Includes $62 million of increases in fair value and an increase for realized losses due to settlements of $20 million recorded in purchased power expense associated with floating-to-fixed energy swap contracts with unaffiliated suppliers for the year ended December 31, 2021. Includes $33 million of decreases in fair value and an increase for realized losses due to settlements of $33 million recorded in purchased power expense associated with floating-to-fixed energy swap contracts with unaffiliated suppliers for the year ended December 31, 2020. Valuation Techniques Used to Determine Fair Value Cash Equivalents (All Registrants). Investments with original maturities of three months or less when purchased, including mutual and money market funds, are considered cash equivalents. The fair values are based on observable market prices and, therefore, are included in the recurring fair value measurements hierarchy as Level 1. Rabbi Trust Investments (Exelon, PECO, BGE, PHI, Pepco, DPL, and ACE). The Rabbi trusts were established to hold assets related to deferred compensation plans existing for certain active and retired members of Exelon’s executive management and directors. The Rabbi trusts' assets are included in investments in the Registrants’ Consolidated Balance Sheets and consist primarily of money market funds, mutual funds, fixed income securities, and life insurance policies. Money market funds and mutual funds are publicly quoted and have been categorized as Level 1 given the clear observability of the prices. The fair values of fixed income securities are based on evaluated prices that reflect observable market information, such as actual trade information or similar securities, adjusted for observable differences and are categorized in Level 2. The life insurance policies are valued using the cash surrender value of the policies, net of loans against those policies, which is provided by a third-party. Certain life insurance policies, which consist primarily of mutual funds that are priced based on observable market data, have been categorized as Level 2 because the life insurance policies can be liquidated at the reporting date for the value of the underlying assets. Life insurance policies that are valued using unobservable inputs have been categorized as Level 3, where the fair value is determined based on the cash surrender value of the policy, which contains unobservable inputs and assumptions. Because Exelon relies on its third-party insurance provider to develop the inputs without adjustment for the valuations of its Level 3 investments, quantitative information about significant unobservable inputs used in valuing these investments is not reasonably available to Exelon. Therefore, Exelon has not disclosed such inputs. Deferred Compensation Obligations (All Registrants). The Registrants’ deferred compensation plans allow participants to defer certain cash compensation into a notional investment account. The Registrants include such plans in other current and noncurrent liabilities in their Consolidated Balance Sheets. The value of the Registrants’ deferred compensation obligations is based on the market value of the participants’ notional investment accounts. The underlying notional investments are comprised primarily of equities, mutual funds, commingled funds, and fixed income securities which are based on directly and indirectly observable market prices. Since the deferred compensation obligations themselves are not exchanged in an active market, they are categorized as Level 2 in the fair value hierarchy. The value of certain employment agreement obligations (which are included with the Deferred Compensation Obligation in the tables above) are based on a known and certain stream of payments to be made over time and are categorized as Level 2 within the fair value hierarchy. Mark-to-Market Derivatives (Exelon and ComEd). On December 17, 2010, ComEd entered into several 20-year floating to fixed energy swap contracts with unaffiliated suppliers for the procurement of long-term renewable energy and associated RECs. The fair value of these swaps has been designated as a Level 3 valuation due to the long tenure of the positions and internal modeling assumptions. The modeling assumptions include using natural gas heat rates to project long term forward power curves adjusted by a renewable factor that incorporates time of day and seasonality factors to reflect accurate renewable energy pricing. In addition, marketability reserves are applied to the positions based on the tenor and supplier risk. See Note 14 — Derivative Financial Instruments for additional information on mark-to-market derivatives. The following table discloses the significant inputs to the forward curve used to value mark-to-market derivatives: Type of trade Fair Value as of December 31, 2021 Fair Value as of December 31, 2020 Valuation Unobservable 2021 Range & Arithmetic Average 2020 Range & Arithmetic Average Mark-to-market derivatives $ (219) $ (301) Discounted Cash Flow Forward heat rate (a) 9x - 10x 9.13x 8x - 9x 8.85x Marketability 3% - 7% 4.77% 3% - 8% 4.93% Renewable 92% - 120% 97% 91% - 123% 99% __________ (a) Quoted forward natural gas rates are utilized to project the forward power curve for the delivery of energy at specified future dates. The natural gas curve is extrapolated beyond its observable period to the end of the contract’s delivery.

Commitments and Contingencies (

Commitments and Contingencies (All Registrants)	12 Months Ended
Commitments and Contingencies (All Registrants)	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies (All Registrants)	Commitments and Contingencies (All Registrants) Commitments PHI Merger Commitments (Exelon, PHI, Pepco, DPL, and ACE). Approval of the PHI Merger in Delaware, New Jersey, Maryland, and the District of Columbia was conditioned upon Exelon and PHI agreeing to certain commitments. The following amounts represent total commitment costs that have been recorded since the acquisition date and the total remaining obligations for Exelon, PHI, Pepco, DPL, and ACE as of December 31, 2021: Description Exelon PHI Pepco DPL ACE Total commitments $ 513 $ 320 $ 120 $ 89 $ 111 Remaining commitments (a) 68 58 48 6 4 __________ (a) Remaining commitments extend through 2026 and include rate credits, energy efficiency programs, and delivery system modernization. In addition, Exelon has committed to purchase 100 MWs of wind energy in PJM. DPL has committed to conducting three RFPs to procure up to a total of 120 MWs of wind RECs for the purpose of meeting Delaware's renewable portfolio standards. DPL has conducted two of the three wind REC RFPs. The first 40 MW wind REC tranche was conducted in 2017 and did not result in a purchase agreement. The second 40 MW wind REC tranche was conducted in 2018 and resulted in a proposed REC purchase agreement that was approved by the DEPSC in 2019. The RFP for the third and final 40 MW wind REC tranche will be conducted in the second half of 2022. Commercial Commitments (All Registrants). The Registrants' commercial commitments as of December 31, 2021, representing commitments potentially triggered by future events were as follows: Expiration within Exelon Total 2022 2023 2024 2025 2026 2027 and beyond Letters of credit $ 17 $ 17 $ — $ — $ — $ — $ — Surety bonds (a) 109 107 — 2 — — — Financing trust guarantees 378 — — — — — 378 Guaranteed lease residual values (b) 31 — 5 6 6 5 9 Total commercial commitments $ 535 $ 124 $ 5 $ 8 $ 6 $ 5 $ 387 ComEd Letters of credit $ 7 $ 7 $ — $ — $ — $ — $ — Surety bonds (a) 17 15 — 2 — — — Financing trust guarantees 200 — — — — — 200 Total commercial commitments $ 224 $ 22 $ — $ 2 $ — $ — $ 200 PECO Letters of credit $ 1 $ 1 $ — $ — $ — $ — $ — Surety bonds (a) 2 2 — — — — — Financing trust guarantees 178 — — — — — 178 Total commercial commitments $ 181 $ 3 $ — $ — $ — $ — $ 178 BGE Letters of credit $ 2 $ 2 $ — $ — $ — $ — $ — Surety bonds (a) 3 3 — — — — — Total commercial commitments $ 5 $ 5 $ — $ — $ — $ — $ — PHI Surety bonds (a) $ 23 $ 23 $ — $ — $ — $ — $ — Guaranteed lease residual values (b) 31 — 5 6 6 5 9 Total commercial commitments $ 54 $ 23 $ 5 $ 6 $ 6 $ 5 $ 9 Pepco Surety bonds (a) $ 14 $ 14 $ — $ — $ — $ — $ — Guaranteed lease residual values (c) 10 — 1 2 2 2 3 Total commercial commitments $ 24 $ 14 $ 1 $ 2 $ 2 $ 2 $ 3 DPL Surety bonds (a) $ 5 $ 5 $ — $ — $ — $ — $ — Guaranteed lease residual values (b) 13 — 2 3 2 2 4 Total commercial commitments $ 18 $ 5 $ 2 $ 3 $ 2 $ 2 $ 4 ACE Surety bonds (a) $ 4 $ 4 $ — $ — $ — $ — $ — Guaranteed lease residual values (b) 8 — 2 1 2 1 2 Total commercial commitments $ 12 $ 4 $ 2 $ 1 $ 2 $ 1 $ 2 __________ (a) Surety bonds—Guarantees issued related to contract and commercial agreements, excluding bid bonds. (b) Represents the maximum potential obligation in the event that the fair value of certain leased equipment and fleet vehicles is zero at the end of the maximum lease term. The lease term associated with these assets ranges from 1 to 8 years. The maximum potential obligation at the end of the minimum lease term would be $75 million guaranteed by Exelon and PHI, of which $25 million , $31 million, and $19 million is guaranteed by Pepco, DPL, and ACE, respectively. Historically, payments under the guarantees have not been made and PHI believes the likelihood of payments being required under the guarantees is remote. Environmental Remediation Matters General (All Registrants). The Registrants’ operations have in the past, and may in the future, require substantial expenditures to comply with environmental laws. Additionally, under Federal and state environmental laws, the Registrants are generally liable for the costs of remediating environmental contamination of property now or formerly owned by them and of property contaminated by hazardous substances generated by them. The Registrants own or lease a number of real estate parcels, including parcels on which their operations or the operations of others may have resulted in contamination by substances that are considered hazardous under environmental laws. In addition, the Registrants are currently involved in a number of proceedings relating to sites where hazardous substances have been deposited and may be subject to additional proceedings in the future. Unless otherwise disclosed, the Registrants cannot reasonably estimate whether they will incur significant liabilities for additional investigation and remediation costs at these or additional sites identified by the Registrants, environmental agencies or others, or whether such costs will be recoverable from third parties, including customers. Additional costs could have a material, unfavorable impact on the Registrants' financial statements. MGP Sites (All Registrants). ComEd, PECO, BGE, and DPL have identified sites where former MGP or gas purification activities have or may have resulted in actual site contamination. For almost all of these sites, there are additional PRPs that may share responsibility for the ultimate remediation of each location. • ComEd has 21 sites that are currently under some degree of active study and/or remediation. ComEd expects the majority of the remediation at these sites to continue through at least 2027. • PECO ha s 6 site s that are currently under some degree of active study and/or remediation. PECO expects the majority of the remediation at these sites to continue through at least 2023. • BGE has 4 sites that currently require some level of remediation and/or ongoing activity. BGE expects the majority of the remediation at these sites to continue through at least 2023. • DPL has 1 sit e that is currently under study and the required cost at the site is not expected to be material. The historical nature of the MGP and gas purification sites and the fact that many of the sites have been buried and built over, impacts the ability to determine a precise estimate of the ultimate costs prior to initial sampling and determination of the exact scope and method of remedial activity. Management determines its best estimate of remediation costs using all available information at the time of each study, including probabilistic and deterministic modeling for ComEd and PECO, and the remediation standards currently required by the applicable state environmental agency. Prior to completion of any significant clean up, each site remediation plan is approved by the appropriate state environmental agency. ComEd, pursuant to an ICC order, and PECO, pursuant to settlements of natural gas distribution rate cases with the PAPUC, are currently recovering environmental remediation costs of former MGP facility sites through customer rates. While BGE and DPL do not have riders for MGP clean-up costs, they have historically received recovery of actual clean-up costs in distribution rates. As of December 31, 2021 and 2020, the Registrants had accrued the following undiscounted amounts for environmental liabilities in Other current liabilities and Other deferred credits and other liabilities in their respective Consolidated Balance Sheets: December 31, 2021 December 31, 2020 Total environmental Portion of total related to Total environmental Portion of total related to Exelon $ 352 $ 303 $ 366 $ 314 ComEd 279 279 293 293 PECO 22 20 23 21 BGE 6 4 2 — PHI 42 — 44 — Pepco 40 — 42 — DPL 1 — 1 — ACE 1 — 1 — Benning Road Site (Exelon, PHI, and Pepco) . In September 2010, PHI received a letter from EPA identifying the Benning Road site as one of six land-based sites potentially contributing to contamination of the lower Anacostia River. A portion of the site, which is owned by Pepco, was formerly the location of an electric generating facility owned by Pepco subsidiary, Pepco Energy Services, which became a part of Generation, following the 2016 merger between PHI and Exelon. This generating facility was deactivated in June 2012. The remaining portion of the site consists of a Pepco transmission and distribution service center that remains in operation. In December 2011, the U.S. District Court for the District of Columbia approved a Consent Decree entered into by Pepco and Pepco Energy Services (hereinafter "Pepco Entities") with the DOEE, which requires the Pepco Entities to conduct a Remedial Investigation and Feasibility Study (RI/FS) for the Benning Road site and an approximately 10 to 15-acre portion of the adjacent Anacostia River. The purpose of this RI/FS is to define the nature and extent of contamination from the Benning Road site and to evaluate remedial alternatives. Pursuant to an internal agreement between the Pepco Entities, since 2013, Pepco has performed the work required by the Consent Decree and has been reimbursed for that work by an agreed upon allocation of costs between the Pepco Entities. In September 2019, the Pepco Entities issued a draft “final” RI report which DOEE approved on February 3, 2020. The Pepco Entities are developing a FS to evaluate possible remedial alternatives for submission to DOEE. The Court has established a schedule for completion of the FS, and approval by the DOEE, by September 16, 2022. After completion and approval of the FS, DOEE will prepare a Proposed Plan for public comment and then issue a Record of Decision (ROD) identifying any further response actions determined to be necessary. As part of the separation between Exelon and Constellation Energy Corporation in February 2022, the internal agreement between the Pepco Entities for completion and payment for the remaining Consent Decree work was memorialized in a formal agreement for post-separation activities. A second post-separation assumption agreement between Exelon and Constellation Energy Corporation transferred any of the potential remaining remediation liability, if any, of Pepco Energy Services/Generation to a non-utility subsidiary of Exelon which going forward will be responsible for those liabilities. Exelon, PHI, and Pepco, have determined that a loss associated with this matter is probable and have accrued an estimated liability, which is included in the table above. Anacostia River Tidal Reach (Exelon, PHI, and Pepco) . Contemporaneous with the Benning Road site RI/FS being performed by the Pepco Entities , DOEE and National Park Service ("NPS") have been conducting a separate RI/FS focused on the entire tidal reach of the Anacostia River extending from just north of the Maryland-District of Columbia boundary line to the confluence of the Anacostia and Potomac Rivers. The river-wide RI incorporated the results of the river sampling performed by the Pepco Entities as part of the Benning RI/FS, as well as similar sampling efforts conducted by owners of other sites adjacent to this segment of the river and supplemental river sampling conducted by DOEE’s contractor. In April 2018, DOEE released a draft RI report for public review and comment. Pepco submitted written comments to the draft RI and participated in a public hearing. Exelon, PHI, and Pepco have determined that it is probable that costs for remediation will be incurred and recorded a liability in the third quarter 2019 for management’s best estimate of its share of those costs. On September 30, 2020, DOEE released its Interim ROD. The Interim ROD reflects an adaptive management approach which will require several identified “hot spots” in the river to be addressed first while continuing to conduct studies and to monitor the river to evaluate improvements and determine potential future remediation plans. The adaptive management process chosen by DOEE is less intrusive, provides more long-term environmental certainty, is less costly, and allows for site specific remediation plans already underway, including the plan for the Benning Road site to proceed to conclusion. Pepco concluded that incremental exposure remains reasonably possible, but management cannot reasonably estimate a range of loss beyond the amounts recorded, which are included in the table above. On July 12, 2021, DOEE and NPS held a virtual meeting with the PRP's in response to a General Notice Letter sent by each agency inviting the PRP's to participate in discussions, which Pepco attended. In addition to the activities associated with the remedial process outlined above, CERCLA separately requires federal and state (here including Washington, D.C.) Natural Resource Trustees (federal or state agencies designated by the President or the relevant state, respectively, or Indian tribes) to conduct an assessment of any damages to natural resources within their jurisdiction as a result of the contamination that is being remediated. The Trustees can seek compensation from responsible parties for such damages, including restoration costs. During the second quarter of 2018, Pepco became aware that the Trustees are in the beginning stages of a Natural Resources Damages (NRD) assessment, a process that often takes many years beyond the remedial decision to complete. Pepco has concluded that a loss associated with the eventual NRD assessment is reasonably possible. Due to the very early stage of the assessment process, Pepco cannot reasonably estimate the final range of loss potentially resulting from this process. As noted in the Benning Road Site disclosure above, as part of the separation of Exelon and Constellation Energy Corporation in February 2022, an assumption agreement was executed transferring any potential future remediation liabilities associated with the Benning Site remediation to a non-utility subsidiary of Exelon. Litigation and Regulatory Matters Fund Transfer Restrictions (All Registrants). Under applicable law, Exelon may borrow or receive an extension of credit from its subsidiaries. Under the terms of Exelon’s intercompany money pool agreement, Exelon can lend to, but not borrow from the money pool. Under applicable law, ComEd, PECO, BGE, PHI, Pepco, DPL, and ACE can pay dividends only from retained, undistributed or current earnings. A significant loss recorded at ComEd, PECO, BGE, PHI, Pepco, DPL, or ACE may limit the dividends that these companies can distribute to Exelon. ComEd has agreed in connection with financings arranged through ComEd Financing III that it will not declare dividends on any shares of its capital stock in the event that: (1) it exercises its right to extend the interest payment periods on the subordinated debt securities issued to ComEd Financing III; (2) it defaults on its guarantee of the payment of distributions on the preferred trust securities of ComEd Financing III; or (3) an event of default occurs under the Indenture under which the subordinated debt securities are issued. No such event has occurred. PECO has agreed in connection with financings arranged through PEC L.P. and PECO Trust IV that PECO will not declare dividends on any shares of its capital stock in the event that: (1) it exercises its right to extend the interest payment periods on the subordinated debentures, which were issued to PEC L.P. or PECO Trust IV; (2) it defaults on its guarantee of the payment of distributions on the Series D Preferred Securities of PEC L.P. or the preferred trust securities of PECO Trust IV; or (3) an event of default occurs under the Indenture under which the subordinated debentures are issued. No such event has occurred. BGE is subject to restrictions established by the MDPSC that prohibit BGE from paying a dividend on its common shares if (a) after the dividend payment, BGE’s equity ratio would be below 48% as calculated pursuant to the MDPSC’s ratemaking precedents or (b) BGE’s senior unsecured credit rating is rated by two of the three major credit rating agencies below investment grade. No such event has occurred. Pepco is subject to certain dividend restrictions established by settlements approved in Maryland and the District of Columbia. Pepco is prohibited from paying a dividend on its common shares if (a) after the dividend payment, Pepco's equity ratio would be 48% as equity levels are calculated under the ratemaking precedents of the MDPSC and DCPSC or (b) Pepco’s senior unsecured credit rating is rated by one of the three major credit rating agencies below investment grade. No such event has occurred. DPL is subject to certain dividend restrictions established by settlements approved in Delaware and Maryland. DPL is prohibited from paying a dividend on its common shares if (a) after the dividend payment, DPL's equity ratio would be 48% as equity levels are calculated under the ratemaking precedents of the DEPSC and MDPSC or (b) DPL’s senior unsecured credit rating is rated by one of the three major credit rating agencies below investment grade. No such event has occurred. ACE is subject to certain dividend restrictions established by settlements approved in New Jersey. ACE is prohibited from paying a dividend on its common shares if (a) after the dividend payment, ACE's equity ratio would be 48% as equity levels are calculated under the ratemaking precedents of the NJBPU or (b) ACE's senior unsecured credit rating is rated by one of the three major credit rating agencies below investment grade. ACE is also subject to a dividend restriction which requires ACE to obtain the prior approval of the NJBPU before dividends can be paid if its equity as a percent of its total capitalization, excluding securitization debt, falls below 30%. No such events have occurred. Deferred Prosecution Agreement (DPA) and Related Matters (Exelon and ComEd). Exelon and ComEd received a grand jury subpoena in the second quarter of 2019 from the U.S. Attorney’s Office for the Northern District of Illinois (USAO) requiring production of information concerning their lobbying activities in the State of Illinois. On October 4, 2019, Exelon and ComEd received a second grand jury subpoena from the USAO requiring production of records of any communications with certain individuals and entities. On October 22, 2019, the SEC notified Exelon and ComEd that it had also opened an investigation into their lobbying activities. On July 17, 2020, ComEd entered into a DPA with the USAO to resolve the USAO investigation. Under the DPA, the USAO filed a single charge alleging that ComEd improperly gave and offered to give jobs, vendor subcontracts, and payments associated with those jobs and subcontracts for the benefit of the Speaker of the Illinois House of Representatives and the Speaker’s associates, with the intent to influence the Speaker’s action regarding legislation affecting ComEd’s interests. The DPA provides that the USAO will defer any prosecution of such charge and any other criminal or civil case against ComEd in connection with the matters identified therein for a three-year period subject to certain obligations of ComEd, including payment to the U.S. Treasury of $200 million, which was paid in November 2020. Exelon was not made a party to the DPA, and therefore the investigation by the USAO into Exelon’s activities ended with no charges being brought against Exelon. The SEC’s investigation remains ongoing and Exelon and ComEd have cooperated fully and intend to continue to cooperate fully with the SEC. Exelon and ComEd cannot predict the outcome of the SEC investigation. No loss contingency has been reflected in Exelon's and ComEd's consolidated financial statements with respect to the SEC investigation, as this contingency is neither probable nor reasonably estimable at this time. Subsequent to Exelon announcing the receipt of the subpoenas, various lawsuits were filed, and various demand letters were received related to the subject of the subpoenas, the conduct described in the DPA and the SEC's investigation, including: • Four putative class action lawsuits against ComEd and Exelon were filed in federal court on behalf of ComEd customers in the third quarter of 2020 alleging, among other things, civil violations of federal racketeering laws. In addition, the Citizens Utility Board (CUB) filed a motion to intervene in these cases on October 22, 2020 which was granted on December 23, 2020. On December 2, 2020, the court appointed interim lead plaintiffs in the federal cases which consisted of counsel for three of the four federal cases. These plaintiffs filed a consolidated complaint on January 5, 2021. CUB also filed its own complaint against ComEd only on the same day. The remaining federal case, Potter, et al. v. Exelon et al, differed from the other lawsuits as it named additional individual defendants not named in the consolidated complaint. However, the Potter plaintiffs voluntarily dismissed their complaint without prejudice on April 5, 2021. ComEd and Exelon moved to dismiss the consolidated class action complaint and CUB’s complaint on February 4, 2021 and briefing was completed on March 22, 2021. On March 25, 2021, the parties agreed, along with state court plaintiffs, discussed below, to jointly engage in mediation. The parties participated in a one-day mediation on June 7, 2021 but no settlement was reached. On September 9, 2021, the federal court granted Exelon’s and ComEd’s motion to dismiss and dismissed the plaintiffs’ and CUB’s federal law claim with prejudice. The federal court also dismissed the related state law claims made by the federal plaintiffs and CUB on jurisdictional grounds. Plaintiffs have appealed the ruling to the Seventh Circuit Court of Appeals. Plaintiffs' opening appeal brief was filed on January 14, 2022. Exelon and ComEd have requested an extension until March 7, 2022 to file their response brief. Plaintiff's reply brief will be due approximately 21 days thereafter. Plaintiffs also refiled their state law claims in state court and have moved to consolidate that action with the already pending consumer state court class action, discussed below. CUB also refiled its state law claims in state court. • Three putative class action lawsuits against ComEd and Exelon were filed in Illinois state court in the third quarter of 2020 seeking restitution and compensatory damages on behalf of ComEd customers. The cases were consolidated into a single action in October of 2020. In November 2020, CUB filed a motion to intervene in the cases pursuant to an Illinois statute allowing CUB to intervene as a party or otherwise participate on behalf of utility consumers in any proceeding which affects the interest of utility consumers. On November 23, 2020, the court allowed CUB’s intervention, but denied its request to stay these cases. Plaintiffs subsequently filed a consolidated complaint, and ComEd and Exelon filed a motion to dismiss on jurisdictional and substantive grounds on January 11, 2021. Briefing on that motion was completed on March 2, 2021. The parties agreed, on March 25, 2021, along with the federal court plaintiffs discussed above, to jointly engage in mediation. The parties participated in a one-day mediation on June 7, 2021 but no settlement was reached. On December 23, 2021, the state court granted ComEd and Exelon’s motion to dismiss with prejudice. On December 30, 2021, plaintiffs filed a motion to reconsider that dismissal and for permission to amend their complaint. The court denied the plaintiffs' motion on January 21, 2022. Plaintiffs have appealed the court's ruling dismissing their complaint to the First District Court of Appeals. On February 15, 2022, Exelon and ComEd moved to dismiss the federal plaintiffs' refiled state law claims, seeking dismissal on the same legal grounds as those asserted in their motion to dismiss the original state court plaintiffs' complaint. The parties agreed to submit their motion to dismiss briefing as a package, which included Exelon' and ComEd's motion, plaintiffs' response, and Exelon's and ComEd's reply, in order to facilitate a speedy resolution by the court. The court granted dismissal of the refiled state claims on February 16, 2022. The original federal plaintiffs filed their notice of appeal of that dismissal on February 18, 2022. • A putative class action lawsuit against Exelon and certain officers of Exelon and ComEd was filed in federal court in December 2019 alleging misrepresentations and omissions in Exelon’s SEC filings related to ComEd’s lobbying activities and the related investigations. The complaint was amended on September 16, 2020, to dismiss two of the original defendants and add other defendants, including ComEd. Defendants filed a motion to dismiss in November 2020. The court denied the motion in April 2021. On May 26, 2021, defendants moved the court to certify its order denying the motion to dismiss for interlocutory appeal. Briefing on the motion was completed in June 2021. That motion was denied on January 28, 2022. In May 2021, the parties each filed respective initial discovery disclosures. On June 9, 2021, defendants filed their answer and affirmative defenses to the complaint and the parties engaged thereafter in discovery. On September 9, 2021, the U.S. government moved to intervene in the lawsuit and stay discovery until the parties entered into an amendment to their protective order that would prohibit the parties from requesting discovery into certain matters, including communications with the U.S. government. The court ordered said amendment to the protective order on November 15, 2021 and discovery resumed. The parties are required to substantially complete discovery by February 15, 2022. On February 10, 2022, the court granted an extension of the amendment to the protective order, at the U.S. government's request, to May 15, 2022, and directed the parties to submit a proposed joint schedule for the additional case proceedings by May 13, 2022. • Six shareholders have sent letters to the Exelon Board of Directors from 2020 through January 2022 demanding, among other things, that the Exelon Board of Directors investigate and address alleged breaches of fiduciary duties and other alleged violations by Exelon and ComEd officers and directors related to the conduct described in the DPA. In the first quarter of 2021, the Exelon Board of Directors appointed a Special Litigation Committee ("SLC") consisting of disinterested and independent parties to investigate and address these shareholders' allegations and make recommendations to the Exelon Board of Directors based on the outcome of the SLC's investigation. In July 2021, one of the demand letter shareholders filed a derivative action against current and former Exelon and ComEd officers and directors, and against Exelon, as nominal defendant, asserting the same claims made in its demand letter. On October 12, 2021, the parties to the derivative action filed an agreed motion to stay that litigation for 120 days in order to allow the SLC to continue its investigation, which the court granted. On January 31, 2022, the parties jointly moved the court to extend the stay an additional 120 days. • Two separate shareholder requests seeking review of certain Exelon books and records were received in August 2021 and January 2022. Exelon has responded to the first request and the shareholder thereafter sent a formal shareholder demand to the Exelon Board as discussed above. Exelon is in the process of responding to the second request. No loss contingencies have been reflected in Exelon’s and ComEd’s consolidated financial statements with respect to these matters, as such contingencies are neither probable nor reasonably estimable at this time. The ICC continues to conduct an investigation into rate impacts of conduct admitted in the DPA initiated on August 12, 2021. On December 16, 2021 ComEd filed direct testimony addressing the costs recovered from customers related to the DPA and Exelon’s funding of the fine paid by ComEd. In that testimony, ComEd proposed to voluntarily refund to customers compensation costs of the former officers charged with wrongdoing in connection with events described in the DPA for the period during which those events occurred as well as costs, previously proposed to be returned, of individuals and entities specifically identified in the DPA, as well as individuals and entities who were referred to ComEd as part of the conduct described in the DPA and who failed, during their tenure at ComEd, to perform work to management expectations. Exelon and ComEd recorded a loss contingency for these compensation costs as of December 31, 2021, which for financial statement disclosure purposes is not material. The testimony supports the calculation of the refund amount and proposes a refund mechanism (one time bill credit in February 2023) and also addresses other topics outlined by statute and the ICC orders initiating the investigation. ComEd also presented evidence concerning the lawfulness of ComEd’s past rates more generally. However, in response to pre-hearing motions concerning the scope of the hearing and permissible discovery and testimony, the ICC Administrate Law Judge ("ALJ") assigned ruled that scope of this proceeding was limited to whether ComEd used ratepayer funds to pay the “effectuation costs” for the conduct described in the DPA and to pay the criminal fine. Consistent with that scope, the ALJ limited the testimony to those subjects. Consistent with that ruling and a failure to exhaust other discovery, on January 18, 2022 the ALJ denied plaintiffs’ counsel’s request to depose witnesses including several current and former ComEd and Exelon executives. Savings Plan Claim (Exelon). On December 6, 2021, seven current and former employees filed a putative ERISA class action suit in U.S. District Court for the Northern District of Illinois against Exelon, its Board of Directors, the former Board Investment Oversight Committee, the Corporate Investment Committee, individual defendants, and other unnamed fiduciaries of the Exelon Corporation Employee Savings Plan (“Plan”). The complaint alleges that the defendants violated their fiduciary duties under the Plan by including certain investment options that allegedly were more expensive than and underperformed similar passively-managed or other funds available in the marketplace and permitting a third-party administrative service provider/recordkeeper and an investment adviser to charge excessive fees for the services provided. The plaintiffs seek declaratory, equitable and monetary relief on behalf of the Plan and participants. On February 16, 2022, the court granted the parties' stipulated dismissal of the individual named defendants without prejudice. The remaining defendants' responsive pleading is due February 25, 2022. No loss contingencies have been reflected in Exelon’s consolidated financial statements with respect to this matter, as such contingencies are neither probable nor reasonably estimable at this time. General (All Registrants). The Registrants are involved in various other litigation matters that are being defended and handled in the ordinary course of business. The assessment of whether a loss is probable or reasonably possible, and whether the loss or a range of loss is estimable, often involves a series of complex judgments about future events. The Registrants maintain accruals for such losses that are probable of being incurred and subject to reasonable estimation. Management is sometimes unable to estimate an amount or range of reasonably possible loss, particularly where (1) the damages sought are indeterminate, (2) the proceedings are in the early stages, or (3) the matters involve novel or unsettled legal theories. In such cases, there is considerable uncertainty regarding the timing or ultimate resolution of such matters, including a possible eventual loss.

Shareholders' Equity (Exelon an

Shareholders' Equity (Exelon and Utility Registrants)	12 Months Ended
Shareholders' Equity (Exelon and Utility Registrants)	Dec. 31, 2021
Equity [Abstract]
Shareholders' Equity (Exelon and Utility Registrants) [Text Block]	Shareholders' Equity (All Registrants)ComEd Common Stock Warrants The following table presents warrants outstanding to purchase ComEd common stock and shares of common stock reserved for the conversion of warrants. The warrants entitle the holders to convert such warrants into common stock of ComEd at a conversion rate of one share of common stock for three warrants. December 31, 2021 2020 Warrants outstanding 60,061 60,143 Common Stock reserved for conversion 20,020 20,048 Share Repurchases There currently is no Exelon Board of Director authority to repurchase shares. Any previous shares repurchased are held as treasury shares, at cost, unless cancelled or reissued at the discretion of Exelon’s management. Preferred and Preference Securities The following table presents Exelon, ComEd, PECO, BGE, Pepco, and ACE's shares of preferred securities authorized, none of which were outstanding, as of December 31, 2021 and 2020. There are no shares of preferred securities authorized for DPL. Preferred Securities Authorized Exelon 100,000,000 ComEd 850,000 PECO 15,000,000 BGE 1,000,000 Pepco 6,000,000 ACE (a) 2,799,979 __________ (a) Includes 799,979 shares of cumulative preferred stock and 2,000,000 of no-par preferred stock as of December 31, 2021 and 2020. The following table presents ComEd's, BGE's, and ACE's preference securities authorized, none of which were outstanding as of December 31, 2021 and 2020. There are no shares of preference securities authorized for Exelon, PECO, Pepco, and DPL. Preference Securities Authorized ComEd 6,810,451 BGE (a) 6,500,000 ACE 3,000,000 __________

Stock-Based Compensation Plans

Stock-Based Compensation Plans Stock-Based Compensation Plans (All Registrants)	12 Months Ended
	Dec. 31, 2021
Share-based Payment Arrangement [Abstract]
Stock-Based Compensation Plans	Stock-Based Compensation Plans (All Registrants) Stock-Based Compensation Plans Exelon grants stock-based awards through its LTIP, which primarily includes performance share awards, restricted stock units, and stock options. At December 31, 2021, there were approximately 33 million shares authorized for issuance under the LTIP. For the years ended December 31, 2021, 2020, and 2019, exercised and distributed stock-based awards were primarily issued from authorized but unissued common stock shares. The Registrants grant cash awards. The following table does not include expense related to these plans as they are not considered stock-based compensation plans under the applicable authoritative guidance. The following table presents the stock-based compensation expense included in Exelon's Consolidated Statements of Operations and Comprehensive Income. The Utility Registrants' stock-based compensation expense for the years ended December 31, 2021, 2020, and 2019 was not material. Year Ended December 31, Exelon 2021 2020 2019 Total stock-based compensation expense included in operating and maintenance expense $ 95 $ 37 $ 40 Income tax benefit (25) (9) (10) Total after-tax stock-based compensation expense $ 70 $ 28 $ 30 Exelon receives a tax deduction based on the intrinsic value of the award on the exercise date for stock options and the distribution date for performance share awards and restricted stock units. For each award, throughout the requisite service period, Exelon recognizes the tax benefit related to compensation costs. The following table presents information regarding Exelon’s realized tax benefit when distributed: Year Ended December 31, 2021 2020 2019 Performance share awards $ 6 $ 15 $ 27 Restricted stock units 6 8 12 Performance Share Awards Performance share awards are granted under the LTIP. The performance share awards are settled 50% in common stock and 50% in cash at the end of the three-year performance period, except for awards granted to vice presidents and higher officers that are settled 100% in cash if certain ownership requirements are satisfied. The common stock portion of the performance share awards is considered an equity award and is valued based on Exelon's stock price on the grant date. The cash portion of the performance share awards is considered a liability award which is remeasured each reporting period based on Exelon’s current stock price. As the value of the common stock and cash portions of the awards are based on Exelon’s stock price during the performance period, coupled with changes in the total shareholder return modifier and expected payout of the award, the compensation costs are subject to volatility until payout is established. For nonretirement-eligible employees, stock-based compensation costs are recognized over the vesting period of three years using the straight-line method. For performance share awards granted to retirement-eligible employees, the value of the performance shares is recognized ratably over the vesting period, which is the year of grant. Exelon processes forfeitures as they occur for employees who do not complete the requisite service period. The following table summarizes Exelon’s nonvested performance share awards activity: Shares Weighted Average Nonvested at December 31, 2020 (a) 930,392 $ 43.67 Granted 1,131,788 43.37 Change in performance 713,202 45.59 Vested (327,551) 38.66 Forfeited (157,552) 44.45 Undistributed vested awards (b) (1,067,763) 44.58 Nonvested at December 31, 2021 (a) 1,222,516 $ 44.96 __________ (a) Excludes 1,934,238 and 1,414,661 of performance share awards issued to retirement-eligible employees as of December 31, 2021 and 2020, respectively, as they are fully vested. (b) Represents performance share awards that vested but were not distributed to retirement-eligible employees during 2021. The following table summarizes the weighted average grant date fair value and the total fair value of performance share awards vested. Year Ended December 31, 2021 (a) 2020 2019 Weighted average grant date fair value (per share) $ 43.37 $ 46.61 $ 47.37 Total fair value of performance shares vested 44 39 158 Total fair value of performance shares settled in cash 28 63 131 __________ (a) As of December 31, 2021, $26 million of total unrecognized compensation costs related to nonvested performance shares are expected to be recognized over the remaining weighted-average period of 1.8 years. Restricted Stock Units Restricted stock units are granted under the LTIP with the majority being settled in a specific number of shares of common stock after the service condition has been met. The corresponding cost of services is measured based on the grant date fair value of the restricted stock unit issued. The value of the restricted stock units is expensed over the requisite service period using the straight-line method. The requisite service period for restricted stock units is generally three The following table summarizes Exelon’s nonvested restricted stock unit activity: Shares Weighted Average Nonvested at December 31, 2020 (a) 1,114,130 $ 43.67 Granted 879,606 44.21 Vested (397,526) 44.39 Forfeited (57,646) 44.98 Undistributed vested awards (b) (396,515) 43.66 Nonvested at December 31, 2021 (a) 1,142,049 $ 43.52 __________ (a) Excludes 609,934 and 748,165 of restricted stock units issued to retirement-eligible employees as of December 31, 2021 and 2020, respectively, as they are fully vested. (b) Represents restricted stock units that vested but were not distributed to retirement-eligible employees during 2021. The following table summarizes the weighted average grant date fair value and the total fair value of restricted stock units vested. Year Ended December 31, 2021 (a) 2020 2019 Weighted average grant date fair value (per share) $ 44.21 $ 46.33 $ 45.65 Total fair value of restricted stock units vested 34 54 92 __________ (a) As of December 31, 2021, $22 million of total unrecognized compensation costs related to nonvested restricted stock units are expected to be recognized over the remaining weighted-average period of 2.3 years. Stock Options Non-qualified stock options to purchase shares of Exelon’s common stock were granted through 2012 under the LTIP. The exercise price of the stock options is equal to the fair market value of the underlying stock on the date of option grant. Stock options will expire no later than ten years from the date of grant. At December 31, 2021 all stock options were vested and there were no unrecognized compensation costs. The following table presents information with respect to stock option activity: Shares Weighted Weighted Aggregate Balance of shares outstanding at December 31, 2020 1,265,410 $ 40.57 0.91 $ 3 Options exercised (928,003) 39.45 11 Options expired (310,400) 43.40 Balance of shares outstanding at December 31, 2021 27,007 $ 46.47 0.15 $ — Exercisable at December 31, 2021 (a) 27,007 $ 46.47 0.15 $ — __________ (a) Includes stock options issued to retirement eligible employees. The following table summarizes additional information regarding stock options exercised: Year Ended December 31, 2021 2020 2019 Intrinsic value (a) $ 11 $ 5 $ 9 Cash received for exercise price 37 18 59 __________ (a) The difference between the market value on the date of exercise and the option exercise price.

Changes in Accumulated Other Co

Changes in Accumulated Other Comprehensive Income (Exelon)	12 Months Ended
Changes in Accumulated Other Comprehensive Income (Exelon)	Dec. 31, 2021
Equity [Abstract]
Changes in Accumulated Other Comprehensive Income (Exelon)	Changes in Accumulated Other Comprehensive Income (Exelon) The following tables present changes in Exelon's AOCI, net of tax, by component: Losses on Pension and (a) Foreign AOCI of Investments (b) Total Balance at December 31, 2018 $ (2) $ (2,960) $ (33) $ — $ (2,995) OCI before reclassifications — (289) 6 (2) (285) Amounts reclassified from AOCI — 84 — 2 86 Net current-period OCI — (205) 6 — (199) Balance at December 31, 2019 $ (2) $ (3,165) $ (27) $ — $ (3,194) OCI before reclassifications (3) (357) 4 — (356) Amounts reclassified from AOCI — 150 — — 150 Net current-period OCI (3) (207) 4 — (206) Balance at December 31, 2020 $ (5) $ (3,372) $ (23) $ — $ (3,400) OCI before reclassifications (1) 432 — — 431 Amounts reclassified from AOCI — 219 — — 219 Net current-period OCI (1) 651 — — 650 Balance at December 31, 2021 $ (6) $ (2,721) $ (23) $ — $ (2,750) __________ (a) This AOCI component is included in the computation of net periodic pension and OPEB cost. See Note 13 — Retirement Benefits for additional information. See Exelon's Statements of Operations and Comprehensive Income for individual components of AOCI. (b) All amounts are net of noncontrolling interests. The following table presents income tax benefit (expense) allocated to each component of Exelon's other comprehensive income (loss): For the Year Ended December 31, 2021 2020 2019 Pension and non-pension postretirement benefit plans: Prior service benefit reclassified to periodic benefit cost $ 4 $ 16 $ 23 Actuarial loss reclassified to periodic benefit cost (76) (66) (52) Pension and non-pension postretirement benefit plans valuation adjustment (153) 122 100

Variable Interest Entities (Exe

Variable Interest Entities (Exelon, PHI, and ACE)	12 Months Ended
Variable Interest Entities (Exelon, PHI, and ACE)	Dec. 31, 2021
Variable Interest Entity [Abstract]
Variable Interest Entity Disclosure	Variable Interest Entities (PHI and ACE)At December 31, 2021 and 2020, ACE consolidated one VIE for which ACE was the primary beneficiary. As of December 31, 2021 and 2020, PHI's and ACE's consolidated VIE consists of: Consolidated VIEs: Reason entity is a VIE: Reason ACE is the primary beneficiary: ACE Funding - A special purpose entity formed by ACE for the purpose of securitizing authorized portions of ACE’s recoverable stranded costs through the issuance and sale of Transition Bonds. Proceeds from the sale of each series of Transition Bonds by ATF were transferred to ACE in exchange for the transfer by ACE to ATF of the right to collect a non-bypassable Transition Bond Charge from ACE customers pursuant to bondable stranded costs rate orders issued by the NJBPU in an amount sufficient to fund the principal and interest payments on Transition Bonds and related taxes, expenses, and fees. In the fourth quarter of 2021, the Transition bonds were fully redeemed and ACE remitted its final payment to ATF. Upon redemption of the bonds, ATF no longer meets the definition of a variable interest entity. ACE’s equity investment is a variable interest as, by design, it absorbs any initial variability of ATF. The bondholders also have a variable interest for the investment made to purchase the Transition Bonds. ACE controls the servicing activities. The table below shows the carrying amounts and classification of the consolidated VIE’s assets and liabilities included in PHI's and ACE's consolidated financial statements as of December 31, 2020. PHI and ACE did not have any VIE as of December 31, 2021. The assets can only be used to settle obligations of the VIE. The liabilities are such that creditors, or beneficiaries, do not have recourse to the general credit of ACE. December 31, 2020 PHI (a) ACE Restricted cash and cash equivalents 3 3 Other current assets 5 — Total current assets 8 3 Other noncurrent assets 10 10 Total noncurrent assets 10 10 Total assets (c) $ 18 $ 13 Long-term debt due within one year $ 26 $ 21 Total current liabilities 26 21 Total liabilities (d) $ 26 $ 21 __________

Supplemental Financial Informat

Supplemental Financial Information (All Registrants)	12 Months Ended
Supplemental Financial Information (All Registrants)	Dec. 31, 2021
Supplemental Financial Information [Abstract]
Supplemental Financial Information (All Registrants)	Supplemental Financial Information (All Registrants) Supplemental Statement of Operations Information The following tables provide additional information about material items recorded in the Registrants' Consolidated Statements of Operations and Comprehensive Income. Taxes other than income taxes Exelon ComEd PECO BGE PHI Pepco DPL ACE For the year ended December 31, 2021 Utility (a) $ 774 $ 246 $ 139 $ 88 $ 301 $ 278 $ 22 $ 3 Property 364 39 18 176 131 88 40 3 Payroll 124 27 16 18 27 7 5 3 For the year ended December 31, 2020 Utility (a) $ 759 $ 238 $ 135 $ 87 $ 299 $ 275 $ 21 $ 3 Property 336 30 16 164 126 84 39 3 Payroll 121 27 16 17 25 7 5 3 For the year ended December 31, 2019 Utility (a) $ 768 $ 242 $ 132 $ 90 $ 304 $ 286 $ 18 $ — Property 321 29 17 153 122 85 34 2 Payroll 117 27 15 17 24 7 4 2 __________ (a) The Registrants’ utility taxes represents municipal and state utility taxes and gross receipts taxes related to their operating revenues. The offsetting collection of utility taxes from customers is recorded in revenues in the Registrants’ Consolidated Statements of Operations and Comprehensive Income. Other, net Exelon ComEd PECO BGE PHI Pepco DPL ACE For the year ended December 31, 2021 AFUDC—Equity 136 34 26 27 49 40 6 3 Non-service net periodic benefit cost 91 — — — — — — — For the year ended December 31, 2020 AFUDC—Equity 104 29 17 22 36 28 4 4 Non-service net periodic benefit cost 53 — — — — — — — For the year ended December 31, 2019 AFUDC—Equity 85 17 13 21 34 25 4 5 Non-service net periodic benefit cost 13 — — — — — — — Supplemental Cash Flow Information The following tables provide additional information about material items recorded in the Registrants' Consolidated Statements of Cash Flows. Depreciation, amortization, and accretion Exelon (a) ComEd PECO BGE PHI Pepco DPL ACE For the year ended December 31, 2021 Property, plant, and equipment (b) $ 5,384 $ 970 $ 336 $ 439 $ 627 $ 274 $ 169 $ 155 Amortization of regulatory assets (b) 594 235 12 152 194 129 41 24 Amortization of intangible assets, net (b) 58 — — — — — — — Amortization of energy contract assets and liabilities (c) 31 — — — — — — — Nuclear fuel (d) 992 — — — — — — — ARO accretion (e) 514 — — — — — — — Total depreciation, amortization, and accretion $ 7,573 $ 1,205 $ 348 $ 591 $ 821 $ 403 $ 210 $ 179 For the year ended December 31, 2020 Property, plant, and equipment (b) $ 4,364 $ 922 $ 319 $ 397 $ 586 $ 257 $ 155 $ 140 Amortization of regulatory assets (b) 588 211 28 153 196 120 36 40 Amortization of intangible assets, net (b) 62 — — — — — — — Amortization of energy contract assets and liabilities (c) 30 — — — — — — — Nuclear fuel (d) 983 — — — — — — — ARO accretion (e) 500 — — — — — — — Total depreciation, amortization, and accretion $ 6,527 $ 1,133 $ 347 $ 550 $ 782 $ 377 $ 191 $ 180 For the year ended December 31, 2019 Property, plant, and equipment (b) $ 3,665 $ 886 $ 303 $ 359 $ 547 $ 239 $ 146 $ 123 Amortization of regulatory assets (b) 528 147 30 143 207 135 38 34 Amortization of intangible assets, net (b) 59 — — — — — — — Amortization of energy contract assets and liabilities (c) 21 — — — — — — — Nuclear fuel (d) 1,016 — — — — — — — ARO accretion (e) 491 — — — — — — — Total depreciation, amortization, and accretion $ 5,780 $ 1,033 $ 333 $ 502 $ 754 $ 374 $ 184 $ 157 __________ (a) Exelon's amounts include amounts related to Generation prior to the separation. See Note 2 — Discontinued Operations for additional information. (b) Included in Depreciation and amortization in the Registrants' Consolidated Statements of Operations and Comprehensive Income. (c) Included in Operating revenues or Purchased power and fuel expense in Exelon’s Consolidated Statements of Operations and Comprehensive Income. (d) Included in Purchased power and fuel expense in Exelon’s Consolidated Statements of Operations and Comprehensive Income. (e) Included in Operating and maintenance expense in Exelon's Consolidated Statements of Operations and Comprehensive Income. Cash paid (refunded) during the year: Exelon (a) ComEd PECO BGE PHI Pepco DPL ACE For the year ended December 31, 2021 Interest (net of amount capitalized) $ 1,505 $ 372 $ 152 $ 134 $ 255 $ 132 $ 59 $ 56 Income taxes (net of refunds) 281 (72) (4) (38) — 12 (9) 2 For the year ended December 31, 2020 Interest (net of amount capitalized) $ 1,521 $ 371 $ 144 $ 125 $ 257 $ 129 $ 61 $ 57 Income taxes (net of refunds) 10 (61) (37) (57) 46 40 12 (3) For the year ended December 31, 2019 Interest (net of amount capitalized) $ 1,470 $ 343 $ 129 $ 106 $ 255 $ 130 $ 59 $ 55 Income taxes (net of refunds) 265 (42) 82 17 29 7 19 (5) __________ (a) Exelon's amounts include amounts related to Generation prior to the separation. See Note 2 — Discontinued Operations for additional information. Other non-cash operating activities: Exelon (a) ComEd PECO BGE PHI Pepco DPL ACE For the year ended December 31, 2021 Pension and non-pension postretirement benefit costs $ 411 $ 129 $ 8 $ 61 $ 49 $ 6 $ 2 $ 11 Allowance for credit losses 160 47 39 17 24 9 5 10 Other decommissioning-related activity (946) — — — — — — — Energy-related options 125 — — — — — — — True-up adjustments to decoupling mechanisms and formula rates (b) (171) (42) (26) (12) (91) (53) (14) (24) Severance costs (57) 2 — — 1 — — — Long-term incentive plan 137 — — — — — — — Amortization of operating ROU asset 183 1 — 29 28 6 8 4 AFUDC - Equity (136) (34) (26) (27) (49) (40) (6) (3) For the year ended December 31, 2020 Pension and non-pension postretirement benefit costs $ 411 $ 114 $ 5 $ 62 $ 70 $ 15 $ 7 $ 14 Allowance for credit losses 150 32 42 15 43 24 16 2 Other decommissioning-related activity (659) — — — — — — — Energy-related options 104 — — — — — — — True-up adjustments to decoupling mechanisms and formula rates (b) (6) 47 (16) (16) (21) (40) 7 12 Severance costs 105 1 1 — — — — — Provision for excess and obsolete inventory 131 2 1 — — — — — Long-term incentive plan 56 — — — — — — — Amortization of operating ROU asset 222 2 1 31 28 7 8 3 Asset impairments — 15 — — 13 — 7 6 AFUDC - Equity (104) (29) (17) (22) (36) (28) (4) (4) For the year ended December 31, 2019 Pension and non-pension postretirement benefit costs $ 438 $ 96 $ 12 $ 61 $ 95 $ 25 $ 15 $ 16 Allowance for credit losses 120 33 31 8 17 7 4 5 Other decommissioning-related activity (506) — — — — — — — Energy-related options 22 — — — — — — — True-up adjustments to decoupling mechanisms and formula rates (c) 124 128 — — (4) (4) — — Long-term incentive plan 10 — — — — — — — Amortization of operating ROU Asset 244 3 — 30 33 8 8 4 Change in environmental liabilities 23 — — — 23 23 — — AFUDC - Equity (85) (17) (13) (21) (34) (25) (4) (5) __________ (a) Exelon's amounts include amounts related to Generation prior to the separation. See Note 2 — Discontinued Operations for additional information. (b) For ComEd, reflects the true-up adjustments in regulatory assets and liabilities associated with its distribution, energy efficiency, distributed generation, and transmission formula rates. For BGE, Pepco, DPL, and ACE, reflects the change in regulatory assets and liabilities associated with their decoupling mechanisms and transmission formula rates. For PECO, reflects the change in regulatory assets and liabilities associated with its transmission formula rate. See Note 3 — Regulatory Matters for additional information. (c) For ComEd, reflects the true-up adjustments in regulatory assets and liabilities associated with its distribution and energy efficiency formula rates. For Pepco and DPL, reflects the change in regulatory assets and liabilities associated with their decoupling mechanisms. See Note 3 — Regulatory Matters for additional information. The following tables provide a reconciliation of cash, restricted cash, and cash equivalents reported within the Registrants' Consolidated Balance Sheets that sum to the total of the same amounts in their Consolidated Statements of Cash Flows. Exelon ComEd PECO BGE PHI Pepco DPL ACE December 31, 2021 Cash and cash equivalents $ 672 $ 131 $ 36 $ 51 $ 136 $ 34 $ 28 $ 29 Restricted cash and cash equivalents 321 210 8 4 77 34 43 — Restricted cash included in other long-term assets 44 43 — — — — — — Cash, restricted cash, and cash equivalents included in current assets of discontinued operations 582 — — — — — — — Total cash, restricted cash, and cash equivalents $ 1,619 $ 384 $ 44 $ 55 $ 213 $ 68 $ 71 $ 29 December 31, 2020 Cash and cash equivalents $ 432 $ 83 $ 19 $ 144 $ 111 $ 30 $ 15 $ 17 Restricted cash and cash equivalents 349 279 7 1 39 35 — 3 Restricted cash included in other long-term assets 53 43 — — 10 — — 10 Cash, restricted cash, and cash equivalents included in current assets of discontinued operations 332 — — — — — — — Total cash, restricted cash, and cash equivalents $ 1,166 $ 405 $ 26 $ 145 $ 160 $ 65 $ 15 $ 30 December 31, 2019 Cash and cash equivalents $ 587 $ 90 $ 21 $ 24 $ 131 $ 30 $ 13 $ 12 Restricted cash and cash equivalents 358 150 6 1 36 33 — 2 Restricted cash included in other long-term assets 177 163 — — 14 — — 14 Total cash, restricted cash, and cash equivalents(a) $ 1,122 $ 403 $ 27 $ 25 $ 181 $ 63 $ 13 $ 28 December 31, 2018 Cash and cash equivalents $ 1,349 $ 135 $ 130 $ 7 $ 124 $ 16 $ 23 $ 7 Restricted cash and cash equivalents 247 29 5 6 43 37 1 4 Restricted cash included in other long-term assets 185 166 — — 19 — — 19 Total cash, restricted cash, and cash equivalents(a) $ 1,781 $ 330 $ 135 $ 13 $ 186 $ 53 $ 24 $ 30 __________ (a) Exelon's amounts include amounts related to Generation prior to the separation. See Note 2 — Discontinued Operations for additional information. Supplemental Balance Sheet Information The following tables provide additional information about material items recorded in the Registrants' Consolidated Balance Sheets. Investments Exelon ComEd PECO BGE PHI Pepco December 31, 2021 Equity method investments: Other equity method investments $ 15 $ 6 $ 7 $ — $ — $ — Other investments: Employee benefit trusts and investments (a) 235 — 27 14 145 120 Total investments $ 250 $ 6 $ 34 $ 14 $ 145 $ 120 December 31, 2020 Equity method investments: Other equity method investments $ 15 $ 6 $ 8 $ — $ — $ — Other investments: Employee benefit trusts and investments (a) 218 — 22 10 140 115 Equity investments without readily determinable fair values 5 — — — — — Total investments $ 238 $ 6 $ 30 $ 10 $ 140 $ 115 __________ (a) The Registrants’ debt and equity security investments are recorded at fair market value. Accrued expenses Exelon ComEd PECO BGE PHI Pepco DPL ACE December 31, 2021 Compensation-related accruals (a) $ 596 $ 155 $ 77 $ 78 $ 113 $ 35 $ 20 $ 17 Taxes accrued 253 94 14 53 96 88 9 11 Interest accrued 297 116 41 44 52 28 8 11 December 31, 2020 Compensation-related accruals (a) $ 594 $ 170 $ 73 $ 84 $ 109 $ 36 $ 18 $ 17 Taxes accrued 291 94 16 73 117 90 18 12 Interest accrued 289 109 37 46 51 26 7 12 __________ (a) Primarily includes accrued payroll, bonuses and other incentives, vacation, and benefits.

Related Party Transactions (All

Related Party Transactions (All Registrants)	12 Months Ended
Related Party Transactions (All Registrants)	Dec. 31, 2021
Related Party Transactions [Abstract]
Related-Party Transactions (All Registrants)	Related Party Transactions (All Registrants) Utility Registrants' expense with Generation The Utility Registrants incur expenses from transactions with the Generation affiliate as described in the footnotes to the table below. Such expenses are primarily recorded as Purchased power from affiliates and an immaterial amount recorded as Operating and maintenance expense from affiliates at the Utility Registrants: For the Years Ended 2021 2020 2019 ComEd (a) $ 376 $ 330 $ 369 PECO (b) 196 190 158 BGE (c) 236 315 289 PHI 366 367 353 Pepco (d) 270 279 264 DPL (e) 79 75 70 ACE (f) 17 13 19 __________ (a) ComEd has an ICC-approved RFP contract with Generation to provide a portion of ComEd’s electric supply requirements. ComEd also purchases RECs and ZECs from Generation. (b) PECO receives electric supply from Generation under contracts executed through PECO’s competitive procurement process. In addition, PECO has a ten-year agreement with Generation to sell solar AECs. (c) BGE receives a portion of its energy requirements from Generation under its MDPSC-approved market-based SOS and gas commodity programs. (d) Pepco receives electric supply from Generation under contracts executed through Pepco's competitive procurement process approved by the MDPSC and DCPSC. (e) DPL receives a portion of its energy requirements from Generation under its MDPSC and DEPSC approved market-based SOS commodity programs. (f) ACE receives electric supply from Generation under contracts executed through ACE's competitive procurement process. Service Company Costs for Corporate Support The Registrants receive a variety of corporate support services from BSC. Pepco, DPL, and ACE also receive corporate support services from PHISCO. See Note 1 - Significant Accounting Policies for additional information regarding BSC and PHISCO. The following table presents the service company costs allocated to the Registrants: Operating and maintenance from affiliates Capitalized costs For the years ended December 31, For the years ended December 31, 2021 2020 2019 2021 2020 2019 Exelon BSC $ 508 $ 531 $ 450 PHISCO 72 61 72 ComEd BSC 304 283 263 207 186 148 PECO BSC 169 150 149 81 76 88 BGE BSC 189 170 157 92 132 126 PHI BSC 168 152 139 128 149 88 PHISCO — — — 72 61 72 Pepco BSC 96 85 85 50 55 38 PHISCO 114 120 124 31 27 33 DPL BSC 61 54 52 43 51 25 PHISCO 99 97 100 22 18 20 ACE BSC 53 45 42 33 40 19 PHISCO 86 87 90 19 16 19 Current Receivables from/Payables to affiliates The following tables present Current receivables from affiliates and Current payables to affiliates: December 31, 2021 Receivables from affiliates: Payables to affiliates: ComEd PECO BGE Pepco DPL ACE Generation BSC PHISCO Other Total ComEd $ — $ — $ — $ — $ — $ 41 $ 71 $ — $ 9 $ 121 PECO — — — — — 30 36 — 4 70 BGE — — — — — 4 41 — 3 48 PHI — 1 — — — 1 — 5 — 9 16 Pepco — — 1 1 1 20 21 12 3 59 DPL — — — — — 4 17 11 1 33 ACE — — — — — 7 13 9 2 31 Generation 13 — — — — — 102 — 16 131 Other 3 — — — — — 11 — — 14 Total $ 16 $ 1 $ 1 $ — $ 1 $ 2 $ 117 $ 306 $ 32 $ 47 $ 523 December 31, 2020 Receivables from affiliates: Payables to affiliates: ComEd PECO BGE Pepco DPL ACE Generation BSC PHISCO Other Total ComEd $ — $ — $ — $ — $ — $ 28 $ 59 $ — $ 9 $ 96 PECO 1 — — — — 17 28 — 4 50 BGE — — — — — 11 47 — 3 61 PHI — — — — — — — 4 — 11 15 Pepco 2 — 1 — — 13 25 14 — 55 DPL 1 — — — — 3 21 10 1 36 ACE — — — — — 6 15 9 1 31 Generation 13 — — — — — 72 — 22 107 Other 5 2 2 2 1 6 25 — — 43 Total $ 22 $ 2 $ 3 $ 2 $ 1 $ 6 $ 103 $ 271 $ 33 $ 51 $ 494 Borrowings from Exelon/PHI intercompany money pool To provide an additional short-term borrowing option that will generally be more favorable to the borrowing participants than the cost of external financing both Exelon and PHI operate an intercompany money pool. ComEd, PECO, and PHI Corporate participate in the Exelon money pool. Pepco, DPL, and ACE participate in the PHI intercompany money pool. Noncurrent Receivables from affiliates ComEd and PECO have Noncurrent receivables with Generation as a result of the nuclear decommissioning contractual construct whereby, to the extent NDT funds are greater than the underlying ARO at the end of decommissioning, such amounts are due back to ComEd and PECO, as applicable, for payment to their respective customers. See Note 3 — Regulatory Matters for additional information. Long-term debt to financing trusts The following table presents Long-term debt to financing trusts: As of December 31, 2021 2020 Exelon ComEd PECO Exelon ComEd PECO ComEd Financing III $ 206 $ 205 $ — $ 206 $ 205 $ — PECO Trust III 81 — 81 81 — 81 PECO Trust IV 103 — 103 103 — 103 Total $ 390 $ 205 $ 184 $ 390 $ 205 $ 184

Separation (Exelon)

Separation (Exelon)	12 Months Ended
Separation (Exelon)	Dec. 31, 2021
Discontinued Operations and Disposal Groups [Abstract]
Discontinued Operations (Exelon)	Discontinued Operations (Exelon) On February 21, 2021, Exelon's Board of Directors approved a plan to separate the Utility Registrants and Generation, creating two publicly traded companies ("the separation"). On February 25, 2021, Exelon filed applications with FERC, NYPSC, and NRC seeking approvals for the separation of Generation. On March 25, 2021, Exelon filed a request for a private letter ruling with the IRS to confirm the tax-free treatment of the separation, which was received on September 23, 2021. Exelon received approval from FERC on August 24, 2021, NRC on November 16, 2021, and NYPSC on December 16, 2021 for the separation. The Form 10 registration statement was declared effective by the SEC on December 29, 2021. Exelon completed the separation on February 1, 2022, through the distribution of 326,663,937 common stock shares of Constellation Energy Corporation, the new publicly traded company, to Exelon shareholders. Under the separation plan, Exelon shareholders retained their current shares of Exelon stock and received one share of Constellation Energy Corporation common stock for every three shares of Exelon common stock held on January 20, 2022, the record date for the distribution, in a transaction that is tax-free to Exelon and its shareholders for U.S. federal income tax purposes. Constellation Energy Corporation was newly formed and incorporated in Pennsylvania on June 15, 2021 for the purposes of separation and holds Generation (including Generation's subsidiaries). Pursuant to the separation: • Exelon entered into four term loans consisting of a 364-day term loan for $1.15 billion and three 18-month term loans for $300 million, $300 million and $250 million, respectively. Exelon issued these term loans primarily to fund the cash payment described below to Constellation Energy Corporation and for general corporate purposes. See Note 15 — Debt and Credit Agreements for additional information. • Exelon made a cash payment of $1.75 billion to Constellation Energy Corporation on January 31, 2022. • Exelon contributed its equity ownership interest in Generation (including its subsidiaries) to Constellation Energy Corporation. Exelon no longer retains any equity ownership interest in Generation or Constellation Energy Corporation. • Exelon transferred certain corporate assets and employee-related obligations to Constellation Energy Corporation. • Exelon received cash from Generation of $258 million to settle the intercompany loan on January 31, 2022. See Note 15 — Debt and Credit Agreements for additional information. Continuing Involvement In order to govern the ongoing relationships between Exelon and Constellation Energy Corporation after the separation, and to facilitate an orderly transition, Exelon and Constellation Energy Corporation have entered into several agreements, including the following: • Separation Agreement – governs the rights and obligations between Exelon and Constellation Energy Corporation regarding certain actions to be taken in connection with the separation, among others, including the allocation of assets and liabilities between Exelon and Constellation Energy Corporation. • Transition Services Agreement (TSA) – governs the terms and conditions of the services that Exelon will provide to Constellation Energy Corporation and Constellation Energy Corporation will provide to Exelon for an expected period of two years, provided that certain services may be longer than the term and services may be extended with approval from both parties. The services include specified accounting, finance, information technology, human resources, employee benefits and other services that have historically been provided on a centralized basis by BSC. • Tax Matters Agreement (TMA) – governs the respective rights, responsibilities and obligations of Exelon and Constellation Energy Corporation with respect to all tax matters, including tax liabilities and benefits, tax attributes, tax returns, tax contests and other tax sharing regarding U.S. federal, state, local and foreign income taxes, other tax matters and related tax returns. In addition, the Utility Registrants will continue to incur expenses from transactions with Generation after the separation. Prior to the separation, such expenses were primarily recorded as Purchased power from affiliates and an immaterial amount recorded as Operating and maintenance expense from affiliates at the Utility Registrants. • ComEd had an ICC-approved RFP contract with Generation to provide a portion of ComEd’s electric supply requirements. ComEd also purchased RECs and ZECs from Generation. • PECO received electric supply from Generation under contracts executed through PECO’s competitive procurement process. In addition, PECO had a ten-year agreement with Generation to sell solar AECs. • BGE received a portion of its energy requirements from Generation under its MDPSC-approved market-based SOS and gas commodity programs. • Pepco received electric supply from Generation under contracts executed through Pepco’s competitive procurement process approved by the MDPSC and DCPSC. • DPL received a portion of its energy requirements from Generation under its MDPSC and DEPSC approved market-based SOS commodity programs. • ACE received electric supply from Generation under contracts executed through ACE’s competitive procurement process approved by the NJBPU. ComEd and PECO also have receivables with Generation as a result of the nuclear decommissioning contractual construct whereby, to the extent NDT funds are greater than the underlying ARO at the end of decommissioning, such amounts are due back to ComEd and PECO, as applicable, for payment to their respective customers. See Note 3 — Regulatory Matters for additional information. Discontinued Operations The separation represented a strategic shift that would have a major effect on Exelon’s operations and financial results. Accordingly, the separation meets the criteria for discontinued operations. The following table presents the results of Generation that have been reclassified from continuing operations and included in discontinued operations within Exelon’s Consolidated Statements of Operations and Comprehensive Income for the years ended December 31, 2021, 2020, and 2019. These results are primarily Generation, which is comprised of Exelon’s Mid-Atlantic, Midwest, New York, ERCOT, and Other Power Regions reportable segments, and include the impact of transaction costs, certain BSC costs, including any transition costs, that were historically allocated and directly attributable to Generation, transactions between Generation and the Utility Registrants, and tax-related adjustments. Transaction costs include costs for external bankers, accountants, appraisers, lawyers, external counsels and other advisors, among others, who are involved in the negotiation, appraisal, due diligence and regulatory approval of the separation. Transition costs are primarily employee-related costs such as recruitment expenses, costs to establish certain stand-alone functions and information technology systems, professional services fees and other separation-related costs during the transition to separate Generation. For the purposes of reporting discontinued operations, these results also include transactions between Generation and the Utility Registrants that were historically eliminated within Exelon’s Consolidated Statements of Operations as these transactions will be ongoing after the separation. Certain BSC costs that were historically allocated to Generation are presented as part of continuing operations in Exelon’s Consolidated Statements of Operations as these costs do not qualify as expenses of the discontinued operations per the accounting rules. Year Ended 2021 2020 2019 Operating revenues Competitive business revenues $ 18,466 $ 16,399 $ 17,754 Competitive business revenues from affiliates 1,189 1,206 1,171 Total operating revenues 19,655 17,605 18,925 Operating expenses Competitive businesses purchased power and fuel 12,163 9,585 10,856 Operating and maintenance (a) 4,174 4,794 4,324 Depreciation and amortization 3,003 2,123 1,535 Taxes other than income taxes 475 482 519 Total operating expenses 19,815 16,984 17,234 Gain on sales of assets and businesses 201 11 27 Operating income 41 632 1,718 Other income and (deductions) Interest expense, net (282) (328) (394) Other, net 795 937 1,023 Total other income 513 609 629 Income before income taxes 554 1,241 2,347 Income taxes 332 380 621 Equity in losses of unconsolidated affiliates (9) (6) (184) Net income 213 855 1,542 Net income (loss) attributable to noncontrolling interests 123 (9) 92 Net income from discontinued operations $ 90 $ 864 $ 1,450 __________ (a) Includes transaction and transition costs related to the separation of $24 million and $19 million for the year ended December 31, 2021. There were no separation related costs incurred in 2020 or 2019. See discussion above for additional information. The following table presents the assets and liabilities of discontinued operations in Exelon’s Consolidated Balance Sheets as of December 31, 2021 and 2020. December 31, 2021 December 31, 2020 ASSETS Current assets Cash and cash equivalents $ 510 $ 231 Restricted cash and cash equivalents 72 89 Accounts receivable Customer accounts receivable 1,724 1,331 Customer allowance for credit losses (55) (32) Customer accounts receivable, net 1,669 1,299 Other accounts receivable 596 352 Other allowance for credit losses (4) — Other accounts receivable, net 592 352 Mark-to-market derivative assets 2,169 644 Inventories, net Fossil fuel and emission allowances 284 233 Materials and supplies 1,004 978 Renewable energy credits 529 633 Assets held for sale 13 958 Other 993 1,424 Total current assets of discontinued operations 7,835 6,841 Property, plant, and equipment (net of accumulated depreciation and amortization of $15,888 and $13,381, respectively) 19,661 22,252 Deferred debits and other assets Nuclear decommissioning trust funds 15,938 14,464 Investments 193 202 Mark-to-market derivative assets 949 555 Other 1,768 2,180 Total property, plant, and equipment, deferred debits, and other assets of discontinued operations 38,509 39,653 Total assets of discontinued operations $ 46,344 $ 46,494 December 31, 2021 December 31, 2020 LIABILITIES AND SHAREHOLDERS’ EQUITY Current liabilities Short-term borrowings $ 2,082 $ 840 Long-term debt due within one year 1,220 197 Accounts payable 1,757 1,253 Accrued expenses 818 848 Mark-to-market derivative liabilities 981 262 Renewable energy credit obligation 779 661 Liabilities held for sale 3 375 Other 300 487 Total current liabilities of discontinued operations 7,940 4,923 Long-term debt 4,575 5,566 Deferred credits and other liabilities Deferred income taxes and unamortized investment tax credits 3,583 3,443 Asset retirement obligations 12,819 12,054 Pension obligations 939 1,557 Non-pension postretirement benefit obligations 876 1,009 Spent nuclear fuel obligation 1,210 1,208 Mark-to-market derivative liabilities 513 205 Other 1,161 1,303 Total long-term debt, deferred credits, and other liabilities of discontinued operations 25,676 26,345 Total liabilities of discontinued operations $ 33,616 $ 31,268 The following table presents selected financial information regarding cash flows of the discontinued operations that are included within Exelon’s Consolidated Statements of Cash Flows for the years ended December 31, 2021, 2020, and 2019. Year Ended 2021 2020 2019 Non-cash items included in net income (loss) from discontinued operations: Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization $ 4,540 $ 3,636 $ 3,063 Asset impairments 545 563 201 Gain on sales of assets and businesses (201) (11) (27) Deferred income taxes and amortization of investment tax credits (224) 94 376 Net fair value changes related to derivatives (568) (270) 228 Net realized and unrealized gains on NDT fund investments (586) (461) (663) Net unrealized losses (gains) on equity investments 160 (186) — Other decommissioning-related activity (946) (659) (506) Cash flows from investing activities: Capital expenditures (1,341) (1,759) (1,849) Collection of DPP 3,902 3,771 — Supplemental cash flow information: Increase (decrease) in capital expenditures not paid 96 (88) (34) Increase in DPP 3,652 4,441 — Increase in PP&E related to ARO update 618 850 959

Schedule I - Condensed Financia

Schedule I - Condensed Financial Information of Parent (Exelon Corporate)	12 Months Ended
	Dec. 31, 2021
Condensed Financial Information Disclosure [Abstract]
Schedule I - Condensed Financial Information of Parent (Exelon Corporate)	Exelon Corporation and Subsidiary Companies Schedule I – Condensed Financial Information of Parent (Exelon Corporate) Condensed Statements of Operations and Other Comprehensive Income For the Years Ended (In millions) 2021 2020 2019 Operating expenses Operating and maintenance $ (9) $ (2) $ 33 Operating and maintenance from affiliates 14 10 9 Other 2 2 1 Total operating expenses 7 10 43 Operating loss (7) (10) (43) Other income and (deductions) Interest expense, net (333) (378) (321) Equity in earnings of investments 1,908 1,482 1,844 Interest income from affiliates, net — 1 3 Other, net — 15 14 Total other income 1,575 1,120 1,540 Income from continuing operations before income taxes 1,568 1,110 1,497 Income taxes (48) 11 11 Net income (loss) from continuing operations after income taxes 1,616 1,099 1,486 Net income (loss) from discontinued operations after income taxes 90 864 1,450 Net income $ 1,706 $ 1,963 $ 2,936 Other comprehensive income (loss), net of income taxes Pension and non-pension postretirement benefit plans: Prior service benefit reclassified to periodic costs $ (4) $ (40) $ (64) Actuarial loss reclassified to periodic cost 223 190 148 Pension and non-pension postretirement benefit plan valuation adjustment 431 (357) (289) Unrealized (loss) gain on cash flow hedges — (1) 1 Other comprehensive income (loss) 650 (208) (204) Comprehensive income $ 2,356 $ 1,755 $ 2,732 Exelon Corporation and Subsidiary Companies Schedule I – Condensed Financial Information of Parent (Exelon Corporate) Condensed Statements of Cash Flows For the Years Ended (In millions) 2021 2020 2019 Net cash flows provided by operating activities $ 3,629 $ 3,018 $ 1,948 Cash flows from investing activities Changes in Exelon intercompany money pool 381 (477) 95 Notes receivable from affiliates — 550 — Investment in affiliates (2,231) (1,969) (1,071) Other investing activities 1 — — Net cash flows used in investing activities (1,849) (1,896) (976) Cash flows from financing activities Changes in short-term borrowings — (136) 136 Proceeds from short-term borrowings with maturities greater than 90 days 500 — — Repayments on short-term borrowings with maturities greater than 90 days (350) — — Issuance of long-term debt — 2,000 — Retirement of long-term debt (300) (1,450) — Dividends paid on common stock (1,497) (1,492) (1,408) Proceeds from employee stock plans 80 45 112 Other financing activities 19 (27) — Net cash flows used in financing activities (1,548) (1,060) (1,160) Increase (Decrease) in cash, restricted cash, and cash equivalents 232 62 (188) Cash, restricted cash, and cash equivalents at beginning of period 63 1 189 Cash, restricted cash, and cash equivalents at end of period $ 295 $ 63 $ 1 Exelon Corporation and Subsidiary Companies Schedule I – Condensed Financial Information of Parent (Exelon Corporate) Condensed Balance Sheets December 31, (In millions) 2021 2020 ASSETS Current assets Cash and cash equivalents $ 295 $ 63 Accounts receivable, net Other accounts receivable 318 354 Accounts receivable from affiliates 35 11 Notes receivable from affiliates 217 598 Regulatory assets 266 315 Other 41 (23) Total current assets 1,172 1,318 Property, plant, and equipment, net 45 46 Deferred debits and other assets Regulatory assets 3,164 3,816 Investments in affiliates from continuing operations 29,563 27,140 Investments in affiliates from discontinued operations 12,333 12,949 Deferred income taxes 1,351 1,436 Notes receivable from affiliates 319 324 Other 42 312 Total deferred debits and other assets 46,772 45,977 Total assets $ 47,989 $ 47,341 Exelon Corporation and Subsidiary Companies Schedule I – Condensed Financial Information of Parent (Exelon Corporate) Condensed Balance Sheets December 31, (In millions) 2021 2020 LIABILITIES AND SHAREHOLDERS’ EQUITY Current liabilities Short-term borrowings $ 650 $ 500 Long-term debt due within one year 1,150 300 Accounts payable — 1 Accrued expenses 47 66 Payables to affiliates 360 457 Regulatory liabilities 3 4 Pension obligations 49 61 Other 40 (1) Total current liabilities 2,299 1,388 Long-term debt 6,265 7,418 Deferred credits and other liabilities Regulatory liabilities 63 32 Pension obligations 4,416 5,236 Non-pension postretirement benefit obligations 87 236 Deferred income taxes 362 360 Other 104 86 Total deferred credits and other liabilities 5,032 5,950 Total liabilities 13,596 14,756 Commitments and contingencies Shareholders’ equity Common stock (No par value, 2,000 shares authorized, 979 shares and 976 shares outstanding as of December 31, 2021 and 2020, respectively) 20,324 19,373 Treasury stock, at cost (2 shares as of December 31, 2021 and 2020) (123) (123) Retained earnings 16,942 16,735 Accumulated other comprehensive loss, net (2,750) (3,400) Total shareholders’ equity 34,393 32,585 Total liabilities and shareholders’ equity $ 47,989 $ 47,341 Exelon Corporation and Subsidiary Companies Schedule I – Condensed Financial Information of Parent (Exelon Corporate) Notes to Financial Statements Exelon Corporate is a holding company that conducts substantially all of its business operations through its subsidiaries. These condensed financial statements and related footnotes have been prepared in accordance with Rule 12-04, Schedule I of Regulation S-X. These statements should be read in conjunction with the consolidated financial statements and notes thereto of Exelon Corporation. As of December 31, 2021 and 2020, Exelon Corporate owned 100% of all of its significant subsidiaries, either directly or indirectly, except for Commonwealth Edison Company (ComEd), of which Exelon Corporate owns more than 99%. As a February 1, 2022, as a result of the completion of the separation, Exelon Corporate no longer owns any interest in Constellation Energy Generation, LLC (Generation). The separation of Constellation Energy Corporation, including Generation and its subsidiaries, meets the criteria for discontinued operations and as such, results of operations are presented as discontinued operations and have been excluded from continuing operations for all periods presented. Accounting rules require that certain BSC costs previously allocated to Generation be presented as part of Exelon’s continuing operations as these costs do not qualify as expenses of the discontinued operations. Comprehensive income and cash flows related to Generation have not been segregated and are included in the Condensed Statements of Operations and Comprehensive Income and Condensed Statements of Cash Flows, respectively, for all periods presented. See Note 2 — Discontinued Operations of the Combined Notes to Consolidated Financial Statements for additional information. Short-Term Borrowings Exelon Corporate meets its short-term liquidity requirements primarily through the issuance of commercial paper. Exelon Corporate had no outstanding commercial paper borrowings as of December 31, 2021 and 2020. Short-Term Loan Agreements On March 23, 2017, Exelon Corporate entered into a term loan agreement for $500 million. The loan agreement was renewed on March 17, 2021 and will expire on March 16, 2022. Pursuant to the loan agreement, loans made thereunder bear interest at a variable rate equal to LIBOR plus 0.65% and all indebtedness thereunder is unsecured. The loan agreement is reflected in Short-term borrowings in Exelon's Consolidated Balance Sheet. On March 24, 2021, Exelon Corporate entered into a 9-month term loan agreement for $200 million. Pursuant to the loan agreement, loans made thereunder bear interest at a variable rate equal to LIBOR plus 0.65% and all indebtedness thereunder is unsecured. Exelon Corporate repaid the term loan on December 22, 2021. On March 31, 2021, Exelon Corporate entered into a 9-month and 364-day term loan agreement for $150 million each with variable interest rates of LIBOR plus 0.65% and expiration dates of December 31, 2021 and March 30, 2022, respectively. The 364-day loan agreement is reflected in Short-term borrowings in Exelon's Consolidated Balance Sheet. Exelon Corporate repaid the 9-month term loan on December 29, 2021. In connection with the separation, on January 24, 2022, Exelon Corporate entered into a 364-day term loan agreement for $1.15 billion. The loan agreement will expire on January 23, 2023. Pursuant to the loan agreement, loans made thereunder bear interest at a variable rate equal to SOFR plus 0.75% and all indebtedness thereunder is unsecured. Revolving Credit Agreements As of December 31, 2021, Exelon Corporation had a $600 million aggregate bank commitment under its existing syndicated revolving facility in which $594 million was available to support additional commercial paper as of December 31, 2021. See Note 15—Debt and Credit Agreements of the Combined Notes to Consolidated Financial Statements for additional information regarding Exelon Corporation’s credit agreement. On February 1, 2022, Exelon Corporate entered into a new 5-year revolving credit facility with an aggregate bank commitment of $900 million at a variable interest rate of SOFR plus 1.275% which replaced its existing $600 million syndicated revolving credit facility. Long-Term Debt The following tables present the outstanding long-term debt for Exelon Corporate as of December 31, 2021 and December 31, 2020: Maturity December 31, Rates 2021 2020 Long-term debt (a) Junior subordinated notes 3.50 % 2022 $ 1,150 $ 1,150 Senior unsecured notes (b) 3.40 % - 7.60 % 2025 - 2050 6,139 6,439 Total long-term debt 7,289 7,589 Unamortized debt discount and premium, net (10) (10) Unamortized debt issuance costs (39) (47) Fair value adjustment 175 186 Long-term debt due within one year (1,150) (300) Long-term debt $ 6,265 $ 7,418 __________ (a) In connection with the separation, Exelon Corporate entered into three 18-month term loan agreements. On January 21, 2022, two of the loan agreements were issued for $300 million each with an expiration date of July 21, 2023. On January 24, 2022, the third loan agreement was issued for $250 million with an expiration date of July 24, 2023. Pursuant to the loan agreement, loans made thereunder bear interest at a variable rate equal to SOFR plus 0.65%. (b) Senior unsecured notes include mirror debt that is held on Exelon Corporation's balance sheet. In connection with the separation, on January 31, 2022, Exelon Corporate received cash from Generation of $258 million to settle the intercompany loan. See Note 15 — Debt and Credit Agreements for additional information on the merger debt. The debt maturities for Exelon Corporate for the periods 2022, 2023, 2024, 2025, 2026, and thereafter are as follows: 2022 $ 1,150 2023 — 2024 — 2025 807 2026 750 Thereafter 4,582 Total long-term debt $ 7,289 The financial statements of Exelon Corporate include related party transactions as presented in the tables below: For the Years Ended December 31, (In millions) 2021 2020 2019 Operating and maintenance from affiliates: BSC (a) $ 14 $ 10 $ 9 Total operating and maintenance from affiliates: $ 14 $ 10 $ 9 Interest income from affiliates, net: BSC — 1 3 Total interest income from affiliates, net: $ — $ 1 $ 3 Equity in earnings (losses) of investments: BSC $ (301) $ (273) $ (281) EEDC (b) $ 2,215 $ 1,729 $ 2,054 UII — — 97 PCI (1) — 1 Exelon Enterprises — — (16) Exelon INQB8R (7) (1) (6) Exelon Transmission Company — — (2) Other 2 27 (3) Total equity in earnings of investments: $ 1,908 $ 1,482 $ 1,844 Cash contributions received from affiliates $ 1,842 $ 1,638 $ 1,615 As of December 31, (in millions) 2021 2020 Accounts receivable from affiliates (current): BSC (a) $ 4 $ — Generation 13 3 ComEd 5 — PECO 4 1 BGE 2 — PHISCO 6 6 Exelon Enterprises 1 1 Total accounts receivable from affiliates (current): $ 35 $ 11 Notes receivable from affiliates (current): BSC (a) $ 210 $ 252 Generation (c) — 285 PECO — 40 PHI 7 21 Total notes receivable from affiliates (current): $ 217 $ 598 Investments in affiliates from continuing operations: BSC (a) $ 146 $ 183 EEDC (b) 32,621 30,103 PCI 62 62 UII 365 365 Voluntary Employee Beneficiary Association trust 3 — Exelon Enterprises 3 3 Exelon INQB8R, LLC 26 23 Other (d) (3,663) (3,599) Total investments in affiliates from continuing operations: $ 29,563 $ 27,140 Notes receivable from affiliates (non-current): Generation (c) $ 319 $ 324 Accounts payable to affiliates (current): UII $ 360 $ 360 BSC — 91 EEDC (b) — 4 Generation (c) — 2 Total accounts payable to affiliates (current): $ 360 $ 457 __________ (a) Exelon Corporate receives a variety of corporate support services from BSC, including legal, human resources, financial, information technology, and supply management services. All services are provided at cost, including applicable overhead. (b) EEDC consists of ComEd, PECO, BGE, PHI, Pepco, DPL, and ACE. (c) In connection with the debt obligations assumed by Exelon as part of the Constellation merger, Exelon and subsidiaries of Generation (former Constellation subsidiaries) entered into intercompany loan agreements that mirror the terms and amounts of the third-party debt obligations of Exelon, resulting in intercompany notes receivable at Exelon Corporate from Generation. In connection with the separation, on January 31, 2022, Exelon Corporate received cash from Generation of $258 million to settle the intercompany loan. See Schedule 1 - 2. Debit and Credit agreements for additional information on the merger debt.

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
Schedule II - Valuation and Qualifying Accounts	Dec. 31, 2021
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Valuation and Qualifying Accounts	Exelon Corporation and Subsidiary Companies Schedule II – Valuation and Qualifying Accounts Column A Column B Column C Column D Column E Additions and adjustments Description Balance at Charged to Charged Deductions Balance at (In millions) For the year ended December 31, 2021 Allowance for credit losses (a) $ 405 $ 107 (b) $ — $ 120 (c) $ 392 Deferred tax valuation allowance 4 — 33 (d) — 37 Reserve for obsolete materials 11 5 — 3 13 For the year ended December 31, 2020 Allowance for credit losses (a) $ 213 $ 228 (b) $ 38 $ 74 (c) $ 405 Deferred tax valuation allowance 2 — 2 — 4 Reserve for obsolete materials 12 5 — 6 11 For the year ended December 31, 2019 Allowance for credit losses (a) $ 215 $ 92 (b) $ 37 $ 131 (c) $ 213 Deferred tax valuation allowance 9 — (7) — 2 Reserve for obsolete materials 11 6 — 5 12 __________ (a) Excludes the non-current allowance for credit losses related to PECO’s installment plan receivables of $14 million, $5 million, and $9 million for the years ended December 31, 2021, 2020, and 2019, respectively. (b) The amount charged to costs and expenses includes the amount that was reclassified to regulatory assets/liabilities under different mechanisms applicable to the different jurisdictions the Utility Registrants operate in. (c) Primarily reflects write-offs, net of recoveries of individual accounts receivable. (d) DPL recorded a full valuation allowance against Delaware net operating losses carryforwards due to a change in Delaware tax law. See Note 12 — Income Taxes of the Combined Notes to Consolidated Financial Statements for additional information on the valuation allowance. Commonwealth Edison Company and Subsidiary Companies (2) ComEd (i) Financial Statements (Item 8): Report of Independent Registered Public Accounting Firm dated February 25, 2022 of PricewaterhouseCoopers LLP (PCAOB ID 238) Consolidated Statements of Operations and Comprehensive Income for the Years Ended December 31, 2021, 2020, and 2019 Consolidated Statements of Cash Flows for the Years Ended December 31, 2021, 2020, and 2019 Consolidated Balance Sheets at December 31, 2021 and 2020 Consolidated Statements of Changes in Shareholders’ Equity for the Years Ended December 31, 2021, 2020, and 2019 Notes to Consolidated Financial Statements (ii) Financial Statement Schedule: Schedule II—Valuation and Qualifying Accounts for the Years Ended December 31, 2021, 2020, and 2019 Schedules not included are omitted because of the absence of conditions under which they are required or because the required information is provided in the consolidated financial statements, including the notes thereto Commonwealth Edison Company and Subsidiary Companies Schedule II – Valuation and Qualifying Accounts Column A Column B Column C Column D Column E Additions and adjustments Description Balance at Charged to Charged Deductions Balance at (In millions) For the year ended December 31, 2021 Allowance for credit losses $ 118 $ 18 (a) $ 1 $ 47 (b) $ 90 Reserve for obsolete materials 6 3 — 2 7 For the year ended December 31, 2020 Allowance for credit losses $ 79 $ 54 (a) $ 13 $ 28 (b) $ 118 Reserve for obsolete materials 7 3 — 4 6 For the year ended December 31, 2019 Allowance for credit losses $ 81 $ 35 (a) $ 20 $ 57 (b) $ 79 Reserve for obsolete materials 6 6 — 5 7 __________ (a) ComEd is allowed to recover from or refund to customers the difference between its annual credit loss expense and the amounts collected in rates annually through a rider mechanism. The amount charged to costs and expenses includes the amount that was reclassified to regulatory assets/liabilities under such mechanism. See Note 3 – Regulatory Matters of the Combined Notes to Consolidated Financial Statements for additional information. (b) Write-offs, net of recoveries of individual accounts receivable. PECO Energy Company and Subsidiary Companies (3) PECO (i) Financial Statements (Item 8): Report of Independent Registered Public Accounting Firm dated February 25, 2022 of PricewaterhouseCoopers LLP (PCAOB ID 238) Consolidated Statements of Operations and Comprehensive Income for the Years Ended December 31, 2021, 2020, and 2019 Consolidated Statements of Cash Flows for the Years Ended December 31, 2021, 2020, and 2019 Consolidated Balance Sheets at December 31, 2021 and 2020 Consolidated Statements of Changes in Shareholder's Equity for the Years Ended December 31, 2021, 2020, and 2019 Notes to Consolidated Financial Statements (ii) Financial Statement Schedule: Schedule II—Valuation and Qualifying Accounts for the Years Ended December 31, 2021, 2020, and 2019 Schedules not included are omitted because of the absence of conditions under which they are required or because the required information is provided in the consolidated financial statements, including the notes thereto PECO Energy Company and Subsidiary Companies Schedule II – Valuation and Qualifying Accounts Column A Column B Column C Column D Column E Additions and adjustments Description Balance at Charged to Charged Deductions Balance at (In millions) For the year ended December 31, 2021 Allowance for credit losses (a) $ 124 $ 32 (b) $ (6) $ 38 (c) $ 112 Deferred tax valuation allowance 1 — 2 — $ 3 Reserve for obsolete materials 2 1 — 1 2 For the year ended December 31, 2020 Allowance for credit losses (a) $ 62 $ 76 (b) $ 6 $ 20 (c) $ 124 Deferred tax valuation allowance — — 1 — 1 Reserve for obsolete materials 2 1 — 1 2 For the year ended December 31, 2019 Allowance for credit losses (a) $ 61 $ 31 $ 3 $ 33 (c) $ 62 Reserve for obsolete materials 2 — — — 2 __________ (a) Excludes the non-current allowance for credit losses related to PECO’s installment plan receivables of $14 million, $5 million, and $9 million for the years ended December 31, 2021, 2020, and 2019, respectively. (b) The amount charged to costs and expenses includes the amount that was reclassified to the COVID-19 regulatory asset. See Note 3 – Regulatory Matters of the Combined Notes to Consolidated Financial Statements for additional information. (c) Write-offs, net of recoveries of individual accounts receivable. Baltimore Gas and Electric Company (4) BGE (i) Financial Statements (Item 8): Report of Independent Registered Public Accounting Firm dated February 25, 2022 of PricewaterhouseCoopers LLP (PCAOB ID 238) Statements of Operations and Comprehensive Income for the Years Ended December 31, 2021, 2020 and 2019 Statements of Cash Flows for the Years Ended December 31, 2021, 2020 and 2019 Balance Sheets at December 31, 2021 and 2020 Statements of Changes in Shareholder's Equity for the Years Ended December 31, 2021, 2020 and 2019 Notes to Financial Statements (ii) Financial Statement Schedule: Schedule II—Valuation and Qualifying Accounts for the Years Ended December 31, 2021, 2020, and 2019 Schedules not included are omitted because of the absence of conditions under which they are required or because the required information is provided in the consolidated financial statements, including the notes thereto Baltimore Gas and Electric Company Schedule II – Valuation and Qualifying Accounts Column A Column B Column C Column D Column E Additions and adjustments Description Balance at Charged to Charged Deductions Balance at (In millions) For the year ended December 31, 2021 Allowance for credit losses $ 44 $ 16 (a) $ 3 $ 16 (b) $ 47 Reserve for obsolete materials 1 — — — 1 For the year ended December 31, 2020 Allowance for credit losses $ 17 $ 31 (a) $ 6 $ 10 (b) $ 44 Deferred tax valuation allowance 1 — (1) — — Reserve for obsolete materials 1 — — — 1 For the year ended December 31, 2019 Allowance for credit losses $ 20 $ 8 (a) $ 7 $ 18 (b) $ 17 Deferred tax valuation allowance 1 — — — 1 Reserve for obsolete materials 1 — — — 1 __________ (a) The amount charged to costs and expenses includes the amount that was reclassified to regulatory assets/liabilities under different mechanisms as approved by the MDPSC. (b) Write-offs, net of recoveries of individual accounts receivable. Pepco Holdings LLC and Subsidiary Companies (5) PHI (i) Financial Statements (Item 8): Report of Independent Registered Public Accounting Firm dated February 25, 2022 of PricewaterhouseCoopers LLP (PCAOB ID 238) Consolidated Statements of Operations and Comprehensive Income for the Years Ended December 31, 2021, 2020, and 2019 Consolidated Statements of Cash Flows for the Years Ended December 31, 2021, 2020, and 2019 Consolidated Balance Sheets at December 31, 2021 and 2020 Consolidated Statements of Changes in Equity for the Years Ended December 31, 2021, 2020, and 2019 Notes to Consolidated Financial Statements (ii) Financial Statement Schedule: Schedule II—Valuation and Qualifying Accounts for the Years Ended December 31, 2021, 2020, and 2019 Schedules not included are omitted because of the absence of conditions under which they are required or because the required information is provided in the consolidated financial statements, including the notes thereto Pepco Holdings LLC and Subsidiary Companies Schedule II – Valuation and Qualifying Accounts Column A Column B Column C Column D Column E Additions and adjustments Description Balance at Charged to Charged Deductions Balance at (In millions) For the year ended December 31, 2021 Allowance for credit losses $ 119 $ 41 (a) $ 2 $ 19 (b) $ 143 Deferred tax valuation allowance — — 31 (c) — 31 Reserve for obsolete materials 2 1 — — 3 For the year ended December 31, 2020 Allowance for credit losses $ 53 $ 69 (a) $ 13 $ 16 (b) $ 119 Reserve for obsolete materials 3 — — 1 2 For the year ended December 31, 2019 Allowance for credit losses $ 53 $ 17 (a) $ 7 $ 24 (d) $ 53 Deferred tax valuation allowance 8 — (8) — — Reserve for obsolete materials 2 1 — — 3 __________ (a) The amount charged to costs and expenses includes the amount that was reclassified to regulatory assets/liabilities under different mechanisms applicable to the different jurisdictions Pepco, DPL, and ACE operate in. (b) Write-offs, net of recoveries of individual accounts receivable. (c) DPL recorded a full valuation allowance against Delaware net operating losses carryforwards due to a change in Delaware tax law. See Note 12 — Income Taxes of the Combined Notes to Consolidated Financial Statements for additional information on the valuation allowance. (d) Write-offs of individual accounts receivable. Potomac Electric Power Company (6) Pepco (i) Financial Statements (Item 8): Report of Independent Registered Public Accounting Firm dated February 25, 2022 of PricewaterhouseCoopers LLP (PCAOB ID 238) Statements of Operations and Comprehensive Income for the Years Ended December 31, 2021, 2020 and 2019 Statements of Cash Flows for the Years Ended December 31, 2021, 2020 and 2019 Balance Sheets at December 31, 2021 and 2020 Statements of Changes in Shareholder's Equity for the Years Ended December 31, 2021, 2020 and 2019 Notes to Financial Statements (ii) Financial Statement Schedule: Schedule II—Valuation and Qualifying Accounts for the Years Ended December 31, 2021, 2020, and 2019 Schedules not included are omitted because of the absence of conditions under which they are required or because the required information is provided in the consolidated financial statements, including the notes thereto Potomac Electric Power Company Schedule II – Valuation and Qualifying Accounts Column A Column B Column C Column D Column E Additions and adjustments Description Balance at Charged to Charged Deductions Balance at (In millions) For the year ended December 31, 2021 Allowance for credit losses $ 45 $ 14 (a) $ 2 $ 8 (b) $ 53 Reserve for obsolete materials 1 — — — 1 For the year ended December 31, 2020 Allowance for credit losses $ 20 $ 25 (a) $ 5 $ 5 (b) $ 45 Reserve for obsolete materials 1 — — — 1 For the year ended December 31, 2019 Allowance for credit losses $ 21 $ 7 (a) $ 2 $ 10 (c) $ 20 Reserve for obsolete materials 1 — — — 1 __________ (a) The amount charged to costs and expenses includes the amount that was reclassified to regulatory assets/liabilities under different mechanisms as approved by the DCPSC and MDPSC. (b) Write-offs, net of recoveries of individual accounts receivable. (c) Write-off of individual accounts receivable. Delmarva Power & Light Company (7) DPL (i) Financial Statements (Item 8): Report of Independent Registered Public Accounting Firm dated February 25, 2022 of PricewaterhouseCoopers LLP (PCAOB ID 238) Statements of Operations and Comprehensive Income for the Years Ended December 31, 2021, 2020 and 2019 Statements of Cash Flows for the Years Ended December 31, 2021, 2020 and 2019 Balance Sheets at December 31, 2021 and 2020 Statements of Changes in Shareholder's Equity for the Years Ended December 31, 2021, 2020 and 2019 Notes to Financial Statements (ii) Financial Statement Schedule: Schedule II—Valuation and Qualifying Accounts for the Years Ended December 31, 2021, 2020, and 2019 Schedules not included are omitted because of the absence of conditions under which they are required or because the required information is provided in the consolidated financial statements, including the notes thereto Delmarva Power & Light Company Schedule II – Valuation and Qualifying Accounts Column A Column B Column C Column D Column E Additions and adjustments Description Balance at Charged to Charged Deductions Balance at (In millions) For the year ended December 31, 2021 Allowance for credit losses $ 31 $ 6 (a) $ (1) $ 10 (b) $ 26 Deferred tax valuation allowance — — 31 (c) — 31 For the year ended December 31, 2020 Allowance for credit losses $ 15 $ 16 (a) $ 4 $ 4 (b) $ 31 For the year ended December 31, 2019 Allowance for credit losses $ 13 $ 4 (a) $ 3 $ 5 (d) $ 15 __________ (a) The amount charged to costs and expenses includes the amount that was reclassified to regulatory assets/liabilities under different mechanisms as approved by the DEPSC and MDPSC. (b) Write-offs, net of recoveries of individual accounts receivable. (c) DPL recorded a full valuation allowance against Delaware net operating losses carryforwards due to a change in Delaware tax law. See Note 12 — Income Taxes of the Combined Notes to Consolidated Financial Statements for additional information on the valuation allowance. (d) Write-off of individual accounts receivable. Atlantic City Electric Company and Subsidiary Company (8) ACE (i) Financial Statements (Item 8): Report of Independent Registered Public Accounting Firm dated February 25, 2022 of PricewaterhouseCoopers LLP (PCAOB ID 238) Consolidated Statements of Operations and Comprehensive Income for the Years Ended December 31, 2021, 2020, and 2019 Consolidated Statements of Cash Flows for the Years Ended December 31, 2021, 2020, and 2019 Consolidated Balance Sheets at December 31, 2021 and 2020 Consolidated Statements of Changes in Shareholder's Equity for the Years Ended December 31, 2021, 2020, and 2019 Notes to Consolidated Financial Statements (ii) Financial Statement Schedule: Schedule II—Valuation and Qualifying Accounts for the Years Ended December 31, 2021, 2020, and 2019 Schedules not included are omitted because of the absence of conditions under which they are required or because the required information is provided in the consolidated financial statements, including the notes thereto Atlantic City Electric Company and Subsidiary Company Schedule II – Valuation and Qualifying Accounts Column A Column B Column C Column D Column E Additions and adjustments Description Balance at Charged to Charged Deductions Balance at (In millions) For the year ended December 31, 2021 Allowance for credit losses $ 43 $ 21 (a) $ 1 $ 1 (b) $ 64 Reserve for obsolete materials — 1 — — 1 For the year ended December 31, 2020 Allowance for credit losses $ 18 $ 28 (a) $ 4 $ 7 (b) $ 43 Reserve for obsolete materials 1 — — 1 — For the year ended December 31, 2019 Allowance for credit losses $ 19 $ 5 (a) $ 2 $ 8 (c) $ 18 Reserve for obsolete materials 1 — — — 1 __________ (a) ACE is allowed to recover from or refund to customers the difference between its annual credit loss expense and the amounts collected in rates annually through the Societal Benefits Charge. The amount charged to costs and expenses includes the amount that was reclassified to regulatory assets/liabilities under such mechanism. See Note 3 – Regulatory Matters of the Combined Notes to Consolidated Financial Statements for additional information. (b) Write-offs, net of recoveries of individual accounts receivable. (c) Write-off of individual accounts receivable.

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	12 Months Ended
Significant Accounting Policies (Policies)	Dec. 31, 2021
Accounting Policies [Abstract]
Business Description and Basis of Presentation (All Registrants)	Description of Business (All Registrants) As of December 31, 2021, Exelon was a utility services holding company engaged in the generation, delivery and marketing of energy through Generation and the energy distribution and transmission businesses through ComEd, PECO, BGE, Pepco, DPL, and ACE. On February 21, 2021, Exelon’s Board of Directors approved a plan to separate the Utility Registrants and Generation, creating two publicly traded companies. The separation was completed on February 1, 2022. See Note 2 — Discontinued Operations for additional information. Name of Registrant Business Service Territories Commonwealth Edison Company Purchase and regulated retail sale of electricity Northern Illinois, including the City of Chicago Transmission and distribution of electricity to retail customers PECO Energy Company Purchase and regulated retail sale of electricity and natural gas Southeastern Pennsylvania, including the City of Philadelphia (electricity) Transmission and distribution of electricity and distribution of natural gas to retail customers Pennsylvania counties surrounding the City of Philadelphia (natural gas) Baltimore Gas and Electric Company Purchase and regulated retail sale of electricity and natural gas Central Maryland, including the City of Baltimore (electricity and natural gas) Transmission and distribution of electricity and distribution of natural gas to retail customers Pepco Holdings LLC Utility services holding company engaged, through its reportable segments Pepco, DPL, and ACE Service Territories of Pepco, DPL, and ACE Potomac Electric Power Company Purchase and regulated retail sale of electricity District of Columbia, and major portions of Montgomery and Prince George’s Counties, Maryland. Transmission and distribution of electricity to retail customers Delmarva Power & Light Company Purchase and regulated retail sale of electricity and natural gas Portions of Delaware and Maryland (electricity) Transmission and distribution of electricity and distribution of natural gas to retail customers Portions of New Castle County, Delaware (natural gas) Atlantic City Electric Company Purchase and regulated retail sale of electricity Portions of Southern New Jersey Transmission and distribution of electricity to retail customers Basis of Presentation (All Registrants) This is a combined annual report of all Registrants. The Notes to the Consolidated Financial Statements apply to the Registrants as indicated parenthetically next to each corresponding disclosure. When appropriate, the Registrants are named specifically for their related activities and disclosures. Each of the Registrant’s Consolidated Financial Statements includes the accounts of its subsidiaries. All intercompany transactions have been eliminated, except for the historical transactions between the Utility Registrants and Generation for the purposes of presenting discontinued operations in all periods presented in the Consolidated Statements of Operations and Comprehensive Income. Through its business services subsidiary, BSC, Exelon provides its subsidiaries with a variety of support services at cost, including legal, human resources, financial, information technology, and supply management services. PHI also has a business services subsidiary, PHISCO, which provides a variety of support services at cost, including legal, accounting, engineering, customer operations, distribution and transmission planning, asset management, system operations, and power procurement, to PHI operating companies. The costs of BSC and PHISCO are directly charged or allocated to the applicable subsidiaries. The results of Exelon’s corporate operations are presented as “Other” within the consolidated financial statements and include intercompany eliminations unless otherwise disclosed. As of December 31, 2021 and 2020, Exelon owned 100% of Generation, PECO, BGE, and PHI and more than 99% of ComEd. PHI owns 100% of Pepco, DPL, and ACE. As of February 1, 2022, as a result of the completion of the separation, Exelon no longer owns any interest in Generation. The separation of Constellation Energy Corporation, including Generation and its subsidiaries, meets the criteria for discontinued operations and as such, its results of operations are presented as discontinued operations and have been excluded from continuing operations for all periods presented. Accounting rules require that certain BSC costs previously allocated to Generation be presented as part of Exelon’s continuing operations as these costs do not qualify as expenses of the discontinued operations. Comprehensive income, shareholders' equity, and cash flows related to Generation have not been segregated and are included in the Consolidated Statements of Operations and Comprehensive Income, Consolidated Statements of Changes in Shareholders’ Equity, and Consolidated Statements of Cash Flows, respectively, for all periods presented. See Note 2 — Discontinued Operations for additional information. The accompanying consolidated financial statements have been prepared in accordance with GAAP for annual financial statements and in accordance with the instructions to Form 10-K and Regulation S-X promulgated by the SEC.
Use Of Estimates (All Registrants)	Use of Estimates (All Registrants)The preparation of financial statements of each of the Registrants in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Areas in which significant estimates have been made include, but are not limited to, the accounting for AROs, pension and OPEB, inventory reserves, allowance for credit losses, goodwill and long-lived asset impairment assessments, derivative instruments, unamortized energy contracts, fixed asset depreciation, environmental costs and other loss contingencies, taxes, and unbilled energy revenues. Actual results could differ from those estimates.
Accounting for the Effects of Regulation (All Registrants)	Accounting for the Effects of Regulation (All Registrants) For their regulated electric and gas operations, the Registrants reflect the effects of cost-based rate regulation in their financial statements, which is required for entities with regulated operations that meet the following criteria: 1) rates are established or approved by a third-party regulator; (2) rates are designed to recover the entities’ cost of providing services or products; and (3) there is a reasonable expectation that rates designed to recover costs can be charged to and collected from customers. The Registrants account for their regulated operations in accordance with regulatory and legislative guidance from the regulatory authorities having jurisdiction, principally the ICC, PAPUC, MDPSC, DCPSC, DEPSC, and NJBPU, under state public utility laws and the FERC under various Federal laws. Regulatory assets and liabilities are amortized and the related expense or revenue is recognized in the Consolidated Statements of Operations consistent with the recovery or refund included in customer rates. The Registrants' regulatory assets and liabilities as of the balance sheet date are probable of being recovered or settled in future rates. If a separable portion of the Registrants' business was no longer able to meet the criteria discussed above, the affected entities would be required to eliminate from their consolidated financial statements the effects of regulation for that portion, which could have a material impact on their financial statements. See Note 3 — Regulatory Matters for additional information. With the exception of income tax-related regulatory assets and liabilities, the Registrants classify regulatory assets and liabilities with a recovery or settlement period greater than one year as both current and non-current in their Consolidated Balance Sheets, with the current portion representing the amount expected to be recovered from or refunded to customers over the next twelve-month period as of the balance sheet date. Income tax-related regulatory assets and liabilities are classified entirely as non-current in the Registrants’ Consolidated Balance Sheets to align with the classification of the related deferred income tax balances. The Registrants treat the impacts of a final rate order received after the balance sheet date but prior to the issuance of the financial statements as a non-recognized subsequent event, as the receipt of a final rate order is a separate and distinct event that has future impacts on the parties affected by the order.
Revenues (All Registrants)	Revenues (All Registrants) Operating Revenues. The Registrants’ operating revenues generally consist of revenues from contracts with customers involving the sale and delivery of power and natural gas and utility revenues from ARP. The Registrants recognize revenue from contracts with customers to depict the transfer of goods or services to customers in an amount that the entities expect to be entitled to in exchange for those goods or services. The primary sources of revenue include regulated electric and natural gas tariff sales, distribution, and transmission services. At the end of each month, the Registrants accrue an estimate for the unbilled amount of energy delivered or services provided to customers. ComEd records ARP revenue for its best estimate of the electric distribution, energy efficiency, and transmission revenue impacts resulting from future changes in rates that ComEd believes are probable of approval by the ICC and FERC in accordance with its formula rate mechanisms. BGE, Pepco, DPL, and ACE record ARP revenue for their best estimate of the electric and natural gas distribution revenue impacts resulting from future changes in rates that they believe are probable of approval by the MDPSC, DCPSC, and/or NJBPU in accordance with their revenue decoupling mechanisms. PECO, BGE, Pepco, DPL, and ACE record ARP revenue for their best estimate of the transmission revenue impacts resulting from future changes in rates that they believe are probable of approval by FERC in accordance with their formula rate mechanisms. See Note 3 — Regulatory Matters for additional information.
Taxes Directly Imposed on Revenue-Producing Transactions	Taxes Directly Imposed on Revenue-Producing Transactions. The Registrants collect certain taxes from customers such as sales and gross receipts taxes, along with other taxes, surcharges, and fees, that are levied by state or local governments on the sale or distribution of electricity and gas. Some of these taxes are imposed on the customer, but paid by the Registrants, while others are imposed on the Registrants. Where these taxes are imposed on the customer, such as sales taxes, they are reported on a net basis with no impact to the Consolidated Statements of Operations and Comprehensive Income. However, where these taxes are imposed on the Registrants, such as gross receipts taxes or other surcharges or fees, they are reported on a gross basis. Accordingly, revenues are recognized for the taxes collected from customers along with an offsetting expense. Se e Note 22 — Supplemental Financial Information for taxes that are presented on a gross basis.
Leases (All Registrants)	Leases (All Registrants) The Registrants recognize a ROU asset and lease liability for operating and finance leases with a term of greater than one year. Operating lease ROU assets are included in Other deferred debits and other assets and operating lease liabilities are included in Other current liabilities and Other deferred credits and other liabilities on the Consolidated Balance Sheets. Finance lease ROU assets are included in Plant, property, and equipment, net and finance lease liabilities are included in Long-term debt due within one year and Long-term debt on the Consolidated Balance Sheets. The ROU asset is measured as the sum of (1) the present value of all remaining fixed and in-substance fixed payments using t he rate implicit in the lease whenever that is readily determinable or each Registrant’s incremental borrowing rate, (2) any lease payments made at or before the commencement date (less any lease incentives received), and (3) any initial direct costs incurred. The lease liability is measured the same as the ROU asset, but excludes any payments made before the commencement date and initial direct costs incurred. Lease terms include options to extend or terminate the lease if it is reasonably certain they will be exercised. The Registrants include non-lease components for most asset classes, which are service-related costs that are not integral to the use of the asset, in the measurement of the ROU asset and lease liability. Expense for operating leases and leases with a term of one year or less is recognized on a straight-line basis over the term of the lease, unless another systematic and rational basis is more representative of the derivation of benefit from use of the leased property. Variable lease payments are recognized in the period in which the related obligation is incurred. Operating lease expense, finance lease expense, and variable lease payments are primarily recorded to Operating and maintenance expense on the Registrants’ Statements of Operations and Comprehensive Income. Income from operating leases, including subleases, is recognized on a straight-line basis over the term of the lease, unless another systematic and rational basis is more representative of the pattern in which income is earned over the term of the lease. Variable lease income is recognized in the period in which the related obligation is performed. Operating lease income and variable lease income are recorded to Operating revenues on the Registrants’ Statements of Operations and Comprehensive Income. The Registrants’ operating and finance leases consist primarily of real estate including office buildings and vehicles and equipment. The Registrants account for land right arrangements that provide for exclusive use as leases while shared use land arrangements are generally not leases. The Registrants do not account for secondary use pole attachments as leases. See Note 10 — Leases for additional information.
Income Taxes (All Registrants)	Income Taxes (All Registrants) Deferred federal and state income taxes are recorded on significant temporary differences between the book and tax basis of assets and liabilities and for tax benefits carried forward. Investment tax credits have been deferred in the Registrants’ Consolidated Balance Sheets and are recognized in book income over the life of the related property. The Registrants account for uncertain income tax positions using a benefit recognition model with a two-step approach; a more-likely-than-not recognition criterion; and a measurement approach that measures the position as the largest amount of tax benefit that is greater than 50% likely of being realized upon ultimate settlement. If it is not more-likely-than-not that the benefit of the tax position will be sustained on its technical merits, no benefit is recorded. Uncertain tax positions that relate only to timing of when an item is included on a tax return are considered to have met the recognition threshold. The Registrants recognize accrued interest related to unrecognized tax benefits in Interest expense, net or Other, net (interest income) and recognize penalties related to unrecognized tax benefits in Other, net in their Consolidated Statements of Operations and Comprehensive Income.
Cash and Cash Equivalents (All Registrants)	Cash and Cash Equivalents (All Registrants) The Registrants consider investments purchased with an original maturity of three months or less to be cash equivalents. Restricted Cash and Cash Equivalents (All Registrants) Restricted cash and cash equivalents represent funds that are restricted to satisfy designated current liabilities. As of December 31, 2021 and 2020, the Registrants' restricted cash and cash equivalents primarily represented the following items: Registrant Description Exelon Payment of medical, dental, vision, and long-term disability benefits, in addition to the items listed below for the Utility Registrants. ComEd Collateral held from suppliers associated with energy and REC procurement contracts, any over-recovered RPS costs and alternative compliance payments received from RES pursuant to FEJA, and costs for the remediation of an MGP site. PECO Proceeds from the sales of assets that were subject to PECO’s mortgage indenture. BGE Proceeds from the loan program for the completion of certain energy efficiency measures and collateral held from energy suppliers. PHI Payment of merger commitments, collateral held from its energy suppliers associated with procurement contracts, and repayment of Transition Bonds. Pepco Payment of merger commitments and collateral held from energy suppliers. DPL Collateral held from energy suppliers. ACE Repayment of Transition Bonds and collateral held from energy suppliers. Restricted cash and cash equivalents not available to satisfy current liabilities are classified as noncurrent assets. As of December 31, 2021 and 2020, the Registrants' noncurrent restricted cash and cash equivalents primarily represented ComEd’s over-recovered RPS costs and alternative compliance payments received from RES pursuant to FEJA and costs for the remediation of an MGP site, and ACE’s repayment of Transition Bonds. See Note 15 — Debt and Credit Agreements and Note 22 — Supplemental Financial Information for additional information.
Allowance for Credit Losses on Accounts Receivables (All Registrants)	Allowance for Credit Losses on Accounts Receivables (All Registrants) The allowance for credit losses reflects the Registrants’ best estimates of losses on the customers' accounts receivable balances based on historical experience, current information, and reasonable and supportable forecasts. The allowance for credit losses is developed by applying loss rates for each Utility Registrant, based on historical loss experience, current conditions, and forward-looking risk factors, to the outstanding receivable balance by customer risk segment. Utility Registrants' customer accounts are written off consistent with approved regulatory requirements. Adjustments to the allowance for credit losses are primarily recorded to Operating and maintenance expense on the Registrants' Consolidated Statements of Operations and Comprehensive Income or Regulatory assets and liabilities on the Registrants' Consolidated Balance Sheets. See Note 3 - Regulatory Matters for additional information regarding the regulatory recovery of credit losses on customer accounts receivable.
Variable Interest Entities (Exelon, PHI, and ACE)	Variable Interest Entities (Exelon, PHI, and ACE) Exelon accounts for its investments in and arrangements with VIEs based on the following specific requirements: • qualitative assessment of factors determinant in whether it has a controlling financial interest, • ongoing reconsideration of this assessment, and • where it consolidates a VIE (as primary beneficiary), disclosure of (1) the assets of the consolidated VIE, if they can be used to only settle specific obligations of the consolidated VIE, and (2) the liabilities of a consolidated VIE for which creditors do not have recourse to the general credit of the primary beneficiary. See Note 21 — Variable Interest Entities for additional information.
Inventories (All Registrants)	Inventories (All Registrants) Inventory is recorded at the lower of weighted average cost or net realizable value. Provisions are recorded for excess and obsolete inventory. Fossil fuel and materials and supplies are generally included in inventory when purchased. Fossil fuel is expensed to Purchased power and fuel expense when used or sold. Materials and supplies generally includes transmission and distribution materials and are expensed to Operating and maintenance or capitalized to Property, plant, and equipment, as appropriate, when installed or used.
Debt and Equity Security Investments (Exelon)	Equity Security Investments with Readily Determinable Fair Values (Exelon, PECO, BGE, PHI, and Pepco) For investments in equity securities with readily determinable fair values, Exelon reports their investment values based on quoted prices in active markets and realized and unrealized gains and losses are included in earnings. See Note 16 — Fair Value of Financial Assets and Liabilities for additional information.
Property Plant And Equipment (All Registrants)	Property, Plant, and Equipment (All Registrants) Property, plant, and equipment is recorded at original cost. Original cost includes construction-related direct labor and material costs and indirect construction costs including labor and related costs of departments associated with supporting construction activities. When appropriate, original cost also includes capitalized interest for Exelon Corporate and PHI and AFUDC for regulated property at the Utility Registrants. The cost of repairs and maintenance and minor replacements of property is charged to Operating and maintenance expense as incurred. Third parties reimburse the Utility Registrants for all or a portion of expenditures for certain capital projects. Such contributions in aid of construction costs (CIAC) are recorded as a reduction to Property, plant, and equipment, net. Upon retirement, the cost of property, net of salvage, is charged to accumulated depreciation consistent with the composite and group methods of depreciation. Depreciation expense at ComEd, BGE, Pepco, DPL, and ACE includes the estimated cost of dismantling and removing plant from service upon retirement. Actual incurred removal costs are applied against a related regulatory liability or recorded to a regulatory asset if in excess of previously collected removal costs. PECO’s removal costs are capitalized to accumulated depreciation when incurred and recorded to depreciation expense over the life of the new asset constructed consistent with PECO’s regulatory recovery method. Capitalized Software. Certain costs, such as design, coding, and testing incurred during the application development stage of software projects that are internally developed or purchased for operational use are capitalized within Property, plant, and equipment. Similar costs incurred for cloud-based solutions treated as service arrangements are capitalized within Other Current Assets and Deferred Debits and Other Assets. Such capitalized amounts are amortized ratably over the expected lives of the projects when they become operational, generally not to exceed five years. Certain other capitalized software costs are being amortized over longer lives based on the expected life or pursuant to prescribed regulatory requirements. Capitalized Interest and AFUDC. During construction, Exelon capitalizes the costs of debt funds used to finance non-regulated construction projects. Capitalization of debt funds is recorded as a charge to construction work in progress and as a non-cash credit to interest expense. AFUDC is the cost, during the period of construction, of debt and equity funds used to finance construction projects for regulated operations. AFUDC is recorded to construction work in progress and as a non-cash credit to an allowance that is included in interest expense for debt-related funds and other income and deductions for equity-related funds. The rates used for capitalizing AFUDC are computed under a method prescribed by regulatory authorities. See Note 7 — Property, Plant, and Equipment, Note 8 — Jointly Owned Electric Utility Plant and Note 22 — Supplemental Financial Information for additional information.
Depreciation and Amortization (All Registrants)	Depreciation and Amortization (All Registrants) Depreciation is generally recorded over the estimated service lives of property, plant, and equipment on a straight-line basis using the group or composite methods of depreciation. The group approach is typically for groups of similar assets that have approximately the same useful lives and the composite approach is used for dissimilar assets that have different lives. Under both methods, a reporting entity depreciates the assets over the average life of the assets in the group. ComEd, BGE, Pepco, DPL, and ACE's depreciation expense includes the estimated cost of dismantling and removing plant from service upon retirement, which is consistent with each utility's regulatory recovery method. PECO's removal costs are capitalized to accumulated depreciation when incurred and recorded to depreciation expense over the life of the new asset constructed consistent with PECO's regulatory recovery method. The estimated service lives for the Registrants are based on a combination of depreciation studies and historical retirements. See Note 7 — Property, Plant, and Equipment for additional information regarding depreciation. Amortization of regulatory assets and liabilities are recorded over the recovery or refund period specified in the related legislation or regulatory order or agreement. When the recovery or refund period is less than one year, amortization is recorded to the line item in which the deferred cost or income would have originally been recorded in the Registrants’ Consolidated Statements of Operations and Comprehensive Income. Amortization of ComEd’s electric distribution and energy efficiency formula rate regulatory assets and the Utility Registrants' transmission formula rate regulatory assets is recorded to Operating revenues. Amortization of income tax related regulatory assets and liabilities is generally recorded to Income tax expense. Except for the regulatory assets and liabilities discussed above, amortization is generally recorded to Depreciation and amortization in the Registrants’ Consolidated Statements of Operations and Comprehensive Income when the recovery period is more than one year. See Note 3 — Regulatory Matters and Note 22 — Supplemental Financial Information for additional information regarding the amortization of the Registrants' regulatory assets.
Asset Retirement Obligations (All Registrants)	Asset Retirement Obligations (All Registrants) The Registrants estimate and recognize a liability for their legal obligation to perform asset retirement activities even though the timing and/or methods of settlement may be conditional on future events. The Registrants update their AROs either annually or on a rotational basis at least once every three years, based on a risk profile, unless circumstances warrant more frequent updates. The updates factor in new cost estimates, credit-adjusted, risk-free rates (CARFR) and escalation rates, and the timing of cash flows. AROs are accreted throughout each year to reflect the time value of money for these present value obligations through an increase to regulatory assets. See Note 9 — Asset Retirement Obligations for additional information.
Guarantees (All Registrants)	Guarantees (All Registrants) If necessary, the Registrants recognize a liability at the time of issuance of a guarantee for the fair value of the obligations they have undertaken by issuing the guarantee. The liability is reduced or eliminated as the Registrants are released from risk under the guarantee. Depending on the nature of the guarantee, the release from risk of the Registrant may be recognized only upon the expiration or settlement of the guarantee or by a systematic and rational amortization method over the term of the guarantee. See Note 17 — Commitments and Contingencies for additional information.
Asset Impairments	Asset Impairments Long-Lived Assets (All Registrants). The Registrants evaluate the carrying value of long-lived assets for recoverability whenever events or changes in circumstances indicate that the carrying value of those assets may not be recoverable. Indicators of impairment may include specific regulatory disallowance, abandonment, or plans to dispose of a long-lived asset significantly before the end of its useful life. When the estimated undiscounted future cash flows attributable to the long-lived asset may not be recoverable, the amount of the impairment loss is determined by measuring the excess of the carrying amount of the long-lived asset over its fair value. Goodwill (Exelon, ComEd, and PHI). Goodwill represents the excess of the purchase price paid over the estimated fair value of the net assets acquired and liabilities assumed in the acquisition of a business. Goodwill is
Derivatives Financial Instruments (All Registrants)	Derivative Financial Instruments (All Registrants) Derivatives are recognized on the balance sheet at their fair value unless they qualify for certain exceptions, including NPNS. For derivatives intended to serve as economic hedges, changes in fair value are recognized in earnings each period. Changes in fair value may be recorded as a regulatory asset or liability if there is an ability to recover or return the associated costs. Cash inflows and outflows related to derivative instruments are included as a component of operating, investing, or financing cash flows in the Consolidated Statements of Cash Flows, depending on the nature of each transaction. See Note 3 — Regulatory Matters and Note 14 — Derivative Financial Instruments for additional information.
Retirement Benefits (All Registrants)	Retirement Benefits (All Registrants) Exelon sponsors defined benefit pension plans and OPEB plans for substantially all current employees. The plan obligations and costs of providing benefits under these plans are measured as of December 31. The measurement involves various factors, assumptions, and accounting elections. The impact of assumption changes or experience different from that assumed on pension and OPEB obligations is recognized over time rather than immediately recognized in the Consolidated Statements of Operations and Comprehensive Income. Gains or losses in excess of the greater of ten percent of the projected benefit obligation or the MRV of plan assets are amortized over the expected average remaining service period of plan participants. See Note 13 — Retirement Benefits for additional information.

Discontinued Operations (Tables

Discontinued Operations (Tables) - Exelon Generation Co L L C [Member]	12 Months Ended
	Dec. 31, 2021
Business Dispositions [Line Items]
Discontinued Operations - Income Statement	The following table presents the results of Generation that have been reclassified from continuing operations and included in discontinued operations within Exelon’s Consolidated Statements of Operations and Comprehensive Income for the years ended December 31, 2021, 2020, and 2019. These results are primarily Generation, which is comprised of Exelon’s Mid-Atlantic, Midwest, New York, ERCOT, and Other Power Regions reportable segments, and include the impact of transaction costs, certain BSC costs, including any transition costs, that were historically allocated and directly attributable to Generation, transactions between Generation and the Utility Registrants, and tax-related adjustments. Transaction costs include costs for external bankers, accountants, appraisers, lawyers, external counsels and other advisors, among others, who are involved in the negotiation, appraisal, due diligence and regulatory approval of the separation. Transition costs are primarily employee-related costs such as recruitment expenses, costs to establish certain stand-alone functions and information technology systems, professional services fees and other separation-related costs during the transition to separate Generation. For the purposes of reporting discontinued operations, these results also include transactions between Generation and the Utility Registrants that were historically eliminated within Exelon’s Consolidated Statements of Operations as these transactions will be ongoing after the separation. Certain BSC costs that were historically allocated to Generation are presented as part of continuing operations in Exelon’s Consolidated Statements of Operations as these costs do not qualify as expenses of the discontinued operations per the accounting rules. Year Ended 2021 2020 2019 Operating revenues Competitive business revenues $ 18,466 $ 16,399 $ 17,754 Competitive business revenues from affiliates 1,189 1,206 1,171 Total operating revenues 19,655 17,605 18,925 Operating expenses Competitive businesses purchased power and fuel 12,163 9,585 10,856 Operating and maintenance (a) 4,174 4,794 4,324 Depreciation and amortization 3,003 2,123 1,535 Taxes other than income taxes 475 482 519 Total operating expenses 19,815 16,984 17,234 Gain on sales of assets and businesses 201 11 27 Operating income 41 632 1,718 Other income and (deductions) Interest expense, net (282) (328) (394) Other, net 795 937 1,023 Total other income 513 609 629 Income before income taxes 554 1,241 2,347 Income taxes 332 380 621 Equity in losses of unconsolidated affiliates (9) (6) (184) Net income 213 855 1,542 Net income (loss) attributable to noncontrolling interests 123 (9) 92 Net income from discontinued operations $ 90 $ 864 $ 1,450 __________ (a) Includes transaction and transition costs related to the separation of $24 million and $19 million for the year ended December 31, 2021. There were no separation related costs incurred in 2020 or 2019. See discussion above for additional information.
Discontinued Operations - Balance Sheet	The following table presents the assets and liabilities of discontinued operations in Exelon’s Consolidated Balance Sheets as of December 31, 2021 and 2020. December 31, 2021 December 31, 2020 ASSETS Current assets Cash and cash equivalents $ 510 $ 231 Restricted cash and cash equivalents 72 89 Accounts receivable Customer accounts receivable 1,724 1,331 Customer allowance for credit losses (55) (32) Customer accounts receivable, net 1,669 1,299 Other accounts receivable 596 352 Other allowance for credit losses (4) — Other accounts receivable, net 592 352 Mark-to-market derivative assets 2,169 644 Inventories, net Fossil fuel and emission allowances 284 233 Materials and supplies 1,004 978 Renewable energy credits 529 633 Assets held for sale 13 958 Other 993 1,424 Total current assets of discontinued operations 7,835 6,841 Property, plant, and equipment (net of accumulated depreciation and amortization of $15,888 and $13,381, respectively) 19,661 22,252 Deferred debits and other assets Nuclear decommissioning trust funds 15,938 14,464 Investments 193 202 Mark-to-market derivative assets 949 555 Other 1,768 2,180 Total property, plant, and equipment, deferred debits, and other assets of discontinued operations 38,509 39,653 Total assets of discontinued operations $ 46,344 $ 46,494 December 31, 2021 December 31, 2020 LIABILITIES AND SHAREHOLDERS’ EQUITY Current liabilities Short-term borrowings $ 2,082 $ 840 Long-term debt due within one year 1,220 197 Accounts payable 1,757 1,253 Accrued expenses 818 848 Mark-to-market derivative liabilities 981 262 Renewable energy credit obligation 779 661 Liabilities held for sale 3 375 Other 300 487 Total current liabilities of discontinued operations 7,940 4,923 Long-term debt 4,575 5,566 Deferred credits and other liabilities Deferred income taxes and unamortized investment tax credits 3,583 3,443 Asset retirement obligations 12,819 12,054 Pension obligations 939 1,557 Non-pension postretirement benefit obligations 876 1,009 Spent nuclear fuel obligation 1,210 1,208 Mark-to-market derivative liabilities 513 205 Other 1,161 1,303 Total long-term debt, deferred credits, and other liabilities of discontinued operations 25,676 26,345 Total liabilities of discontinued operations $ 33,616 $ 31,268
Discontinued Operations - Cash Flows	The following table presents selected financial information regarding cash flows of the discontinued operations that are included within Exelon’s Consolidated Statements of Cash Flows for the years ended December 31, 2021, 2020, and 2019. Year Ended 2021 2020 2019 Non-cash items included in net income (loss) from discontinued operations: Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization $ 4,540 $ 3,636 $ 3,063 Asset impairments 545 563 201 Gain on sales of assets and businesses (201) (11) (27) Deferred income taxes and amortization of investment tax credits (224) 94 376 Net fair value changes related to derivatives (568) (270) 228 Net realized and unrealized gains on NDT fund investments (586) (461) (663) Net unrealized losses (gains) on equity investments 160 (186) — Other decommissioning-related activity (946) (659) (506) Cash flows from investing activities: Capital expenditures (1,341) (1,759) (1,849) Collection of DPP 3,902 3,771 — Supplemental cash flow information: Increase (decrease) in capital expenditures not paid 96 (88) (34) Increase in DPP 3,652 4,441 — Increase in PP&E related to ARO update 618 850 959

Regulatory Matters (Tables)

Regulatory Matters (Tables)	12 Months Ended
Regulatory Matters (Tables)	Dec. 31, 2021
Public Utilities, General Disclosures [Line Items]
Public Utilities Distribution Rate Cases [Table Text Block]	The following tables show the completed and pending distribution base rate case proceedings in 2021. Completed Distribution Base Rate Case Proceedings Registrant/Jurisdiction Filing Date Service Requested Revenue Requirement (Decrease) Increase Approved Revenue Requirement (Decrease) Increase Approved ROE Approval Date Rate Effective Date ComEd - Illinois (a) April 16, 2020 Electric $ (11) $ (14) 8.38 % December 9, 2020 January 1, 2021 April 16, 2021 Electric 51 46 7.36 % December 1, 2021 January 1, 2022 PECO - Pennsylvania September 30, 2020 Natural Gas 69 29 10.24 % June 22, 2021 July 1, 2021 March 30, 2021 Electric 246 132 N/A (b) November 18, 2021 January 1, 2022 BGE - Maryland (c) May 15, 2020 (amended September 11, 2020) Electric 203 140 9.50 % December 16, 2020 January 1, 2021 Natural Gas 108 74 9.65 % Pepco - District of Columbia (d) May 30, 2019 (amended June 1, 2020) Electric 136 109 9.275 % June 8, 2021 July 1, 2021 Pepco - Maryland (e) October 26, 2020 (amended March 31, 2021) Electric 104 52 9.55 % June 28, 2021 June 28, 2021 DPL - Delaware March 6, 2020 (amended February 2, 2021) Electric 23 14 9.60 % September 15, 2021 October 6, 2020 ACE - New Jersey (f) December 9, 2020 (amended February 26, 2021) Electric 67 41 9.60 % July 14, 2021 January 1, 2022 __________ (a) Pursuant to EIMA and FEJA, ComEd’s electric distribution rates are established through a performance-based formula, which sunsets at the end of 2022. See discussion of the Clean Energy Law below for details on the transition away from the electric distribution formula rate. The electric distribution formula rate includes decoupling provisions and, as a result, ComEd's electric distribution formula rate revenues are not impacted by abnormal weather, usage per customer, or number of customers. ComEd is required to file an annual update to its electric distribution formula rate on or before May 1 st , with resulting rates effective in January of the following year. ComEd’s annual electric distribution formula rate update is based on prior year actual costs and current year projected capital additions (initial year revenue requirement). The update also reconciles any differences between the revenue requirement in effect for the prior year and actual costs incurred from the year (annual reconciliation). ComEd’s 2021 approved revenue requirement reflects an increase of $50 million for the initial year revenue requirement for 2021 and a decrease of $64 million related to the annual reconciliation for 2019. The revenue requirement for 2021 and the revenue requirement for 2019 provide for a weighted average debt and equity return on distribution rate base of 6.28% inclusive of an allowed ROE of 8.38%, reflecting the monthly average yields for 30-year treasury bonds plus 580 basis points . ComEd’s 2022 approved revenue requirement above reflects an increase of $37 million for the initial year revenue requirement for 2022 and an increase of $9 million related to the annual reconciliation for 2020. The revenue requirement for 2022 provides for a weighted average debt and equity return on distribution rate base of 5.72% inclusive of an allowed ROE of 7.36%, reflecting the monthly average yields for 30-year treasury bonds plus 580 basis points. The reconciliation revenue requirement for 2020 provides for a weighted average debt and equity return on distribution rate base of 5.69%, inclusive of an allowed ROE of 7.29%, reflecting the monthly yields on 30-year treasury bonds plus 580 basis points less a performance metrics penalty of 7 basis points. (b) The PECO electric base rate case proceeding was resolved through a settlement agreement, which did not specify an approved ROE. (c) Reflects a three-year cumulative multi-year plan for 2021 through 2023. The MDPSC awarded BGE electric revenue requirement increases of $59 million, $39 million, and $42 million, before offsets, in 2021, 2022, and 2023, respectively, and natural gas revenue requirement increases of $53 million, $11 million, and $10 million, before offsets, in 2021, 2022, and 2023, respectively. BGE proposed to use certain tax benefits to fully offset the increases in 2021 and 2022 and partially offset the increase in 2023. However, the MDPSC utilized the tax benefits to fully offset the increases in 2021 and January 2022 such that customer rates remained unchanged. For the remainder of 2022, the MDPSC chose to offset only 25% of the cumulative 2021 and 2022 electric revenue requirement increases and 50% of the cumulative gas revenue requirement increases. Whether certain tax benefits will be used to offset the customer rate increases in 2023 has not been decided, and BGE cannot predict the outcome. (d) Reflects a cumulative multi-year plan with 18-months remaining in 2021 through 2022. The DCPSC awarded Pepco electric incremental revenue requirement increases of $42 million and $67 million, before offsets, for the remainder of 2021 and 2022, respectively. However, the DCPSC utilized the acceleration of refunds for certain tax benefits along with other rate relief to partially offset the customer rate increases by $22 million and $40 million for the remainder of 2021 and 2022, respectively. (e) Reflects a three-year cumulative multi-year plan for April 1, 2021 through March 31, 2024. The MDPSC awarded Pepco electric incremental revenue requirement increases of $21 million, $16 million, and $15 million, before offsets, for the 12-month periods ending March 31, 2022, 2023, and 2024, respectively. Pepco proposed to utilize certain tax benefits to fully offset the increase through 2023 and partially offset customer rate increases in 2024. However, the MDPSC only utilized the acceleration of refunds for certain tax benefits to fully offset the increases such that customer rates remain unchanged through March 31, 2022. On February 23, 2022, the MDPSC chose to offset 25% of the cumulative revenue requirement increase through March 31, 2023. Whether certain tax benefits will be used to offset the customer rate increases for the twelve months ended March 31, 2024 has not been decided, and Pepco cannot predict the outcome. (f) Requested and approved increases are before New Jersey sales and use tax. The order allows ACE to retain approximately $11 million of certain tax benefits which resulted in a decrease to income tax expense in Exelon's, PHI's, and ACE's Consolidated Statements of Operations and Comprehensive Income in the third quarter of 2021. Pending Distribution Base Rate Case Proceedings Registrant/Jurisdiction Filing Date Service Requested Revenue Requirement Increase Requested ROE Expected Approval Timing DPL - Delaware January 14, 2022 Natural Gas $ 14 10.30 % First quarter of 2023 DPL - Maryland (a) September 1, 2021 (amended December 23, 2021) Electric 27 10.10 % First quarter of 2022 __________ (a) On January 24, 2022, DPL filed a settlement agreement with the MDPSC. The settlement provides for a revenue requirement increase of $13 million. The 9.60% ROE in the agreement is solely for the purposes of calculating AFUDC and regulatory asset carrying costs. On February 15, 2021, the Chief Public Utility Law Judge issued a proposed order approving the settlement agreement without modification. The proposed order will become a final order of the MDPSC on March 2, 2022, subject to modification or reversal by the MDPSC.
Public Utilities Transmission Rate Filings [Table Text Block]	For 2021, the following total increases/(decreases) were included in the Utility Registrants' electric transmission formula rate updates: Registrant (a) Initial Revenue Requirement Increase (Decrease) Annual Reconciliation Increase Total Revenue Requirement Increase (b) Allowed Return on Rate Base (c) Allowed ROE (d) ComEd $ 33 $ 12 $ 45 8.20 % 11.50 % PECO (2) 26 24 7.37 % 10.35 % BGE 38 27 65 7.35 % 10.50 % Pepco (9) 21 12 7.68 % 10.50 % DPL 19 33 52 7.20 % 10.50 % ACE 27 24 51 7.45 % 10.50 % __________ (a) All rates are effective June 1, 2021 - May 31, 2022, subject to review by interested parties pursuant to review protocols of each Utility Registrant's tariff. (b) In 2020, ComEd, BGE, Pepco, DPL, and ACE's transmission revenue requirement included a one-time decrease in accordance with the April 24, 2020 settlement agreement related to excess deferred income taxes which now completed has resulted in an increase to the 2021 transmission revenue requirement. In 2020, PECO's transmission revenue requirement included a one-time decrease in accordance with the December 5, 2019 settlement agreement related to refunds which now completed has resulted in an increase to the 2021 transmission revenue requirement. (c) Represents the weighted average debt and equity return on transmission rate bases. (d) As part of the FERC-approved settlements of ComEd’s 2007 and PECO's 2017 transmission rate cases, the rate of return on common equity is 11.50% and 10.35%, respectively, inclusive of a 50-basis-point incentive adder for being a member of a RTO, and the common equity component of the ratio used to calculate the weighted average debt and equity return for the transmission formula rate is currently capped at 55% and 55.75%, respectively. As part of the FERC-approved settlement of the ROE complaint against BGE, Pepco, DPL, and ACE, the rate of return on common equity is 10.50%, inclusive of a 50-basis-point incentive adder for being a member of a RTO.
Public Utilities Energy Efficiency Revenue [Table Text Block]	During 2021, the ICC approved the following total increases in ComEd's requested energy efficiency revenue requirement: Filing Date Requested Revenue Requirement Increase Approved Revenue Requirement Increase (a) Approved ROE Approval Date Rate Effective Date June 1, 2021 $ 54 $ 54 7.36 % November 18, 2021 January 1, 2022 _________ (a) ComEd’s 2022 approved revenue requirement above reflects an increase of $55 million for the initial year revenue requirement for 2022 and a decrease of $1 million related to the annual reconciliation for 2020. The revenue requirement for 2022 provides for a weighted average debt and equity return on the energy efficiency regulatory asset and rate base of 5.72% inclusive of an allowed ROE of 7.36%, reflecting the monthly average yields for 30-year treasury bonds plus 580 basis points. The revenue requirement for the 2020 reconciliation year provides for a weighted average debt and equity return on the energy efficiency asset and rate base of 6.26% inclusive of an allowed ROE of 8.46%, which includes an upward performance adjustment that increased the ROE. The performance adjustment can either increase or decrease the ROE based upon the achievement of energy efficiency savings goals. See table below for ComEd's regulatory assets associated with its energy efficiency formula rate.
Public Utilities General Disclosures [Table Text Block]	The following table presents authorized amounts capitalized for ratemaking purposes related to earnings on shareholders’ investment that are not recognized for financial reporting purposes in the Registrants' Consolidated Balance Sheets. These amounts will be recognized as revenues in the related Consolidated Statements of Operations and Comprehensive Income in the periods they are billable to the Utility Registrants' customers. Exelon ComEd (a) PECO BGE (b) PHI Pepco (c) DPL (c) ACE December 31, 2021 $ 43 $ 1 $ — $ 37 $ 5 $ 3 $ 2 $ — December 31, 2020 51 (1) — 45 7 4 3 — __________ (a) Reflects ComEd's unrecognized equity returns/(losses) earned/(incurred) for ratemaking purposes on its electric distribution formula rate regulatory assets. (b) BGE's authorized amounts capitalized for ratemaking purposes primarily relate to earnings on shareholders' investment on its AMI programs.
Regulatory assets 2021 [Member]
Public Utilities, General Disclosures [Line Items]
Schedule of Regulatory Assets	The following tables provide information about the regulatory assets and liabilities of the Registrants as of December 31, 2021 and 2020: December 31, 2021 Exelon ComEd PECO BGE PHI Pepco DPL ACE Regulatory assets Pension and OPEB $ 2,409 $ — $ — $ — $ — $ — $ — $ — Pension and OPEB - merger related 893 — — — — — — — Deferred income taxes 883 — 873 — 10 10 — — AMI programs - deployment costs 145 — — 89 56 30 26 — AMI programs - legacy meters 186 69 — 29 88 60 21 7 Electric distribution formula rate annual reconciliations 44 44 — — — — — — Electric distribution formula rate significant one-time events 104 104 — — — — — — Energy efficiency costs 1,181 1,181 — — — — — — Fair value of long-term debt 557 — — — 443 — — — Fair value of PHI's unamortized energy contracts 236 — — — 236 — — — Asset retirement obligations 145 99 21 19 6 5 — 1 MGP remediation costs 283 266 8 9 — — — — Renewable energy 219 219 — — — — — — Electric energy and natural gas costs 96 — — 49 47 29 13 5 Transmission formula rate annual reconciliations 43 — 14 1 28 — 8 20 Energy efficiency and demand response programs 564 — — 283 281 199 79 3 Under-recovered revenue decoupling 157 — — 32 125 125 — — Removal costs 758 — — 143 615 147 109 360 DC PLUG charge 70 — — — 70 70 — — Deferred storm costs 49 — — — 49 3 3 43 COVID-19 82 28 33 8 13 10 3 — Under-recovered credit loss expense 89 60 — — 29 — — 29 Other 327 135 42 30 130 57 18 23 Total regulatory assets 9,520 2,205 991 692 2,226 745 280 491 Less: current portion 1,296 335 48 215 432 213 68 61 Total noncurrent regulatory assets $ 8,224 $ 1,870 $ 943 $ 477 $ 1,794 $ 532 $ 212 $ 430
Regulatory liabilities 2021 [Member]
Public Utilities, General Disclosures [Line Items]
Schedule of Regulatory Liabilities	December 31, 2021 Exelon ComEd PECO BGE PHI Pepco DPL ACE Regulatory liabilities Deferred income taxes $ 4,005 $ 2,105 $ — $ 819 $ 1,081 $ 525 $ 354 $ 202 Decommissioning the Regulatory Agreement Units 3,357 2,760 597 — — — — — Removal costs 1,694 1,541 — 39 114 20 94 — Electric energy and natural gas costs 113 25 71 — 17 9 3 5 Transmission formula rate annual reconciliations 8 7 — — 1 1 — — Renewable portfolio standards costs 500 500 — — — — — — Stranded costs 35 — — — 35 — — 35 Other 292 6 61 102 58 8 15 10 Total regulatory liabilities 10,004 6,944 729 960 1,306 563 466 252 Less: current portion 376 185 94 26 68 14 25 28 Total noncurrent regulatory liabilities $ 9,628 $ 6,759 $ 635 $ 934 $ 1,238 $ 549 $ 441 $ 224
Regulatory assets 2020 [Member]
Public Utilities, General Disclosures [Line Items]
Schedule of Regulatory Assets	December 31, 2020 Exelon ComEd PECO BGE PHI Pepco DPL ACE Regulatory assets Pension and OPEB $ 3,010 $ — $ — $ — $ — $ — $ — $ — Pension and OPEB - merger related 1,014 — — — — — — — Deferred income taxes 715 — 705 — 10 10 — — AMI programs - deployment costs 174 — — 109 65 35 30 — AMI programs - legacy meters 219 90 — 37 92 68 24 — Electric distribution formula rate annual reconciliations (14) (14) — — — — — — Electric distribution formula rate significant one-time events 117 117 — — — — — — Energy efficiency costs 982 982 — — — — — — Fair value of long-term debt 598 — — — 478 — — — Fair value of PHI's unamortized energy contracts 328 — — — 328 — — — Asset retirement obligations 135 92 21 18 4 3 — 1 MGP remediation costs 285 271 10 4 — — — — Renewable energy 301 301 — — — — — — Electric energy and natural gas costs 95 — — 23 72 37 5 30 Transmission formula rate annual reconciliations 5 — — 2 3 — 2 1 Energy efficiency and demand response programs 572 — — 289 283 203 80 — Under-recovered revenue decoupling 113 — — 20 93 93 — — Stranded costs 25 — — — 25 — — 25 Removal costs 701 — — 107 594 151 105 339 DC PLUG charge 100 — — — 100 100 — — Deferred storm costs 50 — — — 50 5 4 41 COVID-19 81 22 38 10 11 7 4 — Under-recovered credit loss expense 107 89 — — 18 — — 18 Other 274 78 27 30 147 72 26 15 Total regulatory assets 9,987 2,028 801 649 2,373 784 280 470 Less: current portion 1,228 279 25 168 440 214 58 75 Total noncurrent regulatory assets $ 8,759 $ 1,749 $ 776 $ 481 $ 1,933 $ 570 $ 222 $ 395
Regulatory liabilities 2020 [Member]
Public Utilities, General Disclosures [Line Items]
Schedule of Regulatory Liabilities	December 31, 2020 Exelon ComEd PECO BGE PHI Pepco DPL ACE Regulatory liabilities Deferred income taxes $ 4,502 $ 2,205 $ — $ 1,001 $ 1,296 $ 621 $ 404 $ 271 Decommissioning the Regulatory Units 3,016 2,541 475 — — — — — Removal costs 1,649 1,482 — 47 120 20 100 — Electric energy and natural gas costs 175 34 97 6 38 24 10 4 Transmission formula rate annual reconciliations 52 2 12 — 38 23 9 6 Renewable portfolio standards costs 427 427 — — — — — — Stranded costs 24 — — — 24 — — 24 Other 221 1 40 85 59 2 17 13 Total regulatory liabilities 10,066 6,692 624 1,139 1,575 690 540 318 Less: current portion 581 289 121 30 137 46 47 44 Total noncurrent regulatory liabilities $ 9,485 $ 6,403 $ 503 $ 1,109 $ 1,438 $ 644 $ 493 $ 274

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	12 Months Ended
Revenue from Contracts with Customers (Tables)	Dec. 31, 2021
Contract Asset/Liabilities [Line Items]
Contract with Customer, Prior Year Contract Revenues Recognized in Current Year [Table Text Block]	The following table reflects revenues recognized in the years ended December 31, 2021, 2020 and 2019, which were included in contract liabilities at December 31, 2020, 2019, and 2018, respectively: 2021 Exelon $ 9 PHI 9 Pepco 7 DPL 1 ACE 1
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Table Text Block]	The following table shows the amounts of future revenues expected to be recorded in each year for performance obligations that are unsatisfied or partially unsatisfied as of December 31, 2021. This disclosure only includes contracts for which the total consideration is fixed and determinable at contract inception. The average contract term varies by customer type and commodity but ranges from one month to several years. This disclosure excludes the Utility Registrants' gas and electric tariff sales contracts and transmission revenue contracts as they generally have an original expected duration of one year or less and, therefore, do not contain any future, unsatisfied performance obligations to be included in this disclosure. 2022 2023 2024 2025 2026 and thereafter Total Exelon $ 8 $ 8 $ 6 $ 5 $ 82 $ 109 PHI 8 8 6 5 82 109 Pepco 6 6 5 5 65 87 DPL 1 1 — — 9 11 ACE 1 1 1 — 8 11
Contract Liabilities [Member]
Contract Asset/Liabilities [Line Items]
Contract with Customer, Contract Asset, Contract Liability, and Receivable [Table Text Block]	The following table provides a rollforward of the contract liabilities reflected in Exelon's, PHI's, Pepco's, DPL's, and ACE'S Consolidated Balance Sheets. As of December 31, 2021, 2020, and 2019, ComEd's, PECO's, and BGE's contract liabilities were not material. Exelon PHI Pepco DPL ACE Balance as of December 31, 2019 $ — $ — $ — $ — $ — Consideration received or due 122 122 98 12 12 Revenues recognized (4) (4) (4) — — Balance as of December 31, 2020 118 118 94 12 12 Revenues recognized (9) (9) (7) (1) (1) Balance as of December 31, 2021 $ 109 $ 109 $ 87 $ 11 $ 11

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
Segment Information (Tables)	Dec. 31, 2021
Segment Reporting [Abstract]
Analysis and reconciliation of reportable segment information	An analysis and reconciliation of the reportable segment information to the respective information in the Exelon consolidated financial statements for the years ended December 31, 2021, 2020, and 2019 is as follows: ComEd PECO BGE PHI Other (a) Intersegment Exelon Operating revenues (b) : 2021 Electric revenues $ 6,406 $ 2,659 $ 2,505 $ 4,860 $ — $ (35) $ 16,395 Natural gas revenues — 539 836 168 — — 1,543 Shared service and other revenues — — — 13 2,213 (2,226) — Total operating revenues $ 6,406 $ 3,198 $ 3,341 $ 5,041 $ 2,213 $ (2,261) $ 17,938 2020 Electric revenues $ 5,904 $ 2,543 $ 2,336 $ 4,485 $ — $ (44) $ 15,224 Natural gas revenues — 515 762 162 — — 1,439 Shared service and other revenues — — — 16 2,035 (2,051) — Total operating revenues $ 5,904 $ 3,058 $ 3,098 $ 4,663 $ 2,035 $ (2,095) $ 16,663 2019 Electric revenues $ 5,747 $ 2,490 $ 2,379 $ 4,626 $ — $ (21) $ 15,221 Natural gas revenues — 610 727 167 — — 1,504 Shared service and other revenues — — — 13 1,921 (1,934) — Total operating revenues $ 5,747 $ 3,100 $ 3,106 $ 4,806 $ 1,921 $ (1,955) $ 16,725 Intersegment revenues (c) : 2021 $ 41 $ 21 $ 31 $ 13 $ 2,203 $ (2,252) $ 57 2020 37 9 20 17 2,024 (2,084) 23 2019 30 6 26 14 1,913 (1,948) 41 Depreciation and amortization: 2021 $ 1,205 $ 348 $ 591 $ 821 $ 67 $ 1 $ 3,033 2020 1,133 347 550 782 79 — 2,891 2019 1,033 333 502 754 95 — 2,717 Operating expenses: 2021 $ 5,151 $ 2,547 $ 2,860 $ 4,240 $ 2,045 $ (1,587) $ 15,256 2020 4,950 2,512 2,598 4,045 1,882 (1,502) 14,485 2019 4,580 2,388 2,574 4,084 1,830 (1,383) 14,073 ComEd PECO BGE PHI Other (a) Intersegment Exelon Interest expense, net: 2021 $ 389 $ 161 $ 138 $ 267 $ 335 $ (1) $ 1,289 2020 382 147 133 268 380 (3) 1,307 2019 359 136 121 263 343 — 1,222 Income (loss) from continuing operations before income taxes: 2021 $ 914 $ 516 $ 373 $ 603 $ (149) $ (603) $ 1,654 2020 615 417 390 418 (151) (597) 1,092 2019 851 593 439 514 (127) (632) 1,638 Income taxes: 2021 $ 172 $ 12 $ (35) $ 42 $ 8 $ (161) $ 38 2020 177 (30) 41 (77) 35 (153) (7) 2019 163 65 79 38 (32) (160) 153 Net income (loss) from continuing operations: 2021 $ 742 $ 504 $ 408 $ 561 $ (156) $ (443) $ 1,616 2020 438 447 349 495 (184) (446) 1,099 2019 688 528 360 477 (95) (472) 1,486 Capital expenditures: 2021 $ 2,387 $ 1,240 $ 1,226 $ 1,720 $ 67 $ — $ 6,640 2020 2,217 1,147 1,247 1,604 74 — 6,289 2019 1,915 939 1,145 1,355 45 — 5,399 Total assets: 2021 $ 36,470 $ 13,824 $ 12,324 $ 24,744 $ 7,626 $ (8,319) $ 86,669 2020 34,466 12,531 11,650 23,736 8,894 (8,454) 82,823 __________ (a) Other primarily includes Exelon’s corporate operations, shared service entities, and other financing and investment activities. (b) Includes gross utility tax receipts from customers. The offsetting remittance of utility taxes to the governing bodies is recorded in expenses in the Registrants’ Consolidated Statements of Operations and Comprehensive Income. See Note 22 — Supplemental Financial Information for additional information on total utility taxes. (c) See Note 23 — Related Party Transactions for additional information on intersegment revenues. PHI: Pepco DPL ACE Other (a) Intersegment PHI Operating revenues (b) : 2021 Electric revenues $ 2,274 $ 1,212 $ 1,388 $ — $ (14) $ 4,860 Natural gas revenues — 168 — — — 168 Shared service and other revenues — — — 379 (366) 13 Total operating revenues $ 2,274 $ 1,380 $ 1,388 $ 379 $ (380) $ 5,041 2020 Electric revenues $ 2,149 $ 1,109 $ 1,245 $ — $ (18) $ 4,485 Natural gas revenues — 162 — — — 162 Shared service and other revenues — — — 372 (356) 16 Total operating revenues $ 2,149 $ 1,271 $ 1,245 $ 372 $ (374) $ 4,663 2019 Electric revenues $ 2,260 $ 1,139 $ 1,240 $ — $ (13) $ 4,626 Natural gas revenues — 167 — — — 167 Shared service and other revenues — — — 396 (383) 13 Total operating revenues $ 2,260 $ 1,306 $ 1,240 $ 396 $ (396) $ 4,806 Intersegment revenues (c) : 2021 $ 5 $ 7 $ 2 $ 380 $ (381) $ 13 2020 7 9 4 372 (375) 17 2019 5 7 3 396 (397) 14 Depreciation and amortization: 2021 $ 403 $ 210 $ 179 $ 29 $ — $ 821 2020 377 191 180 34 — 782 2019 374 184 157 39 — 754 Operating expenses: 2021 $ 1,871 $ 1,161 $ 1,201 $ 388 $ (381) $ 4,240 2020 1,799 1,120 1,123 378 (375) 4,045 2019 1,899 1,089 1,089 403 (396) 4,084 Interest expense, net: 2021 $ 140 $ 61 $ 58 $ 8 $ — $ 267 2020 138 61 59 10 — 268 2019 133 61 58 10 1 263 Income (loss) before income taxes: 2021 $ 311 $ 170 $ 133 $ (11) $ — $ 603 2020 259 100 71 (12) — 418 2019 259 169 99 (13) — 514 Income taxes: 2021 $ 15 $ 42 $ (13) $ (2) $ — $ 42 2020 (7) (25) (41) (4) — (77) 2019 16 22 — — — 38 Pepco DPL ACE Other (a) Intersegment PHI Net income (loss): 2021 $ 296 $ 128 $ 146 $ (9) $ — $ 561 2020 266 125 112 (8) — 495 2019 243 147 99 (12) — 477 Capital expenditures: 2021 $ 843 $ 429 $ 445 $ 3 $ — $ 1,720 2020 773 424 401 6 — 1,604 2019 626 348 375 6 — 1,355 Total assets: 2021 $ 9,903 $ 5,412 $ 4,556 $ 4,933 $ (60) $ 24,744 2020 9,264 5,140 4,286 5,079 (33) 23,736 __________ (a) Other primarily includes PHI’s corporate operations, shared service entities, and other financing and investment activities. (b) Includes gross utility tax receipts from customers. The offsetting remittance of utility taxes to the governing bodies is recorded in expenses in the Registrants’ Consolidated Statements of Operations and Comprehensive Income. See Note 22 — Supplemental Financial Information for additional information on total utility taxes. (c) Includes intersegment revenues with ComEd, BGE, and PECO, which are eliminated at Exelon.
Analysis and reconciliation of reportable segment revenues for Generation	The following tables disaggregate the revenues recognized from contracts with customers into categories that depict how the nature, amount, timing, and uncertainty of revenue and cash flows are affected by economic factors. For the Utility Registrants, the disaggregation of revenues reflects the two primary utility services of electric sales and natural gas sales (where applicable), with further disaggregation of these tariff sales provided by major customer groups. Exelon's disaggregated revenues are consistent with the Utility Registrants, but exclude any intercompany revenues.
Schedule of Revenue by Major Customers by Reporting Segments	2021 Revenues from contracts with customers ComEd PECO BGE PHI Pepco DPL ACE Electric revenues Residential $ 3,233 $ 1,704 $ 1,375 $ 2,441 $ 1,003 $ 694 $ 744 Small commercial & industrial 1,571 422 267 521 135 193 193 Large commercial & industrial 559 243 459 1,123 844 94 185 Public authorities & electric railroads 45 31 27 58 31 14 13 Other (a) 926 229 371 634 205 201 229 Total electric revenues (b) $ 6,334 $ 2,629 $ 2,499 $ 4,777 $ 2,218 $ 1,196 $ 1,364 Natural gas revenues Residential $ — $ 372 $ 518 $ 97 $ — $ 97 $ — Small commercial & industrial — 136 83 42 — 42 — Large commercial & industrial — — 147 7 — 7 — Transportation — 24 — 14 — 14 — Other (c) — 7 68 8 — 8 — Total natural gas revenues (d) $ — $ 539 $ 816 $ 168 $ — $ 168 $ — Total revenues from contracts with customers $ 6,334 $ 3,168 $ 3,315 $ 4,945 $ 2,218 $ 1,364 $ 1,364 Other revenues Revenues from alternative revenue programs $ 42 $ 26 $ 12 $ 91 $ 53 $ 14 $ 24 Other electric revenues (e) 30 4 11 5 3 2 — Other natural gas revenues (e) — — 3 — — — — Total other revenues $ 72 $ 30 $ 26 $ 96 $ 56 $ 16 $ 24 Total revenues for reportable segments $ 6,406 $ 3,198 $ 3,341 $ 5,041 $ 2,274 $ 1,380 $ 1,388 2020 Revenues from contracts with customers ComEd PECO BGE PHI Pepco DPL ACE Electric revenues Residential $ 3,090 $ 1,656 $ 1,345 $ 2,332 $ 988 $ 652 $ 692 Small commercial & industrial 1,399 386 241 472 132 171 169 Large commercial & industrial 515 228 406 1,001 736 89 176 Public authorities & electric railroads 45 29 27 60 34 13 13 Other (a) 884 225 309 613 218 190 207 Total electric revenues (b) $ 5,933 $ 2,524 $ 2,328 $ 4,478 $ 2,108 $ 1,115 $ 1,257 Natural gas revenues Residential $ — $ 361 $ 504 $ 96 $ — $ 96 $ — Small commercial & industrial — 126 79 42 — 42 — Large commercial & industrial — — 135 4 — 4 — Transportation — 24 — 14 — 14 — Other (c) — 4 29 6 — 6 — Total natural gas revenues (d) $ — $ 515 $ 747 $ 162 $ — $ 162 $ — Total revenues from contracts with customers $ 5,933 $ 3,039 $ 3,075 $ 4,640 $ 2,108 $ 1,277 $ 1,257 Other revenues Revenues from alternative revenue programs $ (47) $ 16 $ 16 $ 21 $ 40 $ (7) $ (12) Other electric revenues (e) 18 3 5 2 1 1 — Other natural gas revenues (e) — — 2 — — — — Total other revenues $ (29) $ 19 $ 23 $ 23 $ 41 $ (6) $ (12) Total revenues for reportable segments $ 5,904 $ 3,058 $ 3,098 $ 4,663 $ 2,149 $ 1,271 $ 1,245 2019 Revenues from contracts with customers ComEd PECO BGE PHI Pepco DPL ACE Electric revenues Residential $ 2,916 $ 1,596 $ 1,326 $ 2,316 $ 1,012 $ 645 $ 659 Small commercial & industrial 1,463 404 254 505 149 186 170 Large commercial & industrial 540 219 436 1,112 833 99 180 Public authorities & electric railroads 47 29 27 61 34 14 13 Other (a) 888 249 321 650 227 204 218 Total electric revenues (b) $ 5,854 $ 2,497 $ 2,364 $ 4,644 $ 2,255 $ 1,148 $ 1,240 Natural gas revenues Residential $ — $ 409 $ 474 $ 96 $ — $ 96 $ — Small commercial & industrial — 169 77 44 — 45 — Large commercial & industrial — 1 132 5 — 5 — Transportation — 25 — 14 — 14 — Other (c) — 6 31 7 — 7 — Total natural gas revenues (d) $ — $ 610 $ 714 $ 166 $ — $ 167 $ — Total revenues from contracts with customers $ 5,854 $ 3,107 $ 3,078 $ 4,810 $ 2,255 $ 1,315 $ 1,240 Other revenues Revenues from alternative revenue programs $ (133) $ (21) $ 12 $ (14) $ (3) $ (11) $ — Other electric revenues (e) 26 13 12 10 8 2 — Other natural gas revenues (e) — 1 4 — — — — Total other revenues $ (107) $ (7) $ 28 $ (4) $ 5 $ (9) $ — Total revenues for reportable segments $ 5,747 $ 3,100 $ 3,106 $ 4,806 $ 2,260 $ 1,306 $ 1,240 __________ (a) Includes revenues from transmission revenue from PJM, wholesale electric revenue and mutual assistance revenue. (b) Includes operating revenues from affiliates in 2021, 2020, and 2019 respectively of: • $41 million, $37 million, and $30 million at ComEd • $20 million, $8 million, and $5 million at PECO • $13 million, $10 million, and $8 million at BGE • $13 million, $17 million, and $14 million at PHI • $5 million, $7 million, and $5 million at Pepco • $7 million, $9 million, and $7 million at DPL • $2 million, $4 million, and $3 million at ACE (c) Includes revenues from off-system natural gas sales. (d) Includes operating revenues from affiliates in 2021, 2020, and 2019 respectively of: • $1 million, $1 million, and $1 million at PECO • $18 million, $10 million, and $18 million at BGE (e) Includes late payment charge revenues.

Accounts Receivable (Tables)

Accounts Receivable (Tables)	12 Months Ended
Accounts Receivable (Tables)	Dec. 31, 2021
Receivables [Abstract]
Allowance for Credit Losses Rollforward	The following tables present the rollforward of Allowance for Credit Losses on Customer Accounts Receivable. Year Ended December 31, 2021 Exelon ComEd PECO BGE PHI Pepco DPL ACE Balance as of December 31, 2020 $ 334 $ 97 $ 116 $ 35 $ 86 $ 32 $ 22 $ 32 Plus: Current period provision for expected credit losses (a) 96 21 23 15 37 13 6 18 Less: Write-offs, net of recoveries (b)(c) 110 45 34 12 19 8 10 1 Balance as of December 31, 2021 $ 320 $ 73 $ 105 $ 38 $ 104 $ 37 $ 18 $ 49 Year Ended December 31, 2020 Exelon ComEd PECO BGE PHI Pepco DPL ACE Balance as of December 31, 2019 $ 163 $ 59 $ 55 $ 12 $ 37 $ 13 $ 11 $ 13 Plus: Current period provision for expected credit losses (d) 235 62 79 30 64 24 15 25 Less: Write-offs, net of recoveries (c) 64 24 18 7 15 5 4 6 Balance as of December 31, 2020 $ 334 $ 97 $ 116 $ 35 $ 86 $ 32 $ 22 $ 32 _________ (a) The increase is primarily a result of increased aging of receivables. (b) For ComEd, PECO and DPL, the increase in 2021 is primarily related to the termination of the moratorium which, beginning in March 2020, prevented customer disconnections for non-payment. With disconnection activities restarting in 2021, write-offs of aging accounts receivable increased throughout the year. (c) Recoveries were not material to the Registrants. (d) The increase is primarily as a result of increased aging of receivables, the temporary suspension of customer disconnections for non-payment, temporary cessation of new late payment fees, and reconnection of service to customers previously disconnected due to COVID-19. The following tables present the rollforward of Allowance for Credit Losses on Other Accounts Receivable. Year Ended December 31, 2021 Exelon ComEd PECO BGE PHI Pepco DPL ACE Balance as of December 31, 2020 $ 71 $ 21 $ 8 $ 9 $ 33 $ 13 $ 9 $ 11 Plus: Current period provision for expected credit losses 11 (2) 3 4 6 3 (1) 4 Less: Write-offs, net of recoveries (a) 10 2 4 4 — — — — Balance as of December 31, 2021 $ 72 $ 17 $ 7 $ 9 $ 39 $ 16 $ 8 $ 15 Year Ended December 31, 2020 Exelon ComEd PECO BGE PHI Pepco DPL ACE Balance as of December 31, 2019 $ 48 $ 20 $ 7 $ 5 $ 16 $ 7 $ 4 $ 5 Plus: Current period provision for expected credit losses 33 5 3 7 18 6 5 7 Less: Write-offs, net of recoveries (a) 10 4 2 3 1 — — 1 Balance as of December 31, 2020 $ 71 $ 21 $ 8 $ 9 $ 33 $ 13 $ 9 $ 11 _________ (a) Recoveries were not material to the Registrants.
Unbilled Customer Revenue	The following table provides additional information about unbilled customer revenues recorded in the Registrants' Consolidated Balance Sheets as of December 31, 2021 and 2020. Unbilled customer revenues (a) Exelon ComEd PECO BGE PHI Pepco DPL ACE December 31, 2021 $ 747 $ 240 $ 161 $ 171 $ 175 $ 82 $ 53 $ 40 December 31, 2020 740 218 147 197 178 87 62 29 _________ (a) Unbilled customer revenues are classified in Customer accounts receivables, net in the Registrants' Consolidated Balance Sheets.
Purchases and Sales of Accounts Receivable	The following tables present the total receivables purchased and sold. Year Ended December 31, 2021 Exelon ComEd PECO BGE PHI Pepco DPL ACE Total receivables purchased $ 3,840 $ 1,031 $ 1,041 $ 687 $ 1,081 $ 660 $ 217 $ 204 Related party transactions: Receivables purchased from Generation — 1 1 21 — — — — Year Ended December 31, 2020 Exelon ComEd PECO BGE PHI Pepco DPL ACE Total receivables purchased $ 3,781 $ 1,094 $ 1,020 $ 652 $ 1,015 $ 622 $ 207 $ 186 Related party transactions: Receivables purchased from Generation — 34 67 79 72 51 13 8

Property, Plant and Equipment_2

Property, Plant and Equipment (Tables)	12 Months Ended
Property, Plant and Equipment (Tables)	Dec. 31, 2021
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	The following tables present a summary of property, plant, and equipment by asset category as of December 31, 2021 and 2020: Asset Category Exelon ComEd PECO BGE PHI Pepco DPL ACE December 31, 2021 Electric—transmission and distribution $ 64,771 $ 31,077 $ 10,076 $ 9,352 $ 16,062 $ 10,798 $ 4,957 $ 4,882 Gas—transportation and distribution 7,429 — 3,339 3,712 646 — 806 — Common—electric and gas 2,335 — 1,005 1,224 201 — 180 — Construction work in progress 3,698 918 620 554 1,590 1,118 229 242 Other property, plant, and equipment (a) 755 99 41 34 107 63 23 25 Total property, plant, and equipment 78,988 32,094 15,081 14,876 18,606 11,979 6,195 5,149 Less: accumulated depreciation 14,430 6,099 3,964 4,299 2,108 3,875 1,635 1,420 Property, plant, and equipment, net $ 64,558 $ 25,995 $ 11,117 $ 10,577 $ 16,498 $ 8,104 $ 4,560 $ 3,729 December 31, 2020 Electric—transmission and distribution $ 60,946 $ 29,371 $ 9,462 $ 8,797 $ 15,137 $ 10,264 $ 4,730 $ 4,568 Gas—transportation and distribution 6,733 — 3,098 3,315 591 — 751 — Common—electric and gas 2,170 — 956 1,138 178 — 180 — Construction work in progress 3,107 799 474 627 1,174 824 163 182 Other property, plant and equipment (a) 722 59 34 29 108 65 23 28 Total property, plant and equipment 73,678 30,229 14,024 13,906 17,188 11,153 5,847 4,778 Less: accumulated depreciation 13,346 5,672 3,843 4,034 1,811 3,697 1,533 1,303 Property, plant, and equipment, net $ 60,332 $ 24,557 $ 10,181 $ 9,872 $ 15,377 $ 7,456 $ 4,314 $ 3,475 __________ (a) Primarily composed of land and non-utility property. The following table presents the average service life for each asset category in number of years: Average Service Life (years) Asset Category Exelon ComEd PECO BGE PHI Pepco DPL ACE Electric - transmission and distribution 5-80 5-80 5-70 5-80 5-75 5-75 5-70 5-65 Gas - transportation and distribution 5-80 N/A 5-70 5-80 5-75 N/A 5-75 N/A Common - electric and gas 4-75 N/A 5-55 4-50 5-75 N/A 5-75 N/A Other property, plant, and equipment 3-61 32-50 50 20-50 3-50 33-50 8-50 13-15
Property Plant And Equipment Average Service Life Percentage By Asset Category Table	The following table presents the annual depreciation rates for each asset category. Annual Depreciation Rates Exelon ComEd PECO BGE PHI Pepco DPL ACE December 31, 2021 Electric—transmission and distribution 2.81 % 2.94 % 2.28 % 2.80 % 2.87 % 2.56 % 2.86 % 3.21 % Gas—transportation and distribution 2.13 % N/A 1.84 % 2.54 % 1.47 % N/A 1.47 % N/A Common—electric and gas 7.31 % N/A 6.34 % 7.88 % 8.33 % N/A 8.69 % N/A December 31, 2020 Electric—transmission and distribution 2.79 % 2.95 % 2.31 % 2.69 % 2.81 % 2.53 % 2.85 % 3.08 % Gas—transportation and distribution 2.14 % N/A 1.85 % 2.56 % 1.50 % N/A 1.50 % N/A Common—electric and gas 7.01 % N/A 6.39 % 7.45 % 7.36 % N/A 6.72 % N/A December 31, 2019 Electric—transmission and distribution 2.80 % 2.99 % 2.36 % 2.60 % 2.77 % 2.47 % 2.86 % 2.94 % Gas—transportation and distribution 2.04 % N/A 1.89 % 2.30 % 1.55 % N/A 1.55 % N/A Common—electric and gas 7.37 % N/A 6.06 % 8.30 % 8.25 % N/A 6.24 % N/A
Schedule Of Capitalized Interest And AFUDC	The following table summarizes capitalized interest and credits to AFUDC by year: Exelon ComEd PECO BGE PHI Pepco DPL ACE December 31, 2021 Capitalized interest $ — $ — $ — $ — $ — $ — $ — $ — AFUDC debt and equity 189 47 34 36 72 59 8 5 December 31, 2020 Capitalized interest $ — $ — $ — $ — $ — $ — $ — $ — AFUDC debt and equity 150 42 23 30 55 42 6 7 December 31, 2019 Capitalized interest $ — $ — $ — $ — $ — $ — $ — $ — AFUDC debt and equity 132 32 17 29 54 39 6 9

Jointly Owned Electric Utilit_2

Jointly Owned Electric Utility Plant (Tables)	12 Months Ended
Jointly Owned Electric Utility Plant (Tables)	Dec. 31, 2021
Public Utilities, Property, Plant and Equipment [Abstract]
Schedule of Jointly Owned Utility Plants	PECO's, DPL's, and ACE's material undivided ownership interests in jointly owned electric plants and transmission facilities as of December 31, 2021 and 2020 were as follows: Transmission NJ/DE (a) Operator PSEG/DPL Ownership interest various Exelon’s share as of December 31, 2021: Plant in service $ 103 Accumulated depreciation 55 Exelon’s share as of December 31, 2020: Plant in service $ 103 Accumulated depreciation 54 __________ (a) PECO, DPL, and ACE own a 42.55%, 1%, and 13.9% share, respectively in 151.3 miles of 500kV lines located in New Jersey and of the Salem generating plant substation. PECO, DPL, and ACE also own a 42.55%, 7.45%, and 7.45% share, respectively, in 2.5 miles of 500kV line located over the Delaware River. ACE also has a 21.78% share in a 500kV New Freedom Switching substation.

Asset Retirement Obligations (T

Asset Retirement Obligations (Tables)	12 Months Ended
Asset Retirement Obligations (Tables)	Dec. 31, 2021
Asset Retirement Obligation Disclosure [Abstract]
Asset Retirement Obligation Rollforward	The following table provides a rollforward of the AROs reflected in the Registrants’ Consolidated Balance Sheets from December 31, 2019 to December 31, 2021: Exelon ComEd PECO BGE PHI Pepco DPL ACE AROs as of December 31, 2019 $ 244 $ 129 $ 28 $ 23 $ 57 $ 41 $ 12 $ 4 Net increase (decrease) due to changes in, and timing of, estimated future cash flows 5 — 2 1 1 (3) 2 2 Accretion expense (a) 5 1 1 1 1 1 — — Payments (5) (1) (2) (2) — — — — AROs as of December 31, 2020 249 129 29 23 59 39 14 6 Net increase due to changes in, and timing of, estimated future cash flows 26 15 — 2 10 5 2 3 Accretion expense (a) 7 4 1 1 1 1 — — Payments (8) (2) (1) — — — — — AROs as of December 31, 2021 $ 274 $ 146 $ 29 $ 26 $ 70 $ 45 $ 16 $ 9 __________ (a) For ComEd, PECO, BGE, PHI, and Pepco, the majority of the accretion is recorded as an increase to a regulatory asset due to the associated regulatory treatment.

Leases (Tables)

Leases (Tables)	12 Months Ended
Leases (Tables)	Dec. 31, 2021
Leases [Abstract]
Components of Lease Cost [Table Text Block]	The components of operating lease costs were as follows: Exelon ComEd PECO BGE PHI Pepco DPL ACE For the year ended December 31, 2021 Operating lease costs $ 84 $ 3 $ — $ 30 $ 43 $ 10 $ 12 $ 6 Variable lease costs 7 1 — 1 1 — — — Total lease costs (a) $ 91 $ 4 $ — $ 31 $ 44 $ 10 $ 12 $ 6 For the year ended December 31, 2020 Operating lease costs $ 98 $ 3 $ 1 $ 33 $ 46 $ 11 $ 13 $ 6 Variable lease costs 7 1 — 1 2 1 1 — Total lease costs (a) $ 105 $ 4 $ 1 $ 34 $ 48 $ 12 $ 14 $ 6 For the year ended December 31, 2019 Operating lease costs $ 98 $ 3 $ 1 $ 33 $ 48 $ 12 $ 14 $ 7 Variable lease costs 18 2 — 2 6 2 2 1 Total lease costs (a) $ 116 $ 5 $ 1 $ 35 $ 54 $ 14 $ 16 $ 8 __________ (a) Excludes sublease income recorded at Exelon, PHI, and DPL of $4 million, $4 million, and $7 million for the years ended December 31, 2021, 2020, and 2019, respectively. PHI, Pepco, DPL, and ACE recorded finance lease costs of $13 million, $5 million, $5 million, and $3 million, respectively, for the year ended December 31, 2021 and $9 million, $3 million, $4 million, and $2 million, respectively, for the year ended December 31, 2020. The weighted average remaining lease terms, in years, for operating and finance leases were as follows: Operating Leases Exelon ComEd PECO BGE PHI Pepco DPL ACE As of December 31, 2021 8.9 3.3 6.1 13.7 7.5 8.6 8.5 3.5 As of December 31, 2020 9.0 3.8 4.2 8.3 8.2 9.1 9.1 4.0 As of December 31, 2019 8.7 4.6 4.4 5.4 9.0 9.8 9.7 4.7 Finance Leases PHI Pepco DPL ACE As of December 31, 2021 6.1 5.9 6.1 6.3 As of December 31, 2020 6.5 6.3 6.5 6.5 The weighted average discount rates for operating and finance leases were as follows: Operating Leases Exelon ComEd PECO BGE PHI Pepco DPL ACE As of December 31, 2021 4.0 % 2.8 % 2.2 % 4.0 % 4.2 % 4.0 % 4.0 % 3.4 % As of December 31, 2020 4.0 % 3.0 % 2.9 % 3.8 % 4.2 % 4.0 % 4.0 % 3.5 % As of December 31, 2019 3.9 % 3.0 % 3.2 % 3.6 % 4.2 % 4.0 % 4.0 % 3.6 % Finance Leases PHI Pepco DPL ACE As of December 31, 2021 2.2 % 2.3 % 2.1 % 2.1 % As of December 31, 2020 2.5 % 2.6 % 2.4 % 2.4 % ROU assets obtained in exchange for operating and finance lease obligations were as follows: Operating Leases Exelon ComEd PECO BGE PHI Pepco DPL ACE For the year ended December 31, 2021 $ 1 $ — $ — $ (1) $ 1 $ — $ 1 $ — For the year ended December 31, 2020 (2) — 1 — (1) — (1) — For the year ended December 31, 2019 38 6 — 2 (3) (1) (2) (1) Finance Leases PHI Pepco DPL ACE For the year ended December 31, 2021 $ 32 $ 12 $ 12 $ 8 For the year ended December 31, 2020 29 8 14 7
Supplemental Balance Sheet Information Related to Lessee Right-of-Use Assets and Lease Liabilities [Table Text Block]	The following tables provide additional information regarding the presentation of operating and finance lease ROU assets and lease liabilities within the Registrants’ Consolidated Balance Sheets: Operating Leases Exelon ComEd PECO BGE PHI Pepco DPL ACE As of December 31, 2021 Operating lease ROU assets Other deferred debits and other assets $ 271 $ 5 $ 1 $ 16 $ 209 $ 43 $ 46 $ 11 Operating lease liabilities Other current liabilities 52 2 — 15 31 6 8 3 Other deferred credits and other liabilities 263 3 1 4 195 40 49 9 Total operating lease liabilities $ 315 $ 5 $ 1 $ 19 $ 226 $ 46 $ 57 $ 12 As of December 31, 2020 Operating lease ROU assets Other deferred debits and other assets $ 338 $ 7 $ 1 $ 46 $ 241 $ 49 $ 54 $ 15 Operating lease liabilities Other current liabilities 81 3 — 45 31 6 9 4 Other deferred credits and other liabilities 314 5 1 19 224 46 56 11 Total operating lease liabilities $ 395 $ 8 $ 1 $ 64 $ 255 $ 52 $ 65 $ 15 Finance Leases PHI Pepco DPL ACE As of December 31, 2021 Finance lease ROU assets Plant, property and equipment, net $ 73 $ 25 $ 29 $ 19 Finance lease liabilities Long-term debt due within one year 10 3 4 3 Long-term debt 64 23 25 16 Total finance lease liabilities $ 74 $ 26 $ 29 $ 19 As of December 31, 2020 Finance lease ROU assets Plant, property and equipment, net $ 50 $ 17 $ 20 $ 13 Finance lease liabilities Long-term debt due within one year 7 2 3 2 Long-term debt 43 15 17 11 Total finance lease liabilities $ 50 $ 17 $ 20 $ 13
Lessee, Operating Lease, Liability, Maturity [Table Text Block]	Future minimum lease payments for operating and finance leases as of December 31, 2021 were as follows: Operating Leases Year Exelon ComEd PECO BGE PHI Pepco DPL ACE 2022 $ 64 $ 2 $ — $ 16 $ 38 $ 8 $ 10 $ 4 2023 45 1 — 1 37 7 10 3 2024 43 1 — — 36 7 8 3 2025 41 1 — — 34 6 7 2 2026 35 — — — 29 5 5 1 Remaining years 162 — 1 18 94 22 30 — Total 390 5 1 35 268 55 70 13 Interest 75 — — 16 42 9 13 1 Total operating lease liabilities $ 315 $ 5 $ 1 $ 19 $ 226 $ 46 $ 57 $ 12
Finance Lease, Liability, Fiscal Year Maturity	Finance Leases Year PHI Pepco DPL ACE 2022 $ 12 $ 4 $ 5 $ 3 2023 12 4 5 3 2024 13 5 5 3 2025 12 4 5 3 2026 12 4 5 3 Remaining years 18 6 7 5 Total 79 27 32 20 Interest 5 1 3 1 Total finance lease liabilities $ 74 $ 26 $ 29 $ 19
Schedule of Supplemental Cash Flow Information Related to Leases [Table Text Block]	Cash paid for amounts included in the measurement of operating and finance lease liabilities were as follows: Operating cash flows from operating leases Exelon ComEd PECO BGE PHI Pepco DPL ACE For the year ended December 31, 2021 $ 93 $ 3 $ — $ 46 $ 39 $ 8 $ 9 $ 4 For the year ended December 31, 2020 67 3 1 20 39 8 9 4 For the year ended December 31, 2019 81 3 — 33 37 9 6 5 Financing cash flows from finance leases PHI Pepco DPL ACE For the year ended December 31, 2021 $ 10 $ 3 $ 4 $ 3 For the year ended December 31, 2020 6 2 3 1
Components of Operating Lease Income [Table Text Block]	The components of lease income were as follows: Exelon ComEd PECO BGE PHI Pepco DPL ACE For the year ended December 31, 2021 Operating lease income $ 5 $ — $ — $ — $ 4 $ — $ 3 $ — Variable lease income 1 — — — 1 — 1 — For the year ended December 31, 2020 Operating lease income $ 5 $ — $ — $ — $ 3 $ — $ 3 $ — Variable lease income 1 — — — 1 — 1 — For the year ended December 31, 2019 Operating lease income $ 7 $ — $ — $ — $ 5 $ — $ 4 $ — Variable lease income 3 — — — 3 — 3 —
Lessor, Operating Lease, Payment to be Received, Fiscal Year Maturity [Table Text Block]	Future minimum lease payments to be recovered under operating leases as of December 31, 2021 were as follows: Year Exelon ComEd PECO BGE PHI Pepco DPL ACE 2022 $ 5 $ — $ — $ — $ 4 $ — $ 3 $ — 2023 4 — — — 3 — 3 — 2024 4 — — — 4 — 4 — 2025 4 — — — 4 — 4 — 2026 4 — — — 4 — 4 — Remaining years 32 1 4 1 26 — 26 — Total $ 53 $ 1 $ 4 $ 1 $ 45 $ — $ 44 $ —

Intangible Assets (Tables)

Intangible Assets (Tables)	12 Months Ended
Intangible Assets (Tables)	Dec. 31, 2021
Finite-Lived Intangible Assets [Line Items]
Schedule Of Goodwill	The following table presents the gross amount, accumulated impairment loss, and carrying amount of goodwill at Exelon, ComEd, and PHI as of December 31, 2021 and 2020. There were no additions or impairments during the years ended December 31, 2021 and 2020. Gross Amount Accumulated Impairment Loss Carrying Amount Exelon $ 8,613 $ 1,983 $ 6,630 ComEd (a) 4,608 1,983 2,625 PHI (b) 4,005 — 4,005 __________ (a) Reflects goodwill recorded in 2000 from the PECO/Unicom merger (predecessor parent company of ComEd). (b) Reflects goodwill recorded in 2016 from the PHI merger.
Schedule of Finite-Lived Intangible Assets	Exelon’s other intangible assets, included in Other current assets and Other deferred debits and other assets in the Consolidated Balance Sheets, consisted of the following as of December 31, 2021 and 2020. Exelon's and PHI's other intangible liabilities, included in current and noncurrent Unamortized energy contract liabilities in their Consolidated Balance Sheets, consisted of the following as of December 31, 2021 and 2020. The intangible assets and liabilities shown below are amortized on a straight-line basis, except for unamortized energy contracts which are amortized in relation to the expected realization of the underlying cash flows: December 31, 2021 December 31, 2020 Gross Accumulated Amortization Net Gross Accumulated Amortization Net Exelon Unamortized Energy Contracts $ (1,515) $ 1,280 $ (235) $ (1,515) $ 1,188 $ (327) Software License 81 (53) 28 81 (44) 37 Exelon Total $ (1,434) $ 1,227 $ (207) $ (1,434) $ 1,144 $ (290) PHI Unamortized Energy Contracts $ (1,515) $ 1,280 $ (235) $ (1,515) $ 1,188 $ (327)
Schedule Of Finite-Lived Intangible Assets Amortization Expense	The following table summarizes the amortization expense related to intangible assets and liabilities for each of the years ended December 31, 2021, 2020, and 2019: For the Years Ended December 31, Exelon (a) PHI (a) 2021 $ (83) $ (92) 2020 (98) (115) 2019 (102) (119) __________ (a) For PHI unamortized energy contracts, the amortization of the fair value adjustment amounts and the corresponding offsetting regulatory asset amounts are amortized through Purchased power and fuel expense in their Consolidated Statements of Operations and Comprehensive Income resulting in no effect to net income.
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]	The following table summarizes the estimated future amortization expense related to intangible assets and liabilities as of December 31, 2021: For the Years Ending December 31, Exelon PHI 2022 $ (80) $ (89) 2023 (72) (81) 2024 (29) (38) 2025 (2) (5) 2026 (5) (5)

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
Income Taxes (Tables)	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense (Benefit)	Income tax expense (benefit) from continuing operations is comprised of the following components: For the Year Ended December 31, 2021 Exelon ComEd PECO BGE PHI Pepco DPL ACE Included in operations: Federal Current $ (152) $ (30) $ 1 $ (18) $ 18 $ 22 $ 2 $ 1 Deferred 89 113 20 34 (52) (17) (14) (26) Investment tax credit amortization (2) (1) — — (1) — — — State Current (46) (41) — — — 1 1 — Deferred 149 131 (9) (51) 77 9 53 12 Total $ 38 $ 172 $ 12 $ (35) $ 42 $ 15 $ 42 $ (13) For the Year Ended December 31, 2020 Exelon ComEd PECO BGE PHI Pepco DPL ACE Included in operations: Federal Current $ (180) $ (24) $ (7) $ 4 $ 25 $ 40 $ (13) $ (4) Deferred 10 112 1 10 (129) (62) (20) (43) Investment tax credit amortization (3) (2) — — (1) — — — State Current (37) (27) — — (5) — — — Deferred 203 118 (24) 27 33 15 8 6 Total $ (7) $ 177 $ (30) $ 41 $ (77) $ (7) $ (25) $ (41) For the Year Ended December 31, 2019 Exelon ComEd PECO BGE PHI Pepco DPL ACE Included in operations: Federal Current $ (143) $ 59 $ 45 $ (51) $ 43 $ 16 $ 29 $ (3) Deferred 139 15 20 95 (34) (6) (21) (6) Investment tax credit amortization (3) (2) — — (1) — — — State Current (44) (5) — — 3 — — — Deferred 204 96 — 35 27 6 14 9 Total $ 153 $ 163 $ 65 $ 79 $ 38 $ 16 $ 22 $ —
Effective Income Tax Rate Reconciliation	The effective income tax rate from continuing operations varies from the U.S. federal statutory rate principally due to the following: For the Year Ended December 31, 2021 (a) Exelon ComEd PECO (b) BGE (b) PHI Pepco DPL (b) ACE (b) U.S. federal statutory rate 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % Increase (decrease) due to: State income taxes, net of federal income tax benefit 5.0 7.8 (1.4) (10.8) 10.1 2.7 25.0 7.4 Amortization of investment tax credit, including deferred taxes on basis differences (0.1) (0.1) — (0.1) (0.1) — (0.2) (0.2) Plant basis differences (5.4) (0.8) (13.6) (1.7) (1.1) (1.6) (0.8) (0.2) Tax credits (0.7) (0.5) — (0.9) (0.5) (0.5) (0.4) (0.5) Excess deferred tax amortization (17.2) (7.6) (3.8) (16.3) (22.4) (16.4) (20.0) (37.1) Other (0.3) (1.0) 0.1 (0.6) — (0.4) 0.1 (0.2) Effective income tax rate 2.3 % 18.8 % 2.3 % (9.4) % 7.0 % 4.8 % 24.7 % (9.8) % For the Year Ended December 31, 2020 (a) Exelon ComEd (c) PECO (c) BGE (d) PHI (d) Pepco (d) DPL (d) ACE (d) U.S. federal statutory rate 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % Increase (decrease) due to: State income taxes, net of federal income tax benefit 11.9 11.6 (4.5) 5.5 5.1 4.5 6.6 7.0 Deferred Prosecution Agreement payments 3.8 6.8 — — — — — — Amortization of investment tax credit, including deferred taxes on basis differences (0.3) (0.3) — (0.1) (0.2) (0.1) (0.3) (0.5) Plant basis differences (8.6) (0.6) (18.7) (1.5) (1.6) (1.7) (0.4) (3.0) Tax credits (0.5) (0.3) — (0.4) (0.3) (0.3) (0.3) (0.5) Excess deferred tax amortization (29.1) (11.2) (4.6) (13.9) (42.0) (25.4) (51.7) (82.1) Other 1.2 1.8 (0.4) (0.1) (0.4) (0.7) 0.1 0.4 Effective income tax rate (0.6) % 28.8 % (7.2) % 10.5 % (18.4) % (2.7) % (25.0) % (57.7) % For the Year Ended December 31, 2019 (a) Exelon ComEd PECO BGE PHI Pepco DPL ACE U.S. federal statutory rate 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % Increase (decrease) due to: State income taxes, net of federal income tax benefit 7.8 8.5 — 6.4 4.7 2.0 6.8 7.0 Amortization of investment tax credit, including deferred taxes on basis differences (0.2) (0.2) — (0.1) (0.2) (0.1) (0.2) (0.3) Plant basis differences (3.3) — (7.2) (1.2) (1.2) (1.8) (0.4) (0.7) Tax credits (1.9) (1.2) — (1.3) (0.2) (0.1) — (0.1) Excess deferred tax amortization (13.4) (9.7) (2.8) (6.8) (17.5) (15.1) (14.2) (27.0) Other (0.7) 0.8 — — 0.8 0.3 — 0.1 Effective income tax rate 9.3 % 19.2 % 11.0 % 18.0 % 7.4 % 6.2 % 13.0 % — % __________ (a) Positive percentages represent income tax expense. Negative percentages represent income tax benefit. (b) For PECO, the lower effective tax rate is primarily related to plant basis differences attributable to tax repair deductions. For BGE, the income tax benefit is primarily due to the Maryland multi-year plan which resulted in the acceleration of certain income tax benefits. For DPL, the higher effective tax rate is primarily related to a state income tax expense, net of federal income tax benefit, due to the recognition of a valuation allowance of approximately $31 million against a deferred tax asset associated with Delaware net operating loss carryforwards as a result of a change in Delaware tax law. For ACE, the income tax benefit is primarily due to a distribution rate case settlement which allows ACE to retain certain tax benefits. (c) At ComEd, the higher effective tax rate is primarily related to the nondeductible Deferred Prosecution Agreement payments. At PECO, the negative effective tax rate is primarily related to an increase in plant basis differences attributable to tax repair deductions related to an increase in storms and qualifying projects in 2021. (d) For BGE, PHI, Pepco, DPL, and ACE, the income tax benefit is primarily attributable to accelerated amortization of transmission related deferred income tax regulatory liabilities as a result of regulatory settlements. See Note 3 — Regulatory Matters for additional information.
Tax Effects of Temporary Differences	The tax effects of temporary differences and carryforwards, which give rise to significant portions of the deferred tax assets (liabilities), as of December 31, 2021 and 2020 are presented below: As of December 31, 2021 Exelon ComEd PECO BGE PHI Pepco DPL ACE Plant basis differences $ (11,606) $ (4,648) $ (2,271) $ (1,826) $ (2,976) $ (1,321) $ (853) $ (777) Accrual based contracts 56 — — — 56 — — — Derivatives and other financial instruments 63 61 — — 2 — — — Deferred pension and postretirement obligation 641 (308) (32) (37) (90) (76) (40) (6) Deferred debt refinancing costs 146 (6) — (2) 123 (2) (1) (1) Regulatory assets and liabilities (1,130) 8 (280) 92 (53) 24 55 31 Tax loss carryforward, net of valuation allowances 242 — 65 68 64 2 18 42 Tax credit carryforward 584 — — — — — — — Investment in partnerships (21) — — — — — — — Other, net 449 216 97 21 212 99 19 34 Deferred income tax liabilities (net) $ (10,576) $ (4,677) $ (2,421) $ (1,684) $ (2,662) $ (1,274) $ (802) $ (677) Unamortized investment tax credits (15) (8) — (2) (5) (1) (1) (2) Total deferred income tax liabilities (net) and unamortized investment tax credits $ (10,591) $ (4,685) $ (2,421) $ (1,686) $ (2,667) $ (1,275) $ (803) $ (679) As of December 31, 2020 Exelon ComEd PECO BGE PHI Pepco DPL ACE Plant basis differences $ (11,272) $ (4,432) $ (2,131) $ (1,711) $ (2,822) $ (1,259) $ (806) $ (725) Accrual based contracts 77 — — — 77 — — — Derivatives and other financial instruments 82 84 — — 2 — — — Deferred pension and postretirement obligation 954 (288) (30) (33) (80) (74) (40) (7) Deferred debt refinancing costs 153 (6) — (2) 131 (3) (1) (1) Regulatory assets and liabilities (1,107) 87 (231) 142 (41) 38 67 46 Tax loss carryforward, net of valuation allowances 231 — 47 57 90 4 49 38 Tax credit carryforward 648 — — — — — — — Investment in partnerships (22) — — — — — — — Other, net 701 223 104 29 220 107 18 27 Deferred income tax liabilities (net) $ (9,555) $ (4,332) $ (2,241) $ (1,518) $ (2,423) $ (1,187) $ (713) $ (622) Unamortized investment tax credits (19) (9) (1) (3) (6) (2) (2) (3) Total deferred income tax liabilities (net) and $ (9,574) $ (4,341) $ (2,242) $ (1,521) $ (2,429) $ (1,189) $ (715) $ (625)
Summary of Loss Carryforwards	The following table provides Exelon’s, PECO’s, BGE’s, PHI’s, Pepco’s, DPL’s, and ACE’s carryforwards, of which the state related items are presented on a post-apportioned basis, and any corresponding valuation allowances as of December 31, 2021. ComEd does not have net operating losses or credit carryforwards for the year ended December 31, 2021. Exelon PECO BGE PHI Pepco DPL ACE Federal Federal general business credits carryforwards and other carryforwards (a) $ 584 $ — $ — $ — $ — $ — $ — State State net operating losses and other carryforwards 4,616 890 1,098 1,512 42 736 605 Deferred taxes on state tax attributes (net of federal taxes) 291 70 72 104 3 50 43 Valuation allowance on state tax attributes (net of federal taxes) (b) 37 3 — 31 — 31 — Year in which net operating loss or credit carryforwards will begin to expire (c) 2035 2032 2033 2029 N/A 2032 2031 __________ (a) For Exelon, the federal general business credit carryforward will begin expiring in 2035. (b) At Exelon, a full valuation allowance has been recorded against certain separate company state net operating loss carryforwards that are expected to expire before realization. At PECO, a full valuation allowance has been recorded against Pennsylvania charitable contributions carryforwards that are expected to expire before realization. At DPL, a full valuation allowance has been recorded against Delaware net operating losses carryforwards due to a change in Delaware tax law. (c) A portion of Exelon's, BGE's, Pepco's, and DPL's Maryland state net operating loss carryforward have an indefinite carryforward period.
Schedule of Unrecognized Tax Benefits Roll Forward	The following table presents changes in unrecognized tax benefits, for Exelon, PHI, and ACE. ComEd's, PECO's, BGE's, Pepco's, and DPL's amounts are not material. Exelon PHI ACE Balance at January 1, 2019 $ 65 $ 45 $ 14 Change to positions that only affect timing 26 3 — Increases based on tax positions related to 2019 2 — — Increases based on tax positions prior to 2019 34 — — Decreases based on tax positions prior to 2019 (3) — — Decrease from settlements with taxing authorities (29) — — Balance at December 31, 2019 95 48 14 Change to positions that only affect timing 6 3 1 Increases based on tax positions related to 2020 3 — — Increases based on tax positions prior to 2020 26 1 — Decreases based on tax positions prior to 2020 (5) — — Balance at December 31, 2020 125 52 15 Change to positions that only affect timing 13 3 1 Increases based on tax positions related to 2021 4 1 — Increases based on tax positions prior to 2021 4 — — Decreases based on tax positions prior to 2021 (3) — — Balance at December 31, 2021 $ 143 $ 56 $ 16
Summary of Positions for which Significant Change in Unrecognized Tax Benefits is Reasonably Possible	The following table presents Exelon's unrecognized tax benefits that, if recognized, would decrease the effe ctive tax rate. The Utility Registrants' amounts are not material. Exelon December 31, 2021 $ 77 December 31, 2020 73 December 31, 2019 51
Total amounts of interest and penalties recognized	The following table represents the net interest and penalties receivable (payable) related to tax positions reflected in Exelon's Consolidated Balance Sheets. The Utility Registrants' amounts are not material. Net interest and penalties receivable as of Exelon December 31, 2021 (a) $ 43 December 31, 2020 314 __________ (a) As of December 31, 2021, the interest receivable balance is not expected to be settled in cash within the next twelve months and therefore classified as non-current receivable. In December of 2021, Exelon received a refund of approximately $272 million related to an interest netting refund claim.
Long-Term Marginal State Income Tax Rate	The impacts to the Utility Registrants for the years ended December 31, 2021, 2020, and 2019 were not material. December 31, 2021 Exelon Increase to Deferred Income Tax Liability and Income Tax Expense, Net of Federal Taxes $ 27 December 31, 2020 Increase to Deferred Income Tax Liability and Income Tax Expense, Net of Federal Taxes $ 66 December 31, 2019 Increase to Deferred Income Tax Liability and Income Tax Expense, Net of Federal Taxes $ 20
Allocation of Federal Tax Benefit Under Tax Sharing Agreement	The following table presents the allocation of tax benefits from Exelon under the Tax Sharing Agreement. ComEd PECO BGE PHI Pepco DPL ACE December 31, 2021 (a) $ 1 $ 19 $ — $ 17 $ 16 $ — $ — December 31, 2020 (b) 14 17 — 17 8 6 1 December 31, 2019 (c) — 14 3 7 6 1 — __________ (a) BGE, DPL, and ACE did not record an allocation of federal tax benefits from Exelon under the Tax Sharing Agreement as a result of a tax net operating loss. (b) BGE did not record an allocation of federal tax benefits from Exelon under the Tax Sharing Agreement as a result of a tax net operating loss. (c) ComEd and ACE did not record an allocation of federal tax benefits from Exelon under the Tax Sharing Agreement as a result of a tax net operating loss.

Retirement Benefits (Tables)

Retirement Benefits (Tables)	12 Months Ended
Retirement Benefits (Tables)	Dec. 31, 2021
Retirement Benefits [Abstract]
Defined Benefit Plan Change In Benefit Obligation RollForward	The following tables provide a rollforward of the changes in the benefit obligations and plan assets of Exelon for the most recent two years for all plans combined: Pension Benefits OPEB 2021 2020 2021 2020 Change in benefit obligation: Net benefit obligation as of the beginning of year $ 14,861 $ 13,652 $ 2,661 $ 2,692 Service cost 294 251 51 56 Interest cost 406 476 69 93 Plan participants’ contributions — — 32 31 Actuarial (gain) loss (a) (442) 1,252 (116) 38 Plan amendments — — — (64) Settlements (23) (19) (5) (5) Gross benefits paid (860) (751) (190) (180) Net benefit obligation as of the end of year $ 14,236 $ 14,861 $ 2,502 $ 2,661 Pension Benefits OPEB 2021 2020 2021 2020 Change in plan assets: Fair value of net plan assets as of the beginning of year $ 11,883 $ 10,859 $ 1,635 $ 1,627 Actual return on plan assets 822 1,488 130 122 Employer contributions 343 306 63 40 Plan participants’ contributions — — 32 31 Gross benefits paid (860) (751) (190) (180) Settlements (23) (19) (5) (5) Fair value of net plan assets as of the end of year $ 12,165 $ 11,883 $ 1,665 $ 1,635 __________ (a) The pension and OPEB gains in 2021 primarily reflect an increase in the discount rate. In 2020, the actuarial losses primarily reflect a decrease in the discount rate. OPEB losses in 2020 were offset by gains related to plan changes.
Schedule of Amounts Recognized in Balance Sheet	Exelon presents its benefit obligations and plan assets net on its balance sheet within the following line items: Pension Benefits OPEB 2021 2020 2021 2020 Other current liabilities $ 20 $ 32 $ 26 $ 24 Pension obligations 2,051 2,946 — — Non-pension postretirement benefit obligations — — 811 1,002 Unfunded status (net benefit obligation less plan assets) $ 2,071 $ 2,978 $ 837 $ 1,026
Defined Benefit Plan, Plan with Accumulated Benefit Obligation in Excess of Plan Assets	The following table provides the ABO and fair value of plan assets for all pension plans with an ABO in excess of plan assets. Information for pension and OPEB plans with projected benefit obligations (PBO) and accumulated postretirement benefit obligation (APBO), respectively, in excess of plan assets has been disclosed in the Obligations and Plan Assets table above as all pension and OPEB plans are underfunded. Exelon ABO in Excess of Plan Assets 2021 2020 ABO $ 13,497 $ 14,037 Fair value of net plan assets 12,165 11,883
Calculation of Net Periodic Benefit Costs	The following table presents the components of Exelon’s net periodic benefit costs, prior to capitalization, for the years ended December 31, 2021, 2020, and 2019. Pension Benefits OPEB 2021 2020 2019 2021 2020 2019 Components of net periodic benefit cost: Service cost $ 294 $ 251 $ 218 $ 51 $ 56 $ 55 Interest cost 406 476 553 69 93 114 Expected return on assets (843) (796) (763) (99) (101) (95) Amortization of: Prior service cost (credit) 2 3 1 (25) (76) (104) Actuarial loss 399 349 289 27 34 32 Curtailment benefits — — — — (1) — Settlement and other charges 7 6 6 1 1 — Contractual termination benefits — — 1 — — — Net periodic benefit cost $ 265 $ 289 $ 305 $ 24 $ 6 $ 2
Schedule Of Pension And Other Postretirement Benefit Costs	The amounts below represent the Registrants' allocated pension and OPEB costs. For Exelon, the service cost component is included in Operating and maintenance expense and Property, plant, and equipment, net while the non-service cost components are included in Other, net and Regulatory assets. For the Utility Registrants, the service cost and non-service cost components are included in Operating and maintenance expense and Property, plant, and equipment, net in their consolidated financial statements. For the Years Ended December 31, Exelon ComEd PECO BGE PHI Pepco DPL ACE 2021 $ 288 $ 129 $ 8 $ 64 $ 49 $ 6 $ 2 $ 11 2020 296 114 5 64 70 15 7 14 2019 307 96 12 61 95 25 15 16
Changes In Plan Assets And Benefit Obligations Recognized In OCI And Regulatory Assets	The following tables provide the components of AOCI and regulatory assets (liabilities) for Exelon for the years ended December 31, 2021, 2020, and 2019 for all plans combined. The tables include amounts related to Generation prior to the separation. Pension Benefits OPEB 2021 2020 2019 2021 2020 2019 Changes in plan assets and benefit obligations recognized in AOCI and regulatory assets (liabilities): Current year actuarial (gain) loss $ (700) $ 941 $ 538 $ (270) $ 22 $ 80 Amortization of actuarial loss (598) (512) (414) (37) (49) (45) Current year prior service cost (credit) — — 68 — (111) — Amortization of prior service (cost) credit (3) (4) — 34 124 179 Curtailments — — (3) — 1 — Settlements (27) (14) (17) (1) (1) (1) Total recognized in AOCI and regulatory assets (liabilities) $ (1,328) $ 411 $ 172 $ (274) $ (14) $ 213 Total recognized in AOCI $ (747) $ 271 $ 169 $ (130) $ 6 $ 107 Total recognized in regulatory assets (liabilities) $ (581) $ 140 $ 3 $ (144) $ (20) $ 106
Schedule of Amounts in Accumulated Other Comprehensive Income (Loss) to be Recognized over Next Fiscal Year	The following table provides the components of gross accumulated other comprehensive loss and regulatory assets (liabilities) for Exelon that have not been recognized as components of periodic benefit cost as of December 31, 2021 and 2020, respectively, for all plans combined: Pension Benefits OPEB 2021 2020 2021 2020 Prior service cost (credit) $ 32 $ 35 $ (111) $ (145) Actuarial loss 6,752 8,077 230 538 Total $ 6,784 $ 8,112 $ 119 $ 393 Total included in AOCI $ 3,592 $ 4,339 $ 53 $ 183 Total included in regulatory assets (liabilities) $ 3,192 $ 3,773 $ 66 $ 210
Defined Benefit Plan Weighted Average Assumptions Used In Calculating Benefit Obligation	For Exelon, the following assumptions were used to determine the benefit obligations for the plans as of December 31, 2021 and 2020. Assumptions used to determine year-end benefit obligations are the assumptions used to estimate the subsequent year’s net periodic benefit costs. Pension Benefits OPEB 2021 2020 2021 2020 Discount rate 2.92 % (a) 2.58 % (a) 2.88 % (a) 2.51 % (a) Investment crediting rate 3.75 % (b) 3.72 % (b) N/A N/A Rate of compensation increase 3.75 % 3.75 % 3.75 % 3.75 % Mortality table Pri-2012 table with MP- 2021 improvement scale (adjusted) Pri-2012 table with MP- 2020 improvement scale (adjusted) Pri-2012 table with MP- 2021 improvement scale (adjusted) Pri-2012 table with MP- 2020 improvement scale (adjusted) Health care cost trend on covered charges N/A N/A Initial and ultimate rate of 5.00% Initial and ultimate trend of 5.00% __________ (a) The discount rates above represent the blended rates used to determine the majority of Exelon’s pension and OPEB obligations. Certain benefit plans used individual rates, which range from 2.55% - 3.02% and 2.84% - 2.92% for pension and OPEB plans, respectively, as of December 31, 2021 and 2.11% - 2.73% and 2.45% - 2.63% for pension and OPEB plans, respectively, as of December 31, 2020. (b) The investment crediting rate above represents a weighted average rate.
Defined Benefit Plan Weighted Average Assumptions Used In Calculating Net Periodic Benefit Cost	The following assumptions were used to determine the net periodic benefit cost for Exelon for the years ended December 31, 2021, 2020 and 2019: Pension Benefits OPEB 2021 2020 2019 2021 2020 2019 Discount rate 2.58 % (a) 3.34 % (a) 4.31 % (a) 2.51 % (a) 3.31 % (a) 4.30 % (a) Investment crediting rate 3.72 % (b) 3.82 % (b) 4.46 % (b) N/A N/A N/A Expected return on plan assets 7.00 % (c) 7.00 % (c) 7.00 % (c) 6.46 % (c) 6.69 % (c) 6.67 % (c) Rate of compensation increase 3.75 % (d) 3.75 % (d) 3.25 % (d) 3.75 % (d) 3.75 % (d) 3.25 % (d) Mortality table Pri-2012 table with MP- 2020 improvement scale (adjusted) Pri-2012 table with MP - 2019 improvement scale (adjusted) RP-2000 table projected to 2012 with improvement scale AA, with Scale BB-2D improvements (adjusted) Pri-2012 table with MP- 2020 improvement scale (adjusted) Pri-2012 table with MP - 2019 improvement scale (adjusted) RP-2000 table projected to 2012 with improvement scale AA, with Scale BB-2D improvements (adjusted) Health care cost trend on covered charges N/A N/A N/A Initial and ultimate rate of 5.00% Initial and ultimate rate of 5.00% 5.00% with ultimate trend of 5.00% in 2017 __________ (a) The discount rates above represent the blended rates used to establish the majority of Exelon’s pension and OPEB costs. Certain benefit plans used individual rates, which range from 2.11%-2.73% and 2.45%-2.63% for pension and OPEB plans, respectively, for the year ended December 31, 2021; 3.02%-3.44% and 3.27%-3.40% for pension and OPEB plans; respectively, for the year ended December 31, 2020; and 4.13%-4.36% and 4.27%-4.38% for pension and OPEB plans, respectively, for the year ended December 31, 2019. (b) The investment crediting rate above represents a weighted average rate. (c) Not applicable to pension and OPEB plans that do not have plan assets. (d) 3.25% through 2019 and 3.75% thereafter.
Pension And Other Postretirement Benefit Contributions	The following tables provide contributions to the pension and OPEB plans: Pension Benefits OPEB 2021 2020 2019 2021 2020 2019 Exelon $ 343 $ 306 $ 196 $ 63 $ 40 $ 36 ComEd 174 143 72 22 5 5 PECO 17 18 27 1 — 1 BGE 57 56 34 24 22 14 PHI 39 30 10 9 9 15 Pepco 2 2 2 9 9 12 DPL 1 — 1 — — — ACE 3 2 — — — 1 The following table provides all Registrants' planned contributions to the qualified pension plans, planned benefit payments to non-qualified pension plans, and planned contributions to OPEB plans in 2022: Qualified Pension Plans Non-Qualified Pension Plans OPEB Exelon $ 313 $ 23 $ 39 ComEd 173 2 12 PECO 12 1 2 BGE 48 2 16 PHI 60 10 7 Pepco 2 1 6 DPL 1 1 — ACE 7 — —
Schedule of Expected Benefit Payments	Estimated future benefit payments to participants in all of the pension plans and postretirement benefit plans as of December 31, 2021 were: Pension Benefits OPEB 2022 $ 769 $ 146 2023 775 147 2024 792 147 2025 794 147 2026 792 149 2027 through 2031 4,021 742 Total estimated future benefits payments through 2031 $ 7,943 $ 1,478
Defined Benefit Plan Weighted Average Asset Allocations And Target Allocations	Exelon’s pension and OPEB plan target asset allocations as of December 31, 2021 and 2020 were as follows: December 31, 2021 December 31, 2020 Asset Category Pension Benefits OPEB Pension Benefits OPEB Equity securities 35 % 44 % 34 % 45 % Fixed income securities 41 % 41 % 43 % 39 % Alternative investments (a) 24 % 15 % 23 % 16 % Total 100 % 100 % 100 % 100 % __________ (a) Alternative investments include private equity, hedge funds, real estate, and private credit.
Defined Benefit Plan Fair Value Of Plan Assets	The following tables present pension and OPEB plan assets measured and recorded at fair value in Exelon's Consolidated Balance Sheets on a recurring basis and their level within the fair value hierarchy as of December 31, 2021 and 2020: December 31, 2021 December 31, 2020 Level 1 Level 2 Level 3 Not subject to leveling Total Level 1 Level 2 Level 3 Not subject to leveling Total Pension plan assets (a) Cash equivalents $ 260 $ 91 $ — $ — $ 351 $ 238 $ 71 $ — $ — $ 309 Equities (b) 2,699 — 2 1,273 3,974 2,485 — 1 1,491 3,977 Fixed income: U.S. Treasury and agencies 1,002 176 — — 1,178 664 214 — — 878 State and municipal debt — 47 — — 47 — 50 — — 50 Corporate debt (c) — 2,523 325 — 2,848 — 2,846 336 — 3,182 Other (b) 43 161 12 301 517 — 140 12 314 466 Fixed income subtotal 1,045 2,907 337 301 4,590 664 3,250 348 314 4,576 Private equity — — — 1,124 1,124 — — — 953 953 Hedge funds — — — 774 774 — — — 768 768 Real estate — — — 760 760 — — — 631 631 Private credit — — 130 603 733 — — 136 611 747 Pension plan assets subtotal 4,004 2,998 469 4,835 12,306 3,387 3,321 485 4,768 11,961 OPEB plan assets (a) Cash equivalents 54 41 — — 95 32 33 — — 65 Equities 387 2 — 324 713 396 1 — 364 761 Fixed income: U.S. Treasury and agencies 14 44 — — 58 10 42 — — 52 State and municipal debt — 7 — — 7 — 57 — — 57 Corporate debt (c) — 74 — — 74 — 57 — — 57 Other 223 4 — 136 363 182 2 — 115 299 Fixed income subtotal 237 129 — 136 502 192 158 — 115 465 Hedge funds — — — 175 175 — — — 197 197 Real estate — — — 86 86 — — — 71 71 Private credit — — — 84 84 — — — 75 75 OPEB plan assets subtotal 678 172 — 805 1,655 620 192 — 822 1,634 Total pension and OPEB plan assets (d) $ 4,682 $ 3,170 $ 469 $ 5,640 $ 13,961 $ 4,007 $ 3,513 $ 485 $ 5,590 $ 13,595 __________ (a) See Note 16—Fair Value of Financial Assets and Liabilities for a description of levels within the fair value hierarchy. (b) Includes derivative instruments of $(2) million and $1 million for the years ended December 31, 2021 and 2020, respectively, which have total notional amounts of $3,481 million and $4,018 million as of December 31, 2021 and 2020, respectively. The notional principal amounts for these instruments provide one measure of the transaction volume outstanding as of the fiscal years ended and do not represent the amount of the company’s exposure to credit or market loss. (c) Includes investments in equities sold short held in investment vehicles primarily to hedge the equity option component of its convertible debt. Pension equities sold short totaled $(44) million and $(56) million as of December 31, 2021 and 2020, respectively. OPEB equities sold short totaled $(18) million and $(27) million as of December 31, 2021 and 2020, respectively. (d) Excludes net liabilities of $131 million and $77 million as of December 31, 2021 and 2020, respectively, which include certain derivative assets that have notional amounts of $127 million and $140 million as of December 31, 2021 and 2020, respectively. These items are required to reconcile to the fair value of net plan assets and consist primarily of receivables or payables related to pending securities sales and purchases, interest and dividends receivable, and repurchase agreement obligations. The repurchase agreements generally have maturities ranging from 3-6 months.
Schedule of Changes in Fair Value of Plan Assets	The following table presents the reconciliation of Level 3 assets and liabilities for Exelon measured at fair value for pension and OPEB plans for the years ended December 31, 2021 and 2020: Fixed Income Equities Private Total Pension Assets Balance as of January 1, 2021 $ 348 $ 1 $ 136 $ 485 Actual return on plan assets: Relating to assets still held as of the (12) — 18 6 Purchases, sales and settlements: Purchases 10 — 5 15 Settlements (a) (13) — (29) (42) Transfers into Level 3 4 1 — 5 Balance as of December 31, 2021 $ 337 $ 2 $ 130 $ 469 Fixed Income Equities Private Total Pension Assets Balance as of January 1, 2020 $ 144 $ 3 $ 138 $ 285 Actual return on plan assets: Relating to assets still held as of the reporting date 11 (2) 9 18 Purchases, sales and settlements: Purchases 20 — 14 34 Settlements (a) (2) — (25) (27) Transfers into Level 3 (b) 175 — — 175 Balance as of December 31, 2020 $ 348 $ 1 $ 136 $ 485 __________ (a) Represents cash settlements only. (b) In 2020, a contract was terminated for a certain fixed income commingled fund resulting in the ownership of certain fixed income securities which led to a transfer into Level 3 from not subject to leveling of $175 million.
Schedule Of Defined Contributions	The Registrants participate in various 401(k) defined contribution savings plans that are sponsored by Exelon. The plans are qualified under applicable sections of the IRC and allow employees to contribute a portion of their pre-tax and/or after-tax income in accordance with specified guidelines. All Registrants match a percentage of the employee contributions up to certain limits. The following table presents matching contributions to the savings plan for the years ended December 31, 2021, 2020, and 2019: For the Years Ended December 31, Exelon ComEd PECO BGE PHI Pepco DPL ACE 2021 $ 90 $ 35 $ 12 $ 12 14 $ 4 $ 3 $ 2 2020 95 36 12 13 14 4 3 3 2019 88 35 11 12 13 3 3 2

Derivative Financial Instrume_2

Derivative Financial Instruments (Tables)	12 Months Ended
Derivative Financial Instruments (Tables)	Dec. 31, 2021
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Summary of the derivative fair value	The following tables provide a summary of the derivative fair value balances recorded by Exelon and ComEd as of December 31, 2021 and 2020: December 31, 2021 Mark-to-market derivative liabilities (current liabilities) $ (18) Mark-to-market derivative liabilities (noncurrent liabilities) (201) Total mark-to-market derivative liabilities $ (219) December 31, 2020 Mark-to-market derivative liabilities (current liabilities) $ (33) Mark-to-market derivative liabilities (noncurrent liabilities) (268) Total mark-to-market derivative liabilities $ (301)

Debt and Credit Agreements (Tab

Debt and Credit Agreements (Tables)	12 Months Ended
Debt and Credit Agreements (Tables)	Dec. 31, 2021
Short-term and Long-term Debt [Line Items]
Schedule of Commercial Paper Borrowings	The following table reflects the Registrants' commercial paper programs supported by the revolving credit agreements and bilateral credit agreements as of December 31, 2021 and 2020: Maximum Outstanding Average Interest Rate on Commercial Paper Issuer 2021 (a)(b) 2020 (a)(b) 2021 2020 2021 2020 Exelon (c) $ 3,700 $ 3,700 $ 599 $ 691 0.35 % 0.24 % ComEd 1,000 1,000 — 323 — % 0.23 % PECO 600 600 — — — % — % BGE 600 600 130 — 0.37 % — % PHI (d) 900 900 469 368 0.35 % 0.24 % Pepco 300 300 175 35 0.33 % 0.22 % DPL 300 300 149 146 0.36 % 0.24 % ACE 300 300 145 187 0.35 % 0.25 % __________ (a) As of December 31, 2021, excludes $98 million of credit facility agreements arranged at minority and community banks, including $33 million, $33 million, $8 million, $8 million, $8 million, and $8 million, at ComEd, PECO, BGE, Pepco, DPL, and ACE, respectively. These facilities expire on October 7, 2022. These facilities are solely utilized to issue letters of credit. As of December 31, 2020, excludes $97 million of credit facility agreements arranged primarily at minority and community banks, including $32 million, $33 million, $8 million, $8 million, $8 million, and $8 million, at ComEd, PECO, BGE, Pepco, DPL, and ACE, respectively. (b) Pepco, DPL, and ACE's revolving credit facility has the ability to flex to $500 million, $500 million, and $350 million, respectively. The borrowing capacity may be increased or decreased during the term of the facility, except that (i) the sum of the borrowing capacity must equal the total amount of the facility, and (ii) the aggregate amount of credit used at any given time by each of Pepco, DPL, or ACE may not exceed $900 million or the maximum amount of short-term debt the company is permitted to have outstanding by its regulatory authorities. The total number of the borrowing reallocations may not exceed eight per year during the term of the facility. (c) Includes revolving credit agreement at Exelon Corporate with a maximum program size of $600 million as of December 31, 2021 and 2020. Exelon Corporate had no outstanding commercial paper as of December 31, 2021 and 2020. (d) Represents the consolidated amounts of Pepco, DPL, and ACE.
Schedule of Aggregate Bank Commitments, Credit Facility Borrowings, and Available Capacity	As of December 31, 2021, the Registrants had the following aggregate bank commitments, credit facility borrowings, and available capacity under their respective credit facilities: Available Capacity as of December 31, 2021 Borrower (a) Facility Type Aggregate Bank (b) Facility Draws Outstanding Actual To Support Additional Commercial (c) Exelon (c) Syndicated Revolver $ 3,700 $ — $ 8 $ 3,692 $ 3,093 ComEd Syndicated Revolver 1,000 — 2 998 998 PECO Syndicated Revolver 600 — — 600 600 BGE Syndicated Revolver 600 — — 600 470 PHI (d) Syndicated Revolver 900 — — 900 431 Pepco Syndicated Revolver 300 — — 300 125 DPL Syndicated Revolver 300 — — 300 151 ACE Syndicated Revolver 300 — — 300 155 __________ (a) On February 1, 2022, Exelon Corporate and the Utility Registrants' respective syndicated revolving credit facilities were replaced with a new 5-year revolving credit facility. (b) As of December 31, 2021, excludes $98 million of credit facility agreements arranged at minority and community banks, including $33 million, $33 million, $8 million, $8 million, $8 million, and $8 million, at ComEd, PECO, BGE, Pepco, DPL, and ACE, respectively. These facilities expire on October 7, 2022. These facilities are solely utilized to issue letters of credit. As of December 31, 2021, letters of credit issued under these facilities totaled $5 million, $1 million, and $2 million for ComEd, PECO, and BGE, respectively. (c) Includes $600 million aggregate bank commitment related to Exelon Corporate. Exelon Corporate had $6 million outstanding letters of credit as of December 31, 2021. Exelon Corporate had $594 million in available capacity to support additional commercial paper as of December 31, 2021. (d) Represents the consolidated amounts of Pepco, DPL, and ACE.
Schedule of Basis Spread	Borrowings under Exelon’s, ComEd’s, PECO’s, BGE's, Pepco's, DPL's, and ACE's revolving credit agreements bear interest at a rate based upon either the prime rate or a LIBOR-based rate, plus an adder based upon the particular Registrant’s credit rating. The adders for the prime based borrowings and LIBOR-based borrowings are presented in the following table: Exelon (a) ComEd PECO BGE Pepco DPL ACE Prime based borrowings 0 - 27.5 — — — 7.5 — 7.5 LIBOR-based borrowings 90.0 - 127.5 100.0 90.0 90.0 107.5 100.0 107.5 __________ (a) Includes interest rate adders at Exelon Corporate of 27.5 basis points and 127.5 basis points for prime and LIBOR-based borrowings, respectively.
Schedule of long-term debt instruments	Long-Term Debt The following tables present the outstanding long-term debt at the Registrants as of December 31, 2021 and 2020: Exelon Maturity December 31, Rates 2021 2020 Long-term debt First mortgage bonds (a)(b)(c) 0.14 % - 7.90 % 2022 - 2051 $ 20,751 $ 18,915 Senior unsecured notes 3.40 % - 7.60 % 2025 - 2050 6,324 6,624 Unsecured notes 2.25 % - 6.35 % 2022 - 2050 4,000 3,700 Notes payable and other 1.64 % - 7.49 % 2022 - 2053 86 59 Junior subordinated notes 3.50 % 2022 1,150 1,150 Long-term software licensing agreement 3.62 % - 3.95 % 2024 - 2025 9 30 Unsecured tax-exempt bonds 0.12 % - 1.70 % 2022 - 2024 143 143 Medium-terms notes (unsecured) 7.72 % 2027 10 10 Transition bonds 5.55 % 2021 — 21 Loan agreement (d) 2.00 % 2023 50 50 Total long-term debt 32,523 30,702 Unamortized debt discount and premium, net (70) (72) Unamortized debt issuance costs (220) (202) Fair value adjustment 669 721 Long-term debt due within one year (2,153) (1,622) Long-term debt $ 30,749 $ 29,527 Long-term debt to financing trusts (e) Subordinated debentures to ComEd Financing III 6.35 % 2033 $ 206 $ 206 Subordinated debentures to PECO Trust III 5.25 % - 7.38 % 2028 81 81 Subordinated debentures to PECO Trust IV 5.75 % 2033 103 103 Total long-term debt to financing trusts $ 390 $ 390 __________ (a) Substantially all of ComEd’s assets other than expressly excepted property and substantially all of PECO’s, Pepco's, DPL's, and ACE's assets are subject to the liens of their respective mortgage indentures. (b) On November 16, 2021, DPL entered into a purchase agreement of First Mortgage Bonds of $125 million at 3.06% due on February 15, 2052. The closing date of the issuance occurred on February 15, 2022. (c) On November 16, 2021, ACE entered into a purchase agreement of First Mortgage Bonds of $25 million and $150 million at 2.27% and 3.06% due on February 15, 2032 and February 15, 2052, respectively. The closing date of the issuance occurred on February 15, 2022. (d) In connection with the separation, Exelon Corporate entered into three 18-month term loan agreements. On January 21, 2022, two of the loan agreements were issued for $300 million each with an expiration date of July 21, 2023. On January 24, 2022, the third loan agreement was issued for $250 million with an expiration date of July 24, 2023. Pursuant to the loan agreement, loans made thereunder bear interest at a variable rate equal to SOFR plus 0.65%. (e) Amounts owed to these financing trusts are recorded as Long-term debt to financing trusts within Exelon’s Consolidated Balance Sheet. ComEd Maturity December 31, Rates 2021 2020 Long-term debt First mortgage bonds (a) 2.20 % - 6.45 % 2024 - 2051 $ 9,879 $ 9,079 Other 7.49 % 2053 8 8 Total long-term debt 9,887 9,087 Unamortized debt discount and premium, net (27) (28) Unamortized debt issuance costs (87) (76) Long-term debt due within one year — (350) Long-term debt $ 9,773 $ 8,633 Long-term debt to financing trust (b) Subordinated debentures to ComEd Financing III 6.35 % 2033 $ 206 $ 206 Total long-term debt to financing trusts 206 206 Unamortized debt issuance costs (1) (1) Long-term debt to financing trusts $ 205 $ 205 __________ (a) Substantially all of ComEd’s assets, other than expressly excepted property, are subject to the lien of its mortgage indenture. (b) Amount owed to this financing trust is recorded as Long-term debt to financing trust within ComEd’s Consolidated Balance Sheet. PECO Maturity December 31, Rates 2021 2020 Long-term debt First mortgage bonds (a) 2.38 % - 5.95 % 2022 - 2051 $ 4,200 $ 3,750 Loan agreement 2.00 % 2023 50 50 Total long-term debt 4,250 3,800 Unamortized debt discount and premium, net (20) (20) Unamortized debt issuance costs (33) (27) Long-term debt due within one year (350) (300) Long-term debt $ 3,847 $ 3,453 Long-term debt to financing trusts (b) Subordinated debentures to PECO Trust III 5.25 % - 7.38 % 2028 $ 81 $ 81 Subordinated debentures to PECO Trust IV 5.75 % 2033 103 103 Long-term debt to financing trusts $ 184 $ 184 __________ (a) Substantially all of PECO’s assets are subject to the lien of its mortgage indenture. (b) Amounts owed to this financing trust are recorded as Long-term debt to financing trusts within PECO’s Consolidated Balance Sheet. BGE Maturity December 31, Rates 2021 2020 Long-term debt Unsecured notes 2.25 % - 6.35 % 2022 - 2050 $ 4,000 $ 3,700 Total long-term debt 4,000 3,700 Unamortized debt discount and premium, net (12) (12) Unamortized debt issuance costs (27) (24) Long-term debt due within one year (250) (300) Long-term debt $ 3,711 $ 3,364 PHI Maturity December 31, Rates 2021 2020 Long-term debt First mortgage bonds (a) 0.14 % - 7.90 % 2022 - 2051 $ 6,672 $ 6,086 Senior unsecured notes 7.45 % 2032 185 185 Unsecured tax-exempt bonds 0.12 % - 1.70 % 2022 - 2024 143 143 Medium-terms notes (unsecured) 7.72 % 2027 10 10 Transition bonds 5.55 % 2021 — 21 Finance leases 3.54 % 2022 - 2029 74 50 Other (b) 7.28 % - 7.49 % 2022 — 1 Total long-term debt 7,084 6,496 Unamortized debt discount and premium, net 4 4 Unamortized debt issuance costs (36) (28) Fair value adjustment 495 534 Long-term debt due within one year (399) (347) Long-term debt $ 7,148 $ 6,659 _________ (a) Substantially all of Pepco's, DPL's, and ACE's assets are subject to the liens of their respective mortgage indentures. (b) The amount in the Other category was less than 1 million as of December 31, 2021. Pepco Maturity December 31, Rates 2021 2020 Long-term debt First mortgage bonds (a) 2.32 % - 7.90 % 2022 - 2051 $ 3,350 $ 3,075 Unsecured tax-exempt bonds 1.70 % 2022 110 110 Finance leases 3.54 % 2025 - 2029 26 17 Other (b) 7.28 % - 7.49 % 2022 — 1 Total long-term debt 3,486 3,203 Unamortized debt discount and premium, net 2 2 Unamortized debt issuance costs (43) (40) Long-term debt due within one year (313) (3) Long-term debt $ 3,132 $ 3,162 ________ (a) Substantially all of Pepco's assets are subject to the lien of its mortgage indenture. (b) The amount in the Other category was less than 1 million as of December 31, 2021. DPL Maturity December 31, Rates 2021 2020 Long-term debt First mortgage bonds (a)(b) 0.14 % - 4.27 % 2023 - 2051 $ 1,749 $ 1,624 Unsecured tax-exempt bonds 0.12 % - 0.13 % 2024 33 33 Medium-terms notes (unsecured) 7.72 % 2027 10 10 Finance leases 3.54 % 2025 - 2029 29 20 Total long-term debt 1,821 1,687 Unamortized debt discount and premium, net — 1 Unamortized debt issuance costs (11) (11) Long-term debt due within one year (83) (82) Long-term debt $ 1,727 $ 1,595 __________ (a) Substantially all of DPL's assets are subject to the lien of its mortgage indenture. (b) On November 16, 2021, DPL entered into a purchase agreement of First Mortgage Bonds of $125 million at 3.06% due on February 15, 2052. The closing date of the issuance occurred on February 15, 2022. ACE Maturity December 31, Rates 2021 2020 Long-term debt First mortgage bonds (a)(b) 2.25 % - 5.80 % 2024 - 2050 $ 1,573 $ 1,387 Transition bonds 5.55 % 2021 — 21 Finance leases 3.54 % 2022 - 2029 19 13 Total long-term debt 1,592 1,421 Unamortized debt discount and premium, net (1) (1) Unamortized debt issuance costs (9) (7) Long-term debt due within one year (3) (261) Long-term debt $ 1,579 $ 1,152 __________ (a) Substantially all of ACE's assets are subject to the lien of its mortgage indenture. (b) On November 16, 2021, ACE entered into a purchase agreement of First Mortgage Bonds of $25 million and $150 million at 2.27% and 3.06% due on February 15, 2032 and February 15, 2052, respectively. The closing date of the issuance occurred on February 15, 2022.
Schedule of maturities of long-term debt	Long-term debt maturities at the Registrants in the periods 2022 through 2026 and thereafter are as follows: Year Exelon ComEd PECO BGE PHI Pepco DPL ACE 2022 $ 2,153 $ — $ 350 $ 250 $ 399 $ 313 $ 83 $ 3 2023 864 — 50 300 512 4 505 3 2024 817 250 — — 562 404 5 153 2025 1,322 — 350 — 162 4 5 153 2026 1,611 500 — 350 11 4 4 3 Thereafter 25,888 (a) 9,342 (b) 3,684 (c) 3,100 5,438 2,757 1,219 1,277 Total $ 32,655 $ 10,092 $ 4,434 $ 4,000 $ 7,084 $ 3,486 $ 1,821 $ 1,592 __________ (a) Includes $390 million due to ComEd and PECO financing trusts. (b) Includes $206 million due to ComEd financing trust. (c) Includes $184 million due to PECO financing trusts.
Revolving Credit Facility [Member]
Short-term and Long-term Debt [Line Items]
Schedule of Aggregate Bank Commitments, Credit Facility Borrowings, and Available Capacity	Revolving Credit Agreements On February 1, 2022, Exelon Corporate and the Utility Registrants each entered into a new 5-year revolving credit facility that replaced its existing syndicated revolving credit facility. The following table reflects the credit agreements: Borrower Aggregate Bank Commitment Interest Rate Exelon Corporate $ 900 SOFR plus 1.275 % ComEd 1,000 SOFR plus 1.000 % PECO 600 SOFR plus 0.900 % BGE 600 SOFR plus 0.900 % Pepco 300 SOFR plus 1.075 % DPL 300 SOFR plus 1.000 % ACE 300 SOFR plus 1.075 %

Fair Value of Financial Asset_2

Fair Value of Financial Assets and Liabilities (Tables)	12 Months Ended
Fair Value of Financial Assets and Liabilities (Tables)	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value of Financial Liabilities Recorded at Amortized Cost	The following tables present the carrying amounts and fair values of the Registrants’ short-term liabilities, long-term debt, and trust preferred securities (long-term debt to financing trusts or junior subordinated debentures) as of December 31, 2021 and 2020. The Registrants have no financial liabilities classified as Level 1. The carrying amounts of the Registrants’ short-term liabilities as presented in their Consolidated Balance Sheets are representative of their fair value (Level 2) because of the short-term nature of these instruments. December 31, 2021 December 31, 2020 Carrying Amount Fair Value Carrying Amount Fair Value Level 2 Level 3 Total Level 2 Level 3 Total Long-Term Debt, including amounts due within one year (a) Exelon $ 32,902 $ 34,897 $ 2,217 $ 37,114 $ 31,149 $ 35,416 $ 1,856 $ 37,272 ComEd 9,773 11,305 — 11,305 8,983 11,117 — 11,117 PECO 4,197 4,740 50 4,790 3,753 4,553 50 4,603 BGE 3,961 4,406 — 4,406 3,664 4,366 — 4,366 PHI 7,547 5,970 2,167 8,137 7,006 6,099 1,806 7,905 Pepco 3,445 3,201 975 4,176 3,165 3,336 748 4,084 DPL 1,810 1,426 552 1,978 1,677 1,484 455 1,939 ACE 1,582 1,091 641 1,732 1,413 1,018 602 1,620 Long-Term Debt to Financing Trusts Exelon $ 390 $ — $ 470 $ 470 $ 390 $ — $ 467 $ 467 ComEd 205 — 248 248 205 — 246 246 PECO 184 — 222 222 184 — 221 221 __________ (a) Includes unamortized debt issuance costs, unamortized debt discount and premium, net, purchase accounting fair value adjustments, and finance lease liabilities which are not fair valued. Refer to Note 15 — Debt and Credit Agreements for unamortized debt issuance costs, unamortized debt discount and premium, net, and purchase accounting fair value adjustments and Note 10 — Leases for finance lease liabilities .
Assets and Liabilities Measured and Recorded at Fair Value on Recurring Basis	The following tables present assets and liabilities measured and recorded at fair value in the Registrants' Consolidated Balance Sheets on a recurring basis and their level within the fair value hierarchy as of December 31, 2021 and 2020: Exelon As of December 31, 2021 As of December 31, 2020 Level 1 Level 2 Level 3 Total (a) Level 1 Level 2 Level 3 Total (a) Assets Cash equivalents (b) $ 524 $ — $ — $ 524 $ 558 $ — $ — $ 558 Rabbi trust investments Cash equivalents 60 — — 60 59 — — 59 Mutual funds 60 — — 60 54 — — 54 Fixed income — 10 — 10 — 11 — 11 Life insurance contracts — 61 37 98 — 60 34 94 Rabbi trust investments subtotal 120 71 37 228 113 71 34 218 Total assets 644 71 37 752 671 71 34 776 Liabilities Mark-to-market derivative liabilities — — (219) (219) — — (301) (301) Deferred compensation obligation — (131) — (131) — (121) — (121) Total liabilities — (131) (219) (350) — (121) (301) (422) Total net assets $ 644 $ (60) $ (182) $ 402 $ 671 $ (50) $ (267) $ 354 __________ (a) There were no assets and liabilities that were not subject to leveling as of December 31, 2021 and 2020. (b) Excludes cash of $464 million and $237 million as of December 31, 2021 and 2020, respectively, and restricted cash of $49 million and $39 million as of December 31, 2021 and 2020, respectively, and includes long-term restricted cash of $44 million and $53 million as of December 31, 2021 and 2020, respectively, which is reported in Other deferred debits in the Consolidated Balance Sheets. ComEd, PECO, and BGE ComEd PECO BGE As of December 31, 2021 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets Cash equivalents (a) $ 237 $ — $ — $ 237 $ 9 $ — $ — $ 9 $ — $ — $ — $ — Rabbi trust investments Mutual funds — — — — 11 — — 11 14 — — 14 Life insurance contracts — — — — — 16 — 16 — — — — Rabbi trust investments subtotal — — — — 11 16 — 27 14 — — 14 Total assets 237 — — 237 20 16 — 36 14 — — 14 Liabilities Mark-to-market derivative liabilities (b) — — (219) (219) — — — — — — — — Deferred compensation obligation — (10) — (10) — (9) — (9) — (7) — (7) Total liabilities — (10) (219) (229) — (9) — (9) — (7) — (7) Total net assets (liabilities) $ 237 $ (10) $ (219) $ 8 $ 20 $ 7 $ — $ 27 $ 14 $ (7) $ — $ 7 ComEd PECO BGE As of December 31, 2020 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets Cash equivalents (a) $ 285 $ — $ — $ 285 $ 8 $ — $ — $ 8 $ 120 $ — $ — $ 120 Rabbi trust investments Mutual funds — — — — 9 — — 9 10 — — 10 Life insurance contracts — — — — — 13 — 13 — — — — Rabbi trust investments subtotal — — — — 9 13 — 22 10 — — 10 Total assets 285 — — 285 17 13 — 30 130 — — 130 Liabilities Mark-to-market derivative liabilities (b) — — (301) (301) — — — — — — — — Deferred compensation obligation — (8) — (8) — (9) — (9) — (5) — (5) Total liabilities — (8) (301) (309) — (9) — (9) — (5) — (5) Total net assets (liabilities) $ 285 $ (8) $ (301) $ (24) $ 17 $ 4 $ — $ 21 $ 130 $ (5) $ — $ 125 __________ (a) ComEd excludes cash of $105 million and $83 million as of December 31, 2021 and 2020, respectively, and restricted cash of $42 million and $37 million as of December 31, 2021 and 2020, respectively, and includes long-term restricted cash of $43 million as of both December 31, 2021 and 2020, which is reported in Other deferred debits in the Consolidated Balance Sheets. PECO excludes cash of $35 million and $18 million as of December 31, 2021 and 2020, respectively. BGE excludes cash of $51 million and $24 million as of December 31, 2021 and 2020, respectively, and restricted cash of $4 million and $1 million as of December 31, 2021 and 2020, respectively. (b) The Level 3 balance consists of the current and noncurrent liability of $18 million and $201 million, respectively, as of December 31, 2021 and $33 million and $268 million, respectively, as of December 31, 2020 related to floating-to-fixed energy swap contracts with unaffiliated suppliers. PHI, Pepco, DPL, and ACE As of December 31, 2021 As of December 31, 2020 PHI Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets Cash equivalents (a) $ 110 $ — $ — $ 110 $ 86 $ — $ — $ 86 Rabbi trust investments Cash equivalents 59 — — 59 55 — — 55 Mutual funds 14 — — 14 14 — — 14 Fixed income — 10 — 10 — 11 — 11 Life insurance contracts — 27 35 62 — 26 34 60 Rabbi trust investments subtotal 73 37 35 145 69 37 34 140 Total assets 183 37 35 255 155 37 34 226 Liabilities Deferred compensation obligation — (18) — (18) — (17) — (17) Total liabilities — (18) — (18) — (17) — (17) Total net assets $ 183 $ 19 $ 35 $ 237 $ 155 $ 20 $ 34 $ 209 Pepco DPL ACE As of December 31, 2021 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets Cash equivalents (a) $ 31 $ — $ — $ 31 $ 43 $ — $ — $ 43 $ — $ — $ — $ — Rabbi trust investments Cash equivalents 58 — — 58 — — — — — — — — Life insurance contracts — 27 35 62 — — — — — — — — Rabbi trust investments subtotal 58 27 35 120 — — — — — — — — Total assets 89 27 35 151 43 — — 43 — — — — Liabilities Deferred compensation obligation — (2) — (2) — — — — — — — — Total liabilities — (2) — (2) — — — — — — — — Total net assets $ 89 $ 25 $ 35 $ 149 $ 43 $ — $ — $ 43 $ — $ — $ — $ — Pepco DPL ACE As of December 31, 2020 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets Cash equivalents (a) $ 35 $ — $ — $ 35 $ — $ — $ — $ — $ 13 $ — $ — $ 13 Rabbi trust investments Cash equivalents 53 — — 53 — — — — — — — — Fixed income — 2 — 2 — — — — — — — — Life insurance contracts — 26 34 60 — — — — — — — — Rabbi trust investments subtotal 53 28 34 115 — — — — — — — — Total assets 88 28 34 150 — — — — 13 — — 13 Liabilities Deferred compensation obligation — (2) — (2) — — — — — — — — Total liabilities — (2) — (2) — — — — — — — — Total net assets $ 88 $ 26 $ 34 $ 148 $ — $ — $ — $ — $ 13 $ — $ — $ 13 __________ (a) PHI excludes cash of $100 million and $74 million as of December 31, 2021 and 2020, respectively, and restricted cash of $3 million and none as of December 31, 2021 and 2020, respectively, and includes long-term restricted cash of none and $10 million as of December 31, 2021 and 2020, respectively, which is reported in Other deferred debits in the Consolidated Balance Sheets. Pepco excludes cash of $34 million and $30 million as of December 31, 2021 and 2020, respectively, and restricted cash of $3 million and none as of December 31, 2021 and 2020, respectively. DPL excludes cash of $28 million and $15 million as of December 31, 2021 and 2020, respectively. ACE excludes cash of $29 million and $17 million as of December 31, 2021 and 2020, respectively, and includes long-term restricted cash of none and $10 million as of December 31, 2021 and 2020, respectively, which is reported in Other deferred debits in the Consolidated Balance Sheets.
Fair Value Reconciliation of Level 3 Assets and Liabilities Measured at Fair Value on a Recurring Basis	The following tables present the fair value reconciliation of Level 3 assets and liabilities measured at fair value on a recurring basis during the years ended December 31, 2021 and 2020: Exelon ComEd PHI and Pepco For the year ended December 31, 2021 Total Mark-to-Market Life Insurance Contracts Balance as of January 1, 2021 $ (267) $ (301) $ 34 Total realized / unrealized gains (losses) Included in net income (a) 3 — 3 Included in regulatory assets/liabilities 82 82 (b) — Purchases, sales, and settlements Settlements (2) — (2) Transfers into Level 3 2 — — Balance as of December 31, 2021 $ (182) $ (219) $ 35 The amount of total gains included in income attributed to the change in unrealized gains (losses) related to assets and liabilities as of December 31, 2021 3 $ — $ 3 Exelon ComEd PHI and Pepco For the year ended December 31, 2020 Total Mark-to-Market Life Insurance Contracts Balance as of January 1, 2020 $ (260) $ (301) $ 41 Total realized / unrealized gains (losses) Included in net income (a) 3 — 3 Included in regulatory assets/liabilities — — (b) — Purchases, sales, and settlements Settlements (10) — (10) Balance as of December 31, 2020 $ (267) $ (301) $ 34 The amount of total gains included in income attributed to the change in unrealized gains (losses) related to assets and liabilities as of December 31, 2020 $ 3 $ — $ 3 __________ (a) Classified in Operating and maintenance expense in the Consolidated Statements of Operations and Comprehensive Income. (b) Includes $62 million of increases in fair value and an increase for realized losses due to settlements of $20 million recorded in purchased power expense associated with floating-to-fixed energy swap contracts with unaffiliated suppliers for the year ended December 31, 2021. Includes $33 million of decreases in fair value and an increase for realized losses due to settlements of $33 million recorded in purchased power expense associated with floating-to-fixed energy swap contracts with unaffiliated suppliers for the year ended December 31, 2020.
Fair Value Reconciliation of Level 3 Assets and Liabilities Measured at Fair Value on a Recurring Basis, Valuation Technique	The following table discloses the significant inputs to the forward curve used to value mark-to-market derivatives: Type of trade Fair Value as of December 31, 2021 Fair Value as of December 31, 2020 Valuation Unobservable 2021 Range & Arithmetic Average 2020 Range & Arithmetic Average Mark-to-market derivatives $ (219) $ (301) Discounted Cash Flow Forward heat rate (a) 9x - 10x 9.13x 8x - 9x 8.85x Marketability 3% - 7% 4.77% 3% - 8% 4.93% Renewable 92% - 120% 97% 91% - 123% 99% __________ (a) Quoted forward natural gas rates are utilized to project the forward power curve for the delivery of energy at specified future dates. The natural gas curve is extrapolated beyond its observable period to the end of the contract’s delivery.

Commitments and Contingencies_2

Commitments and Contingencies (Tables)	12 Months Ended
Commitments and Contingencies (Tables)	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
PHI Merger Commitments [Table Text Block]	The following amounts represent total commitment costs that have been recorded since the acquisition date and the total remaining obligations for Exelon, PHI, Pepco, DPL, and ACE as of December 31, 2021: Description Exelon PHI Pepco DPL ACE Total commitments $ 513 $ 320 $ 120 $ 89 $ 111 Remaining commitments (a) 68 58 48 6 4 __________ (a) Remaining commitments extend through 2026 and include rate credits, energy efficiency programs, and delivery system modernization.
Commercial Commitments	The Registrants' commercial commitments as of December 31, 2021, representing commitments potentially triggered by future events were as follows: Expiration within Exelon Total 2022 2023 2024 2025 2026 2027 and beyond Letters of credit $ 17 $ 17 $ — $ — $ — $ — $ — Surety bonds (a) 109 107 — 2 — — — Financing trust guarantees 378 — — — — — 378 Guaranteed lease residual values (b) 31 — 5 6 6 5 9 Total commercial commitments $ 535 $ 124 $ 5 $ 8 $ 6 $ 5 $ 387 ComEd Letters of credit $ 7 $ 7 $ — $ — $ — $ — $ — Surety bonds (a) 17 15 — 2 — — — Financing trust guarantees 200 — — — — — 200 Total commercial commitments $ 224 $ 22 $ — $ 2 $ — $ — $ 200 PECO Letters of credit $ 1 $ 1 $ — $ — $ — $ — $ — Surety bonds (a) 2 2 — — — — — Financing trust guarantees 178 — — — — — 178 Total commercial commitments $ 181 $ 3 $ — $ — $ — $ — $ 178 BGE Letters of credit $ 2 $ 2 $ — $ — $ — $ — $ — Surety bonds (a) 3 3 — — — — — Total commercial commitments $ 5 $ 5 $ — $ — $ — $ — $ — PHI Surety bonds (a) $ 23 $ 23 $ — $ — $ — $ — $ — Guaranteed lease residual values (b) 31 — 5 6 6 5 9 Total commercial commitments $ 54 $ 23 $ 5 $ 6 $ 6 $ 5 $ 9 Pepco Surety bonds (a) $ 14 $ 14 $ — $ — $ — $ — $ — Guaranteed lease residual values (c) 10 — 1 2 2 2 3 Total commercial commitments $ 24 $ 14 $ 1 $ 2 $ 2 $ 2 $ 3 DPL Surety bonds (a) $ 5 $ 5 $ — $ — $ — $ — $ — Guaranteed lease residual values (b) 13 — 2 3 2 2 4 Total commercial commitments $ 18 $ 5 $ 2 $ 3 $ 2 $ 2 $ 4 ACE Surety bonds (a) $ 4 $ 4 $ — $ — $ — $ — $ — Guaranteed lease residual values (b) 8 — 2 1 2 1 2 Total commercial commitments $ 12 $ 4 $ 2 $ 1 $ 2 $ 1 $ 2 __________ (a) Surety bonds—Guarantees issued related to contract and commercial agreements, excluding bid bonds. (b) Represents the maximum potential obligation in the event that the fair value of certain leased equipment and fleet vehicles is zero at the end of the maximum lease term. The lease term associated with these assets ranges from 1 to 8 years. The maximum potential obligation at the end of the minimum lease term would be $75 million guaranteed by Exelon and PHI, of which $25 million , $31 million, and $19 million is guaranteed by Pepco, DPL, and ACE, respectively. Historically, payments under the guarantees have not been made and PHI believes the likelihood of payments being required under the guarantees is remote.
Accrued environmental liabilities	As of December 31, 2021 and 2020, the Registrants had accrued the following undiscounted amounts for environmental liabilities in Other current liabilities and Other deferred credits and other liabilities in their respective Consolidated Balance Sheets: December 31, 2021 December 31, 2020 Total environmental Portion of total related to Total environmental Portion of total related to Exelon $ 352 $ 303 $ 366 $ 314 ComEd 279 279 293 293 PECO 22 20 23 21 BGE 6 4 2 — PHI 42 — 44 — Pepco 40 — 42 — DPL 1 — 1 — ACE 1 — 1 —

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	12 Months Ended
Shareholders' Equity (Tables)	Dec. 31, 2021
Shareholder [Abstract]
Common Stock Warrants [Table Text Block]	The following table presents warrants outstanding to purchase ComEd common stock and shares of common stock reserved for the conversion of warrants. The warrants entitle the holders to convert such warrants into common stock of ComEd at a conversion rate of one share of common stock for three warrants. December 31, 2021 2020 Warrants outstanding 60,061 60,143 Common Stock reserved for conversion 20,020 20,048
Preferred Stock [Table Text Block]	The following table presents Exelon, ComEd, PECO, BGE, Pepco, and ACE's shares of preferred securities authorized, none of which were outstanding, as of December 31, 2021 and 2020. There are no shares of preferred securities authorized for DPL. Preferred Securities Authorized Exelon 100,000,000 ComEd 850,000 PECO 15,000,000 BGE 1,000,000 Pepco 6,000,000 ACE (a) 2,799,979 __________
Preference Securities [Table Text Block]	The following table presents ComEd's, BGE's, and ACE's preference securities authorized, none of which were outstanding as of December 31, 2021 and 2020. There are no shares of preference securities authorized for Exelon, PECO, Pepco, and DPL. Preference Securities Authorized ComEd 6,810,451 BGE (a) 6,500,000 ACE 3,000,000 __________

Stock-Based Compensation Plan_2

Stock-Based Compensation Plans Stock-Based Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2021
Share-based Payment Arrangement [Abstract]
Share-based Payment Arrangement, Cost by Plan [Table Text Block]	The following table presents the stock-based compensation expense included in Exelon's Consolidated Statements of Operations and Comprehensive Income. The Utility Registrants' stock-based compensation expense for the years ended December 31, 2021, 2020, and 2019 was not material. Year Ended December 31, Exelon 2021 2020 2019 Total stock-based compensation expense included in operating and maintenance expense $ 95 $ 37 $ 40 Income tax benefit (25) (9) (10) Total after-tax stock-based compensation expense $ 70 $ 28 $ 30
Stock Based Compensation Tax Benefit	The following table presents information regarding Exelon’s realized tax benefit when distributed: Year Ended December 31, 2021 2020 2019 Performance share awards $ 6 $ 15 $ 27 Restricted stock units 6 8 12
Schedule of Nonvested Performance-based Units Activity	The following table summarizes Exelon’s nonvested performance share awards activity: Shares Weighted Average Nonvested at December 31, 2020 (a) 930,392 $ 43.67 Granted 1,131,788 43.37 Change in performance 713,202 45.59 Vested (327,551) 38.66 Forfeited (157,552) 44.45 Undistributed vested awards (b) (1,067,763) 44.58 Nonvested at December 31, 2021 (a) 1,222,516 $ 44.96 __________ (a) Excludes 1,934,238 and 1,414,661 of performance share awards issued to retirement-eligible employees as of December 31, 2021 and 2020, respectively, as they are fully vested. (b) Represents performance share awards that vested but were not distributed to retirement-eligible employees during 2021.
Schedule of weighted average grant date fair value	The following table summarizes the weighted average grant date fair value and the total fair value of performance share awards vested. Year Ended December 31, 2021 (a) 2020 2019 Weighted average grant date fair value (per share) $ 43.37 $ 46.61 $ 47.37 Total fair value of performance shares vested 44 39 158 Total fair value of performance shares settled in cash 28 63 131 __________ (a) As of December 31, 2021, $26 million of total unrecognized compensation costs related to nonvested performance shares are expected to be recognized over the remaining weighted-average period of 1.8 years.
Schedule of Nonvested Restricted Stock Units Activity	The following table summarizes Exelon’s nonvested restricted stock unit activity: Shares Weighted Average Nonvested at December 31, 2020 (a) 1,114,130 $ 43.67 Granted 879,606 44.21 Vested (397,526) 44.39 Forfeited (57,646) 44.98 Undistributed vested awards (b) (396,515) 43.66 Nonvested at December 31, 2021 (a) 1,142,049 $ 43.52 __________ (a) Excludes 609,934 and 748,165 of restricted stock units issued to retirement-eligible employees as of December 31, 2021 and 2020, respectively, as they are fully vested. (b) Represents restricted stock units that vested but were not distributed to retirement-eligible employees during 2021.
Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity	The following table summarizes the weighted average grant date fair value and the total fair value of restricted stock units vested. Year Ended December 31, 2021 (a) 2020 2019 Weighted average grant date fair value (per share) $ 44.21 $ 46.33 $ 45.65 Total fair value of restricted stock units vested 34 54 92 __________
Schedule of Share-based Compensation, Stock Options, Activity	The following table presents information with respect to stock option activity: Shares Weighted Weighted Aggregate Balance of shares outstanding at December 31, 2020 1,265,410 $ 40.57 0.91 $ 3 Options exercised (928,003) 39.45 11 Options expired (310,400) 43.40 Balance of shares outstanding at December 31, 2021 27,007 $ 46.47 0.15 $ — Exercisable at December 31, 2021 (a) 27,007 $ 46.47 0.15 $ — __________ (a) Includes stock options issued to retirement eligible employees.
Stock Options Exercised	The following table summarizes additional information regarding stock options exercised: Year Ended December 31, 2021 2020 2019 Intrinsic value (a) $ 11 $ 5 $ 9 Cash received for exercise price 37 18 59 __________ (a) The difference between the market value on the date of exercise and the option exercise price.

Changes in Accumulated Other _2

Changes in Accumulated Other Comprehensive Income (Tables)	12 Months Ended
Changes in Accumulated Other Comprehensive Income (Tables)	Dec. 31, 2021
Equity [Abstract]
Schedule Of Changes In Accumulated Other Comprehensive Income (Loss)	The following tables present changes in Exelon's AOCI, net of tax, by component: Losses on Pension and (a) Foreign AOCI of Investments (b) Total Balance at December 31, 2018 $ (2) $ (2,960) $ (33) $ — $ (2,995) OCI before reclassifications — (289) 6 (2) (285) Amounts reclassified from AOCI — 84 — 2 86 Net current-period OCI — (205) 6 — (199) Balance at December 31, 2019 $ (2) $ (3,165) $ (27) $ — $ (3,194) OCI before reclassifications (3) (357) 4 — (356) Amounts reclassified from AOCI — 150 — — 150 Net current-period OCI (3) (207) 4 — (206) Balance at December 31, 2020 $ (5) $ (3,372) $ (23) $ — $ (3,400) OCI before reclassifications (1) 432 — — 431 Amounts reclassified from AOCI — 219 — — 219 Net current-period OCI (1) 651 — — 650 Balance at December 31, 2021 $ (6) $ (2,721) $ (23) $ — $ (2,750) __________ (a) This AOCI component is included in the computation of net periodic pension and OPEB cost. See Note 13 — Retirement Benefits for additional information. See Exelon's Statements of Operations and Comprehensive Income for individual components of AOCI. (b) All amounts are net of noncontrolling interests.
Schedule of Income Taxes Allocated to Other Comprehensive Income (Loss) Components	The following table presents income tax benefit (expense) allocated to each component of Exelon's other comprehensive income (loss): For the Year Ended December 31, 2021 2020 2019 Pension and non-pension postretirement benefit plans: Prior service benefit reclassified to periodic benefit cost $ 4 $ 16 $ 23 Actuarial loss reclassified to periodic benefit cost (76) (66) (52) Pension and non-pension postretirement benefit plans valuation adjustment (153) 122 100

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	12 Months Ended
Variable Interest Entities (Tables)	Dec. 31, 2021
Variable Interest Entity [Abstract]
Consolidated VIEs- Assets and Liabilities	The table below shows the carrying amounts and classification of the consolidated VIE’s assets and liabilities included in PHI's and ACE's consolidated financial statements as of December 31, 2020. PHI and ACE did not have any VIE as of December 31, 2021. The assets can only be used to settle obligations of the VIE. The liabilities are such that creditors, or beneficiaries, do not have recourse to the general credit of ACE. December 31, 2020 PHI (a) ACE Restricted cash and cash equivalents 3 3 Other current assets 5 — Total current assets 8 3 Other noncurrent assets 10 10 Total noncurrent assets 10 10 Total assets (c) $ 18 $ 13 Long-term debt due within one year $ 26 $ 21 Total current liabilities 26 21 Total liabilities (d) $ 26 $ 21 __________

Supplemental Financial Inform_2

Supplemental Financial Information (Tables)	12 Months Ended
Supplemental Financial Information (Tables)	Dec. 31, 2021
Supplemental Financial Information [Abstract]
Taxes Other Than Income Taxes	The following tables provide additional information about material items recorded in the Registrants' Consolidated Statements of Operations and Comprehensive Income. Taxes other than income taxes Exelon ComEd PECO BGE PHI Pepco DPL ACE For the year ended December 31, 2021 Utility (a) $ 774 $ 246 $ 139 $ 88 $ 301 $ 278 $ 22 $ 3 Property 364 39 18 176 131 88 40 3 Payroll 124 27 16 18 27 7 5 3 For the year ended December 31, 2020 Utility (a) $ 759 $ 238 $ 135 $ 87 $ 299 $ 275 $ 21 $ 3 Property 336 30 16 164 126 84 39 3 Payroll 121 27 16 17 25 7 5 3 For the year ended December 31, 2019 Utility (a) $ 768 $ 242 $ 132 $ 90 $ 304 $ 286 $ 18 $ — Property 321 29 17 153 122 85 34 2 Payroll 117 27 15 17 24 7 4 2 __________ (a) The Registrants’ utility taxes represents municipal and state utility taxes and gross receipts taxes related to their operating revenues. The offsetting collection of utility taxes from customers is recorded in revenues in the Registrants’ Consolidated Statements of Operations and Comprehensive Income.
Schedule of Other Nonoperating Income, by Component	Other, net Exelon ComEd PECO BGE PHI Pepco DPL ACE For the year ended December 31, 2021 AFUDC—Equity 136 34 26 27 49 40 6 3 Non-service net periodic benefit cost 91 — — — — — — — For the year ended December 31, 2020 AFUDC—Equity 104 29 17 22 36 28 4 4 Non-service net periodic benefit cost 53 — — — — — — — For the year ended December 31, 2019 AFUDC—Equity 85 17 13 21 34 25 4 5 Non-service net periodic benefit cost 13 — — — — — — —
Cash Flow Supplemental Disclosures	The following tables provide additional information about material items recorded in the Registrants' Consolidated Statements of Cash Flows. Depreciation, amortization, and accretion Exelon (a) ComEd PECO BGE PHI Pepco DPL ACE For the year ended December 31, 2021 Property, plant, and equipment (b) $ 5,384 $ 970 $ 336 $ 439 $ 627 $ 274 $ 169 $ 155 Amortization of regulatory assets (b) 594 235 12 152 194 129 41 24 Amortization of intangible assets, net (b) 58 — — — — — — — Amortization of energy contract assets and liabilities (c) 31 — — — — — — — Nuclear fuel (d) 992 — — — — — — — ARO accretion (e) 514 — — — — — — — Total depreciation, amortization, and accretion $ 7,573 $ 1,205 $ 348 $ 591 $ 821 $ 403 $ 210 $ 179 For the year ended December 31, 2020 Property, plant, and equipment (b) $ 4,364 $ 922 $ 319 $ 397 $ 586 $ 257 $ 155 $ 140 Amortization of regulatory assets (b) 588 211 28 153 196 120 36 40 Amortization of intangible assets, net (b) 62 — — — — — — — Amortization of energy contract assets and liabilities (c) 30 — — — — — — — Nuclear fuel (d) 983 — — — — — — — ARO accretion (e) 500 — — — — — — — Total depreciation, amortization, and accretion $ 6,527 $ 1,133 $ 347 $ 550 $ 782 $ 377 $ 191 $ 180 For the year ended December 31, 2019 Property, plant, and equipment (b) $ 3,665 $ 886 $ 303 $ 359 $ 547 $ 239 $ 146 $ 123 Amortization of regulatory assets (b) 528 147 30 143 207 135 38 34 Amortization of intangible assets, net (b) 59 — — — — — — — Amortization of energy contract assets and liabilities (c) 21 — — — — — — — Nuclear fuel (d) 1,016 — — — — — — — ARO accretion (e) 491 — — — — — — — Total depreciation, amortization, and accretion $ 5,780 $ 1,033 $ 333 $ 502 $ 754 $ 374 $ 184 $ 157 __________ (a) Exelon's amounts include amounts related to Generation prior to the separation. See Note 2 — Discontinued Operations for additional information. (b) Included in Depreciation and amortization in the Registrants' Consolidated Statements of Operations and Comprehensive Income. (c) Included in Operating revenues or Purchased power and fuel expense in Exelon’s Consolidated Statements of Operations and Comprehensive Income. (d) Included in Purchased power and fuel expense in Exelon’s Consolidated Statements of Operations and Comprehensive Income. (e) Included in Operating and maintenance expense in Exelon's Consolidated Statements of Operations and Comprehensive Income. Cash paid (refunded) during the year: Exelon (a) ComEd PECO BGE PHI Pepco DPL ACE For the year ended December 31, 2021 Interest (net of amount capitalized) $ 1,505 $ 372 $ 152 $ 134 $ 255 $ 132 $ 59 $ 56 Income taxes (net of refunds) 281 (72) (4) (38) — 12 (9) 2 For the year ended December 31, 2020 Interest (net of amount capitalized) $ 1,521 $ 371 $ 144 $ 125 $ 257 $ 129 $ 61 $ 57 Income taxes (net of refunds) 10 (61) (37) (57) 46 40 12 (3) For the year ended December 31, 2019 Interest (net of amount capitalized) $ 1,470 $ 343 $ 129 $ 106 $ 255 $ 130 $ 59 $ 55 Income taxes (net of refunds) 265 (42) 82 17 29 7 19 (5) __________ (a) Exelon's amounts include amounts related to Generation prior to the separation. See Note 2 — Discontinued Operations for additional information. Other non-cash operating activities: Exelon (a) ComEd PECO BGE PHI Pepco DPL ACE For the year ended December 31, 2021 Pension and non-pension postretirement benefit costs $ 411 $ 129 $ 8 $ 61 $ 49 $ 6 $ 2 $ 11 Allowance for credit losses 160 47 39 17 24 9 5 10 Other decommissioning-related activity (946) — — — — — — — Energy-related options 125 — — — — — — — True-up adjustments to decoupling mechanisms and formula rates (b) (171) (42) (26) (12) (91) (53) (14) (24) Severance costs (57) 2 — — 1 — — — Long-term incentive plan 137 — — — — — — — Amortization of operating ROU asset 183 1 — 29 28 6 8 4 AFUDC - Equity (136) (34) (26) (27) (49) (40) (6) (3) For the year ended December 31, 2020 Pension and non-pension postretirement benefit costs $ 411 $ 114 $ 5 $ 62 $ 70 $ 15 $ 7 $ 14 Allowance for credit losses 150 32 42 15 43 24 16 2 Other decommissioning-related activity (659) — — — — — — — Energy-related options 104 — — — — — — — True-up adjustments to decoupling mechanisms and formula rates (b) (6) 47 (16) (16) (21) (40) 7 12 Severance costs 105 1 1 — — — — — Provision for excess and obsolete inventory 131 2 1 — — — — — Long-term incentive plan 56 — — — — — — — Amortization of operating ROU asset 222 2 1 31 28 7 8 3 Asset impairments — 15 — — 13 — 7 6 AFUDC - Equity (104) (29) (17) (22) (36) (28) (4) (4) For the year ended December 31, 2019 Pension and non-pension postretirement benefit costs $ 438 $ 96 $ 12 $ 61 $ 95 $ 25 $ 15 $ 16 Allowance for credit losses 120 33 31 8 17 7 4 5 Other decommissioning-related activity (506) — — — — — — — Energy-related options 22 — — — — — — — True-up adjustments to decoupling mechanisms and formula rates (c) 124 128 — — (4) (4) — — Long-term incentive plan 10 — — — — — — — Amortization of operating ROU Asset 244 3 — 30 33 8 8 4 Change in environmental liabilities 23 — — — 23 23 — — AFUDC - Equity (85) (17) (13) (21) (34) (25) (4) (5) __________ (a) Exelon's amounts include amounts related to Generation prior to the separation. See Note 2 — Discontinued Operations for additional information. (b) For ComEd, reflects the true-up adjustments in regulatory assets and liabilities associated with its distribution, energy efficiency, distributed generation, and transmission formula rates. For BGE, Pepco, DPL, and ACE, reflects the change in regulatory assets and liabilities associated with their decoupling mechanisms and transmission formula rates. For PECO, reflects the change in regulatory assets and liabilities associated with its transmission formula rate. See Note 3 — Regulatory Matters for additional information. (c) For ComEd, reflects the true-up adjustments in regulatory assets and liabilities associated with its distribution and energy efficiency formula rates. For Pepco and DPL, reflects the change in regulatory assets and liabilities associated with their decoupling mechanisms. See Note 3 — Regulatory Matters for additional information. The following tables provide a reconciliation of cash, restricted cash, and cash equivalents reported within the Registrants' Consolidated Balance Sheets that sum to the total of the same amounts in their Consolidated Statements of Cash Flows. Exelon ComEd PECO BGE PHI Pepco DPL ACE December 31, 2021 Cash and cash equivalents $ 672 $ 131 $ 36 $ 51 $ 136 $ 34 $ 28 $ 29 Restricted cash and cash equivalents 321 210 8 4 77 34 43 — Restricted cash included in other long-term assets 44 43 — — — — — — Cash, restricted cash, and cash equivalents included in current assets of discontinued operations 582 — — — — — — — Total cash, restricted cash, and cash equivalents $ 1,619 $ 384 $ 44 $ 55 $ 213 $ 68 $ 71 $ 29 December 31, 2020 Cash and cash equivalents $ 432 $ 83 $ 19 $ 144 $ 111 $ 30 $ 15 $ 17 Restricted cash and cash equivalents 349 279 7 1 39 35 — 3 Restricted cash included in other long-term assets 53 43 — — 10 — — 10 Cash, restricted cash, and cash equivalents included in current assets of discontinued operations 332 — — — — — — — Total cash, restricted cash, and cash equivalents $ 1,166 $ 405 $ 26 $ 145 $ 160 $ 65 $ 15 $ 30 December 31, 2019 Cash and cash equivalents $ 587 $ 90 $ 21 $ 24 $ 131 $ 30 $ 13 $ 12 Restricted cash and cash equivalents 358 150 6 1 36 33 — 2 Restricted cash included in other long-term assets 177 163 — — 14 — — 14 Total cash, restricted cash, and cash equivalents(a) $ 1,122 $ 403 $ 27 $ 25 $ 181 $ 63 $ 13 $ 28 December 31, 2018 Cash and cash equivalents $ 1,349 $ 135 $ 130 $ 7 $ 124 $ 16 $ 23 $ 7 Restricted cash and cash equivalents 247 29 5 6 43 37 1 4 Restricted cash included in other long-term assets 185 166 — — 19 — — 19 Total cash, restricted cash, and cash equivalents(a) $ 1,781 $ 330 $ 135 $ 13 $ 186 $ 53 $ 24 $ 30 __________ (a) Exelon's amounts include amounts related to Generation prior to the separation. See Note 2 — Discontinued Operations for additional information.
Supplemental Balance Sheet Disclosures	The following tables provide additional information about material items recorded in the Registrants' Consolidated Balance Sheets. Investments Exelon ComEd PECO BGE PHI Pepco December 31, 2021 Equity method investments: Other equity method investments $ 15 $ 6 $ 7 $ — $ — $ — Other investments: Employee benefit trusts and investments (a) 235 — 27 14 145 120 Total investments $ 250 $ 6 $ 34 $ 14 $ 145 $ 120 December 31, 2020 Equity method investments: Other equity method investments $ 15 $ 6 $ 8 $ — $ — $ — Other investments: Employee benefit trusts and investments (a) 218 — 22 10 140 115 Equity investments without readily determinable fair values 5 — — — — — Total investments $ 238 $ 6 $ 30 $ 10 $ 140 $ 115 __________ (a) The Registrants’ debt and equity security investments are recorded at fair market value. Accrued expenses Exelon ComEd PECO BGE PHI Pepco DPL ACE December 31, 2021 Compensation-related accruals (a) $ 596 $ 155 $ 77 $ 78 $ 113 $ 35 $ 20 $ 17 Taxes accrued 253 94 14 53 96 88 9 11 Interest accrued 297 116 41 44 52 28 8 11 December 31, 2020 Compensation-related accruals (a) $ 594 $ 170 $ 73 $ 84 $ 109 $ 36 $ 18 $ 17 Taxes accrued 291 94 16 73 117 90 18 12 Interest accrued 289 109 37 46 51 26 7 12 __________ (a) Primarily includes accrued payroll, bonuses and other incentives, vacation, and benefits.

Related Party Transactions (Tab

Related Party Transactions (Tables)	12 Months Ended
Related Party Transactions (Tables)	Dec. 31, 2021
Related Party Transactions [Abstract]
Schedule of Related Party Transactions [Table Text Block]	The Utility Registrants incur expenses from transactions with the Generation affiliate as described in the footnotes to the table below. Such expenses are primarily recorded as Purchased power from affiliates and an immaterial amount recorded as Operating and maintenance expense from affiliates at the Utility Registrants: For the Years Ended 2021 2020 2019 ComEd (a) $ 376 $ 330 $ 369 PECO (b) 196 190 158 BGE (c) 236 315 289 PHI 366 367 353 Pepco (d) 270 279 264 DPL (e) 79 75 70 ACE (f) 17 13 19 __________ (a) ComEd has an ICC-approved RFP contract with Generation to provide a portion of ComEd’s electric supply requirements. ComEd also purchases RECs and ZECs from Generation. (b) PECO receives electric supply from Generation under contracts executed through PECO’s competitive procurement process. In addition, PECO has a ten-year agreement with Generation to sell solar AECs. (c) BGE receives a portion of its energy requirements from Generation under its MDPSC-approved market-based SOS and gas commodity programs. (d) Pepco receives electric supply from Generation under contracts executed through Pepco's competitive procurement process approved by the MDPSC and DCPSC. (e) DPL receives a portion of its energy requirements from Generation under its MDPSC and DEPSC approved market-based SOS commodity programs. (f) ACE receives electric supply from Generation under contracts executed through ACE's competitive procurement process.
Related Party Transactions - BSC and PHISCO Service Companies [Table Text Block]	The following table presents the service company costs allocated to the Registrants: Operating and maintenance from affiliates Capitalized costs For the years ended December 31, For the years ended December 31, 2021 2020 2019 2021 2020 2019 Exelon BSC $ 508 $ 531 $ 450 PHISCO 72 61 72 ComEd BSC 304 283 263 207 186 148 PECO BSC 169 150 149 81 76 88 BGE BSC 189 170 157 92 132 126 PHI BSC 168 152 139 128 149 88 PHISCO — — — 72 61 72 Pepco BSC 96 85 85 50 55 38 PHISCO 114 120 124 31 27 33 DPL BSC 61 54 52 43 51 25 PHISCO 99 97 100 22 18 20 ACE BSC 53 45 42 33 40 19 PHISCO 86 87 90 19 16 19
Related Party Transactions - Current Receivables From/Payables To Affiliates [Table Text Block]	The following tables present Current receivables from affiliates and Current payables to affiliates: December 31, 2021 Receivables from affiliates: Payables to affiliates: ComEd PECO BGE Pepco DPL ACE Generation BSC PHISCO Other Total ComEd $ — $ — $ — $ — $ — $ 41 $ 71 $ — $ 9 $ 121 PECO — — — — — 30 36 — 4 70 BGE — — — — — 4 41 — 3 48 PHI — 1 — — — 1 — 5 — 9 16 Pepco — — 1 1 1 20 21 12 3 59 DPL — — — — — 4 17 11 1 33 ACE — — — — — 7 13 9 2 31 Generation 13 — — — — — 102 — 16 131 Other 3 — — — — — 11 — — 14 Total $ 16 $ 1 $ 1 $ — $ 1 $ 2 $ 117 $ 306 $ 32 $ 47 $ 523 December 31, 2020 Receivables from affiliates: Payables to affiliates: ComEd PECO BGE Pepco DPL ACE Generation BSC PHISCO Other Total ComEd $ — $ — $ — $ — $ — $ 28 $ 59 $ — $ 9 $ 96 PECO 1 — — — — 17 28 — 4 50 BGE — — — — — 11 47 — 3 61 PHI — — — — — — — 4 — 11 15 Pepco 2 — 1 — — 13 25 14 — 55 DPL 1 — — — — 3 21 10 1 36 ACE — — — — — 6 15 9 1 31 Generation 13 — — — — — 72 — 22 107 Other 5 2 2 2 1 6 25 — — 43 Total $ 22 $ 2 $ 3 $ 2 $ 1 $ 6 $ 103 $ 271 $ 33 $ 51 $ 494
Related Party Transactions - Long Term Debt to Financing Trusts [Table Text Block]	The following table presents Long-term debt to financing trusts: As of December 31, 2021 2020 Exelon ComEd PECO Exelon ComEd PECO ComEd Financing III $ 206 $ 205 $ — $ 206 $ 205 $ — PECO Trust III 81 — 81 81 — 81 PECO Trust IV 103 — 103 103 — 103 Total $ 390 $ 205 $ 184 $ 390 $ 205 $ 184

Significant Accounting Polici_3

Significant Accounting Policies - Narrative (Details)	12 Months Ended
Significant Accounting Policies - Narrative (Details)	Dec. 31, 2021	Dec. 31, 2020
Significant Accounting Policies Additional Narrative Information [Line Items]
Minimum expectation of tax position to be realized	50%
Exelon Generation Co L L C [Member]
Significant Accounting Policies Additional Narrative Information [Line Items]
Percentage ownership of consolidated subsidiaries	100%	100%
Commonwealth Edison Company [Member]
Significant Accounting Policies Additional Narrative Information [Line Items]
Percentage ownership of consolidated subsidiaries	99%	99%
PECO Energy Co [Member]
Significant Accounting Policies Additional Narrative Information [Line Items]
Percentage ownership of consolidated subsidiaries	100%	100%
Baltimore Gas and Electric Company [Member]
Significant Accounting Policies Additional Narrative Information [Line Items]
Percentage ownership of consolidated subsidiaries	100%	100%
Pepco Holdings LLC [Member]
Significant Accounting Policies Additional Narrative Information [Line Items]
Percentage ownership of consolidated subsidiaries	100%	100%
Pepco Holdings LLC [Member] \| Potomac Electric Power Company [Member]
Significant Accounting Policies Additional Narrative Information [Line Items]
Percentage ownership of consolidated subsidiaries	100%	100%
Pepco Holdings LLC [Member] \| Delmarva Power & Light Company [Member]
Significant Accounting Policies Additional Narrative Information [Line Items]
Percentage ownership of consolidated subsidiaries	100%	100%
Pepco Holdings LLC [Member] \| Atlantic City Electric Company [Member]
Significant Accounting Policies Additional Narrative Information [Line Items]
Percentage ownership of consolidated subsidiaries	100%	100%

Discontinued Operations and Dis

Discontinued Operations and Disposal Groups (Details) - Corporate, Non-Segment [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Feb. 01, 2022	Jan. 31, 2022
Business Dispositions [Line Items]
Common Stock, Shares, Issued		326,663,937
Separation Cash Payment			$ 1,750
Proceeds from Sale and Collection of Notes Receivable	$ 258
ShortTermDebtSOFRplus075Jan2023
Business Dispositions [Line Items]
Short-Term Loans	1,150
SMBCTermLoanJuly2023 \| Nuclear fuel procurement contracts
Business Dispositions [Line Items]
Debt Instrument, Face Amount	300
USBTermLoanJuly2023 \| Nuclear fuel procurement contracts
Business Dispositions [Line Items]
Debt Instrument, Face Amount	300
PNCTermLoanJuly2023 \| Nuclear fuel procurement contracts
Business Dispositions [Line Items]
Debt Instrument, Face Amount	$ 250

Discontinued Operations (Detail

Discontinued Operations (Details) - Income Statement - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Business Dispositions [Line Items]
Operating and maintenance	$ 4,547	$ 4,641	$ 4,324
Depreciation and Amortization	3,033	2,891	2,717
Taxes, Miscellaneous	1,291	1,232	1,213
Costs and Expenses	15,256	14,485	14,073
Other Nonoperating Income (Expense)	261	208	204
Nonoperating Income (Expense)	(1,028)	(1,099)	(1,018)
Income taxes	38	(7)	153
Equity in losses of unconsolidated affiliates	0	0	1
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	213	855	1,542
Net income (loss) attributable to noncontrolling interests	123	(9)	92
Net Income (Loss) from Discontinued Operations Available to Common Shareholders, Basic	90	864	1,450
Exelon Generation Co L L C [Member]
Business Dispositions [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	18,466	16,399	17,754
Operating revenues from affiliates	1,189	1,206	1,171
Disposal Group, Including Discontinued Operation, Revenue	19,655	17,605	18,925
Purchased power and/or fuel	12,163	9,585	10,856
Operating and maintenance	4,174	4,794	4,324
Depreciation and Amortization	3,003	2,123	1,535
Taxes, Miscellaneous	475	482	519
Costs and Expenses	19,815	16,984	17,234
Gain (Loss) on Disposition of Assets	201	11	27
Disposal Group, Including Discontinued Operation, Operating Income (Loss)	41	632	1,718
Disposal Group, Including Discontinued Operation, Interest Expense	(282)	(328)	(394)
Other Nonoperating Income (Expense)	795	937	1,023
Nonoperating Income (Expense)	513	609	629
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax	554	1,241	2,347
Income taxes	332	380	621
Equity in losses of unconsolidated affiliates	(9)	(6)	(184)
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	213	855	1,542
Net income (loss) attributable to noncontrolling interests	123	(9)	92
Net Income (Loss) from Discontinued Operations Available to Common Shareholders, Basic	90	$ 864	$ 1,450
Total transaction costs relating to the Separation	24
Transition costs relating to the Separation included in discontinued operations	$ 19

Discontinued Operations (Deta_2

Discontinued Operations (Details) - Balance Sheet - USD ($) $ in Millions		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Business Dispositions [Line Items]
Restricted cash		$ 321	$ 349	$ 358	$ 247
Customer accounts receivable		2,189	2,266
Customer allowance for credit losses		320	334
Other accounts receivable		1,068	1,117
Other allowance for uncollectible accounts		72	71
Other accounts receivable, net		996	1,046
Fossil fuel and emission allowances		105	64
Materials and supplies		476	447
Currents assets of discontinued operations		7,835	6,841
Accumulated depreciation and amortization		14,430	13,346
Investments		250	238
Other		885	1,143
Disposal Group, Including Discontinued Operation, Other Assets, Noncurrent		38,509	39,653
Total assets	[1]	133,013	129,317
Short-term Debt		1,248	1,191
Long-term Debt and Lease Obligation, Current		2,153	1,622
Market-to-market derivative liabilities, current		18	33
Liabilities held for sale		7,940	4,923
Long-term Debt, Excluding Current Maturities		30,749	29,527
Deferred income taxes and unamortized investment tax credits		10,611	9,592
Asset retirement obligations, noncurrent		271	246
Derivative Liability, Noncurrent		201	268
Other deferred credits and other liabilities		1,573	1,642
Disposal Group, Including Discontinued Operation, Other Liabilities, Noncurrent		25,676	26,345
Total liabilities	[1]	98,218	94,449
Exelon Generation Co L L C [Member]
Business Dispositions [Line Items]
Disposal Group, Including Discontinued Operation, Cash and Cash Equivalents		510	231
Restricted cash		72	89
Customer accounts receivable		1,724	1,331
Customer allowance for credit losses		(55)	(32)
Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net		1,669	1,299
Other accounts receivable		596	352
Other allowance for uncollectible accounts		(4)	0
Other accounts receivable, net		592	352
Mark-to-market derivative assets, current		2,169	644
Fossil fuel and emission allowances		284	233
Materials and supplies		1,004	978
Renewable energy credits, current		529	633
Disposal Group, Including Discontinued Operations, Assets, Current - Assets held for sale		13	958
Disposal Group, Including Discontinued Operation, Other Assets, Current		993	1,424
Currents assets of discontinued operations		7,835	6,841
Disposal Group, Including Discontinued Operation, Property, Plant and Equipment, Noncurrent		19,661	22,252
Accumulated depreciation and amortization		15,888	13,381
Decommissioning Fund Investments		15,938	14,464
Investments		193	202
Mark-to-market derivative assets, noncurrent		949	555
Other		1,768	2,180
Disposal Group, Including Discontinued Operation, Other Assets, Noncurrent		38,509	39,653
Total assets		46,344	46,494
Short-term Debt		2,082	840
Long-term Debt and Lease Obligation, Current		1,220	197
Disposal Group, Including Discontinued Operation, Accounts Payable, Current		1,757	1,253
Disposal Group, Including Discontinued Operation, Accrued Liabilities, Current		818	848
Market-to-market derivative liabilities, current		981	262
Renewable energy credit obligation		779	661
Disposal Group, Including Discontinued Operations, Assets, Current - Liabilities held for sale		3	375
Disposal Group, Including Discontinued Operation, Other Liabilities, Current		300	487
Liabilities held for sale		7,940	4,923
Long-term Debt, Excluding Current Maturities		4,575	5,566
Deferred income taxes and unamortized investment tax credits		3,583	3,443
Asset retirement obligations, noncurrent		12,819	12,054
Disposal Group, Including Discontinued Operation, Pension Plan Benefit Obligation, Noncurrent		939	1,557
Disposal Group, Including Discontinued Operation, Postretirement Plan Benefit Obligation, Noncurrent		876	1,009
Spent Nuclear Fuel Obligation, Noncurrent		1,210	1,208
Derivative Liability, Noncurrent		513	205
Other deferred credits and other liabilities		1,161	1,303
Disposal Group, Including Discontinued Operation, Other Liabilities, Noncurrent		25,676	26,345
Total liabilities		$ 33,616	$ 31,268

[1]Exelon’s consolidated assets include $18 million as of December 31, 2020, of certain VIEs that can only be used to settle the liabilities of the VIE. Exelon’s consolidated liabilities include $26 million as of December 31, 2020, of certain VIEs for which the VIE creditors do not have recourse to Exelon. See Note 21–Variable Interest Entities for additional information.

Discontinued Operations (Deta_3

Discontinued Operations (Details) - Cash Flow - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Business Dispositions [Line Items]
Depreciation, Amortization and Accretion, Net	$ 7,573	$ 6,527	$ 5,780
Gain (Loss) on Sale of Assets and Asset Impairment Charges	201	24	27
Deferred Income Taxes and Tax Credits	18	309	681
Unrealized Gain (Loss) on Derivatives	568	268	(222)
Gain (Loss) on Investments	586	461	663
Other non-cash operating activities	(200)	592	613
Payments to Acquire Property, Plant, and Equipment	7,981	8,048	7,248
Collection of deferred purchase price	3,902	3,771	0
Increase (decrease) in capital expenditures not paid	16	194	(7)
Increase in Deferred Purchase Price	3,652	4,441	0
Increase (decrease) in PPE related to ARO update	642	850	968
Exelon Generation Co L L C [Member]
Business Dispositions [Line Items]
Depreciation, Amortization and Accretion, Net	4,540	3,636	3,063
Asset Impairment Charges	545	563	201
Gain (Loss) on Sale of Assets and Asset Impairment Charges	(201)	(11)	(27)
Deferred Income Taxes and Tax Credits	(224)	94	376
Unrealized Gain (Loss) on Derivatives	(568)	(270)	228
Gain (Loss) on Investments	(586)	(461)	(663)
Net unrealized losses (gains) on equity investments	160	(186)	0
Other non-cash operating activities	(946)	(659)	(506)
Payments to Acquire Property, Plant, and Equipment	(1,341)	(1,759)	(1,849)
Collection of deferred purchase price	3,902	3,771	0
Increase (decrease) in capital expenditures not paid	96	(88)	(34)
Increase in Deferred Purchase Price	3,652	4,441	0
Increase (decrease) in PPE related to ARO update	$ 618	$ 850	$ 959

Mergers, Acquisitions, and Disp

Mergers, Acquisitions, and Dispositions - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Business Acquisitions
Acquisition of CENG noncontrolling interest	$ 885	$ 0	$ 0
Deferred Tax Liability Adjustment - Noncontrolling Interest	(290)
Business Dispositions
Gain (Loss) on Sale of Assets and Asset Impairment Charges	$ 201	$ 24	$ 27
Nine Mile Point [Member] \| CENG [Member]
Business Acquisitions
Equity Method Investment, Ownership Percentage	82%
Nine Mile Point [Member] \| Exelon Generation Co L L C [Member]
Business Acquisitions
Equity Method Investment, Ownership Percentage	82%

Mergers, Acquisitions, and Di_2

Mergers, Acquisitions, and Dispositions - Changes in Ownership Equity (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Schedule of Changes in Ownership Interest [Line Items]
Net income attributable to common shareholders	$ 1,706	$ 1,963	$ 2,936
Acquisition of CENG noncontrolling interest	885	$ 0	$ 0
Deferred Tax Liability Adjustment - Noncontrolling Interest	$ (290)

Regulatory Matters- Narrative (

Regulatory Matters- Narrative (Details) $ in Millions		12 Months Ended	48 Months Ended			72 Months Ended
Regulatory Matters- Narrative (Details) $ in Millions	Feb. 02, 2022	Dec. 31, 2021	Dec. 31, 2024 USD ($)	Jun. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)	Jul. 10, 2023 USD ($)	Jul. 09, 2021 USD ($)	Jul. 02, 2021 USD ($)
Commonwealth Edison Co [Member]
Regulatory Matters Additional Narrative Information [Line Items]
Carbon mitigation credit		54,500,000
Maximum increase of revenue requirement		5%
Basis points for ComEd's Electric Distribution rates	580
Commonwealth Edison Co [Member] \| Minimum [Member]
Regulatory Matters Additional Narrative Information [Line Items]
Basis points for ComEd's Electric Distribution rates		20
Commonwealth Edison Co [Member] \| Maximum [Member]
Regulatory Matters Additional Narrative Information [Line Items]
Basis points for ComEd's Electric Distribution rates		60
Baltimore Gas and Electric Company [Member]
Regulatory Matters Additional Narrative Information [Line Items]
Maryland Relief Act Funds								$ 50
Potomac Electric Power Company [Member]
Regulatory Matters Additional Narrative Information [Line Items]
Maryland Relief Act Funds								$ 12
Potomac Electric Power Company [Member] \| Forecast [Member]
Regulatory Matters Additional Narrative Information [Line Items]
Proposed Capital Expenditure						$ 500
Delmarva Power & Light Company [Member]
Regulatory Matters Additional Narrative Information [Line Items]
Maryland Relief Act Funds							$ 8
Atlantic City Electric Company [Member]
Regulatory Matters Additional Narrative Information [Line Items]
Proposed Capital Expenditure			$ 220
Atlantic City Electric Company [Member] \| Forecast [Member]
Regulatory Matters Additional Narrative Information [Line Items]
Proposed Capital Expenditure					$ 338
Public Utilities, Approved Rate Increase (Decrease), Amount				$ 96

Regulatory Matters - Schedule o

Regulatory Matters - Schedule of Completed Rate Cases (Details) - USD ($) $ in Millions

12 Months Ended

Feb. 23, 2022

Dec. 22, 2021

Dec. 01, 2021

Nov. 18, 2021

Sep. 15, 2021

Jul. 14, 2021

Jun. 28, 2021

Jun. 22, 2021

Jun. 08, 2021

Apr. 16, 2021

Mar. 31, 2021

Mar. 30, 2021

Feb. 26, 2021

Feb. 02, 2021

Dec. 16, 2020

Dec. 09, 2020

Sep. 30, 2020

Sep. 11, 2020

Jun. 01, 2020

Apr. 16, 2020

Dec. 31, 2023

Dec. 31, 2022

Dec. 31, 2021

Commonwealth Edison Co [Member] | Illinois 2020 Electric Distribution Base Rate Case

Regulatory Matters Completed Rate Cases [Line Items]

Public Utilities, Requested Rate Increase (Decrease), Amount

$ (11)

Public Utilities, Approved Rate Increase (Decrease), Amount

$ (14)

Public Utilities, Approved Return on Equity, Percentage

8.38%

Commonwealth Edison Co [Member] | Illinois 2020 Electric Distribution Base Rate Case | 2021

Regulatory Matters Completed Rate Cases [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Amount

$ 50

Commonwealth Edison Co [Member] | Illinois 2020 Electric Distribution Base Rate Case | 2019

Regulatory Matters Completed Rate Cases [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Amount

$ (64)

Public Utilities, Approved Return on Equity, Percentage

8.38%

Public Utilities, Approved Equity Capital Structure, Percentage

6.28%

Basis points for ComEd's Revenue Requirement

580

Commonwealth Edison Co [Member] | Illinois 2021 Electric Distribution Base Rate Case

Regulatory Matters Completed Rate Cases [Line Items]

Public Utilities, Requested Rate Increase (Decrease), Amount

$ 51

Public Utilities, Approved Rate Increase (Decrease), Amount

$ 46

Public Utilities, Approved Return on Equity, Percentage

7.36%

Commonwealth Edison Co [Member] | Illinois 2021 Electric Distribution Base Rate Case | 2022

Regulatory Matters Completed Rate Cases [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Amount

$ 37

Public Utilities, Approved Return on Equity, Percentage

7.36%

Public Utilities, Approved Equity Capital Structure, Percentage

5.72%

Basis points for ComEd's Revenue Requirement

580

Commonwealth Edison Co [Member] | Illinois 2021 Electric Distribution Base Rate Case | 2020

Regulatory Matters Completed Rate Cases [Line Items]

Public Utilities, Approved Equity Capital Structure, Percentage

5.69%

Basis points for ComEd's Revenue Requirement

580

Public Utilities Approved Rate Increase (Decrease), Prior Year Annual Reconciliation

$ 9

Public Utilities, Approved Return on Equity, Percentage, Prior Year Reconciliation

7.29%

Commonwealth Edison Co [Member] | Illinois 2021 Electric Distribution Base Rate Case | 2020 | Performance Metrics Penalty

Regulatory Matters Completed Rate Cases [Line Items]

Basis points for ComEd's Revenue Requirement

PECO Energy Co [Member] | Pennsylvania 2020 Natural Gas Distribution Base Rate Case

Regulatory Matters Completed Rate Cases [Line Items]

Public Utilities, Requested Rate Increase (Decrease), Amount

$ 69

Public Utilities, Approved Rate Increase (Decrease), Amount

$ 29

Public Utilities, Approved Return on Equity, Percentage

10.24%

PECO Energy Co [Member] | Pennsylvania 2021 Electric Distribution Base Rate Case [Member]

Regulatory Matters Completed Rate Cases [Line Items]

Public Utilities, Requested Rate Increase (Decrease), Amount

$ 246

Public Utilities, Approved Rate Increase (Decrease), Amount

$ 132

Baltimore Gas and Electric Company [Member] | Maryland 2020 Electric Distribution Base Rate Case [Member]

Regulatory Matters Completed Rate Cases [Line Items]

Public Utilities, Requested Rate Increase (Decrease), Amended, Amount

$ 203

Public Utilities, Approved Rate Increase (Decrease), Amount

$ 140

$ 42

$ 39

$ 59

Public Utilities, Approved Return on Equity, Percentage

9.50%

Baltimore Gas and Electric Company [Member] | Maryland 2020 Electric Distribution Base Rate Case [Member] | 2022 | Offsets

Regulatory Matters Completed Rate Cases [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Percentage

25%

Baltimore Gas and Electric Company [Member] | Maryland 2020 Gas Distribution Base Rate Case [Member]

Regulatory Matters Completed Rate Cases [Line Items]

Public Utilities, Requested Rate Increase (Decrease), Amended, Amount

$ 108

Public Utilities, Approved Rate Increase (Decrease), Amount

$ 74

$ 10

$ 11

$ 53

Public Utilities, Approved Return on Equity, Percentage

9.65%

Baltimore Gas and Electric Company [Member] | Maryland 2020 Gas Distribution Base Rate Case [Member] | 2022 | Offsets

Regulatory Matters Completed Rate Cases [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Percentage

50%

Potomac Electric Power Company [Member] | Maryland 2020 Electric Distribution Base Rate Case [Member]

Regulatory Matters Completed Rate Cases [Line Items]

Public Utilities, Requested Rate Increase (Decrease), Amended, Amount

$ 104

Public Utilities, Approved Rate Increase (Decrease), Amount

$ 52

Public Utilities, Approved Return on Equity, Percentage

9.55%

Potomac Electric Power Company [Member] | Maryland 2020 Electric Distribution Base Rate Case [Member] | March 31, 2022

Regulatory Matters Completed Rate Cases [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Amount

$ 21

Potomac Electric Power Company [Member] | Maryland 2020 Electric Distribution Base Rate Case [Member] | March 31, 2023

Regulatory Matters Completed Rate Cases [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Amount

Potomac Electric Power Company [Member] | Maryland 2020 Electric Distribution Base Rate Case [Member] | March 31, 2023 | Offsets

Regulatory Matters Completed Rate Cases [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Percentage

25%

Potomac Electric Power Company [Member] | Maryland 2020 Electric Distribution Base Rate Case [Member] | March 31, 2024

Regulatory Matters Completed Rate Cases [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Amount

$ 15

Potomac Electric Power Company [Member] | District of Columbia 2019 Electric Distribution Base Rate Case

Regulatory Matters Completed Rate Cases [Line Items]

Public Utilities, Requested Rate Increase (Decrease), Amended, Amount

$ 136

Public Utilities, Approved Rate Increase (Decrease), Amount

$ 109

Public Utilities, Approved Return on Equity, Percentage

9.275%

Potomac Electric Power Company [Member] | District of Columbia 2019 Electric Distribution Base Rate Case | 2021

Regulatory Matters Completed Rate Cases [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Amount

$ 42

Potomac Electric Power Company [Member] | District of Columbia 2019 Electric Distribution Base Rate Case | 2021 | Offsets

Regulatory Matters Completed Rate Cases [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Amount

(22)

Potomac Electric Power Company [Member] | District of Columbia 2019 Electric Distribution Base Rate Case | 2022

Regulatory Matters Completed Rate Cases [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Amount

Potomac Electric Power Company [Member] | District of Columbia 2019 Electric Distribution Base Rate Case | 2022 | Offsets

Regulatory Matters Completed Rate Cases [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Amount

$ (40)

Delmarva Power & Light Company [Member] | Delaware 2020 Electric Distribution Base Rate Case

Regulatory Matters Completed Rate Cases [Line Items]

Public Utilities, Requested Rate Increase (Decrease), Amended, Amount

$ 23

Public Utilities, Approved Rate Increase (Decrease), Amount

$ 14

Public Utilities, Approved Return on Equity, Percentage

9.60%

Atlantic City Electric Company [Member] | New Jersey 2020 Electric Distribution Base Rate Case

Regulatory Matters Completed Rate Cases [Line Items]

Public Utilities, Requested Rate Increase (Decrease), Amended, Amount

$ 67

Public Utilities, Approved Rate Increase (Decrease), Amount

$ 41

Public Utilities, Approved Return on Equity, Percentage

9.60%

Atlantic City Electric Company [Member] | New Jersey 2020 Electric Distribution Base Rate Case | Tax Benefits

Regulatory Matters Completed Rate Cases [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Amount

$ 11

Regulatory Matters - Schedule_2

Regulatory Matters - Schedule of Pending Rate Cases (Details) - Delmarva Power & Light Company [Member] - USD ($) $ in Millions	Jan. 24, 2022	Jan. 14, 2022	Dec. 23, 2021
Delaware 2022 Natural Gas Distribution Base Rate Case
Regulatory Matters Pending Rate Cases [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount		$ 14
Public Utilities, Requested Return on Equity, Percentage		10.30%
Maryland 2021 Electric Distribution Base Rate Case
Regulatory Matters Pending Rate Cases [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount	$ 13		$ 27
Public Utilities, Requested Return on Equity, Percentage	9.60%		10.10%

Regulatory Matters - Annual Ele

Regulatory Matters - Annual Electric Transmission Filings (Details) - 2021 Transmission Formula Rate Annual Update [Domain] - USD ($) $ in Millions	May 28, 2021	May 14, 2021	May 10, 2021	Apr. 16, 2021
Commonwealth Edison Co [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount				$ 33
Annual Reconciliation Increase (Decrease)				12
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount				$ 45
Public Utilities, Approved Equity Capital Structure, Percentage				8.20%
Public Utilities, Approved Return on Equity, Percentage				11.50%
Cap on Equity Component of Rate of Return on Common Equity in Federal Energy Regulatory Committee Complaint				55%
PECO Energy Co [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount	$ (2)
Annual Reconciliation Increase (Decrease)	26
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount	$ 24
Public Utilities, Approved Equity Capital Structure, Percentage	7.37%
Public Utilities, Approved Return on Equity, Percentage	10.35%
Cap on Equity Component of Rate of Return on Common Equity in Federal Energy Regulatory Committee Complaint	55.75%
Baltimore Gas and Electric Company [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount			$ 38
Annual Reconciliation Increase (Decrease)			27
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount			$ 65
Public Utilities, Approved Equity Capital Structure, Percentage			7.35%
Public Utilities, Approved Return on Equity, Percentage			10.50%
Potomac Electric Power Company [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount		$ (9)
Annual Reconciliation Increase (Decrease)		21
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount		$ 12
Public Utilities, Approved Equity Capital Structure, Percentage		7.68%
Public Utilities, Approved Return on Equity, Percentage		10.50%
Delmarva Power & Light Company [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount		$ 19
Annual Reconciliation Increase (Decrease)		33
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount		$ 52
Public Utilities, Approved Equity Capital Structure, Percentage		7.20%
Public Utilities, Approved Return on Equity, Percentage		10.50%
Atlantic City Electric Company [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount		$ 27
Annual Reconciliation Increase (Decrease)		24
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount		$ 51
Public Utilities, Approved Equity Capital Structure, Percentage		7.45%
Public Utilities, Approved Return on Equity, Percentage		10.50%

Regulatory Matters - Energy Eff

Regulatory Matters - Energy Efficiency Formula Rate (Details) - Commonwealth Edison Co [Member] - ComEd 2021 Energy Efficiency Formula Rate [Domain] - USD ($) $ in Millions	Nov. 18, 2021	Jun. 01, 2021
Schedule of Energy Efficiency Formula Rate Updates [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount		$ 54
Public Utilities, Approved Rate Increase (Decrease), Amount	$ 54
Public Utilities, Approved Return on Equity, Percentage	7.36%
2022
Schedule of Energy Efficiency Formula Rate Updates [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Amount	$ 55
Public Utilities, Requested Equity Capital Structure, Percentage	5.72%
Basis points for ComEd's Revenue Requirement	580
2020
Schedule of Energy Efficiency Formula Rate Updates [Line Items]
Public Utilities, Approved Rate Increase (Decrease), Amount	$ (1)
Public Utilities, Approved Return on Equity, Percentage	8.46%
Public Utilities, Approved Equity Capital Structure, Percentage	6.26%

Regulatory Matters - Schedule_3

Regulatory Matters - Schedule of Regulatory Assets (Details) - USD ($) $ in Millions	48 Months Ended		72 Months Ended
	Dec. 31, 2024	Dec. 31, 2022	Jul. 10, 2023	Dec. 31, 2021	Dec. 31, 2020
Regulatory Assets [Line Items]
Regulatory Assets				$ 9,520	$ 9,987
Current regulatory assets				1,296	1,228
Noncurrent regulatory assets				8,224	8,759
Pension and Other Postretirement Plans Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				2,409	3,010
Pension and Post Retirement Plan Merger Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				893	1,014
Deferred income taxes
Regulatory Assets [Line Items]
Regulatory Assets				883	715
Advanced Metering Infrastructure Deployment Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				145	174
Advanced Metering Infrastructure Legacy Meter Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				186	219
Electric Distribution Formula Rate Annual Reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets				44	(14)
Electric Distribution Formula Rate One-time Events [Member]
Regulatory Assets [Line Items]
Regulatory Assets				104	117
Energy Efficiency Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				1,181	982
Fair value of long-term debt
Regulatory Assets [Line Items]
Regulatory Assets				557	598
Fair value of PHI's unamortized energy contracts
Regulatory Assets [Line Items]
Regulatory Assets				236	328
Asset retirement obligations
Regulatory Assets [Line Items]
Regulatory Assets				145	135
MGP remediation costs
Regulatory Assets [Line Items]
Regulatory Assets				283	285
Renewable Energy Program [Member]
Regulatory Assets [Line Items]
Regulatory Assets				219	301
Electric energy and natural gas costs
Regulatory Assets [Line Items]
Regulatory Assets				96	95
Transmission formula rate annual reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets				43	5
Energy efficiency and demand response programs
Regulatory Assets [Line Items]
Regulatory Assets				564	572
Under-recovered revenue decoupling
Regulatory Assets [Line Items]
Regulatory Assets				157	113
Stranded costs
Regulatory Assets [Line Items]
Regulatory Assets					25
Removal costs
Regulatory Assets [Line Items]
Regulatory Assets				758	701
DC PLUG charge
Regulatory Assets [Line Items]
Regulatory Assets				70	100
Deferred storm costs
Regulatory Assets [Line Items]
Regulatory Assets				49	50
COVID-19 Regulatory Asset
Regulatory Assets [Line Items]
Regulatory Assets				82	81
Under-Recovered Credit Loss Expense
Regulatory Assets [Line Items]
Regulatory Assets				89	107
Other
Regulatory Assets [Line Items]
Regulatory Assets				327	274
Commonwealth Edison Co [Member]
Regulatory Assets [Line Items]
Regulatory Assets				2,205	2,028
Current regulatory assets				335	279
Noncurrent regulatory assets				1,870	1,749
Commonwealth Edison Co [Member] \| Pension and Other Postretirement Plans Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Commonwealth Edison Co [Member] \| Pension and Post Retirement Plan Merger Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Commonwealth Edison Co [Member] \| Deferred income taxes
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Commonwealth Edison Co [Member] \| Advanced Metering Infrastructure Deployment Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Commonwealth Edison Co [Member] \| Advanced Metering Infrastructure Legacy Meter Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				69	90
Commonwealth Edison Co [Member] \| Electric Distribution Formula Rate Annual Reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets				44	(14)
Commonwealth Edison Co [Member] \| Electric Distribution Formula Rate One-time Events [Member]
Regulatory Assets [Line Items]
Regulatory Assets				104	117
Commonwealth Edison Co [Member] \| Energy Efficiency Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				1,181	982
Commonwealth Edison Co [Member] \| Fair value of long-term debt
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Commonwealth Edison Co [Member] \| Fair value of PHI's unamortized energy contracts
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Commonwealth Edison Co [Member] \| Asset retirement obligations
Regulatory Assets [Line Items]
Regulatory Assets				99	92
Commonwealth Edison Co [Member] \| MGP remediation costs
Regulatory Assets [Line Items]
Regulatory Assets				266	271
Commonwealth Edison Co [Member] \| Renewable Energy Program [Member]
Regulatory Assets [Line Items]
Regulatory Assets				219	301
Commonwealth Edison Co [Member] \| Electric energy and natural gas costs
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Commonwealth Edison Co [Member] \| Transmission formula rate annual reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Commonwealth Edison Co [Member] \| Energy efficiency and demand response programs
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Commonwealth Edison Co [Member] \| Under-recovered revenue decoupling
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Commonwealth Edison Co [Member] \| Stranded costs
Regulatory Assets [Line Items]
Regulatory Assets					0
Commonwealth Edison Co [Member] \| Removal costs
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Commonwealth Edison Co [Member] \| DC PLUG charge
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Commonwealth Edison Co [Member] \| Deferred storm costs
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Commonwealth Edison Co [Member] \| COVID-19 Regulatory Asset
Regulatory Assets [Line Items]
Regulatory Assets				28	22
Commonwealth Edison Co [Member] \| Under-Recovered Credit Loss Expense
Regulatory Assets [Line Items]
Regulatory Assets				60	89
Commonwealth Edison Co [Member] \| Other
Regulatory Assets [Line Items]
Regulatory Assets				135	78
PECO Energy Co [Member]
Regulatory Assets [Line Items]
Regulatory Assets				991	801
Current regulatory assets				48	25
Noncurrent regulatory assets				943	776
PECO Energy Co [Member] \| Pension and Other Postretirement Plans Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
PECO Energy Co [Member] \| Pension and Post Retirement Plan Merger Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
PECO Energy Co [Member] \| Deferred income taxes
Regulatory Assets [Line Items]
Regulatory Assets				873	705
PECO Energy Co [Member] \| Advanced Metering Infrastructure Deployment Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
PECO Energy Co [Member] \| Advanced Metering Infrastructure Legacy Meter Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
PECO Energy Co [Member] \| Electric Distribution Formula Rate Annual Reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
PECO Energy Co [Member] \| Electric Distribution Formula Rate One-time Events [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
PECO Energy Co [Member] \| Energy Efficiency Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
PECO Energy Co [Member] \| Fair value of long-term debt
Regulatory Assets [Line Items]
Regulatory Assets				0	0
PECO Energy Co [Member] \| Fair value of PHI's unamortized energy contracts
Regulatory Assets [Line Items]
Regulatory Assets				0	0
PECO Energy Co [Member] \| Asset retirement obligations
Regulatory Assets [Line Items]
Regulatory Assets				21	21
PECO Energy Co [Member] \| MGP remediation costs
Regulatory Assets [Line Items]
Regulatory Assets				8	10
PECO Energy Co [Member] \| Renewable Energy Program [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
PECO Energy Co [Member] \| Electric energy and natural gas costs
Regulatory Assets [Line Items]
Regulatory Assets				0	0
PECO Energy Co [Member] \| Transmission formula rate annual reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets				14	0
PECO Energy Co [Member] \| Energy efficiency and demand response programs
Regulatory Assets [Line Items]
Regulatory Assets				0	0
PECO Energy Co [Member] \| Under-recovered revenue decoupling
Regulatory Assets [Line Items]
Regulatory Assets				0	0
PECO Energy Co [Member] \| Stranded costs
Regulatory Assets [Line Items]
Regulatory Assets					0
PECO Energy Co [Member] \| Removal costs
Regulatory Assets [Line Items]
Regulatory Assets				0	0
PECO Energy Co [Member] \| DC PLUG charge
Regulatory Assets [Line Items]
Regulatory Assets				0	0
PECO Energy Co [Member] \| Deferred storm costs
Regulatory Assets [Line Items]
Regulatory Assets				0	0
PECO Energy Co [Member] \| COVID-19 Regulatory Asset
Regulatory Assets [Line Items]
Regulatory Assets				33	38
PECO Energy Co [Member] \| Under-Recovered Credit Loss Expense
Regulatory Assets [Line Items]
Regulatory Assets				0	0
PECO Energy Co [Member] \| Other
Regulatory Assets [Line Items]
Regulatory Assets				42	27
Baltimore Gas and Electric Company [Member]
Regulatory Assets [Line Items]
Regulatory Assets				692	649
Current regulatory assets				215	168
Noncurrent regulatory assets				477	481
Baltimore Gas and Electric Company [Member] \| Pension and Other Postretirement Plans Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Baltimore Gas and Electric Company [Member] \| Pension and Post Retirement Plan Merger Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Baltimore Gas and Electric Company [Member] \| Deferred income taxes
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Baltimore Gas and Electric Company [Member] \| Advanced Metering Infrastructure Deployment Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				89	109
Baltimore Gas and Electric Company [Member] \| Advanced Metering Infrastructure Legacy Meter Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				29	37
Baltimore Gas and Electric Company [Member] \| Electric Distribution Formula Rate Annual Reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Baltimore Gas and Electric Company [Member] \| Electric Distribution Formula Rate One-time Events [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Baltimore Gas and Electric Company [Member] \| Energy Efficiency Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Baltimore Gas and Electric Company [Member] \| Fair value of long-term debt
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Baltimore Gas and Electric Company [Member] \| Fair value of PHI's unamortized energy contracts
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Baltimore Gas and Electric Company [Member] \| Asset retirement obligations
Regulatory Assets [Line Items]
Regulatory Assets				19	18
Baltimore Gas and Electric Company [Member] \| MGP remediation costs
Regulatory Assets [Line Items]
Regulatory Assets				9	4
Baltimore Gas and Electric Company [Member] \| Renewable Energy Program [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Baltimore Gas and Electric Company [Member] \| Electric energy and natural gas costs
Regulatory Assets [Line Items]
Regulatory Assets				49	23
Baltimore Gas and Electric Company [Member] \| Transmission formula rate annual reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets				1	2
Baltimore Gas and Electric Company [Member] \| Energy efficiency and demand response programs
Regulatory Assets [Line Items]
Regulatory Assets				283	289
Baltimore Gas and Electric Company [Member] \| Under-recovered revenue decoupling
Regulatory Assets [Line Items]
Regulatory Assets				32	20
Baltimore Gas and Electric Company [Member] \| Stranded costs
Regulatory Assets [Line Items]
Regulatory Assets					0
Baltimore Gas and Electric Company [Member] \| Removal costs
Regulatory Assets [Line Items]
Regulatory Assets				143	107
Baltimore Gas and Electric Company [Member] \| DC PLUG charge
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Baltimore Gas and Electric Company [Member] \| Deferred storm costs
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Baltimore Gas and Electric Company [Member] \| COVID-19 Regulatory Asset
Regulatory Assets [Line Items]
Regulatory Assets				8	10
Baltimore Gas and Electric Company [Member] \| Under-Recovered Credit Loss Expense
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Baltimore Gas and Electric Company [Member] \| Other
Regulatory Assets [Line Items]
Regulatory Assets				30	30
Baltimore Gas and Electric Company [Member] \| Difference between Carrying Value and Fair Value [Member]
Regulatory Assets [Line Items]
Regulatory Assets				114	120
Pepco Holdings LLC [Member]
Regulatory Assets [Line Items]
Regulatory Assets				2,226	2,373
Current regulatory assets				432	440
Noncurrent regulatory assets				1,794	1,933
Pepco Holdings LLC [Member] \| Pension and Other Postretirement Plans Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Pepco Holdings LLC [Member] \| Pension and Post Retirement Plan Merger Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Pepco Holdings LLC [Member] \| Deferred income taxes
Regulatory Assets [Line Items]
Regulatory Assets				10	10
Pepco Holdings LLC [Member] \| Advanced Metering Infrastructure Deployment Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				56	65
Pepco Holdings LLC [Member] \| Advanced Metering Infrastructure Legacy Meter Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				88	92
Pepco Holdings LLC [Member] \| Electric Distribution Formula Rate Annual Reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Pepco Holdings LLC [Member] \| Electric Distribution Formula Rate One-time Events [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Pepco Holdings LLC [Member] \| Energy Efficiency Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Pepco Holdings LLC [Member] \| Fair value of long-term debt
Regulatory Assets [Line Items]
Regulatory Assets				443	478
Pepco Holdings LLC [Member] \| Fair value of PHI's unamortized energy contracts
Regulatory Assets [Line Items]
Regulatory Assets				236	328
Pepco Holdings LLC [Member] \| Asset retirement obligations
Regulatory Assets [Line Items]
Regulatory Assets				6	4
Pepco Holdings LLC [Member] \| MGP remediation costs
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Pepco Holdings LLC [Member] \| Renewable Energy Program [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Pepco Holdings LLC [Member] \| Electric energy and natural gas costs
Regulatory Assets [Line Items]
Regulatory Assets				47	72
Pepco Holdings LLC [Member] \| Transmission formula rate annual reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets				28	3
Pepco Holdings LLC [Member] \| Energy efficiency and demand response programs
Regulatory Assets [Line Items]
Regulatory Assets				281	283
Pepco Holdings LLC [Member] \| Under-recovered revenue decoupling
Regulatory Assets [Line Items]
Regulatory Assets				125	93
Pepco Holdings LLC [Member] \| Stranded costs
Regulatory Assets [Line Items]
Regulatory Assets					25
Pepco Holdings LLC [Member] \| Removal costs
Regulatory Assets [Line Items]
Regulatory Assets				615	594
Pepco Holdings LLC [Member] \| DC PLUG charge
Regulatory Assets [Line Items]
Regulatory Assets				70	100
Pepco Holdings LLC [Member] \| Deferred storm costs
Regulatory Assets [Line Items]
Regulatory Assets				49	50
Pepco Holdings LLC [Member] \| COVID-19 Regulatory Asset
Regulatory Assets [Line Items]
Regulatory Assets				13	11
Pepco Holdings LLC [Member] \| Under-Recovered Credit Loss Expense
Regulatory Assets [Line Items]
Regulatory Assets				29	18
Pepco Holdings LLC [Member] \| Other
Regulatory Assets [Line Items]
Regulatory Assets				130	147
Pepco Holdings LLC [Member] \| Difference between Carrying Value and Fair Value [Member]
Regulatory Assets [Line Items]
Regulatory Assets				443	478
Potomac Electric Power Company [Member]
Regulatory Assets [Line Items]
Regulatory Assets				745	784
Current regulatory assets				213	214
Noncurrent regulatory assets				532	570
Potomac Electric Power Company [Member] \| Forecast [Member]
Regulatory Assets [Line Items]
Proposed Capital Expenditure			$ 500
Potomac Electric Power Company [Member] \| Pension and Other Postretirement Plans Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Potomac Electric Power Company [Member] \| Pension and Post Retirement Plan Merger Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Potomac Electric Power Company [Member] \| Deferred income taxes
Regulatory Assets [Line Items]
Regulatory Assets				10	10
Potomac Electric Power Company [Member] \| Advanced Metering Infrastructure Deployment Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				30	35
Potomac Electric Power Company [Member] \| Advanced Metering Infrastructure Legacy Meter Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				60	68
Potomac Electric Power Company [Member] \| Electric Distribution Formula Rate Annual Reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Potomac Electric Power Company [Member] \| Electric Distribution Formula Rate One-time Events [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Potomac Electric Power Company [Member] \| Energy Efficiency Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Potomac Electric Power Company [Member] \| Fair value of long-term debt
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Potomac Electric Power Company [Member] \| Fair value of PHI's unamortized energy contracts
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Potomac Electric Power Company [Member] \| Asset retirement obligations
Regulatory Assets [Line Items]
Regulatory Assets				5	3
Potomac Electric Power Company [Member] \| MGP remediation costs
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Potomac Electric Power Company [Member] \| Renewable Energy Program [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Potomac Electric Power Company [Member] \| Electric energy and natural gas costs
Regulatory Assets [Line Items]
Regulatory Assets				29	37
Potomac Electric Power Company [Member] \| Transmission formula rate annual reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Potomac Electric Power Company [Member] \| Energy efficiency and demand response programs
Regulatory Assets [Line Items]
Regulatory Assets				199	203
Potomac Electric Power Company [Member] \| Under-recovered revenue decoupling
Regulatory Assets [Line Items]
Regulatory Assets				125	93
Potomac Electric Power Company [Member] \| Under-recovered revenue decoupling \| MARYLAND \| 2022
Regulatory Assets [Line Items]
Regulatory Assets				22
Potomac Electric Power Company [Member] \| Under-recovered revenue decoupling \| DISTRICT OF COLUMBIA
Regulatory Assets [Line Items]
Regulatory Assets				103
Potomac Electric Power Company [Member] \| Under-recovered revenue decoupling \| DISTRICT OF COLUMBIA \| 2024
Regulatory Assets [Line Items]
Regulatory Assets				66
Potomac Electric Power Company [Member] \| Under-recovered revenue decoupling \| DISTRICT OF COLUMBIA \| 2028
Regulatory Assets [Line Items]
Regulatory Assets				37
Potomac Electric Power Company [Member] \| Stranded costs
Regulatory Assets [Line Items]
Regulatory Assets					0
Potomac Electric Power Company [Member] \| Removal costs
Regulatory Assets [Line Items]
Regulatory Assets				147	151
Potomac Electric Power Company [Member] \| DC PLUG charge
Regulatory Assets [Line Items]
Regulatory Assets				70	100
Potomac Electric Power Company [Member] \| DC PLUG charge \| Forecast [Member]
Regulatory Assets [Line Items]
Proposed Capital Expenditure			250
Potomac Electric Power Company [Member] \| DC PLUG charge \| Forecast [Member] \| DISTRICT OF COLUMBIA
Regulatory Assets [Line Items]
Proposed Capital Expenditure			$ 250
Potomac Electric Power Company [Member] \| Deferred storm costs
Regulatory Assets [Line Items]
Regulatory Assets				3	5
Potomac Electric Power Company [Member] \| COVID-19 Regulatory Asset
Regulatory Assets [Line Items]
Regulatory Assets				10	7
Potomac Electric Power Company [Member] \| COVID-19 Regulatory Asset \| MARYLAND
Regulatory Assets [Line Items]
Regulatory Assets				1
Potomac Electric Power Company [Member] \| COVID-19 Regulatory Asset \| MARYLAND \| 2026
Regulatory Assets [Line Items]
Regulatory Assets				1
Potomac Electric Power Company [Member] \| COVID-19 Regulatory Asset \| DISTRICT OF COLUMBIA
Regulatory Assets [Line Items]
Regulatory Assets				8
Potomac Electric Power Company [Member] \| Under-Recovered Credit Loss Expense
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Potomac Electric Power Company [Member] \| Other
Regulatory Assets [Line Items]
Regulatory Assets				57	72
Delmarva Power & Light Company [Member]
Regulatory Assets [Line Items]
Regulatory Assets				280	280
Current regulatory assets				68	58
Noncurrent regulatory assets				212	222
Delmarva Power & Light Company [Member] \| Pension and Other Postretirement Plans Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Delmarva Power & Light Company [Member] \| Pension and Post Retirement Plan Merger Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Delmarva Power & Light Company [Member] \| Deferred income taxes
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Delmarva Power & Light Company [Member] \| Advanced Metering Infrastructure Deployment Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				26	30
Delmarva Power & Light Company [Member] \| Advanced Metering Infrastructure Legacy Meter Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				21	24
Delmarva Power & Light Company [Member] \| Electric Distribution Formula Rate Annual Reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Delmarva Power & Light Company [Member] \| Electric Distribution Formula Rate One-time Events [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Delmarva Power & Light Company [Member] \| Energy Efficiency Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Delmarva Power & Light Company [Member] \| Fair value of long-term debt
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Delmarva Power & Light Company [Member] \| Fair value of PHI's unamortized energy contracts
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Delmarva Power & Light Company [Member] \| Asset retirement obligations
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Delmarva Power & Light Company [Member] \| MGP remediation costs
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Delmarva Power & Light Company [Member] \| Renewable Energy Program [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Delmarva Power & Light Company [Member] \| Electric energy and natural gas costs
Regulatory Assets [Line Items]
Regulatory Assets				13	5
Delmarva Power & Light Company [Member] \| Transmission formula rate annual reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets				8	2
Delmarva Power & Light Company [Member] \| Energy efficiency and demand response programs
Regulatory Assets [Line Items]
Regulatory Assets				79	80
Delmarva Power & Light Company [Member] \| Under-recovered revenue decoupling
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Delmarva Power & Light Company [Member] \| Stranded costs
Regulatory Assets [Line Items]
Regulatory Assets					0
Delmarva Power & Light Company [Member] \| Removal costs
Regulatory Assets [Line Items]
Regulatory Assets				109	105
Delmarva Power & Light Company [Member] \| DC PLUG charge
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Delmarva Power & Light Company [Member] \| Deferred storm costs
Regulatory Assets [Line Items]
Regulatory Assets				3	4
Delmarva Power & Light Company [Member] \| Deferred storm costs \| 2025
Regulatory Assets [Line Items]
Regulatory Assets				1
Delmarva Power & Light Company [Member] \| Deferred storm costs \| MARYLAND
Regulatory Assets [Line Items]
Regulatory Assets				2
Delmarva Power & Light Company [Member] \| COVID-19 Regulatory Asset
Regulatory Assets [Line Items]
Regulatory Assets				3	4
Delmarva Power & Light Company [Member] \| COVID-19 Regulatory Asset \| MARYLAND
Regulatory Assets [Line Items]
Regulatory Assets				1
Delmarva Power & Light Company [Member] \| COVID-19 Regulatory Asset \| DELAWARE
Regulatory Assets [Line Items]
Regulatory Assets				2
Delmarva Power & Light Company [Member] \| Under-Recovered Credit Loss Expense
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Delmarva Power & Light Company [Member] \| Other
Regulatory Assets [Line Items]
Regulatory Assets				18	26
Atlantic City Electric Company [Member]
Regulatory Assets [Line Items]
Regulatory Assets				491	470
Current regulatory assets				61	75
Noncurrent regulatory assets				430	395
Proposed Capital Expenditure	$ 220
Atlantic City Electric Company [Member] \| Forecast [Member]
Regulatory Assets [Line Items]
Proposed Capital Expenditure		$ 338
Atlantic City Electric Company [Member] \| Pension and Other Postretirement Plans Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Atlantic City Electric Company [Member] \| Pension and Post Retirement Plan Merger Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Atlantic City Electric Company [Member] \| Deferred income taxes
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Atlantic City Electric Company [Member] \| Advanced Metering Infrastructure Deployment Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Atlantic City Electric Company [Member] \| Advanced Metering Infrastructure Legacy Meter Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				7	0
Atlantic City Electric Company [Member] \| Electric Distribution Formula Rate Annual Reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Atlantic City Electric Company [Member] \| Electric Distribution Formula Rate One-time Events [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Atlantic City Electric Company [Member] \| Energy Efficiency Costs [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Atlantic City Electric Company [Member] \| Fair value of long-term debt
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Atlantic City Electric Company [Member] \| Fair value of PHI's unamortized energy contracts
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Atlantic City Electric Company [Member] \| Asset retirement obligations
Regulatory Assets [Line Items]
Regulatory Assets				1	1
Atlantic City Electric Company [Member] \| MGP remediation costs
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Atlantic City Electric Company [Member] \| Renewable Energy Program [Member]
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Atlantic City Electric Company [Member] \| Electric energy and natural gas costs
Regulatory Assets [Line Items]
Regulatory Assets				5	30
Atlantic City Electric Company [Member] \| Transmission formula rate annual reconciliations [Member]
Regulatory Assets [Line Items]
Regulatory Assets				20	1
Atlantic City Electric Company [Member] \| Energy efficiency and demand response programs
Regulatory Assets [Line Items]
Regulatory Assets				3	0
Atlantic City Electric Company [Member] \| Under-recovered revenue decoupling
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Atlantic City Electric Company [Member] \| Stranded costs
Regulatory Assets [Line Items]
Regulatory Assets					25
Atlantic City Electric Company [Member] \| Removal costs
Regulatory Assets [Line Items]
Regulatory Assets				360	339
Atlantic City Electric Company [Member] \| DC PLUG charge
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Atlantic City Electric Company [Member] \| Deferred storm costs
Regulatory Assets [Line Items]
Regulatory Assets				43	41
Atlantic City Electric Company [Member] \| Deferred storm costs \| 2024
Regulatory Assets [Line Items]
Regulatory Assets				36
Atlantic City Electric Company [Member] \| Deferred storm costs \| NEW JERSEY
Regulatory Assets [Line Items]
Regulatory Assets				7
Atlantic City Electric Company [Member] \| COVID-19 Regulatory Asset
Regulatory Assets [Line Items]
Regulatory Assets				0	0
Atlantic City Electric Company [Member] \| Under-Recovered Credit Loss Expense
Regulatory Assets [Line Items]
Regulatory Assets				29	18
Atlantic City Electric Company [Member] \| Other
Regulatory Assets [Line Items]
Regulatory Assets				$ 23	$ 15

Regulatory Matters - Schedule_4

Regulatory Matters - Schedule of Regulatory Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Regulatory Liabilities [Line Items]
Regulatory Liabilities	$ 10,004	$ 10,066
Regulatory liabilities, current	376	581
Noncurrent regulatory liabilities	9,628	9,485
Deferred income taxes
Regulatory Liabilities [Line Items]
Regulatory Liabilities	4,005	4,502
Decommissioning the Regulatory Agreement Units
Regulatory Liabilities [Line Items]
Regulatory Liabilities	3,357	3,016
Removal costs
Regulatory Liabilities [Line Items]
Regulatory Liabilities	1,694	1,649
Over Recovered Energy and Natural Gas Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	113	175
Transmission formula rate annual reconciliations [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	8	52
Renewable portfolio standards costs
Regulatory Liabilities [Line Items]
Regulatory Liabilities	500	427
Stranded costs
Regulatory Liabilities [Line Items]
Regulatory Liabilities	35	24
Other
Regulatory Liabilities [Line Items]
Regulatory Liabilities	292	221
Commonwealth Edison Co [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	6,944	6,692
Regulatory liabilities, current	185	289
Noncurrent regulatory liabilities	6,759	6,403
Commonwealth Edison Co [Member] \| Deferred income taxes
Regulatory Liabilities [Line Items]
Regulatory Liabilities	2,105	2,205
Commonwealth Edison Co [Member] \| Decommissioning the Regulatory Agreement Units
Regulatory Liabilities [Line Items]
Regulatory Liabilities	2,760	2,541
Commonwealth Edison Co [Member] \| Removal costs
Regulatory Liabilities [Line Items]
Regulatory Liabilities	1,541	1,482
Commonwealth Edison Co [Member] \| Over Recovered Energy and Natural Gas Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	25	34
Commonwealth Edison Co [Member] \| Transmission formula rate annual reconciliations [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	7	2
Commonwealth Edison Co [Member] \| Renewable portfolio standards costs
Regulatory Liabilities [Line Items]
Regulatory Liabilities	500	427
Commonwealth Edison Co [Member] \| Renewable portfolio standards costs \| Illinois Commerce Commission
Regulatory Liabilities [Line Items]
Regulatory Liabilities	432
Commonwealth Edison Co [Member] \| Renewable portfolio standards costs \| Illinois Power Agency
Regulatory Liabilities [Line Items]
Regulatory Liabilities	68
Commonwealth Edison Co [Member] \| Stranded costs
Regulatory Liabilities [Line Items]
Regulatory Liabilities	0	0
Commonwealth Edison Co [Member] \| Other
Regulatory Liabilities [Line Items]
Regulatory Liabilities	6	1
PECO Energy Co [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	729	624
Regulatory liabilities, current	94	121
Noncurrent regulatory liabilities	635	503
PECO Energy Co [Member] \| Deferred income taxes
Regulatory Liabilities [Line Items]
Regulatory Liabilities	0	0
PECO Energy Co [Member] \| Decommissioning the Regulatory Agreement Units
Regulatory Liabilities [Line Items]
Regulatory Liabilities	597	475
PECO Energy Co [Member] \| Removal costs
Regulatory Liabilities [Line Items]
Regulatory Liabilities	0	0
PECO Energy Co [Member] \| Over Recovered Energy and Natural Gas Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	71	97
PECO Energy Co [Member] \| Transmission formula rate annual reconciliations [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	0	12
PECO Energy Co [Member] \| Renewable portfolio standards costs
Regulatory Liabilities [Line Items]
Regulatory Liabilities	0	0
PECO Energy Co [Member] \| Stranded costs
Regulatory Liabilities [Line Items]
Regulatory Liabilities	0	0
PECO Energy Co [Member] \| Other
Regulatory Liabilities [Line Items]
Regulatory Liabilities	61	40
Baltimore Gas and Electric Company [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	960	1,139
Regulatory liabilities, current	26	30
Noncurrent regulatory liabilities	934	1,109
Baltimore Gas and Electric Company [Member] \| Deferred income taxes
Regulatory Liabilities [Line Items]
Regulatory Liabilities	819	1,001
Baltimore Gas and Electric Company [Member] \| Decommissioning the Regulatory Agreement Units
Regulatory Liabilities [Line Items]
Regulatory Liabilities	0	0
Baltimore Gas and Electric Company [Member] \| Removal costs
Regulatory Liabilities [Line Items]
Regulatory Liabilities	39	47
Baltimore Gas and Electric Company [Member] \| Over Recovered Energy and Natural Gas Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	0	6
Baltimore Gas and Electric Company [Member] \| Transmission formula rate annual reconciliations [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	0	0
Baltimore Gas and Electric Company [Member] \| Renewable portfolio standards costs
Regulatory Liabilities [Line Items]
Regulatory Liabilities	0	0
Baltimore Gas and Electric Company [Member] \| Stranded costs
Regulatory Liabilities [Line Items]
Regulatory Liabilities	0	0
Baltimore Gas and Electric Company [Member] \| Other
Regulatory Liabilities [Line Items]
Regulatory Liabilities	102	85
Pepco Holdings LLC [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	1,306	1,575
Regulatory liabilities, current	68	137
Noncurrent regulatory liabilities	1,238	1,438
Pepco Holdings LLC [Member] \| Deferred income taxes
Regulatory Liabilities [Line Items]
Regulatory Liabilities	1,081	1,296
Pepco Holdings LLC [Member] \| Decommissioning the Regulatory Agreement Units
Regulatory Liabilities [Line Items]
Regulatory Liabilities	0	0
Pepco Holdings LLC [Member] \| Removal costs
Regulatory Liabilities [Line Items]
Regulatory Liabilities	114	120
Pepco Holdings LLC [Member] \| Over Recovered Energy and Natural Gas Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	17	38
Pepco Holdings LLC [Member] \| Transmission formula rate annual reconciliations [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	1	38
Pepco Holdings LLC [Member] \| Renewable portfolio standards costs
Regulatory Liabilities [Line Items]
Regulatory Liabilities	0	0
Pepco Holdings LLC [Member] \| Stranded costs
Regulatory Liabilities [Line Items]
Regulatory Liabilities	35	24
Pepco Holdings LLC [Member] \| Other
Regulatory Liabilities [Line Items]
Regulatory Liabilities	58	59
Potomac Electric Power Company [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	563	690
Regulatory liabilities, current	14	46
Noncurrent regulatory liabilities	549	644
Potomac Electric Power Company [Member] \| Deferred income taxes
Regulatory Liabilities [Line Items]
Regulatory Liabilities	525	621
Potomac Electric Power Company [Member] \| Decommissioning the Regulatory Agreement Units
Regulatory Liabilities [Line Items]
Regulatory Liabilities	0	0
Potomac Electric Power Company [Member] \| Removal costs
Regulatory Liabilities [Line Items]
Regulatory Liabilities	20	20
Potomac Electric Power Company [Member] \| Over Recovered Energy and Natural Gas Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	9	24
Potomac Electric Power Company [Member] \| Transmission formula rate annual reconciliations [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	1	23
Potomac Electric Power Company [Member] \| Renewable portfolio standards costs
Regulatory Liabilities [Line Items]
Regulatory Liabilities	0	0
Potomac Electric Power Company [Member] \| Stranded costs
Regulatory Liabilities [Line Items]
Regulatory Liabilities	0	0
Potomac Electric Power Company [Member] \| Other
Regulatory Liabilities [Line Items]
Regulatory Liabilities	8	2
Delmarva Power & Light Company [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	466	540
Regulatory liabilities, current	25	47
Noncurrent regulatory liabilities	441	493
Delmarva Power & Light Company [Member] \| Deferred income taxes
Regulatory Liabilities [Line Items]
Regulatory Liabilities	354	404
Delmarva Power & Light Company [Member] \| Decommissioning the Regulatory Agreement Units
Regulatory Liabilities [Line Items]
Regulatory Liabilities	0	0
Delmarva Power & Light Company [Member] \| Removal costs
Regulatory Liabilities [Line Items]
Regulatory Liabilities	94	100
Delmarva Power & Light Company [Member] \| Over Recovered Energy and Natural Gas Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	3	10
Delmarva Power & Light Company [Member] \| Transmission formula rate annual reconciliations [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	0	9
Delmarva Power & Light Company [Member] \| Renewable portfolio standards costs
Regulatory Liabilities [Line Items]
Regulatory Liabilities	0	0
Delmarva Power & Light Company [Member] \| Stranded costs
Regulatory Liabilities [Line Items]
Regulatory Liabilities	0	0
Delmarva Power & Light Company [Member] \| Other
Regulatory Liabilities [Line Items]
Regulatory Liabilities	15	17
Atlantic City Electric Company [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	252	318
Regulatory liabilities, current	28	44
Noncurrent regulatory liabilities	224	274
Atlantic City Electric Company [Member] \| Deferred income taxes
Regulatory Liabilities [Line Items]
Regulatory Liabilities	202	271
Atlantic City Electric Company [Member] \| Decommissioning the Regulatory Agreement Units
Regulatory Liabilities [Line Items]
Regulatory Liabilities	0	0
Atlantic City Electric Company [Member] \| Removal costs
Regulatory Liabilities [Line Items]
Regulatory Liabilities	0	0
Atlantic City Electric Company [Member] \| Over Recovered Energy and Natural Gas Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	5	4
Atlantic City Electric Company [Member] \| Transmission formula rate annual reconciliations [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	0	6
Atlantic City Electric Company [Member] \| Renewable portfolio standards costs
Regulatory Liabilities [Line Items]
Regulatory Liabilities	0	0
Atlantic City Electric Company [Member] \| Stranded costs
Regulatory Liabilities [Line Items]
Regulatory Liabilities	35	24
Atlantic City Electric Company [Member] \| Other
Regulatory Liabilities [Line Items]
Regulatory Liabilities	$ 10	$ 13

Regulatory Matters - Capitalize

Regulatory Matters - Capitalized Ratemaking Amounts Not Recognized (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Public Utilities, Amount of Allowance for Earnings on Equity Capitalized for Rate Making Purposes	$ 43	$ 51
Commonwealth Edison Co [Member]
Public Utilities, Amount of Allowance for Earnings on Equity Capitalized for Rate Making Purposes	1	(1)
PECO Energy Co [Member]
Public Utilities, Amount of Allowance for Earnings on Equity Capitalized for Rate Making Purposes	0	0
Baltimore Gas and Electric Company [Member]
Public Utilities, Amount of Allowance for Earnings on Equity Capitalized for Rate Making Purposes	37	45
Pepco Holdings LLC [Member]
Public Utilities, Amount of Allowance for Earnings on Equity Capitalized for Rate Making Purposes	5	7
Potomac Electric Power Company [Member]
Public Utilities, Amount of Allowance for Earnings on Equity Capitalized for Rate Making Purposes	3	4
Delmarva Power & Light Company [Member]
Public Utilities, Amount of Allowance for Earnings on Equity Capitalized for Rate Making Purposes	2	3
Atlantic City Electric Company [Member]
Public Utilities, Amount of Allowance for Earnings on Equity Capitalized for Rate Making Purposes	$ 0	$ 0

Revenue from Contracts with C_3

Revenue from Contracts with Customers - Contract Liabilities (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Contract Liabilities [Roll Forward]
Beginning Balance - Contract Liabilities	$ 118	$ 0
Contract with Customer, Liability, Cumulative Catch-up Adjustment to Revenue, Modification of Contract		122
Contract with Customer, Liability, Revenue Recognized	(9)	(4)
Ending Balance - Contract Liabilities	109	118
Pepco Holdings LLC [Member]
Contract Liabilities [Roll Forward]
Beginning Balance - Contract Liabilities	118	0
Contract with Customer, Liability, Cumulative Catch-up Adjustment to Revenue, Modification of Contract		122
Contract with Customer, Liability, Revenue Recognized	(9)	(4)
Ending Balance - Contract Liabilities	109	118
Potomac Electric Power Company [Member]
Contract Liabilities [Roll Forward]
Beginning Balance - Contract Liabilities	94	0
Contract with Customer, Liability, Cumulative Catch-up Adjustment to Revenue, Modification of Contract		98
Contract with Customer, Liability, Revenue Recognized	(7)	(4)
Ending Balance - Contract Liabilities	87	94
Delmarva Power & Light Company [Member]
Contract Liabilities [Roll Forward]
Beginning Balance - Contract Liabilities	12	0
Contract with Customer, Liability, Cumulative Catch-up Adjustment to Revenue, Modification of Contract		12
Contract with Customer, Liability, Revenue Recognized	(1)	0
Ending Balance - Contract Liabilities	11	12
Atlantic City Electric Company [Member]
Contract Liabilities [Roll Forward]
Beginning Balance - Contract Liabilities	12	0
Contract with Customer, Liability, Cumulative Catch-up Adjustment to Revenue, Modification of Contract		12
Contract with Customer, Liability, Revenue Recognized	(1)	0
Ending Balance - Contract Liabilities	$ 11	$ 12

Revenue from Contracts with C_4

Revenue from Contracts with Customers - Prior Year Contract Revenues Recognized in Current Year (Details) $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($)
Prior Year Revenue Recognized [Line Items]
Contract with Customer, Performance Obligation Satisfied in Previous Period	$ 9
Pepco Holdings LLC [Member]
Prior Year Revenue Recognized [Line Items]
Contract with Customer, Performance Obligation Satisfied in Previous Period	9
Potomac Electric Power Company [Member]
Prior Year Revenue Recognized [Line Items]
Contract with Customer, Performance Obligation Satisfied in Previous Period	7
Delmarva Power & Light Company [Member]
Prior Year Revenue Recognized [Line Items]
Contract with Customer, Performance Obligation Satisfied in Previous Period	1
Atlantic City Electric Company [Member]
Prior Year Revenue Recognized [Line Items]
Contract with Customer, Performance Obligation Satisfied in Previous Period	$ 1

Revenue from Contracts with C_5

Revenue from Contracts with Customers - Performance Obligations (Details) $ in Millions	Dec. 31, 2021 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 109
Pepco Holdings LLC [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	109
Potomac Electric Power Company [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	87
Delmarva Power & Light Company [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	11
Atlantic City Electric Company [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	11
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 8
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 \| Exelon Generation Co L L C [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 \| Pepco Holdings LLC [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 8
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 \| Potomac Electric Power Company [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 6
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 \| Delmarva Power & Light Company [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 1
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 \| Atlantic City Electric Company [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 1
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 8
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 \| Exelon Generation Co L L C [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 \| Pepco Holdings LLC [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 8
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 \| Potomac Electric Power Company [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 6
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 \| Delmarva Power & Light Company [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 1
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 \| Atlantic City Electric Company [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 1
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 6
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 \| Exelon Generation Co L L C [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 \| Pepco Holdings LLC [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 6
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 \| Potomac Electric Power Company [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 5
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 \| Delmarva Power & Light Company [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 \| Atlantic City Electric Company [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 1
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 5
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 \| Exelon Generation Co L L C [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 \| Pepco Holdings LLC [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 5
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 \| Potomac Electric Power Company [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 5
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 \| Delmarva Power & Light Company [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 \| Atlantic City Electric Company [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 82
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 \| Exelon Generation Co L L C [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 \| Pepco Holdings LLC [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 82
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 \| Potomac Electric Power Company [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 65
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 \| Delmarva Power & Light Company [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 9
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01 \| Atlantic City Electric Company [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 8
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year

Segment Information - Narrative

Segment Information - Narrative (Details)	12 Months Ended
Segment Information - Narrative (Details)	Dec. 31, 2021 Reportable_segment
Segment Reporting Information [Line Items]
Number of reportable segments	11
Exelon Generation Co L L C [Member]
Segment Reporting Information [Line Items]
Number of reportable segments	5
Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Number of reportable segments	3

Segment Information - Reconcili

Segment Information - Reconciliation to Consolidated Financial Statements (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Revenues		$ 17,938	$ 16,663	$ 16,725
Depreciation and amortization		3,033	2,891	2,717
Operating Expenses		15,256	14,485	14,073
Interest expense, net		1,289	1,307	1,222
Income (loss) before income taxes		1,654	1,092	1,638
Income taxes		38	(7)	153
Net income (loss)		1,829	1,954	3,028
Capital expenditures		7,981	8,048	7,248
Total assets	[1]	133,013	129,317
PECO Energy Co [Member]
Segment Reporting Information [Line Items]
Revenues		3,198	3,058	3,100
Operating revenues from affiliates		21	9	6
Income (loss) before income taxes		516	417	593
Income taxes		12	(30)	65
Net income (loss)		504	447	528
Capital expenditures		1,240	1,147	939
Total assets		13,824	12,531
PECO Energy Co [Member] \| Rate-Regulated Electric Revenues [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates		20	8	5
Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenues		5,041	4,663	4,806
Operating revenues from affiliates		13	17	14
Income (loss) before income taxes		603	418	514
Income taxes		42	(77)	38
Net income (loss)		561	495	477
Capital expenditures		1,720	1,604	1,355
Total assets	[2]	24,744	23,736
Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues		17,938	16,663	16,725
Net income (loss)		1,616	1,099	1,486
Capital expenditures		6,640	6,289	5,399
Total assets		86,669	82,823
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Income taxes		(48)	11	11
Net income (loss)		1,706	1,963	2,936
Total assets		47,989	47,341
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenues		(2,261)	(2,095)	(1,955)
Operating revenues from affiliates		57	23	41
Depreciation and amortization		1	0	0
Operating Expenses		(1,587)	(1,502)	(1,383)
Interest expense, net		(1)	(3)	0
Income (loss) before income taxes		(603)	(597)	(632)
Income taxes		(161)	(153)	(160)
Net income (loss)		(443)	(446)	(472)
Capital expenditures		0	0	0
Total assets		(8,319)	(8,454)
Intersegment Eliminations [Member] \| Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenues		(380)	(374)	(396)
Operating revenues from affiliates		(381)	(375)	(397)
Depreciation and amortization		0	0	0
Operating Expenses		(381)	(375)	(396)
Interest expense, net		0	0	1
Income (loss) before income taxes		0	0	0
Income taxes		0	0	0
Net income (loss)		0	0	0
Capital expenditures		0	0	0
Total assets		(60)	(33)
Commonwealth Edison Co [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues		6,406	5,904	5,747
Depreciation and amortization		1,205	1,133	1,033
Operating Expenses		5,151	4,950	4,580
Interest expense, net		389	382	359
Income (loss) before income taxes		914	615	851
Income taxes		172	177	163
Net income (loss)		742	438	688
Capital expenditures		2,387	2,217	1,915
Total assets		36,470	34,466
Commonwealth Edison Co [Member] \| Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates		41	37	30
PECO Energy Co [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues		3,198	3,058	3,100
Depreciation and amortization		348	347	333
Operating Expenses		2,547	2,512	2,388
Interest expense, net		161	147	136
Income (loss) before income taxes		516	417	593
Income taxes		12	(30)	65
Net income (loss)		504	447	528
Capital expenditures		1,240	1,147	939
Total assets		13,824	12,531
PECO Energy Co [Member] \| Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates		21	9	6
Baltimore Gas and Electric Company [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues		3,341	3,098	3,106
Depreciation and amortization		591	550	502
Operating Expenses		2,860	2,598	2,574
Interest expense, net		138	133	121
Income (loss) before income taxes		373	390	439
Income taxes		(35)	41	79
Net income (loss)		408	349	360
Capital expenditures		1,226	1,247	1,145
Total assets		12,324	11,650
Baltimore Gas and Electric Company [Member] \| Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates		31	20	26
Pepco Holdings LLC [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues		5,041	4,663	4,806
Depreciation and amortization		821	782	754
Operating Expenses		4,240	4,045	4,084
Interest expense, net		267	268	263
Income (loss) before income taxes		603	418	514
Income taxes		42	(77)	38
Net income (loss)		561	495	477
Capital expenditures		1,720	1,604	1,355
Total assets		24,744	23,736
Pepco Holdings LLC [Member] \| Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates		13	17	14
Potomac Electric Power Company [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues		2,274	2,149	2,260
Depreciation and amortization		403	377	374
Operating Expenses		1,871	1,799	1,899
Interest expense, net		140	138	133
Income (loss) before income taxes		311	259	259
Income taxes		15	(7)	16
Net income (loss)		296	266	243
Capital expenditures		843	773	626
Total assets		9,903	9,264
Potomac Electric Power Company [Member] \| Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates		5	7	5
Delmarva Power & Light Company [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues		1,380	1,271	1,306
Depreciation and amortization		210	191	184
Operating Expenses		1,161	1,120	1,089
Interest expense, net		61	61	61
Income (loss) before income taxes		170	100	169
Income taxes		42	(25)	22
Net income (loss)		128	125	147
Capital expenditures		429	424	348
Total assets		5,412	5,140
Delmarva Power & Light Company [Member] \| Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates		7	9	7
Atlantic City Electric Company [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues		1,388	1,245	1,240
Depreciation and amortization		179	180	157
Operating Expenses		1,201	1,123	1,089
Interest expense, net		58	59	58
Income (loss) before income taxes		133	71	99
Income taxes		(13)	(41)	0
Net income (loss)		146	112	99
Capital expenditures		445	401	375
Total assets		4,556	4,286
Atlantic City Electric Company [Member] \| Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates		2	4	3
Corporate and Other [Member] \| Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Revenues		2,213	2,035	1,921
Depreciation and amortization		67	79	95
Operating Expenses		2,045	1,882	1,830
Interest expense, net		335	380	343
Income (loss) before income taxes		(149)	(151)	(127)
Income taxes		8	35	(32)
Net income (loss)		(156)	(184)	(95)
Capital expenditures		67	74	45
Total assets		7,626	8,894
Corporate and Other [Member] \| Corporate, Non-Segment [Member] \| Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenues		379	372	396
Depreciation and amortization		29	34	39
Operating Expenses		388	378	403
Interest expense, net		8	10	10
Income (loss) before income taxes		(11)	(12)	(13)
Income taxes		(2)	(4)	0
Net income (loss)		(9)	(8)	(12)
Capital expenditures		3	6	6
Total assets		4,933	5,079
Corporate and Other [Member] \| Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates		2,203	2,024	1,913
Corporate and Other [Member] \| Intersegment Eliminations [Member] \| Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates		380	372	396
Segment Elimination [Member] \| Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Operating revenues from affiliates		(2,252)	(2,084)	(1,948)
Electricity, US Regulated [Member] \| PECO Energy Co [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		2,613	2,519	2,505
Electricity, US Regulated [Member] \| Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		4,769	4,463	4,639
Electricity, US Regulated [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		16,395	15,224	15,221
Electricity, US Regulated [Member] \| Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		(35)	(44)	(21)
Electricity, US Regulated [Member] \| Intersegment Eliminations [Member] \| Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		(14)	(18)	(13)
Electricity, US Regulated [Member] \| Commonwealth Edison Co [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		6,406	5,904	5,747
Electricity, US Regulated [Member] \| PECO Energy Co [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		2,659	2,543	2,490
Electricity, US Regulated [Member] \| Baltimore Gas and Electric Company [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		2,505	2,336	2,379
Electricity, US Regulated [Member] \| Pepco Holdings LLC [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		4,860	4,485	4,626
Electricity, US Regulated [Member] \| Potomac Electric Power Company [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		2,274	2,149	2,260
Electricity, US Regulated [Member] \| Delmarva Power & Light Company [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		1,212	1,109	1,139
Electricity, US Regulated [Member] \| Atlantic City Electric Company [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		1,388	1,245	1,240
Electricity, US Regulated [Member] \| Corporate and Other [Member] \| Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		0	0	0
Electricity, US Regulated [Member] \| Corporate and Other [Member] \| Corporate, Non-Segment [Member] \| Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		0	0	0
Natural Gas, US Regulated [Member] \| PECO Energy Co [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		538	514	610
Natural Gas, US Regulated [Member] \| Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		168	162	167
Natural Gas, US Regulated [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		1,543	1,439	1,504
Natural Gas, US Regulated [Member] \| Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		0	0	0
Natural Gas, US Regulated [Member] \| Intersegment Eliminations [Member] \| Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		0	0	0
Natural Gas, US Regulated [Member] \| Commonwealth Edison Co [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		0	0	0
Natural Gas, US Regulated [Member] \| PECO Energy Co [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		539	515	610
Natural Gas, US Regulated [Member] \| Baltimore Gas and Electric Company [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		836	762	727
Natural Gas, US Regulated [Member] \| Pepco Holdings LLC [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		168	162	167
Natural Gas, US Regulated [Member] \| Potomac Electric Power Company [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		0	0	0
Natural Gas, US Regulated [Member] \| Delmarva Power & Light Company [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		168	162	167
Natural Gas, US Regulated [Member] \| Atlantic City Electric Company [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		0	0	0
Natural Gas, US Regulated [Member] \| Corporate and Other [Member] \| Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		0	0	0
Natural Gas, US Regulated [Member] \| Corporate and Other [Member] \| Corporate, Non-Segment [Member] \| Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		0	0	0
Service, Other [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		0	0	0
Service, Other [Member] \| Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		(2,226)	(2,051)	(1,934)
Service, Other [Member] \| Intersegment Eliminations [Member] \| Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		(366)	(356)	(383)
Service, Other [Member] \| Commonwealth Edison Co [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		0	0	0
Service, Other [Member] \| PECO Energy Co [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		0	0	0
Service, Other [Member] \| Baltimore Gas and Electric Company [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		0	0	0
Service, Other [Member] \| Pepco Holdings LLC [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		13	16	13
Service, Other [Member] \| Potomac Electric Power Company [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		0	0	0
Service, Other [Member] \| Delmarva Power & Light Company [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		0	0	0
Service, Other [Member] \| Atlantic City Electric Company [Member] \| Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		0	0	0
Service, Other [Member] \| Corporate and Other [Member] \| Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		2,213	2,035	1,921
Service, Other [Member] \| Corporate and Other [Member] \| Corporate, Non-Segment [Member] \| Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax		$ 379	$ 372	$ 396

[1]Exelon’s consolidated assets include $18 million as of December 31, 2020, of certain VIEs that can only be used to settle the liabilities of the VIE. Exelon’s consolidated liabilities include $26 million as of December 31, 2020, of certain VIEs for which the VIE creditors do not have recourse to Exelon. See Note 21–Variable Interest Entities for additional information.[2]PHI’s consolidated total assets include $0 million and $18 million as of December 31, 2021 and 2020, respectively, of PHI's consolidated VIE that can only be used to settle the liabilities of the VIE. PHI’s consolidated total liabilities include $0 million and $26 million as of December 31, 2021 and 2020, respectively, of PHI's consolidated VIE for which the VIE creditors do not have recourse to PHI. See Note 21 - Variable Interest Entities for additional information.

Segment Information - Generatio

Segment Information - Generation Total Revenues (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Segment Reporting Information [Line Items]
Revenues	$ 17,938	$ 16,663	$ 16,725
Operating Segments [Member]
Segment Reporting Information [Line Items]
Revenues	17,938	16,663	16,725
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenues	(2,261)	(2,095)	(1,955)
Revenue from Related Parties	$ 57	$ 23	$ 41

Segment Information - Electric

Segment Information - Electric and Gas Revenue by Customer Class (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenue, Major Customer [Line Items]
Revenues	$ 17,938	$ 16,663	$ 16,725
Operating Segments [Member]
Revenue, Major Customer [Line Items]
Revenues	17,938	16,663	16,725
Operating Segments [Member] \| Pepco Holdings LLC [Member]
Revenue, Major Customer [Line Items]
Revenues	5,041	4,663	4,806
Commonwealth Edison Co [Member]
Revenue, Major Customer [Line Items]
Revenues	6,406	5,904	5,747
Revenue from Related Parties	41	37	30
Commonwealth Edison Co [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenues	6,334	5,933	5,854
Commonwealth Edison Co [Member] \| Other Regulated Revenue [Member]
Revenue, Major Customer [Line Items]
Revenues	72	(29)	(107)
PECO Energy Co [Member]
Revenue, Major Customer [Line Items]
Revenues	3,198	3,058	3,100
Revenue from Related Parties	21	9	6
PECO Energy Co [Member] \| Rate-Regulated Electric Revenues [Member]
Revenue, Major Customer [Line Items]
Revenue from Related Parties	20	8	5
PECO Energy Co [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenues	3,168	3,039	3,107
PECO Energy Co [Member] \| Other Regulated Revenue [Member]
Revenue, Major Customer [Line Items]
Revenues	30	19	(7)
PECO Energy Co [Member] \| Rate-Regulated Natural Gas Revenues [Member]
Revenue, Major Customer [Line Items]
Revenue from Related Parties	1	1	1
Baltimore Gas and Electric Company [Member]
Revenue, Major Customer [Line Items]
Revenues	3,341	3,098	3,106
Revenue from Related Parties	31	20	26
Baltimore Gas and Electric Company [Member] \| Rate-Regulated Electric Revenues [Member]
Revenue, Major Customer [Line Items]
Revenue from Related Parties	13	10	8
Baltimore Gas and Electric Company [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenues	3,315	3,075	3,078
Baltimore Gas and Electric Company [Member] \| Other Regulated Revenue [Member]
Revenue, Major Customer [Line Items]
Revenues	26	23	28
Baltimore Gas and Electric Company [Member] \| Rate-Regulated Natural Gas Revenues [Member]
Revenue, Major Customer [Line Items]
Revenue from Related Parties	18	10	18
Pepco Holdings LLC [Member]
Revenue, Major Customer [Line Items]
Revenues	5,041	4,663	4,806
Revenue from Related Parties	13	17	14
Pepco Holdings LLC [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenues	4,945	4,640	4,810
Pepco Holdings LLC [Member] \| Other Regulated Revenue [Member]
Revenue, Major Customer [Line Items]
Revenues	96	23	(4)
Potomac Electric Power Company [Member]
Revenue, Major Customer [Line Items]
Revenues	2,274	2,149	2,260
Revenue from Related Parties	5	7	5
Potomac Electric Power Company [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenues	2,218	2,108	2,255
Potomac Electric Power Company [Member] \| Other Regulated Revenue [Member]
Revenue, Major Customer [Line Items]
Revenues	56	41	5
Delmarva Power & Light Company [Member]
Revenue, Major Customer [Line Items]
Revenues	1,380	1,271	1,306
Revenue from Related Parties	7	9	7
Delmarva Power & Light Company [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenues	1,364	1,277	1,315
Delmarva Power & Light Company [Member] \| Other Regulated Revenue [Member]
Revenue, Major Customer [Line Items]
Revenues	16	(6)	(9)
Atlantic City Electric Company [Member]
Revenue, Major Customer [Line Items]
Revenues	1,388	1,245	1,240
Revenue from Related Parties	2	4	3
Atlantic City Electric Company [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenues	1,364	1,257	1,240
Atlantic City Electric Company [Member] \| Other Regulated Revenue [Member]
Revenue, Major Customer [Line Items]
Revenues	24	(12)	0
Electricity, US Regulated [Member] \| Operating Segments [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	16,395	15,224	15,221
Electricity, US Regulated [Member] \| Operating Segments [Member] \| Pepco Holdings LLC [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	4,860	4,485	4,626
Electricity, US Regulated [Member] \| Commonwealth Edison Co [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	6,323	5,914	5,850
Electricity, US Regulated [Member] \| Commonwealth Edison Co [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	6,334	5,933	5,854
Electricity, US Regulated [Member] \| Commonwealth Edison Co [Member] \| Regulated Operation [Member] \| Residential [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	3,233	3,090	2,916
Electricity, US Regulated [Member] \| Commonwealth Edison Co [Member] \| Regulated Operation [Member] \| Small Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,571	1,399	1,463
Electricity, US Regulated [Member] \| Commonwealth Edison Co [Member] \| Regulated Operation [Member] \| Large Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	559	515	540
Electricity, US Regulated [Member] \| Commonwealth Edison Co [Member] \| Regulated Operation [Member] \| Public Authorities & Electric Railroads [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	45	45	47
Electricity, US Regulated [Member] \| Commonwealth Edison Co [Member] \| Regulated Operation [Member] \| Other [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	926	884	888
Electricity, US Regulated [Member] \| Commonwealth Edison Co [Member] \| Regulated Operation [Member] \| Operating Segments [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	30	18	26
Electricity, US Regulated [Member] \| PECO Energy Co [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	2,613	2,519	2,505
Electricity, US Regulated [Member] \| PECO Energy Co [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	2,629	2,524	2,497
Electricity, US Regulated [Member] \| PECO Energy Co [Member] \| Regulated Operation [Member] \| Residential [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,704	1,656	1,596
Electricity, US Regulated [Member] \| PECO Energy Co [Member] \| Regulated Operation [Member] \| Small Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	422	386	404
Electricity, US Regulated [Member] \| PECO Energy Co [Member] \| Regulated Operation [Member] \| Large Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	243	228	219
Electricity, US Regulated [Member] \| PECO Energy Co [Member] \| Regulated Operation [Member] \| Public Authorities & Electric Railroads [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	31	29	29
Electricity, US Regulated [Member] \| PECO Energy Co [Member] \| Regulated Operation [Member] \| Other [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	229	225	249
Electricity, US Regulated [Member] \| PECO Energy Co [Member] \| Regulated Operation [Member] \| Operating Segments [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	4	3	13
Electricity, US Regulated [Member] \| Baltimore Gas and Electric Company [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	2,497	2,323	2,368
Electricity, US Regulated [Member] \| Baltimore Gas and Electric Company [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	2,499	2,328	2,364
Electricity, US Regulated [Member] \| Baltimore Gas and Electric Company [Member] \| Regulated Operation [Member] \| Residential [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,375	1,345	1,326
Electricity, US Regulated [Member] \| Baltimore Gas and Electric Company [Member] \| Regulated Operation [Member] \| Small Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	267	241	254
Electricity, US Regulated [Member] \| Baltimore Gas and Electric Company [Member] \| Regulated Operation [Member] \| Large Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	459	406	436
Electricity, US Regulated [Member] \| Baltimore Gas and Electric Company [Member] \| Regulated Operation [Member] \| Public Authorities & Electric Railroads [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	27	27	27
Electricity, US Regulated [Member] \| Baltimore Gas and Electric Company [Member] \| Regulated Operation [Member] \| Other [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	371	309	321
Electricity, US Regulated [Member] \| Baltimore Gas and Electric Company [Member] \| Regulated Operation [Member] \| Operating Segments [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	11	5	12
Electricity, US Regulated [Member] \| Pepco Holdings LLC [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	4,769	4,463	4,639
Electricity, US Regulated [Member] \| Pepco Holdings LLC [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	4,777	4,478	4,644
Electricity, US Regulated [Member] \| Pepco Holdings LLC [Member] \| Regulated Operation [Member] \| Residential [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	2,441	2,332	2,316
Electricity, US Regulated [Member] \| Pepco Holdings LLC [Member] \| Regulated Operation [Member] \| Small Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	521	472	505
Electricity, US Regulated [Member] \| Pepco Holdings LLC [Member] \| Regulated Operation [Member] \| Large Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,123	1,001	1,112
Electricity, US Regulated [Member] \| Pepco Holdings LLC [Member] \| Regulated Operation [Member] \| Public Authorities & Electric Railroads [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	58	60	61
Electricity, US Regulated [Member] \| Pepco Holdings LLC [Member] \| Regulated Operation [Member] \| Other [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	634	613	650
Electricity, US Regulated [Member] \| Pepco Holdings LLC [Member] \| Regulated Operation [Member] \| Operating Segments [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	5	2	10
Electricity, US Regulated [Member] \| Potomac Electric Power Company [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	2,216	2,102	2,258
Electricity, US Regulated [Member] \| Potomac Electric Power Company [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	2,218	2,108	2,255
Electricity, US Regulated [Member] \| Potomac Electric Power Company [Member] \| Regulated Operation [Member] \| Residential [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,003	988	1,012
Electricity, US Regulated [Member] \| Potomac Electric Power Company [Member] \| Regulated Operation [Member] \| Small Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	135	132	149
Electricity, US Regulated [Member] \| Potomac Electric Power Company [Member] \| Regulated Operation [Member] \| Large Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	844	736	833
Electricity, US Regulated [Member] \| Potomac Electric Power Company [Member] \| Regulated Operation [Member] \| Public Authorities & Electric Railroads [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	31	34	34
Electricity, US Regulated [Member] \| Potomac Electric Power Company [Member] \| Regulated Operation [Member] \| Other [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	205	218	227
Electricity, US Regulated [Member] \| Potomac Electric Power Company [Member] \| Regulated Operation [Member] \| Operating Segments [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	3	1	8
Electricity, US Regulated [Member] \| Delmarva Power & Light Company [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,191	1,107	1,143
Electricity, US Regulated [Member] \| Delmarva Power & Light Company [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,196	1,115	1,148
Electricity, US Regulated [Member] \| Delmarva Power & Light Company [Member] \| Regulated Operation [Member] \| Residential [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	694	652	645
Electricity, US Regulated [Member] \| Delmarva Power & Light Company [Member] \| Regulated Operation [Member] \| Small Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	193	171	186
Electricity, US Regulated [Member] \| Delmarva Power & Light Company [Member] \| Regulated Operation [Member] \| Large Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	94	89	99
Electricity, US Regulated [Member] \| Delmarva Power & Light Company [Member] \| Regulated Operation [Member] \| Public Authorities & Electric Railroads [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	14	13	14
Electricity, US Regulated [Member] \| Delmarva Power & Light Company [Member] \| Regulated Operation [Member] \| Other [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	201	190	204
Electricity, US Regulated [Member] \| Delmarva Power & Light Company [Member] \| Regulated Operation [Member] \| Operating Segments [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	2	1	2
Electricity, US Regulated [Member] \| Atlantic City Electric Company [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,362	1,253	1,237
Electricity, US Regulated [Member] \| Atlantic City Electric Company [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,364	1,257	1,240
Electricity, US Regulated [Member] \| Atlantic City Electric Company [Member] \| Regulated Operation [Member] \| Residential [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	744	692	659
Electricity, US Regulated [Member] \| Atlantic City Electric Company [Member] \| Regulated Operation [Member] \| Small Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	193	169	170
Electricity, US Regulated [Member] \| Atlantic City Electric Company [Member] \| Regulated Operation [Member] \| Large Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	185	176	180
Electricity, US Regulated [Member] \| Atlantic City Electric Company [Member] \| Regulated Operation [Member] \| Public Authorities & Electric Railroads [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	13	13	13
Electricity, US Regulated [Member] \| Atlantic City Electric Company [Member] \| Regulated Operation [Member] \| Other [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	229	207	218
Electricity, US Regulated [Member] \| Atlantic City Electric Company [Member] \| Regulated Operation [Member] \| Operating Segments [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0
Natural Gas, US Regulated [Member] \| Operating Segments [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,543	1,439	1,504
Natural Gas, US Regulated [Member] \| Operating Segments [Member] \| Pepco Holdings LLC [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	168	162	167
Natural Gas, US Regulated [Member] \| Commonwealth Edison Co [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0
Natural Gas, US Regulated [Member] \| Commonwealth Edison Co [Member] \| Regulated Operation [Member] \| Residential [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0
Natural Gas, US Regulated [Member] \| Commonwealth Edison Co [Member] \| Regulated Operation [Member] \| Small Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0
Natural Gas, US Regulated [Member] \| Commonwealth Edison Co [Member] \| Regulated Operation [Member] \| Large Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0
Natural Gas, US Regulated [Member] \| Commonwealth Edison Co [Member] \| Regulated Operation [Member] \| Transportation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0
Natural Gas, US Regulated [Member] \| Commonwealth Edison Co [Member] \| Regulated Operation [Member] \| Other [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0
Natural Gas, US Regulated [Member] \| Commonwealth Edison Co [Member] \| Regulated Operation [Member] \| Operating Segments [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0
Natural Gas, US Regulated [Member] \| PECO Energy Co [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	538	514	610
Natural Gas, US Regulated [Member] \| PECO Energy Co [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	539	515	610
Natural Gas, US Regulated [Member] \| PECO Energy Co [Member] \| Regulated Operation [Member] \| Residential [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	372	361	409
Natural Gas, US Regulated [Member] \| PECO Energy Co [Member] \| Regulated Operation [Member] \| Small Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	136	126	169
Natural Gas, US Regulated [Member] \| PECO Energy Co [Member] \| Regulated Operation [Member] \| Large Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	1
Natural Gas, US Regulated [Member] \| PECO Energy Co [Member] \| Regulated Operation [Member] \| Transportation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	24	24	25
Natural Gas, US Regulated [Member] \| PECO Energy Co [Member] \| Regulated Operation [Member] \| Other [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	7	4	6
Natural Gas, US Regulated [Member] \| PECO Energy Co [Member] \| Regulated Operation [Member] \| Operating Segments [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	1
Natural Gas, US Regulated [Member] \| Baltimore Gas and Electric Company [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	801	739	700
Natural Gas, US Regulated [Member] \| Baltimore Gas and Electric Company [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	816	747	714
Natural Gas, US Regulated [Member] \| Baltimore Gas and Electric Company [Member] \| Regulated Operation [Member] \| Residential [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	518	504	474
Natural Gas, US Regulated [Member] \| Baltimore Gas and Electric Company [Member] \| Regulated Operation [Member] \| Small Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	83	79	77
Natural Gas, US Regulated [Member] \| Baltimore Gas and Electric Company [Member] \| Regulated Operation [Member] \| Large Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	147	135	132
Natural Gas, US Regulated [Member] \| Baltimore Gas and Electric Company [Member] \| Regulated Operation [Member] \| Transportation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0
Natural Gas, US Regulated [Member] \| Baltimore Gas and Electric Company [Member] \| Regulated Operation [Member] \| Other [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	68	29	31
Natural Gas, US Regulated [Member] \| Baltimore Gas and Electric Company [Member] \| Regulated Operation [Member] \| Operating Segments [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	3	2	4
Natural Gas, US Regulated [Member] \| Pepco Holdings LLC [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	168	162	167
Natural Gas, US Regulated [Member] \| Pepco Holdings LLC [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	168	162	166
Natural Gas, US Regulated [Member] \| Pepco Holdings LLC [Member] \| Regulated Operation [Member] \| Residential [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	97	96	96
Natural Gas, US Regulated [Member] \| Pepco Holdings LLC [Member] \| Regulated Operation [Member] \| Small Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	42	42	44
Natural Gas, US Regulated [Member] \| Pepco Holdings LLC [Member] \| Regulated Operation [Member] \| Large Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	7	4	5
Natural Gas, US Regulated [Member] \| Pepco Holdings LLC [Member] \| Regulated Operation [Member] \| Transportation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	14	14	14
Natural Gas, US Regulated [Member] \| Pepco Holdings LLC [Member] \| Regulated Operation [Member] \| Other [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	8	6	7
Natural Gas, US Regulated [Member] \| Pepco Holdings LLC [Member] \| Regulated Operation [Member] \| Operating Segments [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0
Natural Gas, US Regulated [Member] \| Potomac Electric Power Company [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0
Natural Gas, US Regulated [Member] \| Potomac Electric Power Company [Member] \| Regulated Operation [Member] \| Residential [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0
Natural Gas, US Regulated [Member] \| Potomac Electric Power Company [Member] \| Regulated Operation [Member] \| Small Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0
Natural Gas, US Regulated [Member] \| Potomac Electric Power Company [Member] \| Regulated Operation [Member] \| Large Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0
Natural Gas, US Regulated [Member] \| Potomac Electric Power Company [Member] \| Regulated Operation [Member] \| Transportation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0
Natural Gas, US Regulated [Member] \| Potomac Electric Power Company [Member] \| Regulated Operation [Member] \| Other [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0
Natural Gas, US Regulated [Member] \| Potomac Electric Power Company [Member] \| Regulated Operation [Member] \| Operating Segments [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0
Natural Gas, US Regulated [Member] \| Delmarva Power & Light Company [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	168	162	167
Natural Gas, US Regulated [Member] \| Delmarva Power & Light Company [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	168	162	167
Natural Gas, US Regulated [Member] \| Delmarva Power & Light Company [Member] \| Regulated Operation [Member] \| Residential [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	97	96	96
Natural Gas, US Regulated [Member] \| Delmarva Power & Light Company [Member] \| Regulated Operation [Member] \| Small Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	42	42	45
Natural Gas, US Regulated [Member] \| Delmarva Power & Light Company [Member] \| Regulated Operation [Member] \| Large Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	7	4	5
Natural Gas, US Regulated [Member] \| Delmarva Power & Light Company [Member] \| Regulated Operation [Member] \| Transportation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	14	14	14
Natural Gas, US Regulated [Member] \| Delmarva Power & Light Company [Member] \| Regulated Operation [Member] \| Other [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	8	6	7
Natural Gas, US Regulated [Member] \| Delmarva Power & Light Company [Member] \| Regulated Operation [Member] \| Operating Segments [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0
Natural Gas, US Regulated [Member] \| Atlantic City Electric Company [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0
Natural Gas, US Regulated [Member] \| Atlantic City Electric Company [Member] \| Regulated Operation [Member] \| Residential [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0
Natural Gas, US Regulated [Member] \| Atlantic City Electric Company [Member] \| Regulated Operation [Member] \| Small Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0
Natural Gas, US Regulated [Member] \| Atlantic City Electric Company [Member] \| Regulated Operation [Member] \| Large Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0
Natural Gas, US Regulated [Member] \| Atlantic City Electric Company [Member] \| Regulated Operation [Member] \| Transportation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0
Natural Gas, US Regulated [Member] \| Atlantic City Electric Company [Member] \| Regulated Operation [Member] \| Other [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0
Natural Gas, US Regulated [Member] \| Atlantic City Electric Company [Member] \| Regulated Operation [Member] \| Operating Segments [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0	0
Alternative Revenue [Member] \| Commonwealth Edison Co [Member] \| Operating Segments [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	42	(47)	(133)
Alternative Revenue [Member] \| PECO Energy Co [Member] \| Operating Segments [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	26	16	(21)
Alternative Revenue [Member] \| Baltimore Gas and Electric Company [Member] \| Operating Segments [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	12	16	12
Alternative Revenue [Member] \| Pepco Holdings LLC [Member] \| Operating Segments [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	91	21	(14)
Alternative Revenue [Member] \| Potomac Electric Power Company [Member] \| Operating Segments [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	53	40	(3)
Alternative Revenue [Member] \| Delmarva Power & Light Company [Member] \| Operating Segments [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	14	(7)	(11)
Alternative Revenue [Member] \| Atlantic City Electric Company [Member] \| Operating Segments [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	$ 24	$ (12)	$ 0

Accounts Receivable - Allowance

Accounts Receivable - Allowance for Credit Losses Rollforward (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Accounts Receivable, Allowance for Credit Loss [Line Items]
Current Period Provision for Expected Credit Losses	$ (160)	$ (150)	$ (120)
Commonwealth Edison Co [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Current Period Provision for Expected Credit Losses	(47)	(32)	(33)
PECO Energy Co [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Current Period Provision for Expected Credit Losses	(39)	(42)	(31)
Baltimore Gas and Electric Company [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Current Period Provision for Expected Credit Losses	(17)	(15)	(8)
Pepco Holdings LLC [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Current Period Provision for Expected Credit Losses	(24)	(43)	(17)
Potomac Electric Power Company [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Current Period Provision for Expected Credit Losses	(9)	(24)	(7)
Delmarva Power & Light Company [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Current Period Provision for Expected Credit Losses	(5)	(16)	(4)
Atlantic City Electric Company [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Current Period Provision for Expected Credit Losses	(10)	(2)	(5)
Customer accounts receivable
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	334	163
Current Period Provision for Expected Credit Losses	96	235
Writeoffs, net of recoveries	110	64
Ending balance	320	334	163
Customer accounts receivable \| Commonwealth Edison Co [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	97	59
Current Period Provision for Expected Credit Losses	21	62
Writeoffs, net of recoveries	45	24
Ending balance	73	97	59
Customer accounts receivable \| PECO Energy Co [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	116	55
Current Period Provision for Expected Credit Losses	23	79
Writeoffs, net of recoveries	34	18
Ending balance	105	116	55
Customer accounts receivable \| Baltimore Gas and Electric Company [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	35	12
Current Period Provision for Expected Credit Losses	15	30
Writeoffs, net of recoveries	12	7
Ending balance	38	35	12
Customer accounts receivable \| Pepco Holdings LLC [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	86	37
Current Period Provision for Expected Credit Losses	37	64
Writeoffs, net of recoveries	19	15
Ending balance	104	86	37
Customer accounts receivable \| Potomac Electric Power Company [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	32	13
Current Period Provision for Expected Credit Losses	13	24
Writeoffs, net of recoveries	8	5
Ending balance	37	32	13
Customer accounts receivable \| Delmarva Power & Light Company [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	22	11
Current Period Provision for Expected Credit Losses	6	15
Writeoffs, net of recoveries	10	4
Ending balance	18	22	11
Customer accounts receivable \| Atlantic City Electric Company [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	32	13
Current Period Provision for Expected Credit Losses	18	25
Writeoffs, net of recoveries	1	6
Ending balance	49	32	13
Other Receivables
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	71	48
Current Period Provision for Expected Credit Losses	11	33
Writeoffs, net of recoveries	10	10
Ending balance	72	71	48
Other Receivables \| Commonwealth Edison Co [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	21	20
Current Period Provision for Expected Credit Losses	(2)	5
Writeoffs, net of recoveries	2	4
Ending balance	17	21	20
Other Receivables \| PECO Energy Co [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	8	7
Current Period Provision for Expected Credit Losses	3	3
Writeoffs, net of recoveries	4	2
Ending balance	7	8	7
Other Receivables \| Baltimore Gas and Electric Company [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	9	5
Current Period Provision for Expected Credit Losses	4	7
Writeoffs, net of recoveries	4	3
Ending balance	9	9	5
Other Receivables \| Pepco Holdings LLC [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	33	16
Current Period Provision for Expected Credit Losses	6	18
Writeoffs, net of recoveries	0	1
Ending balance	39	33	16
Other Receivables \| Potomac Electric Power Company [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	13	7
Current Period Provision for Expected Credit Losses	3	6
Writeoffs, net of recoveries	0	0
Ending balance	16	13	7
Other Receivables \| Delmarva Power & Light Company [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	9	4
Current Period Provision for Expected Credit Losses	(1)	5
Writeoffs, net of recoveries	0	0
Ending balance	8	9	4
Other Receivables \| Atlantic City Electric Company [Member]
Accounts Receivable, Allowance for Credit Loss [Line Items]
Beginning balance	11	5
Current Period Provision for Expected Credit Losses	4	7
Writeoffs, net of recoveries	0	1
Ending balance	$ 15	$ 11	$ 5

Accounts Receivable - Unbilled

Accounts Receivable - Unbilled Customer Revenue (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled customer revenues	$ 747	$ 740
Commonwealth Edison Co [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled customer revenues	240	218
PECO Energy Co [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled customer revenues	161	147
Baltimore Gas and Electric Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled customer revenues	171	197
Pepco Holdings LLC [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled customer revenues	175	178
Potomac Electric Power Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled customer revenues	82	87
Delmarva Power & Light Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled customer revenues	53	62
Atlantic City Electric Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled customer revenues	$ 40	$ 29

Accounts Receivable - Purchases

Accounts Receivable - Purchases and Sales of Accounts Receivable (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Purchase	$ 3,840	$ 3,781
Commonwealth Edison Co [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Purchase	1,031	1,094
PECO Energy Co [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Purchase	1,041	1,020
Baltimore Gas and Electric Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Purchase	687	652
Pepco Holdings LLC [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Purchase	1,081	1,015
Potomac Electric Power Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Purchase	660	622
Delmarva Power & Light Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Purchase	217	207
Atlantic City Electric Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Purchase	204	186
Exelon Generation Co LLC Affiliate [Member] \| Commonwealth Edison Co [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Related Parties, Purchase	1	34
Exelon Generation Co LLC Affiliate [Member] \| PECO Energy Co [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Related Parties, Purchase	1	67
Exelon Generation Co LLC Affiliate [Member] \| Baltimore Gas and Electric Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Related Parties, Purchase	21	79
Exelon Generation Co LLC Affiliate [Member] \| Pepco Holdings LLC [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Related Parties, Purchase	0	72
Exelon Generation Co LLC Affiliate [Member] \| Potomac Electric Power Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Related Parties, Purchase	0	51
Exelon Generation Co LLC Affiliate [Member] \| Delmarva Power & Light Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Related Parties, Purchase	0	13
Exelon Generation Co LLC Affiliate [Member] \| Atlantic City Electric Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Related Parties, Purchase	$ 0	$ 8

Early Plant Retirements - Narra

Early Plant Retirements - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Operating Expenses	$ 15,256	$ 14,485	$ 14,073
Depreciation and Amortization	$ 3,033	$ 2,891	$ 2,717

Property, Plant and Equipment -

Property, Plant and Equipment - Summary of Property, Plant and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 78,988	$ 73,678
Accumulated depreciation and amortization	14,430	13,346
Property, plant, and equipment, net	64,558	60,332
Exelon Generation Co L L C [Member]
Property, Plant and Equipment [Line Items]
Accumulated depreciation and amortization	15,888	13,381
Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 64,771	60,946
Electric—transmission and distribution \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	5 years
Electric—transmission and distribution \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	80 years
Electric Generation Equipment [Member] \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	1 year
Electric Generation Equipment [Member] \| Minimum [Member] \| Exelon Generation Co L L C [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	1 year
Electric Generation Equipment [Member] \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	52 years
Electric Generation Equipment [Member] \| Maximum [Member] \| Exelon Generation Co L L C [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	58 years
Gas Distribution Equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 7,429	6,733
Gas Distribution Equipment \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	5 years
Gas Distribution Equipment \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	80 years
Common—electric and gas
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 2,335	2,170
Common—electric and gas \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	4 years
Common—electric and gas \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	75 years
Nuclear Fuel [Member] \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	1 year
Nuclear Fuel [Member] \| Minimum [Member] \| Exelon Generation Co L L C [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	1 year
Nuclear Fuel [Member] \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	8 years
Nuclear Fuel [Member] \| Maximum [Member] \| Exelon Generation Co L L C [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	8 years
Construction work in progress
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 3,698	3,107
Other Property Plant and Equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 755	722
Other Property Plant and Equipment \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	3 years
Other Property Plant and Equipment \| Minimum [Member] \| Exelon Generation Co L L C [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	1 year
Other Property Plant and Equipment \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	61 years
Other Property Plant and Equipment \| Maximum [Member] \| Exelon Generation Co L L C [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	10 years
Commonwealth Edison Co [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 32,094	30,229
Accumulated depreciation and amortization	6,099	5,672
Property, plant, and equipment, net	25,995	24,557
Commonwealth Edison Co [Member] \| Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 31,077	29,371
Commonwealth Edison Co [Member] \| Electric—transmission and distribution \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	5 years
Commonwealth Edison Co [Member] \| Electric—transmission and distribution \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	80 years
Commonwealth Edison Co [Member] \| Gas Distribution Equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 0	0
Commonwealth Edison Co [Member] \| Common—electric and gas
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	0	0
Commonwealth Edison Co [Member] \| Construction work in progress
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	918	799
Commonwealth Edison Co [Member] \| Other Property Plant and Equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 99	59
Commonwealth Edison Co [Member] \| Other Property Plant and Equipment \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	32 years
Commonwealth Edison Co [Member] \| Other Property Plant and Equipment \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	50 years
PECO Energy Co [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 15,081	14,024
Accumulated depreciation and amortization	3,964	3,843
Property, plant, and equipment, net	11,117	10,181
PECO Energy Co [Member] \| Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 10,076	9,462
PECO Energy Co [Member] \| Electric—transmission and distribution \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	5 years
PECO Energy Co [Member] \| Electric—transmission and distribution \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	70 years
PECO Energy Co [Member] \| Gas Distribution Equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 3,339	3,098
PECO Energy Co [Member] \| Gas Distribution Equipment \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	5 years
PECO Energy Co [Member] \| Gas Distribution Equipment \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	70 years
PECO Energy Co [Member] \| Common—electric and gas
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 1,005	956
PECO Energy Co [Member] \| Common—electric and gas \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	5 years
PECO Energy Co [Member] \| Common—electric and gas \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	55 years
PECO Energy Co [Member] \| Construction work in progress
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 620	474
PECO Energy Co [Member] \| Other Property Plant and Equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 41	34
Average Service Life (years)	50 years
Baltimore Gas and Electric Company [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 14,876	13,906
Accumulated depreciation and amortization	4,299	4,034
Property, plant, and equipment, net	10,577	9,872
Baltimore Gas and Electric Company [Member] \| Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 9,352	8,797
Baltimore Gas and Electric Company [Member] \| Electric—transmission and distribution \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	5 years
Baltimore Gas and Electric Company [Member] \| Electric—transmission and distribution \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	80 years
Baltimore Gas and Electric Company [Member] \| Gas Distribution Equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 3,712	3,315
Baltimore Gas and Electric Company [Member] \| Gas Distribution Equipment \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	5 years
Baltimore Gas and Electric Company [Member] \| Gas Distribution Equipment \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	80 years
Baltimore Gas and Electric Company [Member] \| Common—electric and gas
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 1,224	1,138
Baltimore Gas and Electric Company [Member] \| Common—electric and gas \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	4 years
Baltimore Gas and Electric Company [Member] \| Common—electric and gas \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	50 years
Baltimore Gas and Electric Company [Member] \| Construction work in progress
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 554	627
Baltimore Gas and Electric Company [Member] \| Other Property Plant and Equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 34	29
Baltimore Gas and Electric Company [Member] \| Other Property Plant and Equipment \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	20 years
Baltimore Gas and Electric Company [Member] \| Other Property Plant and Equipment \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	50 years
Pepco Holdings LLC [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 18,606	17,188
Accumulated depreciation and amortization	2,108	1,811
Property, plant, and equipment, net	16,498	15,377
Pepco Holdings LLC [Member] \| Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 16,062	15,137
Pepco Holdings LLC [Member] \| Electric—transmission and distribution \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	5 years
Pepco Holdings LLC [Member] \| Electric—transmission and distribution \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	75 years
Pepco Holdings LLC [Member] \| Gas Distribution Equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 646	591
Pepco Holdings LLC [Member] \| Gas Distribution Equipment \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	5 years
Pepco Holdings LLC [Member] \| Gas Distribution Equipment \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	75 years
Pepco Holdings LLC [Member] \| Common—electric and gas
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 201	178
Pepco Holdings LLC [Member] \| Common—electric and gas \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	5 years
Pepco Holdings LLC [Member] \| Common—electric and gas \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	75 years
Pepco Holdings LLC [Member] \| Construction work in progress
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 1,590	1,174
Pepco Holdings LLC [Member] \| Other Property Plant and Equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 107	108
Pepco Holdings LLC [Member] \| Other Property Plant and Equipment \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	3 years
Pepco Holdings LLC [Member] \| Other Property Plant and Equipment \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	50 years
Potomac Electric Power Company [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 11,979	11,153
Accumulated depreciation and amortization	3,875	3,697
Property, plant, and equipment, net	8,104	7,456
Potomac Electric Power Company [Member] \| Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 10,798	10,264
Potomac Electric Power Company [Member] \| Electric—transmission and distribution \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	5 years
Potomac Electric Power Company [Member] \| Electric—transmission and distribution \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	75 years
Potomac Electric Power Company [Member] \| Gas Distribution Equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 0	0
Potomac Electric Power Company [Member] \| Common—electric and gas
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	0	0
Potomac Electric Power Company [Member] \| Construction work in progress
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	1,118	824
Potomac Electric Power Company [Member] \| Other Property Plant and Equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 63	65
Potomac Electric Power Company [Member] \| Other Property Plant and Equipment \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	33 years
Potomac Electric Power Company [Member] \| Other Property Plant and Equipment \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	50 years
Delmarva Power & Light Company [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 6,195	5,847
Accumulated depreciation and amortization	1,635	1,533
Property, plant, and equipment, net	4,560	4,314
Delmarva Power & Light Company [Member] \| Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 4,957	4,730
Delmarva Power & Light Company [Member] \| Electric—transmission and distribution \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	5 years
Delmarva Power & Light Company [Member] \| Electric—transmission and distribution \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	70 years
Delmarva Power & Light Company [Member] \| Gas Distribution Equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 806	751
Delmarva Power & Light Company [Member] \| Gas Distribution Equipment \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	5 years
Delmarva Power & Light Company [Member] \| Gas Distribution Equipment \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	75 years
Delmarva Power & Light Company [Member] \| Common—electric and gas
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 180	180
Delmarva Power & Light Company [Member] \| Common—electric and gas \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	5 years
Delmarva Power & Light Company [Member] \| Common—electric and gas \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	75 years
Delmarva Power & Light Company [Member] \| Construction work in progress
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 229	163
Delmarva Power & Light Company [Member] \| Other Property Plant and Equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 23	23
Delmarva Power & Light Company [Member] \| Other Property Plant and Equipment \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	8 years
Delmarva Power & Light Company [Member] \| Other Property Plant and Equipment \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	50 years
Atlantic City Electric Company [Member]
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 5,149	4,778
Accumulated depreciation and amortization	1,420	1,303
Property, plant, and equipment, net	3,729	3,475
Atlantic City Electric Company [Member] \| Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 4,882	4,568
Atlantic City Electric Company [Member] \| Electric—transmission and distribution \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	5 years
Atlantic City Electric Company [Member] \| Electric—transmission and distribution \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	65 years
Atlantic City Electric Company [Member] \| Gas Distribution Equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 0	0
Atlantic City Electric Company [Member] \| Common—electric and gas
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	0	0
Atlantic City Electric Company [Member] \| Construction work in progress
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	242	182
Atlantic City Electric Company [Member] \| Other Property Plant and Equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 25	$ 28
Atlantic City Electric Company [Member] \| Other Property Plant and Equipment \| Minimum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	13 years
Atlantic City Electric Company [Member] \| Other Property Plant and Equipment \| Maximum [Member]
Property, Plant and Equipment [Line Items]
Average Service Life (years)	15 years

Property, Plant and Equipment_3

Property, Plant and Equipment - Annual Depreciation Provisions as Percentage of Average Service Life (Details)	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Annual depreciation rate	2.81%	2.79%	2.80%
Gas Distribution Equipment
Property, Plant and Equipment [Line Items]
Annual depreciation rate	2.13%	2.14%	2.04%
Common—electric and gas
Property, Plant and Equipment [Line Items]
Annual depreciation rate	7.31%	7.01%	7.37%
Commonwealth Edison Co [Member] \| Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Annual depreciation rate	2.94%	2.95%	2.99%
PECO Energy Co [Member] \| Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Annual depreciation rate	2.28%	2.31%	2.36%
PECO Energy Co [Member] \| Gas Distribution Equipment
Property, Plant and Equipment [Line Items]
Annual depreciation rate	1.84%	1.85%	1.89%
PECO Energy Co [Member] \| Common—electric and gas
Property, Plant and Equipment [Line Items]
Annual depreciation rate	6.34%	6.39%	6.06%
Baltimore Gas and Electric Company [Member] \| Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Annual depreciation rate	2.80%	2.69%	2.60%
Baltimore Gas and Electric Company [Member] \| Gas Distribution Equipment
Property, Plant and Equipment [Line Items]
Annual depreciation rate	2.54%	2.56%	2.30%
Baltimore Gas and Electric Company [Member] \| Common—electric and gas
Property, Plant and Equipment [Line Items]
Annual depreciation rate	7.88%	7.45%	8.30%
Pepco Holdings LLC [Member] \| Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Annual depreciation rate	2.87%	2.81%	2.77%
Pepco Holdings LLC [Member] \| Gas Distribution Equipment
Property, Plant and Equipment [Line Items]
Annual depreciation rate	1.47%	1.50%	1.55%
Pepco Holdings LLC [Member] \| Common—electric and gas
Property, Plant and Equipment [Line Items]
Annual depreciation rate	8.33%	7.36%	8.25%
Potomac Electric Power Company [Member] \| Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Annual depreciation rate	2.56%	2.53%	2.47%
Delmarva Power & Light Company [Member] \| Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Annual depreciation rate	2.86%	2.85%	2.86%
Delmarva Power & Light Company [Member] \| Gas Distribution Equipment
Property, Plant and Equipment [Line Items]
Annual depreciation rate	1.47%	1.50%	1.55%
Delmarva Power & Light Company [Member] \| Common—electric and gas
Property, Plant and Equipment [Line Items]
Annual depreciation rate	8.69%	6.72%	6.24%
Atlantic City Electric Company [Member] \| Electric—transmission and distribution
Property, Plant and Equipment [Line Items]
Annual depreciation rate	3.21%	3.08%	2.94%

Property, Plant and Equipment_4

Property, Plant and Equipment - Summary of Capitalized Interest and AFUDC (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Capitalized Interest And AFUDC [Line Items]
Interest Costs Capitalized	$ 0	$ 0	$ 0
Allowance for Funds Used During Construction, Capitalized Interest	189	150	132
Commonwealth Edison Co [Member]
Capitalized Interest And AFUDC [Line Items]
Interest Costs Capitalized	0	0	0
Allowance for Funds Used During Construction, Capitalized Interest	47	42	32
PECO Energy Co [Member]
Capitalized Interest And AFUDC [Line Items]
Interest Costs Capitalized	0	0	0
Allowance for Funds Used During Construction, Capitalized Interest	34	23	17
Baltimore Gas and Electric Company [Member]
Capitalized Interest And AFUDC [Line Items]
Interest Costs Capitalized	0	0	0
Allowance for Funds Used During Construction, Capitalized Interest	36	30	29
Pepco Holdings LLC [Member]
Capitalized Interest And AFUDC [Line Items]
Interest Costs Capitalized	0	0	0
Allowance for Funds Used During Construction, Capitalized Interest	72	55	54
Potomac Electric Power Company [Member]
Capitalized Interest And AFUDC [Line Items]
Interest Costs Capitalized	0	0	0
Allowance for Funds Used During Construction, Capitalized Interest	59	42	39
Delmarva Power & Light Company [Member]
Capitalized Interest And AFUDC [Line Items]
Interest Costs Capitalized	0	0	0
Allowance for Funds Used During Construction, Capitalized Interest	8	6	6
Atlantic City Electric Company [Member]
Capitalized Interest And AFUDC [Line Items]
Interest Costs Capitalized	0	0	0
Allowance for Funds Used During Construction, Capitalized Interest	$ 5	$ 7	$ 9

Jointly Owned Electric Utilit_3

Jointly Owned Electric Utility Plant - Ownership Interests in Jointly Owned Electric Plants and Transmission Facilities (Details) $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($) V mi	Dec. 31, 2020 USD ($)
Delaware And New Jersey [Member]
Schedule Of Jointly Owned Utility Plant Net Ownership [Abstract]
Miles of transmission voltage lines \| mi	151.3
Transmission line capacity	500
Delaware River Crossing [Member]
Schedule Of Jointly Owned Utility Plant Net Ownership [Abstract]
Miles of transmission voltage lines \| mi	2.5
Transmission line capacity	500
New Freedom Switching [Member]
Schedule Of Jointly Owned Utility Plant Net Ownership [Abstract]
Transmission line capacity	500
Electric Transmission [Member] \| Delaware And New Jersey [Member]
Schedule Of Jointly Owned Utility Plant Net Ownership [Abstract]
Plant \| $	$ 103	$ 103
Accumulated depreciation \| $	$ 55	$ 54
PECO Energy Co [Member] \| Delaware And New Jersey [Member]
Schedule Of Jointly Owned Utility Plant Net Ownership [Abstract]
Ownership interest	42.55%
PECO Energy Co [Member] \| Delaware River Crossing [Member]
Schedule Of Jointly Owned Utility Plant Net Ownership [Abstract]
Ownership interest	42.55%
Delmarva Power & Light Company [Member] \| Delaware And New Jersey [Member]
Schedule Of Jointly Owned Utility Plant Net Ownership [Abstract]
Ownership interest	1%
Delmarva Power & Light Company [Member] \| Delaware River Crossing [Member]
Schedule Of Jointly Owned Utility Plant Net Ownership [Abstract]
Ownership interest	7.45%
Atlantic City Electric Company [Member] \| Delaware And New Jersey [Member]
Schedule Of Jointly Owned Utility Plant Net Ownership [Abstract]
Ownership interest	13.90%
Atlantic City Electric Company [Member] \| Delaware River Crossing [Member]
Schedule Of Jointly Owned Utility Plant Net Ownership [Abstract]
Ownership interest	7.45%
Atlantic City Electric Company [Member] \| New Freedom Switching [Member]
Schedule Of Jointly Owned Utility Plant Net Ownership [Abstract]
Ownership interest	21.78%

Asset Retirement Obligations -

Asset Retirement Obligations - Nuclear Decommissioning Asset Retirement Obligation Rollforward (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Accretion expense	$ (514)	$ (500)	$ (491)

Asset Retirement Obligations _2

Asset Retirement Obligations - Non-Nuclear Asset Retirement Obligations Rollforward (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Accretion expense	$ 514	$ 500	$ 491
Commonwealth Edison Co [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Accretion expense	0	0	0
PECO Energy Co [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Accretion expense	0	0	0
Baltimore Gas and Electric Company [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Accretion expense	0	0	0
Pepco Holdings LLC [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Accretion expense	0	0	0
Potomac Electric Power Company [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Accretion expense	0	0	0
Delmarva Power & Light Company [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Accretion expense	0	0	0
Atlantic City Electric Company [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Accretion expense	0	0	0
Nonnuclear Decommissioning Asset Retirement Obligation [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
ARO beginning balance	249	244
Asset Retirement Obligation, Revision of Estimate	26	5
Accretion expense	7	5
Payments	(8)	(5)
ARO ending balance	274	249	244
Nonnuclear Decommissioning Asset Retirement Obligation [Member] \| Commonwealth Edison Co [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
ARO beginning balance	129	129
Asset Retirement Obligation, Revision of Estimate	15	0
Accretion expense	4	1
Payments	(2)	(1)
ARO ending balance	146	129	129
Nonnuclear Decommissioning Asset Retirement Obligation [Member] \| PECO Energy Co [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
ARO beginning balance	29	28
Asset Retirement Obligation, Revision of Estimate	0	2
Accretion expense	1	1
Payments	(1)	(2)
ARO ending balance	29	29	28
Nonnuclear Decommissioning Asset Retirement Obligation [Member] \| Baltimore Gas and Electric Company [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
ARO beginning balance	23	23
Asset Retirement Obligation, Revision of Estimate	2	1
Accretion expense	1	1
Payments	0	(2)
ARO ending balance	26	23	23
Nonnuclear Decommissioning Asset Retirement Obligation [Member] \| Pepco Holdings LLC [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
ARO beginning balance	59	57
Asset Retirement Obligation, Revision of Estimate	10	1
Accretion expense	1	1
Payments	0	0
ARO ending balance	70	59	57
Nonnuclear Decommissioning Asset Retirement Obligation [Member] \| Potomac Electric Power Company [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
ARO beginning balance	39	41
Asset Retirement Obligation, Revision of Estimate	5	(3)
Accretion expense	1	1
Payments	0	0
ARO ending balance	45	39	41
Nonnuclear Decommissioning Asset Retirement Obligation [Member] \| Delmarva Power & Light Company [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
ARO beginning balance	14	12
Asset Retirement Obligation, Revision of Estimate	2	2
Accretion expense	0	0
Payments	0	0
ARO ending balance	16	14	12
Nonnuclear Decommissioning Asset Retirement Obligation [Member] \| Atlantic City Electric Company [Member]
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
ARO beginning balance	6	4
Asset Retirement Obligation, Revision of Estimate	3	2
Accretion expense	0	0
Payments	0	0
ARO ending balance	$ 9	$ 6	$ 4

Lessee - Narrative (Details)

Lessee - Narrative (Details)	12 Months Ended
Lessee - Narrative (Details)	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Operating Lease, Weighted Average Remaining Lease Term	8 years 10 months 24 days	9 years	8 years 8 months 12 days
Operating Lease, Weighted Average Discount Rate, Percent	4%	4%	3.90%
Real Estate [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Description	●
Vehicles [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Description	●
Minimum [Member]
Lessee, Lease, Description [Line Items]
Remaining lease terms, Lessee, Operating Lease	1 year
Options to extend the term, Lessee, Operating Lease	3 years
Option to terminate within, Lessee, Operating Lease	1 years
Maximum [Member]
Lessee, Lease, Description [Line Items]
Remaining lease terms, Lessee, Operating Lease	84 years
Options to extend the term, Lessee, Operating Lease	30 years
Option to terminate within, Lessee, Operating Lease	11 years
Commonwealth Edison Co [Member]
Lessee, Lease, Description [Line Items]
Operating Lease, Weighted Average Remaining Lease Term	3 years 3 months 18 days	3 years 9 months 18 days	4 years 7 months 6 days
Operating Lease, Weighted Average Discount Rate, Percent	2.80%	3%	3%
Commonwealth Edison Co [Member] \| Real Estate [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Description	●
Commonwealth Edison Co [Member] \| Vehicles [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Description	●
Commonwealth Edison Co [Member] \| Minimum [Member]
Lessee, Lease, Description [Line Items]
Remaining lease terms, Lessee, Operating Lease	1 year
Options to extend the term, Lessee, Operating Lease	5 years
Option to terminate within, Lessee, Operating Lease	1 years
Commonwealth Edison Co [Member] \| Maximum [Member]
Lessee, Lease, Description [Line Items]
Remaining lease terms, Lessee, Operating Lease	3 years
Options to extend the term, Lessee, Operating Lease	5 years
Option to terminate within, Lessee, Operating Lease	1 years
PECO Energy Co [Member]
Lessee, Lease, Description [Line Items]
Operating Lease, Weighted Average Remaining Lease Term	6 years 1 month 6 days	4 years 2 months 12 days	4 years 4 months 24 days
Operating Lease, Weighted Average Discount Rate, Percent	2.20%	2.90%	3.20%
PECO Energy Co [Member] \| Real Estate [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Description	●
PECO Energy Co [Member] \| Vehicles [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Description	●
PECO Energy Co [Member] \| Minimum [Member]
Lessee, Lease, Description [Line Items]
Remaining lease terms, Lessee, Operating Lease	1 year
PECO Energy Co [Member] \| Maximum [Member]
Lessee, Lease, Description [Line Items]
Remaining lease terms, Lessee, Operating Lease	12 years
Baltimore Gas and Electric Company [Member]
Lessee, Lease, Description [Line Items]
Operating Lease, Weighted Average Remaining Lease Term	13 years 8 months 12 days	8 years 3 months 18 days	5 years 4 months 24 days
Operating Lease, Weighted Average Discount Rate, Percent	4%	3.80%	3.60%
Baltimore Gas and Electric Company [Member] \| Real Estate [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Description	●
Baltimore Gas and Electric Company [Member] \| Vehicles [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Description	●
Baltimore Gas and Electric Company [Member] \| Minimum [Member]
Lessee, Lease, Description [Line Items]
Remaining lease terms, Lessee, Operating Lease	1 year
Option to terminate within, Lessee, Operating Lease	1 years
Baltimore Gas and Electric Company [Member] \| Maximum [Member]
Lessee, Lease, Description [Line Items]
Remaining lease terms, Lessee, Operating Lease	84 years
Option to terminate within, Lessee, Operating Lease	1 years
Pepco Holdings LLC [Member]
Lessee, Lease, Description [Line Items]
Operating Lease, Weighted Average Remaining Lease Term	7 years 6 months	8 years 2 months 12 days	9 years
Finance Lease, Weighted Average Remaining Lease Term	6 years 1 month 6 days	6 years 6 months
Operating Lease, Weighted Average Discount Rate, Percent	4.20%	4.20%	4.20%
Finance Lease, Weighted Average Discount Rate, Percent	2.20%	2.50%
Pepco Holdings LLC [Member] \| Real Estate [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Description	●
Pepco Holdings LLC [Member] \| Vehicles [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Description	●
Pepco Holdings LLC [Member] \| Minimum [Member]
Lessee, Lease, Description [Line Items]
Remaining lease terms, Lessee, Operating Lease	1 year
Options to extend the term, Lessee, Operating Lease	3 years
Pepco Holdings LLC [Member] \| Maximum [Member]
Lessee, Lease, Description [Line Items]
Remaining lease terms, Lessee, Operating Lease	10 years
Options to extend the term, Lessee, Operating Lease	30 years
Potomac Electric Power Company [Member]
Lessee, Lease, Description [Line Items]
Operating Lease, Weighted Average Remaining Lease Term	8 years 7 months 6 days	9 years 1 month 6 days	9 years 9 months 18 days
Finance Lease, Weighted Average Remaining Lease Term	5 years 10 months 24 days	6 years 3 months 18 days
Operating Lease, Weighted Average Discount Rate, Percent	4%	4%	4%
Finance Lease, Weighted Average Discount Rate, Percent	2.30%	2.60%
Potomac Electric Power Company [Member] \| Real Estate [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Description	●
Potomac Electric Power Company [Member] \| Vehicles [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Description	●
Potomac Electric Power Company [Member] \| Minimum [Member]
Lessee, Lease, Description [Line Items]
Remaining lease terms, Lessee, Operating Lease	1 year
Options to extend the term, Lessee, Operating Lease	5 years
Potomac Electric Power Company [Member] \| Maximum [Member]
Lessee, Lease, Description [Line Items]
Remaining lease terms, Lessee, Operating Lease	10 years
Options to extend the term, Lessee, Operating Lease	5 years
Delmarva Power & Light Company [Member]
Lessee, Lease, Description [Line Items]
Operating Lease, Weighted Average Remaining Lease Term	8 years 6 months	9 years 1 month 6 days	9 years 8 months 12 days
Finance Lease, Weighted Average Remaining Lease Term	6 years 1 month 6 days	6 years 6 months
Operating Lease, Weighted Average Discount Rate, Percent	4%	4%	4%
Finance Lease, Weighted Average Discount Rate, Percent	2.10%	2.40%
Delmarva Power & Light Company [Member] \| Real Estate [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Description	●
Delmarva Power & Light Company [Member] \| Vehicles [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Description	●
Delmarva Power & Light Company [Member] \| Minimum [Member]
Lessee, Lease, Description [Line Items]
Remaining lease terms, Lessee, Operating Lease	1 year
Options to extend the term, Lessee, Operating Lease	3 years
Delmarva Power & Light Company [Member] \| Maximum [Member]
Lessee, Lease, Description [Line Items]
Remaining lease terms, Lessee, Operating Lease	10 years
Options to extend the term, Lessee, Operating Lease	30 years
Atlantic City Electric Company [Member]
Lessee, Lease, Description [Line Items]
Operating Lease, Weighted Average Remaining Lease Term	3 years 6 months	4 years	4 years 8 months 12 days
Finance Lease, Weighted Average Remaining Lease Term	6 years 3 months 18 days	6 years 6 months
Operating Lease, Weighted Average Discount Rate, Percent	3.40%	3.50%	3.60%
Finance Lease, Weighted Average Discount Rate, Percent	2.10%	2.40%
Atlantic City Electric Company [Member] \| Real Estate [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Description	●
Atlantic City Electric Company [Member] \| Vehicles [Member]
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Description	●
Atlantic City Electric Company [Member] \| Minimum [Member]
Lessee, Lease, Description [Line Items]
Remaining lease terms, Lessee, Operating Lease	1 year
Options to extend the term, Lessee, Operating Lease	5 years
Atlantic City Electric Company [Member] \| Maximum [Member]
Lessee, Lease, Description [Line Items]
Remaining lease terms, Lessee, Operating Lease	7 years
Options to extend the term, Lessee, Operating Lease	5 years

Lessee - Components of Lease Co

Lessee - Components of Lease Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Schedule of Components of Lease Cost [Line Items]
Operating Lease, Cost	$ 84	$ 98	$ 98
Variable Lease, Cost	7	7	18
Total Lease Cost	91	105	116
Sublease Income	4	4	7
Commonwealth Edison Co [Member]
Schedule of Components of Lease Cost [Line Items]
Operating Lease, Cost	3	3	3
Variable Lease, Cost	1	1	2
Total Lease Cost	4	4	5
PECO Energy Co [Member]
Schedule of Components of Lease Cost [Line Items]
Operating Lease, Cost	0	1	1
Variable Lease, Cost	0	0	0
Total Lease Cost	0	1	1
Baltimore Gas and Electric Company [Member]
Schedule of Components of Lease Cost [Line Items]
Operating Lease, Cost	30	33	33
Variable Lease, Cost	1	1	2
Total Lease Cost	31	34	35
Pepco Holdings LLC [Member]
Schedule of Components of Lease Cost [Line Items]
Operating Lease, Cost	43	46	48
Variable Lease, Cost	1	2	6
Total Lease Cost	44	48	54
Finance Lease, Cost	13	9
Potomac Electric Power Company [Member]
Schedule of Components of Lease Cost [Line Items]
Operating Lease, Cost	10	11	12
Variable Lease, Cost	0	1	2
Total Lease Cost	10	12	14
Finance Lease, Cost	5	3
Delmarva Power & Light Company [Member]
Schedule of Components of Lease Cost [Line Items]
Operating Lease, Cost	12	13	14
Variable Lease, Cost	0	1	2
Total Lease Cost	12	14	16
Finance Lease, Cost	5	4
Atlantic City Electric Company [Member]
Schedule of Components of Lease Cost [Line Items]
Operating Lease, Cost	6	6	7
Variable Lease, Cost	0	0	1
Total Lease Cost	6	6	$ 8
Finance Lease, Cost	$ 3	$ 2

Lessee - Supplemental Balance S

Lessee - Supplemental Balance Sheet Information (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	$ 766	$ 784
Other deferred credits and other liabilities	1,573	1,642
Operating Lease, Liability	315	395
Other Noncurrent Assets [Member]
Supplemental Balance Sheet Information [Line Items]
Operating Lease, Right-of-Use Asset	(271)	338
Other Current Liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	52	81
Other deferred credits and other liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other deferred credits and other liabilities	263	314
Commonwealth Edison Co [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	133	143
Other deferred credits and other liabilities	592	595
Operating Lease, Liability	5	8
Commonwealth Edison Co [Member] \| Other Noncurrent Assets [Member]
Supplemental Balance Sheet Information [Line Items]
Operating Lease, Right-of-Use Asset	5	7
Commonwealth Edison Co [Member] \| Other Current Liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	2	3
Commonwealth Edison Co [Member] \| Other deferred credits and other liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other deferred credits and other liabilities	3	5
PECO Energy Co [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	35	30
Other deferred credits and other liabilities	83	93
Operating Lease, Liability	1	1
PECO Energy Co [Member] \| Other Noncurrent Assets [Member]
Supplemental Balance Sheet Information [Line Items]
Operating Lease, Right-of-Use Asset	1	1
PECO Energy Co [Member] \| Other Current Liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	0	0
PECO Energy Co [Member] \| Other deferred credits and other liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other deferred credits and other liabilities	1	1
Baltimore Gas and Electric Company [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	48	91
Other deferred credits and other liabilities	98	104
Operating Lease, Liability	19	64
Baltimore Gas and Electric Company [Member] \| Other Noncurrent Assets [Member]
Supplemental Balance Sheet Information [Line Items]
Operating Lease, Right-of-Use Asset	16	46
Baltimore Gas and Electric Company [Member] \| Other Current Liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	15	45
Baltimore Gas and Electric Company [Member] \| Other deferred credits and other liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other deferred credits and other liabilities	4	19
Pepco Holdings LLC [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	171	141
Other deferred credits and other liabilities	570	622
Operating Lease, Liability	226	255
Finance Lease, Liability, Current	10	7
Finance Lease, Liability, Noncurrent	64	43
Finance lease, liability	74	50
Pepco Holdings LLC [Member] \| Other Noncurrent Assets [Member]
Supplemental Balance Sheet Information [Line Items]
Operating Lease, Right-of-Use Asset	209	241
Pepco Holdings LLC [Member] \| Other Current Liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	31	31
Pepco Holdings LLC [Member] \| Other deferred credits and other liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other deferred credits and other liabilities	195	224
Pepco Holdings LLC [Member] \| Property, Plant and Equipment
Supplemental Balance Sheet Information [Line Items]
Finance Lease, Right-of-Use Asset, after Accumulated Amortization	73	50
Potomac Electric Power Company [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	55	61
Other deferred credits and other liabilities	314	340
Operating Lease, Liability	46	52
Finance Lease, Liability, Current	3	2
Finance Lease, Liability, Noncurrent	23	15
Finance lease, liability	26	17
Potomac Electric Power Company [Member] \| Other Noncurrent Assets [Member]
Supplemental Balance Sheet Information [Line Items]
Operating Lease, Right-of-Use Asset	43	49
Potomac Electric Power Company [Member] \| Other Current Liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	6	6
Potomac Electric Power Company [Member] \| Other deferred credits and other liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other deferred credits and other liabilities	40	46
Potomac Electric Power Company [Member] \| Property, Plant and Equipment
Supplemental Balance Sheet Information [Line Items]
Finance Lease, Right-of-Use Asset, after Accumulated Amortization	25	17
Delmarva Power & Light Company [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	59	20
Other deferred credits and other liabilities	89	97
Operating Lease, Liability	57	65
Finance Lease, Liability, Current	4	3
Finance Lease, Liability, Noncurrent	25	17
Finance lease, liability	29	20
Delmarva Power & Light Company [Member] \| Other Noncurrent Assets [Member]
Supplemental Balance Sheet Information [Line Items]
Operating Lease, Right-of-Use Asset	46	54
Delmarva Power & Light Company [Member] \| Other Current Liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	8	9
Delmarva Power & Light Company [Member] \| Other deferred credits and other liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other deferred credits and other liabilities	49	56
Delmarva Power & Light Company [Member] \| Property, Plant and Equipment
Supplemental Balance Sheet Information [Line Items]
Finance Lease, Right-of-Use Asset, after Accumulated Amortization	29	20
Atlantic City Electric Company [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	12	11
Other deferred credits and other liabilities	49	48
Operating Lease, Liability	12	15
Finance Lease, Liability, Current	3	2
Finance Lease, Liability, Noncurrent	16	11
Finance lease, liability	19	13
Atlantic City Electric Company [Member] \| Other Noncurrent Assets [Member]
Supplemental Balance Sheet Information [Line Items]
Operating Lease, Right-of-Use Asset	11	15
Atlantic City Electric Company [Member] \| Other Current Liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other current liabilities	3	4
Atlantic City Electric Company [Member] \| Other deferred credits and other liabilities [Member]
Supplemental Balance Sheet Information [Line Items]
Other deferred credits and other liabilities	9	11
Atlantic City Electric Company [Member] \| Property, Plant and Equipment
Supplemental Balance Sheet Information [Line Items]
Finance Lease, Right-of-Use Asset, after Accumulated Amortization	$ 19	$ 13

Lessee - Lessee Future Minimum

Lessee - Lessee Future Minimum Operating Lease Maturity Payments (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Schedule of Lessee, Operating Lease, Liability, Maturity [Line Items]
2022	$ 64
2023	45
2024	43
2025	41
2026	35
Remaining years	162
Lessee, Operating Lease, Liability, to be Paid	390
Interest	75
Operating Lease, Liability	315	$ 395
Commonwealth Edison Co [Member]
Schedule of Lessee, Operating Lease, Liability, Maturity [Line Items]
2022	2
2023	1
2024	1
2025	1
2026	0
Remaining years	0
Lessee, Operating Lease, Liability, to be Paid	5
Interest	0
Operating Lease, Liability	5	8
PECO Energy Co [Member]
Schedule of Lessee, Operating Lease, Liability, Maturity [Line Items]
2022	0
2023	0
2024	0
2025	0
2026	0
Remaining years	1
Lessee, Operating Lease, Liability, to be Paid	1
Interest	0
Operating Lease, Liability	1	1
Baltimore Gas and Electric Company [Member]
Schedule of Lessee, Operating Lease, Liability, Maturity [Line Items]
2022	16
2023	1
2024	0
2025	0
2026	0
Remaining years	18
Lessee, Operating Lease, Liability, to be Paid	35
Interest	16
Operating Lease, Liability	19	64
Pepco Holdings LLC [Member]
Schedule of Lessee, Operating Lease, Liability, Maturity [Line Items]
2022	38
2023	37
2024	36
2025	34
2026	29
Remaining years	94
Lessee, Operating Lease, Liability, to be Paid	268
Interest	42
Operating Lease, Liability	226	255
Schedule of Lessee, Finance Lease, Liability, Maturity [Line Items]
2022	12
2023	12
2024	13
2025	12
2026	12
Remaining years	18
Finance Lease, Liability, to be Paid	79
Interest	5
Finance lease, liability	74	50
Potomac Electric Power Company [Member]
Schedule of Lessee, Operating Lease, Liability, Maturity [Line Items]
2022	8
2023	7
2024	7
2025	6
2026	5
Remaining years	22
Lessee, Operating Lease, Liability, to be Paid	55
Interest	9
Operating Lease, Liability	46	52
Schedule of Lessee, Finance Lease, Liability, Maturity [Line Items]
2022	4
2023	4
2024	5
2025	4
2026	4
Remaining years	6
Finance Lease, Liability, to be Paid	27
Interest	1
Finance lease, liability	26	17
Delmarva Power & Light Company [Member]
Schedule of Lessee, Operating Lease, Liability, Maturity [Line Items]
2022	10
2023	10
2024	8
2025	7
2026	5
Remaining years	30
Lessee, Operating Lease, Liability, to be Paid	70
Interest	13
Operating Lease, Liability	57	65
Schedule of Lessee, Finance Lease, Liability, Maturity [Line Items]
2022	5
2023	5
2024	5
2025	5
2026	5
Remaining years	7
Finance Lease, Liability, to be Paid	32
Interest	3
Finance lease, liability	29	20
Atlantic City Electric Company [Member]
Schedule of Lessee, Operating Lease, Liability, Maturity [Line Items]
2022	4
2023	3
2024	3
2025	2
2026	1
Remaining years	0
Lessee, Operating Lease, Liability, to be Paid	13
Interest	1
Operating Lease, Liability	12	15
Schedule of Lessee, Finance Lease, Liability, Maturity [Line Items]
2022	3
2023	3
2024	3
2025	3
2026	3
Remaining years	5
Finance Lease, Liability, to be Paid	20
Interest	1
Finance lease, liability	$ 19	$ 13

Lessee - Supplemental Cash Flow

Lessee - Supplemental Cash Flow Information Related to Leases (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Supplemental Cash Flow Information [Line Items]
Operating cash flows from operating leases	$ 93	$ 67	$ 81
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	1	(2)	38
Commonwealth Edison Co [Member]
Supplemental Cash Flow Information [Line Items]
Operating cash flows from operating leases	3	3	3
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	0	0	6
PECO Energy Co [Member]
Supplemental Cash Flow Information [Line Items]
Operating cash flows from operating leases	0	1	0
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	0	1	0
Baltimore Gas and Electric Company [Member]
Supplemental Cash Flow Information [Line Items]
Operating cash flows from operating leases	46	20	33
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	(1)	0	2
Pepco Holdings LLC [Member]
Supplemental Cash Flow Information [Line Items]
Operating cash flows from operating leases	39	39	37
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	1	(1)	(3)
Finance Lease, Principal Payments	10	6
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability	32	29
Potomac Electric Power Company [Member]
Supplemental Cash Flow Information [Line Items]
Operating cash flows from operating leases	8	8	9
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	0	0	(1)
Finance Lease, Principal Payments	3	2
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability	12	8
Delmarva Power & Light Company [Member]
Supplemental Cash Flow Information [Line Items]
Operating cash flows from operating leases	9	9	6
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	1	(1)	(2)
Finance Lease, Principal Payments	4	3
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability	12	14
Atlantic City Electric Company [Member]
Supplemental Cash Flow Information [Line Items]
Operating cash flows from operating leases	4	4	5
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	0	0	$ (1)
Finance Lease, Principal Payments	3	1
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability	$ 8	$ 7

Lessor - Narrative (Details)

Lessor - Narrative (Details)	12 Months Ended
Lessor - Narrative (Details)	Dec. 31, 2021
Minimum [Member]
Lessor, Lease, Description [Line Items]
Remaining lease terms, Lessor, Operating Lease	1 year
Options to extend the term, Lessor, Operating Lease	1 years
Maximum [Member]
Lessor, Lease, Description [Line Items]
Remaining lease terms, Lessor, Operating Lease	81 years
Options to extend the term, Lessor, Operating Lease	79 years
Real Estate [Member]
Lessor, Lease, Description [Line Items]
Lessor, Operating Lease, Description	●
Commonwealth Edison Co [Member] \| Minimum [Member]
Lessor, Lease, Description [Line Items]
Remaining lease terms, Lessor, Operating Lease	1 year
Options to extend the term, Lessor, Operating Lease	5 years
Commonwealth Edison Co [Member] \| Maximum [Member]
Lessor, Lease, Description [Line Items]
Remaining lease terms, Lessor, Operating Lease	15 years
Options to extend the term, Lessor, Operating Lease	79 years
Commonwealth Edison Co [Member] \| Real Estate [Member]
Lessor, Lease, Description [Line Items]
Lessor, Operating Lease, Description	●
PECO Energy Co [Member] \| Minimum [Member]
Lessor, Lease, Description [Line Items]
Remaining lease terms, Lessor, Operating Lease	1 year
Options to extend the term, Lessor, Operating Lease	5 years
PECO Energy Co [Member] \| Maximum [Member]
Lessor, Lease, Description [Line Items]
Remaining lease terms, Lessor, Operating Lease	81 years
Options to extend the term, Lessor, Operating Lease	50 years
PECO Energy Co [Member] \| Real Estate [Member]
Lessor, Lease, Description [Line Items]
Lessor, Operating Lease, Description	●
Baltimore Gas and Electric Company [Member] \| Minimum [Member]
Lessor, Lease, Description [Line Items]
Remaining lease terms, Lessor, Operating Lease	21 years
Baltimore Gas and Electric Company [Member] \| Maximum [Member]
Lessor, Lease, Description [Line Items]
Remaining lease terms, Lessor, Operating Lease	21 years
Baltimore Gas and Electric Company [Member] \| Real Estate [Member]
Lessor, Lease, Description [Line Items]
Lessor, Operating Lease, Description	●
Pepco Holdings LLC [Member] \| Minimum [Member]
Lessor, Lease, Description [Line Items]
Remaining lease terms, Lessor, Operating Lease	1 year
Options to extend the term, Lessor, Operating Lease	5 years
Pepco Holdings LLC [Member] \| Maximum [Member]
Lessor, Lease, Description [Line Items]
Remaining lease terms, Lessor, Operating Lease	11 years
Options to extend the term, Lessor, Operating Lease	5 years
Pepco Holdings LLC [Member] \| Real Estate [Member]
Lessor, Lease, Description [Line Items]
Lessor, Operating Lease, Description	●
Potomac Electric Power Company [Member] \| Minimum [Member]
Lessor, Lease, Description [Line Items]
Remaining lease terms, Lessor, Operating Lease	1 year
Potomac Electric Power Company [Member] \| Maximum [Member]
Lessor, Lease, Description [Line Items]
Remaining lease terms, Lessor, Operating Lease	4 years
Potomac Electric Power Company [Member] \| Real Estate [Member]
Lessor, Lease, Description [Line Items]
Lessor, Operating Lease, Description	●
Delmarva Power & Light Company [Member] \| Minimum [Member]
Lessor, Lease, Description [Line Items]
Remaining lease terms, Lessor, Operating Lease	10 years
Delmarva Power & Light Company [Member] \| Maximum [Member]
Lessor, Lease, Description [Line Items]
Remaining lease terms, Lessor, Operating Lease	11 years
Delmarva Power & Light Company [Member] \| Real Estate [Member]
Lessor, Lease, Description [Line Items]
Lessor, Operating Lease, Description	●
Atlantic City Electric Company [Member] \| Real Estate [Member]
Lessor, Lease, Description [Line Items]
Lessor, Operating Lease, Description

Lessor - Components of Operatin

Lessor - Components of Operating Lease Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Schedule of Operating Lease, Lease Income [Line Items]
Operating Lease Income	$ 5	$ 5	$ 7
Variable Lease Income	1	1	3
Commonwealth Edison Co [Member]
Schedule of Operating Lease, Lease Income [Line Items]
Operating Lease Income	0	0	0
Variable Lease Income	0	0	0
PECO Energy Co [Member]
Schedule of Operating Lease, Lease Income [Line Items]
Operating Lease Income	0	0	0
Variable Lease Income	0	0	0
Baltimore Gas and Electric Company [Member]
Schedule of Operating Lease, Lease Income [Line Items]
Operating Lease Income	0	0	0
Variable Lease Income	0	0	0
Pepco Holdings LLC [Member]
Schedule of Operating Lease, Lease Income [Line Items]
Operating Lease Income	4	3	5
Variable Lease Income	1	1	3
Potomac Electric Power Company [Member]
Schedule of Operating Lease, Lease Income [Line Items]
Operating Lease Income	0	0	0
Variable Lease Income	0	0	0
Delmarva Power & Light Company [Member]
Schedule of Operating Lease, Lease Income [Line Items]
Operating Lease Income	3	3	4
Variable Lease Income	1	1	3
Atlantic City Electric Company [Member]
Schedule of Operating Lease, Lease Income [Line Items]
Operating Lease Income	0	0	0
Variable Lease Income	$ 0	$ 0	$ 0

Lessor - Operating Lease, Payme

Lessor - Operating Lease, Payments, Fiscal Year Maturity (Details) $ in Millions	Dec. 31, 2021 USD ($)
Schedule of Lessor, Operating Lease, Payments to be Received, Maturity [Line Items]
2022	$ 5
2023	4
2024	4
2025	4
2026	4
Remaining years	32
Total Lessor, Operating Lease, Payments to be Received	53
Commonwealth Edison Co [Member]
Schedule of Lessor, Operating Lease, Payments to be Received, Maturity [Line Items]
2022	0
2023	0
2024	0
2025	0
2026	0
Remaining years	1
Total Lessor, Operating Lease, Payments to be Received	1
PECO Energy Co [Member]
Schedule of Lessor, Operating Lease, Payments to be Received, Maturity [Line Items]
2022	0
2023	0
2024	0
2025	0
2026	0
Remaining years	4
Total Lessor, Operating Lease, Payments to be Received	4
Baltimore Gas and Electric Company [Member]
Schedule of Lessor, Operating Lease, Payments to be Received, Maturity [Line Items]
2022	0
2023	0
2024	0
2025	0
2026	0
Remaining years	1
Total Lessor, Operating Lease, Payments to be Received	1
Pepco Holdings LLC [Member]
Schedule of Lessor, Operating Lease, Payments to be Received, Maturity [Line Items]
2022	4
2023	3
2024	4
2025	4
2026	4
Remaining years	26
Total Lessor, Operating Lease, Payments to be Received	45
Potomac Electric Power Company [Member]
Schedule of Lessor, Operating Lease, Payments to be Received, Maturity [Line Items]
2022	0
2023	0
2024	0
2025	0
2026	0
Remaining years	0
Total Lessor, Operating Lease, Payments to be Received	0
Delmarva Power & Light Company [Member]
Schedule of Lessor, Operating Lease, Payments to be Received, Maturity [Line Items]
2022	3
2023	3
2024	4
2025	4
2026	4
Remaining years	26
Total Lessor, Operating Lease, Payments to be Received	44
Atlantic City Electric Company [Member]
Schedule of Lessor, Operating Lease, Payments to be Received, Maturity [Line Items]
2022	0
2023	0
2024	0
2025	0
2026	0
Remaining years	0
Total Lessor, Operating Lease, Payments to be Received	$ 0

Asset Impairments - Narrative (

Asset Impairments - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Impairment of Long-Lived Asset Held-for-use	$ 552	$ 591	$ 201
Net income (loss) attributable to noncontrolling interests	123	(9)	92
Deferred Income Taxes and Tax Credits	$ 18	$ 309	$ 681

Intangible Assets - Narrative (

Intangible Assets - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Mar. 24, 2016	Oct. 20, 2000
Goodwill [Line Items]
Goodwill, Additions	$ 0	$ 0
Goodwill Impairment Loss	0	0
Goodwill	6,630	6,630
Commonwealth Edison Co [Member]
Goodwill [Line Items]
Goodwill	2,625	2,625		$ 2,600
Pepco Holdings LLC [Member]
Goodwill [Line Items]
Goodwill	$ 4,005	$ 4,005	$ 4,000
Potomac Electric Power Company [Member]
Goodwill [Line Items]
Goodwill			2,100
Delmarva Power & Light Company [Member]
Goodwill [Line Items]
Goodwill			1,400
Atlantic City Electric Company [Member]
Goodwill [Line Items]
Goodwill			$ 500

Intangible Assets - Schedule of

Intangible Assets - Schedule of Goodwill (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Mar. 24, 2016	Oct. 20, 2000
Goodwill [Line Items]
Goodwill, Gross	$ 8,613	$ 8,613
Accumulated Impairment Loss	1,983	1,983
Carrying amount	6,630	6,630
Commonwealth Edison Co [Member]
Goodwill [Line Items]
Goodwill, Gross	4,608	4,608
Accumulated Impairment Loss	1,983	1,983
Carrying amount	2,625	2,625		$ 2,600
Pepco Holdings LLC [Member]
Goodwill [Line Items]
Goodwill, Gross	4,005	4,005
Accumulated Impairment Loss	0	0
Carrying amount	$ 4,005	$ 4,005	$ 4,000

Intangible Assets - Schedule _2

Intangible Assets - Schedule of Other Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Gross	$ (1,434)	$ (1,434)
Accumulated Amortization	1,227	1,144
Net	(207)	(290)
Unamortized Energy Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross	(1,515)	(1,515)
Accumulated Amortization	1,280	1,188
Net	(235)	(327)
Business Services Company [Member] \| Licensing Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross	81	81
Accumulated Amortization	(53)	(44)
Net	28	37
Pepco Holdings LLC [Member] \| Unamortized Energy Contracts [Member]
Finite-Lived Intangible Assets [Line Items]
Gross	(1,515)	(1,515)
Accumulated Amortization	1,280	1,188
Net	$ (235)	$ (327)

Intangible Assets Intangible As

Intangible Assets Intangible Assets - Summary of Amortization Expense (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Finite-Lived Intangible Assets [Line Items]
Intangible asset amortization expense	$ (83)	$ (98)	$ (102)
Pepco Holdings LLC [Member]
Finite-Lived Intangible Assets [Line Items]
Intangible asset amortization expense	$ (92)	$ (115)	$ (119)

Intangible Assets Intangible _2

Intangible Assets Intangible Assets - Schedule of Finite-Lived Intangible Assets, Future Amortization Expense (Details) $ in Millions	Dec. 31, 2021 USD ($)
Finite-Lived Intangible Assets [Line Items]
2021	$ (80)
2022	(72)
2023	(29)
2024	(2)
2025	(5)
Pepco Holdings LLC [Member]
Finite-Lived Intangible Assets [Line Items]
2021	(89)
2022	(81)
2023	(38)
2024	(5)
2025	$ (5)

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
Income Taxes - Narrative (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2019
Income Taxes [Line Items]
Deferred Tax Liability Adjustment - Noncontrolling Interest	$ (290)
Income Tax Credits and Adjustments		$ 47
Current Federal, State and Local, Tax Expense (Benefit)		$ 32
Atlantic City Electric Company [Member] \| State and Local Jurisdiction [Member]
Income Taxes [Line Items]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	$ 14

Income Taxes - Components of In

Income Taxes - Components of Income Tax Expense (Benefit) from Continuing Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Income Taxes [Line Items]
Income taxes	$ 38	$ (7)	$ 153
Commonwealth Edison Co [Member]
Income Taxes [Line Items]
Income taxes	172	177	163
PECO Energy Co [Member]
Income Taxes [Line Items]
Income taxes	12	(30)	65
Baltimore Gas and Electric Company [Member]
Income Taxes [Line Items]
Income taxes	(35)	41	79
Pepco Holdings LLC [Member]
Income Taxes [Line Items]
Income taxes	42	(77)	38
Potomac Electric Power Company [Member]
Income Taxes [Line Items]
Income taxes	15	(7)	16
Delmarva Power & Light Company [Member]
Income Taxes [Line Items]
Income taxes	42	(25)	22
Atlantic City Electric Company [Member]
Income Taxes [Line Items]
Income taxes	(13)	(41)	0
Internal Revenue Service (IRS) [Member]
Income Taxes [Line Items]
Current	(152)	(180)	(143)
Deferred	89	10	139
Investment Tax Credit	(2)	(3)	(3)
Internal Revenue Service (IRS) [Member] \| Commonwealth Edison Co [Member]
Income Taxes [Line Items]
Current	(30)	(24)	59
Deferred	113	112	15
Investment Tax Credit	(1)	(2)	(2)
Internal Revenue Service (IRS) [Member] \| PECO Energy Co [Member]
Income Taxes [Line Items]
Current	1	(7)	45
Deferred	20	1	20
Investment Tax Credit	0	0	0
Internal Revenue Service (IRS) [Member] \| Baltimore Gas and Electric Company [Member]
Income Taxes [Line Items]
Current	(18)	4	(51)
Deferred	34	10	95
Investment Tax Credit	0	0	0
Internal Revenue Service (IRS) [Member] \| Pepco Holdings LLC [Member]
Income Taxes [Line Items]
Current	18	25	43
Deferred	(52)	(129)	(34)
Investment Tax Credit	(1)	(1)	(1)
Internal Revenue Service (IRS) [Member] \| Potomac Electric Power Company [Member]
Income Taxes [Line Items]
Current	22	40	16
Deferred	(17)	(62)	(6)
Investment Tax Credit	0	0	0
Internal Revenue Service (IRS) [Member] \| Delmarva Power & Light Company [Member]
Income Taxes [Line Items]
Current	2	(13)	29
Deferred	(14)	(20)	(21)
Investment Tax Credit	0	0	0
Internal Revenue Service (IRS) [Member] \| Atlantic City Electric Company [Member]
Income Taxes [Line Items]
Current	1	(4)	(3)
Deferred	(26)	(43)	(6)
Investment Tax Credit	0	0	0
State and Local Jurisdiction [Member]
Income Taxes [Line Items]
Current	(46)	(37)	(44)
Deferred	149	203	204
State and Local Jurisdiction [Member] \| Commonwealth Edison Co [Member]
Income Taxes [Line Items]
Current	(41)	(27)	(5)
Deferred	131	118	96
State and Local Jurisdiction [Member] \| PECO Energy Co [Member]
Income Taxes [Line Items]
Current	0	0	0
Deferred	(9)	(24)	0
State and Local Jurisdiction [Member] \| Baltimore Gas and Electric Company [Member]
Income Taxes [Line Items]
Current	0	0	0
Deferred	(51)	27	35
State and Local Jurisdiction [Member] \| Pepco Holdings LLC [Member]
Income Taxes [Line Items]
Current	0	(5)	3
Deferred	77	33	27
State and Local Jurisdiction [Member] \| Potomac Electric Power Company [Member]
Income Taxes [Line Items]
Current	1	0	0
Deferred	9	15	6
State and Local Jurisdiction [Member] \| Delmarva Power & Light Company [Member]
Income Taxes [Line Items]
Current	1	0	0
Deferred	53	8	14
State and Local Jurisdiction [Member] \| Atlantic City Electric Company [Member]
Income Taxes [Line Items]
Current	0	0	0
Deferred	$ 12	$ 6	$ 9

Income Taxes - Reconciliation t

Income Taxes - Reconciliation to Effective Tax Rate (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate [Line Items]
U.S. Federal statutory rate	21%	21%	21%
State income taxes, net of Federal income tax benefit	5%	11.90%	7.80%
Effective Income Tax Rate Reconciliation, Deferred Prosecution Agreement payments		3.80%
Amortization of investment tax credit, including deferred taxes on basis difference	(0.10%)	(0.30%)	(0.20%)
Plant basis differences	(5.40%)	(8.60%)	(3.30%)
Production tax credits and other credits	(0.70%)	(0.50%)	(1.90%)
Excess deferred tax amortization	(17.20%)	(29.10%)	(13.40%)
Other	(0.30%)	1.20%	(0.70%)
Effective income tax rate	2.30%	(0.60%)	9.30%
Income taxes	$ 38	$ (7)	$ 153
Commonwealth Edison Co [Member]
Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate [Line Items]
U.S. Federal statutory rate	21%	21%	21%
State income taxes, net of Federal income tax benefit	7.80%	11.60%	8.50%
Effective Income Tax Rate Reconciliation, Deferred Prosecution Agreement payments		6.80%
Amortization of investment tax credit, including deferred taxes on basis difference	(0.10%)	(0.30%)	(0.20%)
Plant basis differences	(0.80%)	(0.60%)	0%
Production tax credits and other credits	(0.50%)	(0.30%)	(1.20%)
Excess deferred tax amortization	(7.60%)	(11.20%)	(9.70%)
Other	(1.00%)	1.80%	0.80%
Effective income tax rate	18.80%	28.80%	19.20%
Income taxes	$ 172	$ 177	$ 163
PECO Energy Co [Member]
Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate [Line Items]
U.S. Federal statutory rate	21%	21%	21%
State income taxes, net of Federal income tax benefit	(1.40%)	(4.50%)	0%
Effective Income Tax Rate Reconciliation, Deferred Prosecution Agreement payments		0%
Amortization of investment tax credit, including deferred taxes on basis difference	0%	0%	0%
Plant basis differences	(13.60%)	(18.70%)	(7.20%)
Production tax credits and other credits	0%	0%	0%
Excess deferred tax amortization	(3.80%)	(4.60%)	(2.80%)
Other	0.10%	(0.40%)	0%
Effective income tax rate	2.30%	(7.20%)	11%
Income taxes	$ 12	$ (30)	$ 65
Baltimore Gas and Electric Company [Member]
Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate [Line Items]
U.S. Federal statutory rate	21%	21%	21%
State income taxes, net of Federal income tax benefit	(10.80%)	5.50%	6.40%
Effective Income Tax Rate Reconciliation, Deferred Prosecution Agreement payments		0%
Amortization of investment tax credit, including deferred taxes on basis difference	(0.10%)	(0.10%)	(0.10%)
Plant basis differences	(1.70%)	(1.50%)	(1.20%)
Production tax credits and other credits	(0.90%)	(0.40%)	(1.30%)
Excess deferred tax amortization	(16.30%)	(13.90%)	(6.80%)
Other	(0.60%)	(0.10%)	0%
Effective income tax rate	(9.40%)	10.50%	18%
Income taxes	$ (35)	$ 41	$ 79
Pepco Holdings LLC [Member]
Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate [Line Items]
U.S. Federal statutory rate	21%	21%	21%
State income taxes, net of Federal income tax benefit	10.10%	5.10%	4.70%
Effective Income Tax Rate Reconciliation, Deferred Prosecution Agreement payments		0%
Amortization of investment tax credit, including deferred taxes on basis difference	(0.10%)	(0.20%)	(0.20%)
Plant basis differences	(1.10%)	(1.60%)	(1.20%)
Production tax credits and other credits	(0.50%)	(0.30%)	(0.20%)
Excess deferred tax amortization	(22.40%)	(42.00%)	(17.50%)
Other	0%	(0.40%)	0.80%
Effective income tax rate	7%	(18.40%)	7.40%
Income taxes	$ 42	$ (77)	$ 38
Potomac Electric Power Company [Member]
Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate [Line Items]
U.S. Federal statutory rate	21%	21%	21%
State income taxes, net of Federal income tax benefit	2.70%	4.50%	2%
Effective Income Tax Rate Reconciliation, Deferred Prosecution Agreement payments		0%
Amortization of investment tax credit, including deferred taxes on basis difference	0%	(0.10%)	(0.10%)
Plant basis differences	(1.60%)	(1.70%)	(1.80%)
Production tax credits and other credits	(0.50%)	(0.30%)	(0.10%)
Excess deferred tax amortization	(16.40%)	(25.40%)	(15.10%)
Other	(0.40%)	(0.70%)	0.30%
Effective income tax rate	4.80%	(2.70%)	6.20%
Income taxes	$ 15	$ (7)	$ 16
Delmarva Power & Light Company [Member]
Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate [Line Items]
U.S. Federal statutory rate	21%	21%	21%
State income taxes, net of Federal income tax benefit	25%	6.60%	6.80%
Effective Income Tax Rate Reconciliation, Deferred Prosecution Agreement payments		0%
Amortization of investment tax credit, including deferred taxes on basis difference	(0.20%)	(0.30%)	(0.20%)
Plant basis differences	(0.80%)	(0.40%)	(0.40%)
Production tax credits and other credits	(0.40%)	(0.30%)	0%
Excess deferred tax amortization	(20.00%)	(51.70%)	(14.20%)
Other	0.10%	0.10%	0%
Effective income tax rate	24.70%	(25.00%)	13%
Operating Loss Carryforwards, Valuation Allowance	$ 31
Income taxes	$ 42	$ (25)	$ 22
Atlantic City Electric Company [Member]
Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate [Line Items]
U.S. Federal statutory rate	21%	21%	21%
State income taxes, net of Federal income tax benefit	7.40%	7%	7%
Effective Income Tax Rate Reconciliation, Deferred Prosecution Agreement payments		0%
Amortization of investment tax credit, including deferred taxes on basis difference	(0.20%)	(0.50%)	(0.30%)
Plant basis differences	(0.20%)	(3.00%)	(0.70%)
Production tax credits and other credits	(0.50%)	(0.50%)	(0.10%)
Excess deferred tax amortization	(37.10%)	(82.10%)	(27.00%)
Other	(0.20%)	0.40%	0.10%
Effective income tax rate	(9.80%)	(57.70%)	0%
Income taxes	$ (13)	$ (41)	$ 0

Income Taxes - Tax Effects of T

Income Taxes - Tax Effects of Temporary Differences and Carryforwards (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Operating Loss Carryforwards [Line Items]
Plant basis differences	$ (11,606)	$ 11,272
Deferred Tax Liabilities, Other Finite-Lived Assets	56	(77)
Derivatives and other financial instruments	63	(82)
Deferred pension and postretirement obligation	641	954
Deferred debt refinancing costs	146	153
Deferred Tax Liabilities, Regulatory Assets and Liabilities	(1,130)	(1,107)
Tax loss carryforward, net of valuation allowances	242	231
Tax credit carryforward	584	648
Investment in partnerships	(21)	(22)
Other, net	449	701
Deferred income tax liabilities (net)	(10,576)	(9,555)
Unamortized investment tax credits	(15)	(19)
Total deferred income tax liabilities (net) and unamortized investment tax credits	(10,591)	(9,574)
Commonwealth Edison Co [Member]
Operating Loss Carryforwards [Line Items]
Plant basis differences	(4,648)	4,432
Deferred Tax Liabilities, Other Finite-Lived Assets	0	0
Derivatives and other financial instruments	61	(84)
Deferred pension and postretirement obligation	(308)	(288)
Deferred debt refinancing costs	(6)	(6)
Deferred Tax Liabilities, Regulatory Assets and Liabilities	8	87
Tax loss carryforward, net of valuation allowances	0	0
Tax credit carryforward	0	0
Investment in partnerships	0	0
Other, net	216	223
Deferred income tax liabilities (net)	(4,677)	(4,332)
Unamortized investment tax credits	(8)	(9)
Total deferred income tax liabilities (net) and unamortized investment tax credits	(4,685)	(4,341)
PECO Energy Co [Member]
Operating Loss Carryforwards [Line Items]
Plant basis differences	(2,271)	2,131
Deferred Tax Liabilities, Other Finite-Lived Assets	0	0
Derivatives and other financial instruments	0	0
Deferred pension and postretirement obligation	(32)	(30)
Deferred debt refinancing costs	0	0
Deferred Tax Liabilities, Regulatory Assets and Liabilities	(280)	(231)
Tax loss carryforward, net of valuation allowances	65	47
Tax credit carryforward	0	0
Investment in partnerships	0	0
Other, net	97	104
Deferred income tax liabilities (net)	(2,421)	(2,241)
Unamortized investment tax credits	0	(1)
Total deferred income tax liabilities (net) and unamortized investment tax credits	(2,421)	(2,242)
Baltimore Gas and Electric Company [Member]
Operating Loss Carryforwards [Line Items]
Plant basis differences	(1,826)	1,711
Deferred Tax Liabilities, Other Finite-Lived Assets	0	0
Derivatives and other financial instruments	0	0
Deferred pension and postretirement obligation	(37)	(33)
Deferred debt refinancing costs	(2)	(2)
Deferred Tax Liabilities, Regulatory Assets and Liabilities	92	142
Tax loss carryforward, net of valuation allowances	68	57
Tax credit carryforward	0	0
Investment in partnerships	0	0
Other, net	21	29
Deferred income tax liabilities (net)	(1,684)	(1,518)
Unamortized investment tax credits	(2)	(3)
Total deferred income tax liabilities (net) and unamortized investment tax credits	(1,686)	(1,521)
Pepco Holdings LLC [Member]
Operating Loss Carryforwards [Line Items]
Plant basis differences	(2,976)	2,822
Deferred Tax Liabilities, Other Finite-Lived Assets	56	(77)
Derivatives and other financial instruments	2	(2)
Deferred pension and postretirement obligation	(90)	(80)
Deferred debt refinancing costs	123	131
Deferred Tax Liabilities, Regulatory Assets and Liabilities	(53)	(41)
Tax loss carryforward, net of valuation allowances	64	90
Tax credit carryforward	0	0
Investment in partnerships	0	0
Other, net	212	220
Deferred income tax liabilities (net)	(2,662)	(2,423)
Unamortized investment tax credits	(5)	(6)
Total deferred income tax liabilities (net) and unamortized investment tax credits	(2,667)	(2,429)
Potomac Electric Power Company [Member]
Operating Loss Carryforwards [Line Items]
Plant basis differences	(1,321)	1,259
Deferred Tax Liabilities, Other Finite-Lived Assets	0	0
Derivatives and other financial instruments	0	0
Deferred pension and postretirement obligation	(76)	(74)
Deferred debt refinancing costs	(2)	(3)
Deferred Tax Liabilities, Regulatory Assets and Liabilities	24	38
Tax loss carryforward, net of valuation allowances	2	4
Tax credit carryforward	0	0
Investment in partnerships	0	0
Other, net	99	107
Deferred income tax liabilities (net)	(1,274)	(1,187)
Unamortized investment tax credits	(1)	(2)
Total deferred income tax liabilities (net) and unamortized investment tax credits	(1,275)	(1,189)
Delmarva Power & Light Company [Member]
Operating Loss Carryforwards [Line Items]
Plant basis differences	(853)	806
Deferred Tax Liabilities, Other Finite-Lived Assets	0	0
Derivatives and other financial instruments	0	0
Deferred pension and postretirement obligation	(40)	(40)
Deferred debt refinancing costs	(1)	(1)
Deferred Tax Liabilities, Regulatory Assets and Liabilities	55	67
Tax loss carryforward, net of valuation allowances	18	49
Tax credit carryforward	0	0
Investment in partnerships	0	0
Other, net	19	18
Deferred income tax liabilities (net)	(802)	(713)
Unamortized investment tax credits	(1)	(2)
Total deferred income tax liabilities (net) and unamortized investment tax credits	(803)	(715)
Atlantic City Electric Company [Member]
Operating Loss Carryforwards [Line Items]
Plant basis differences	(777)	725
Deferred Tax Liabilities, Other Finite-Lived Assets	0	0
Derivatives and other financial instruments	0	0
Deferred pension and postretirement obligation	(6)	(7)
Deferred debt refinancing costs	(1)	(1)
Deferred Tax Liabilities, Regulatory Assets and Liabilities	31	46
Tax loss carryforward, net of valuation allowances	42	38
Tax credit carryforward	0	0
Investment in partnerships	0	0
Other, net	34	27
Deferred income tax liabilities (net)	(677)	(622)
Unamortized investment tax credits	(2)	(3)
Total deferred income tax liabilities (net) and unamortized investment tax credits	$ (679)	$ (625)

Income Taxes - Schedule of Carr

Income Taxes - Schedule of Carryforwards and Corresponding Valuation Allowances (Details) $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($)
Delmarva Power & Light Company [Member]
Operating Loss Carryforwards [Line Items]
Valuation allowance on state tax attributes (net of federal taxes)(b)	$ 31
Internal Revenue Service (IRS) [Member] \| General Business Tax Credit Carryforward [Member]
Operating Loss Carryforwards [Line Items]
Federal general business credits carryforwards and other carryforwards(a)	584
Internal Revenue Service (IRS) [Member] \| General Business Tax Credit Carryforward [Member] \| PECO Energy Co [Member]
Operating Loss Carryforwards [Line Items]
Federal general business credits carryforwards and other carryforwards(a)	0
Internal Revenue Service (IRS) [Member] \| General Business Tax Credit Carryforward [Member] \| Baltimore Gas and Electric Company [Member]
Operating Loss Carryforwards [Line Items]
Federal general business credits carryforwards and other carryforwards(a)	0
Internal Revenue Service (IRS) [Member] \| General Business Tax Credit Carryforward [Member] \| Pepco Holdings LLC [Member]
Operating Loss Carryforwards [Line Items]
Federal general business credits carryforwards and other carryforwards(a)	0
Internal Revenue Service (IRS) [Member] \| General Business Tax Credit Carryforward [Member] \| Potomac Electric Power Company [Member]
Operating Loss Carryforwards [Line Items]
Federal general business credits carryforwards and other carryforwards(a)	0
Internal Revenue Service (IRS) [Member] \| General Business Tax Credit Carryforward [Member] \| Delmarva Power & Light Company [Member]
Operating Loss Carryforwards [Line Items]
Federal general business credits carryforwards and other carryforwards(a)	0
Internal Revenue Service (IRS) [Member] \| General Business Tax Credit Carryforward [Member] \| Atlantic City Electric Company [Member]
Operating Loss Carryforwards [Line Items]
Federal general business credits carryforwards and other carryforwards(a)	0
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
State net operating losses and other carryforwards	4,616
Deferred taxes on state tax attributes (net of federal taxes)	291
Valuation allowance on state tax attributes (net of federal taxes)(b)	$ 37
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2035
Tax Credit Carryforward, Expiration Date	Dec. 31, 2035
State and Local Jurisdiction [Member] \| PECO Energy Co [Member]
Operating Loss Carryforwards [Line Items]
State net operating losses and other carryforwards	$ 890
Deferred taxes on state tax attributes (net of federal taxes)	70
Valuation allowance on state tax attributes (net of federal taxes)(b)	$ 3
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2032
State and Local Jurisdiction [Member] \| Baltimore Gas and Electric Company [Member]
Operating Loss Carryforwards [Line Items]
State net operating losses and other carryforwards	$ 1,098
Deferred taxes on state tax attributes (net of federal taxes)	72
Valuation allowance on state tax attributes (net of federal taxes)(b)	$ 0
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2033
State and Local Jurisdiction [Member] \| Pepco Holdings LLC [Member]
Operating Loss Carryforwards [Line Items]
State net operating losses and other carryforwards	$ 1,512
Deferred taxes on state tax attributes (net of federal taxes)	104
Valuation allowance on state tax attributes (net of federal taxes)(b)	$ 31
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2029
State and Local Jurisdiction [Member] \| Potomac Electric Power Company [Member]
Operating Loss Carryforwards [Line Items]
State net operating losses and other carryforwards	$ 42
Deferred taxes on state tax attributes (net of federal taxes)	3
Valuation allowance on state tax attributes (net of federal taxes)(b)	0
State and Local Jurisdiction [Member] \| Delmarva Power & Light Company [Member]
Operating Loss Carryforwards [Line Items]
State net operating losses and other carryforwards	736
Deferred taxes on state tax attributes (net of federal taxes)	50
Valuation allowance on state tax attributes (net of federal taxes)(b)	$ 31
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2032
State and Local Jurisdiction [Member] \| Atlantic City Electric Company [Member]
Operating Loss Carryforwards [Line Items]
State net operating losses and other carryforwards	$ 605
Deferred taxes on state tax attributes (net of federal taxes)	43
Valuation allowance on state tax attributes (net of federal taxes)(b)	$ 0
Operating Loss Carryforwards, Expiration Date	Dec. 31, 2031

Income Taxes - Rollforward of U

Income Taxes - Rollforward of Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized Tax Benefits - Beginning Balance	$ 125	$ 95	$ 65
Unrecognized Tax Benefits, Period Increase (Decrease)	13	6	26
Increases based on tax positions related to current year	4	3	2
Increases based on tax positions prior to current year	4	26	34
Decreases based on tax positions prior to current year	(3)	(5)	(3)
Decrease from settlements with taxing authorities			(29)
Unrecognized tax benefits - Ending Balance	143	125	95
Income taxes	38	(7)	153
Commonwealth Edison Co [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Income taxes	172	177	163
PECO Energy Co [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Income taxes	12	(30)	65
Baltimore Gas and Electric Company [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Income taxes	(35)	41	79
Pepco Holdings LLC [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized Tax Benefits - Beginning Balance	52	48	45
Unrecognized Tax Benefits, Period Increase (Decrease)	3	3	3
Increases based on tax positions related to current year	1	0	0
Increases based on tax positions prior to current year	0	1	0
Decreases based on tax positions prior to current year	0	0	0
Decrease from settlements with taxing authorities			0
Unrecognized tax benefits - Ending Balance	56	52	48
Income taxes	42	(77)	38
Potomac Electric Power Company [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Income taxes	15	(7)	16
Delmarva Power & Light Company [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Income taxes	42	(25)	22
Atlantic City Electric Company [Member]
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized Tax Benefits - Beginning Balance	15	14	14
Unrecognized Tax Benefits, Period Increase (Decrease)	1	1	0
Increases based on tax positions related to current year	0	0	0
Increases based on tax positions prior to current year	0	0	0
Decreases based on tax positions prior to current year	0	0	0
Decrease from settlements with taxing authorities			0
Unrecognized tax benefits - Ending Balance	16	15	14
Income taxes	$ (13)	$ (41)	$ 0

Income Taxes - Recognition of U

Income Taxes - Recognition of Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Recognition of Unrecognized Tax Benefits [Line Items]
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 77	$ 73	$ 51

Income Taxes - Summary of Inter

Income Taxes - Summary of Interest and Penalties Receivable (Payable) (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Income Taxes [Line Items]
Net Interest Receivable Payable Related To Uncertain Tax Positions	$ 43	$ 314
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority	$ 272

Income Taxes - Long-Term Margin

Income Taxes - Long-Term Marginal State Income Tax Rate (Details) - State and Local Jurisdiction [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Long-Term Marginal State Income Tax Rate [Line Items]
Increase (Decrease) in Deferred Income Taxes	$ 27	$ 66	$ 20
Increase (Decrease) in Income Taxes	$ 27	$ 66	$ 20

Income Taxes - Allocation of Ta

Income Taxes - Allocation of Tax Benefits (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Commonwealth Edison Co [Member]
Income Taxes [Line Items]
Allocation Of Federal Tax Benefit Under Tax Sharing Agreement	$ 1	$ 14	$ 0
PECO Energy Co [Member]
Income Taxes [Line Items]
Allocation Of Federal Tax Benefit Under Tax Sharing Agreement	19	17	14
Baltimore Gas and Electric Company [Member]
Income Taxes [Line Items]
Allocation Of Federal Tax Benefit Under Tax Sharing Agreement	0	0	3
Pepco Holdings LLC [Member]
Income Taxes [Line Items]
Allocation Of Federal Tax Benefit Under Tax Sharing Agreement	17	17	7
Potomac Electric Power Company [Member]
Income Taxes [Line Items]
Allocation Of Federal Tax Benefit Under Tax Sharing Agreement	16	8	6
Delmarva Power and Light Company [Member]
Income Taxes [Line Items]
Allocation Of Federal Tax Benefit Under Tax Sharing Agreement	0	6	1
Atlantic City Electric Company [Member]
Income Taxes [Line Items]
Allocation Of Federal Tax Benefit Under Tax Sharing Agreement	$ 0	$ 1	$ 0

Retirement Benefits- Narrative

Retirement Benefits- Narrative (Details) - USD ($) $ in Millions		3 Months Ended	12 Months Ended
	Feb. 01, 2022	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Increase (Decrease) in Obligation, Pension Benefits		$ 20
Benefit obligation increase (decrease) reflecting actual census data		(5)
Accumulated Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), after Tax		1
Regulatory asset increase (decrease) due to updated valuation adjustment		21
Defined benefit plan, amounts increased (decrease) in regulatory liabilities, before tax		$ 1
Defined Contribution Plan, Employer Discretionary Contribution Amount			$ 90	$ 95	$ 88
Payment for Pension and Other Postretirement Benefits			665	601	408
Pension Plan, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Regulatory asset increase (decrease) due to updated valuation adjustment			$ (581)	$ 140	$ 3
Expected return on plan assets			7%	7%	7%
Discount rate			2.58%	3.34%	4.31%
Defined Contribution Plan, Employer Discretionary Contribution Amount			$ 313
Payment for Pension and Other Postretirement Benefits	$ 207		343	$ 306	$ 196
Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Regulatory asset increase (decrease) due to updated valuation adjustment			$ (144)	$ (20)	$ 106
Expected return on plan assets			6.46%	6.69%	6.67%
Discount rate			2.51%	3.31%	4.30%
Payment for Pension and Other Postretirement Benefits			$ 63	$ 40	$ 36
Change in Assumptions for Defined Benefit Plans [Member] \| Pension Plan, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected return on plan assets			7%
Discount rate			2.58%
Change in Assumptions for Defined Benefit Plans [Member] \| Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected return on plan assets			6.46%
Discount rate			2.51%
Assets [Member] \| Pension Plan, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual Asset Returns			7.21%
Assets [Member] \| Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Actual Asset Returns			9.54%
Subsequent Event [Member] \| Pension Plan, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected return on plan assets			7%
Subsequent Event [Member] \| Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Expected return on plan assets			6.44%

Retirement Benefits - Summary o

Retirement Benefits - Summary of Changes in Benefit Obligations and Plan Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Net benefit obligation as of the beginning of year	$ 14,861	$ 13,652
Service cost	294	251	$ 218
Interest cost	406	476	553
Defined Benefit Plan, Benefit Obligation, Contributions by Plan Participant	0	0
Actuarial (gain) loss(a)	(442)	1,252
Plan amendments	0	0
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Remeasurement due to Settlement	(23)	(19)
Defined Benefit Plan, Benefit Obligation, Benefits Paid	(860)	(751)
Net benefit obligation as of the end of year	14,236	14,861	13,652
Fair value of net plan assets as of the beginning of year	11,883	10,859
Actual return on plan assets	822	1,488
Employer contributions	343	306
Defined Benefit Plan, Plan Assets, Contributions by Plan Participant	0	0
Defined Benefit Plan, Plan Assets, Benefits Paid	(860)	(751)
Defined Benefit Plan, Plan Assets, Payment for Settlement	(23)	(19)
Fair value of net plan assets as of the end of year	12,165	11,883	10,859
Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Net benefit obligation as of the beginning of year	2,661	2,692
Service cost	51	56	55
Interest cost	69	93	114
Defined Benefit Plan, Benefit Obligation, Contributions by Plan Participant	32	31
Actuarial (gain) loss(a)	(116)	38
Plan amendments	0	(64)
Defined Benefit Plan, Benefit Obligation, (Increase) Decrease for Remeasurement due to Settlement	(5)	(5)
Defined Benefit Plan, Benefit Obligation, Benefits Paid	(190)	(180)
Net benefit obligation as of the end of year	2,502	2,661	2,692
Fair value of net plan assets as of the beginning of year	1,635	1,627
Actual return on plan assets	130	122
Employer contributions	63	40
Defined Benefit Plan, Plan Assets, Contributions by Plan Participant	32	31
Defined Benefit Plan, Plan Assets, Benefits Paid	(190)	(180)
Defined Benefit Plan, Plan Assets, Payment for Settlement	(5)	(5)
Fair value of net plan assets as of the end of year	$ 1,665	$ 1,635	$ 1,627

Retirement Benefits - Benefit O

Retirement Benefits - Benefit Obligations and Plan Assets in Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Other current liabilities	$ 20	$ 32
Pension obligations	2,051	2,946
Non-pension postretirement benefit obligations	0	0
Unfunded status (net benefit obligation less plan assets)	2,071	2,978
Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Other current liabilities	26	24
Pension obligations	0	0
Non-pension postretirement benefit obligations	811	1,002
Unfunded status (net benefit obligation less plan assets)	$ 837	$ 1,026

Retirement Benefits- Projected

Retirement Benefits- Projected Benefit Obligations and Accumulated Benefit Obligations in Excess of Plan Assets (Details) - Accumulated Benefit Obligation In Excess Of Plan Assets [Member] - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
ABO	$ 13,497	$ 14,037
Fair value of net plan assets	$ 12,165	$ 11,883

Retirement Benefits - Component

Retirement Benefits - Components of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Amortization of:
Net periodic benefit cost	$ 91	$ 53	$ 13
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	294	251	218
Interest cost	406	476	553
Expected return on assets	(843)	(796)	(763)
Amortization of:
Prior service cost (credit)	2	3	1
Actuarial loss	399	349	289
Curtailment benefits	0	0	0
Settlement and other charges	7	6	6
Contractual termination benefits	0	0	1
Net periodic benefit cost	265	289	305
Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	51	56	55
Interest cost	69	93	114
Expected return on assets	(99)	(101)	(95)
Amortization of:
Prior service cost (credit)	(25)	(76)	(104)
Actuarial loss	27	34	32
Curtailment benefits	0	(1)	0
Settlement and other charges	1	1	0
Contractual termination benefits	0	0	0
Net periodic benefit cost	$ 24	$ 6	$ 2

Retirement Benefits - Allocated

Retirement Benefits - Allocated Portion of Pension and Postretirement Benefit Plan Costs (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and non-pension postretirement benefit costs	$ 411	$ 411	$ 438
Pension and other post retirement benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and non-pension postretirement benefit costs	288	296	307
Commonwealth Edison Co [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and non-pension postretirement benefit costs	129	114	96
Commonwealth Edison Co [Member] \| Pension and other post retirement benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and non-pension postretirement benefit costs	129	114	96
PECO Energy Co [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and non-pension postretirement benefit costs	8	5	12
PECO Energy Co [Member] \| Pension and other post retirement benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and non-pension postretirement benefit costs	8	5	12
Baltimore Gas and Electric Company [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and non-pension postretirement benefit costs	61	62	61
Baltimore Gas and Electric Company [Member] \| Pension and other post retirement benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and non-pension postretirement benefit costs	64	64	61
Pepco Holdings LLC [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and non-pension postretirement benefit costs	49	70	95
Pepco Holdings LLC [Member] \| Pension and other post retirement benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and non-pension postretirement benefit costs	49	70	95
Potomac Electric Power Company [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and non-pension postretirement benefit costs	6	15	25
Potomac Electric Power Company [Member] \| Pension and other post retirement benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and non-pension postretirement benefit costs	6	15	25
Delmarva Power & Light Company [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and non-pension postretirement benefit costs	2	7	15
Delmarva Power & Light Company [Member] \| Pension and other post retirement benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and non-pension postretirement benefit costs	2	7	15
Atlantic City Electric Company [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and non-pension postretirement benefit costs	11	14	16
Atlantic City Electric Company [Member] \| Pension and other post retirement benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Pension and non-pension postretirement benefit costs	$ 11	$ 14	$ 16

Retirement Benefits - Compone_2

Retirement Benefits - Components of Accumulated Other Comprehensive Income and Regulatory Assets (Liabilities) related to Retirement Plans (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, amounts recognized in regulatory assets, before tax	$ 21
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Current year actuarial (gain) loss		$ (700)	$ 941	$ 538
Amortization of actuarial loss		(598)	(512)	(414)
Current year prior service cost (credit)		0	0	68
Amortization of prior service (cost) credit		(3)	(4)	0
Curtailments		0	0	(3)
Settlements		(27)	(14)	(17)
Total recognized in AOCI and regulatory assets (liabilities)		(1,328)	411	172
Defined benefit plan, amounts recognized in OCI, before tax		(747)	271	169
Defined benefit plan, amounts recognized in regulatory assets, before tax		(581)	140	3
Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Current year actuarial (gain) loss		(270)	22	80
Amortization of actuarial loss		(37)	(49)	(45)
Current year prior service cost (credit)		0	(111)	0
Amortization of prior service (cost) credit		34	124	179
Curtailments		0	1	0
Settlements		(1)	(1)	(1)
Total recognized in AOCI and regulatory assets (liabilities)		(274)	(14)	213
Defined benefit plan, amounts recognized in OCI, before tax		(130)	6	107
Defined benefit plan, amounts recognized in regulatory assets, before tax		$ (144)	$ (20)	$ 106

Retirement Benefits - Gross Acc

Retirement Benefits - Gross Accumulated Other Comprehensive Loss and Regulatory Assets (Liabilities) not Recognized as Components of Periodic Benefit Cost (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Prior service cost (credit)	$ 32	$ 35
Actuarial loss	6,752	8,077
Total	6,784	8,112
Benefits included in accumulated other comprehensive income	3,592	4,339
Benefits included in regulatory assets (liabilities)	3,192	3,773
Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Prior service cost (credit)	(111)	(145)
Actuarial loss	230	538
Total	119	393
Benefits included in accumulated other comprehensive income	53	183
Benefits included in regulatory assets (liabilities)	$ 66	$ 210

Retirement Benefits - Assumptio

Retirement Benefits - Assumptions Used in Calculations (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan Assumptions Used In Calculations [Line Items]
Discount rate - Benefit Obligation	2.92%	2.58%
Benefit Obligation Investment Crediting Rate	3.75%	3.72%
Discount rate - Net Periodic Benefit Costs	2.58%	3.34%	4.31%
Net Periodic Benefit Cost Investment Crediting Rate	3.72%	3.82%	4.46%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets	7%	7%	7%
Pension Plan, Defined Benefit [Member] \| CENG Legacy Benefit Plans [Member] \| Minimum [Member]
Defined Benefit Plan Assumptions Used In Calculations [Line Items]
Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Discount Rate Design Changes	2.55%	2.11%
Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Discount Rate Design Changes	2.11%	3.02%	4.13%
Pension Plan, Defined Benefit [Member] \| CENG Legacy Benefit Plans [Member] \| Maximum [Member]
Defined Benefit Plan Assumptions Used In Calculations [Line Items]
Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Discount Rate Design Changes	3.02%	2.73%
Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Discount Rate Design Changes	2.73%	3.44%	4.36%
Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plan Assumptions Used In Calculations [Line Items]
Discount rate - Benefit Obligation	2.88%	2.51%
Health care cost trend rate	5%	5%	5%
Ultimate health care cost trend rate	5%	5%	5%
Discount rate - Net Periodic Benefit Costs	2.51%	3.31%	4.30%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets	6.46%	6.69%	6.67%
Other Postretirement Benefit Plan, Defined Benefit [Member] \| CENG Legacy Benefit Plans [Member] \| Minimum [Member]
Defined Benefit Plan Assumptions Used In Calculations [Line Items]
Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Discount Rate Design Changes	2.84%	2.45%
Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Discount Rate Design Changes	2.45%	3.27%	4.27%
Other Postretirement Benefit Plan, Defined Benefit [Member] \| CENG Legacy Benefit Plans [Member] \| Maximum [Member]
Defined Benefit Plan Assumptions Used In Calculations [Line Items]
Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Discount Rate Design Changes	2.92%	2.63%
Defined Benefit Plan Assumptions Used Calculating Net Periodic Benefit Cost Discount Rate Design Changes	2.63%	3.40%	4.38%
Pension and other post retirement benefit [Member]
Defined Benefit Plan Assumptions Used In Calculations [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase	3.75%	3.75%	3.25%

Retirement Benefits - Contribut

Retirement Benefits - Contributions made to Pension and Other Postretirement Benefit Plans (Details) - USD ($) $ in Millions		12 Months Ended
	Feb. 01, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Pension and non-pension postretirement benefit contributions		$ 665	$ 601	$ 408
Expected qualified pension plan contributions		313
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months		23
Defined Other Postretirement Benefit Plan Estimated Future Employer Contributions In Next Fiscal Year		39
Commonwealth Edison Co [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and non-pension postretirement benefit contributions		196	148	77
Expected qualified pension plan contributions		173
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months		2
Defined Other Postretirement Benefit Plan Estimated Future Employer Contributions In Next Fiscal Year		12
PECO Energy Co [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and non-pension postretirement benefit contributions		18	18	28
Expected qualified pension plan contributions		12
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months		1
Defined Other Postretirement Benefit Plan Estimated Future Employer Contributions In Next Fiscal Year		2
Baltimore Gas and Electric Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and non-pension postretirement benefit contributions		81	78	48
Expected qualified pension plan contributions		48
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months		2
Defined Other Postretirement Benefit Plan Estimated Future Employer Contributions In Next Fiscal Year		16
Pepco Holdings LLC [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and non-pension postretirement benefit contributions		48	39	25
Expected qualified pension plan contributions		60
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months		10
Defined Other Postretirement Benefit Plan Estimated Future Employer Contributions In Next Fiscal Year		7
Potomac Electric Power Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and non-pension postretirement benefit contributions		11	11	14
Expected qualified pension plan contributions		2
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months		1
Defined Other Postretirement Benefit Plan Estimated Future Employer Contributions In Next Fiscal Year		6
Delmarva Power & Light Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and non-pension postretirement benefit contributions		1	0	1
Expected qualified pension plan contributions		1
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months		1
Defined Other Postretirement Benefit Plan Estimated Future Employer Contributions In Next Fiscal Year		0
Atlantic City Electric Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and non-pension postretirement benefit contributions		3	2	1
Expected qualified pension plan contributions		7
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months		0
Defined Other Postretirement Benefit Plan Estimated Future Employer Contributions In Next Fiscal Year		0
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and non-pension postretirement benefit contributions	$ 207	343	306	196
Pension Plan, Defined Benefit [Member] \| Commonwealth Edison Co [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and non-pension postretirement benefit contributions		174	143	72
Pension Plan, Defined Benefit [Member] \| PECO Energy Co [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and non-pension postretirement benefit contributions		17	18	27
Pension Plan, Defined Benefit [Member] \| Baltimore Gas and Electric Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and non-pension postretirement benefit contributions		57	56	34
Pension Plan, Defined Benefit [Member] \| Pepco Holdings LLC [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and non-pension postretirement benefit contributions		39	30	10
Pension Plan, Defined Benefit [Member] \| Potomac Electric Power Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and non-pension postretirement benefit contributions		2	2	2
Pension Plan, Defined Benefit [Member] \| Delmarva Power & Light Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and non-pension postretirement benefit contributions		1	0	1
Pension Plan, Defined Benefit [Member] \| Atlantic City Electric Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and non-pension postretirement benefit contributions		3	2	0
Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and non-pension postretirement benefit contributions		63	40	36
Other Postretirement Benefit Plan, Defined Benefit [Member] \| Commonwealth Edison Co [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and non-pension postretirement benefit contributions		22	5	5
Other Postretirement Benefit Plan, Defined Benefit [Member] \| PECO Energy Co [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and non-pension postretirement benefit contributions		1	0	1
Other Postretirement Benefit Plan, Defined Benefit [Member] \| Baltimore Gas and Electric Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and non-pension postretirement benefit contributions		24	22	14
Other Postretirement Benefit Plan, Defined Benefit [Member] \| Pepco Holdings LLC [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and non-pension postretirement benefit contributions		9	9	15
Other Postretirement Benefit Plan, Defined Benefit [Member] \| Potomac Electric Power Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and non-pension postretirement benefit contributions		9	9	12
Other Postretirement Benefit Plan, Defined Benefit [Member] \| Delmarva Power & Light Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and non-pension postretirement benefit contributions		0	0	0
Other Postretirement Benefit Plan, Defined Benefit [Member] \| Atlantic City Electric Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and non-pension postretirement benefit contributions		$ 0	$ 0	$ 1

Retirement Benefits - Estimated

Retirement Benefits - Estimated Future Benefit Payments (Details) $ in Millions	Dec. 31, 2021 USD ($)
Pension Plan, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
2022	$ 769
2023	775
2024	792
2025	794
2026	792
2027 through 2031	4,021
Total estimated future benefits payments through 2031	7,943
Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
2022	146
2023	147
2024	147
2025	147
2026	149
2027 through 2031	742
Total estimated future benefits payments through 2031	$ 1,478

Retirement Benefits - Pension a

Retirement Benefits - Pension and Other Postretirement Benefit Plan Target Asset Allocations (Details)	Dec. 31, 2021	Dec. 31, 2020
Pension Plan, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target asset allocation percentage	100%	100%
Pension Plan, Defined Benefit [Member] \| Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target asset allocation percentage	35%	34%
Pension Plan, Defined Benefit [Member] \| Fixed Income Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target asset allocation percentage	41%	43%
Pension Plan, Defined Benefit [Member] \| Alternative Investments [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target asset allocation percentage	24%	23%
Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target asset allocation percentage	100%	100%
Other Postretirement Benefit Plan, Defined Benefit [Member] \| Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target asset allocation percentage	44%	45%
Other Postretirement Benefit Plan, Defined Benefit [Member] \| Fixed Income Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target asset allocation percentage	41%	39%
Other Postretirement Benefit Plan, Defined Benefit [Member] \| Alternative Investments [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Target asset allocation percentage	15%	16%

Retirement Benefits - Fair Valu

Retirement Benefits - Fair Value Measurements of Pension and Postretirement Benefit Plan Assets (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Derivative, Fair Value, Net	$ (2)	$ 1
Derivative, Notional Amount	3,481	4,018
Net liabilities pending transactions excluded	(131)	(77)
Pension Plan, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	12,165	11,883	$ 10,859
Financial Instruments Sold, Not yet Purchased, Corporate Debt	(44)	(56)
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	12,306	11,961
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	4,004	3,387
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	2,998	3,321
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	469	485
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	4,835	4,768
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Cash and Cash Equivalents [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	351	309
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Cash and Cash Equivalents [Member] \| Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	260	238
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Cash and Cash Equivalents [Member] \| Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	91	71
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Cash and Cash Equivalents [Member] \| Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Cash and Cash Equivalents [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	3,974	3,977
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Equity Securities [Member] \| Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	2,699	2,485
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Equity Securities [Member] \| Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Equity Securities [Member] \| Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	2	1
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Equity Securities [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	1,273	1,491
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| US Treasury and Government [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	1,178	878
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| US Treasury and Government [Member] \| Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	1,002	664
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| US Treasury and Government [Member] \| Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	176	214
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| US Treasury and Government [Member] \| Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| US Treasury and Government [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| State and Municipal Debt [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	47	50
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| State and Municipal Debt [Member] \| Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| State and Municipal Debt [Member] \| Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	47	50
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| State and Municipal Debt [Member] \| Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| State and Municipal Debt [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Corporate Debt Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	2,848	3,182
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Corporate Debt Securities [Member] \| Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Corporate Debt Securities [Member] \| Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	2,523	2,846
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Corporate Debt Securities [Member] \| Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	325	336
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Corporate Debt Securities [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Other Debt Obligations [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	517	466
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Other Debt Obligations [Member] \| Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	43	0
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Other Debt Obligations [Member] \| Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	161	140
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Other Debt Obligations [Member] \| Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	12	12
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Other Debt Obligations [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	301	314
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Debt Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	4,590	4,576
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Debt Securities [Member] \| Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	1,045	664
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Debt Securities [Member] \| Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	2,907	3,250
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Debt Securities [Member] \| Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	337	348
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Debt Securities [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	301	314
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Private Equity Funds [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	1,124	953
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Private Equity Funds [Member] \| Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Private Equity Funds [Member] \| Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Private Equity Funds [Member] \| Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Private Equity Funds [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	1,124	953
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Hedge Funds [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	774	768
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Hedge Funds [Member] \| Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Hedge Funds [Member] \| Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Hedge Funds [Member] \| Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Hedge Funds [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	774	768
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Real Estate Funds [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	760	631
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Real Estate Funds [Member] \| Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Real Estate Funds [Member] \| Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Real Estate Funds [Member] \| Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Real Estate Funds [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	760	631
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Private Placement [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	733	747
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Private Placement [Member] \| Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Private Placement [Member] \| Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Private Placement [Member] \| Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	130	136
Pension Plan, Defined Benefit [Member] \| Fair Value, Recurring [Member] \| Private Placement [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	603	611
Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	1,665	1,635	1,627
Financial Instruments Sold, Not yet Purchased, Corporate Debt	(18)	(27)
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	1,655	1,634
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	678	620
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	172	192
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	805	822
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Cash and Cash Equivalents [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	95	65
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Cash and Cash Equivalents [Member] \| Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	54	32
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Cash and Cash Equivalents [Member] \| Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	41	33
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Cash and Cash Equivalents [Member] \| Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Cash and Cash Equivalents [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	713	761
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Equity Securities [Member] \| Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	387	396
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Equity Securities [Member] \| Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	2	1
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Equity Securities [Member] \| Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Equity Securities [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	324	364
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| US Treasury and Government [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	58	52
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| US Treasury and Government [Member] \| Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	14	10
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| US Treasury and Government [Member] \| Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	44	42
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| US Treasury and Government [Member] \| Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| US Treasury and Government [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| State and Municipal Debt [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	7	57
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| State and Municipal Debt [Member] \| Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| State and Municipal Debt [Member] \| Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	7	57
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| State and Municipal Debt [Member] \| Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| State and Municipal Debt [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Corporate Debt Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	74	57
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Corporate Debt Securities [Member] \| Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Corporate Debt Securities [Member] \| Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	74	57
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Corporate Debt Securities [Member] \| Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Corporate Debt Securities [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Other Debt Obligations [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	363	299
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Other Debt Obligations [Member] \| Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	223	182
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Other Debt Obligations [Member] \| Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	4	2
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Other Debt Obligations [Member] \| Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Other Debt Obligations [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	136	115
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Debt Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	502	465
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Debt Securities [Member] \| Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	237	192
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Debt Securities [Member] \| Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	129	158
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Debt Securities [Member] \| Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Debt Securities [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	136	115
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Hedge Funds [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	175	197
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Hedge Funds [Member] \| Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Hedge Funds [Member] \| Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Hedge Funds [Member] \| Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Hedge Funds [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	175	197
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Real Estate Funds [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	86	71
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Real Estate Funds [Member] \| Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Real Estate Funds [Member] \| Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Real Estate Funds [Member] \| Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Real Estate Funds [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	86	71
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Private Placement [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	84	75
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Private Placement [Member] \| Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Private Placement [Member] \| Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Private Placement [Member] \| Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	0	0
Other Postretirement Benefits Plan [Member] \| Fair Value, Recurring [Member] \| Private Placement [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	84	75
Pension and other post retirement benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Derivative, Notional Amount	127	140
Pension and other post retirement benefit [Member] \| Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	469	485	285
Pension and other post retirement benefit [Member] \| Equity Securities [Member] \| Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	2	1	3
Pension and other post retirement benefit [Member] \| Debt Securities [Member] \| Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	337	348	144
Pension and other post retirement benefit [Member] \| Private Placement [Member] \| Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	130	136	$ 138
Pension and other post retirement benefit [Member] \| Fair Value, Recurring [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	13,961	13,595
Pension and other post retirement benefit [Member] \| Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	4,682	4,007
Pension and other post retirement benefit [Member] \| Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	3,170	3,513
Pension and other post retirement benefit [Member] \| Fair Value, Recurring [Member] \| Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	469	485
Pension and other post retirement benefit [Member] \| Fair Value, Recurring [Member] \| Fair Value Measured at Net Asset Value Per Share [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Amount	$ 5,640	$ 5,590

Retirement Benefits - Reconcili

Retirement Benefits - Reconciliation of Level 3 Assets and Liabilities measured at Fair Value for Pension and Other Postretirement Benefit Plans (Details) - Pension and other post retirement benefit [Member] - Fair Value, Inputs, Level 3 [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of net plan assets as of the beginning of year	$ 485	$ 285
Relating to assets still held at the reporting date	6	18
Defined Benefit Plan Purchases	15	34
Settlements	(42)	(27)
Transfers into (out of) Level 3	5	175
Fair value of net plan assets as of the end of year	469	485
Debt Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of net plan assets as of the beginning of year	348	144
Relating to assets still held at the reporting date	(12)	11
Defined Benefit Plan Purchases	10	20
Settlements	(13)	(2)
Transfers into (out of) Level 3	4	175
Fair value of net plan assets as of the end of year	337	348
Equity Securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of net plan assets as of the beginning of year	1	3
Relating to assets still held at the reporting date	0	(2)
Defined Benefit Plan Purchases	0	0
Settlements	0	0
Transfers into (out of) Level 3	1	0
Fair value of net plan assets as of the end of year	2	1
Private Placement [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of net plan assets as of the beginning of year	136	138
Relating to assets still held at the reporting date	18	9
Defined Benefit Plan Purchases	5	14
Settlements	(29)	(25)
Transfers into (out of) Level 3	0	0
Fair value of net plan assets as of the end of year	$ 130	$ 136

Retirement Benefits - Defined C

Retirement Benefits - Defined Contribution Savings Plan (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Savings plan matching contributions	$ 90	$ 95	$ 88
Commonwealth Edison Co [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Savings plan matching contributions	35	36	35
PECO Energy Co [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Savings plan matching contributions	12	12	11
Baltimore Gas and Electric Company [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Savings plan matching contributions	12	13	12
Pepco Holdings LLC [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Savings plan matching contributions	14	14	13
Potomac Electric Power Company [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Savings plan matching contributions	4	4	3
Delmarva Power & Light Company [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Savings plan matching contributions	3	3	3
Atlantic City Electric Company [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Savings plan matching contributions	$ 2	$ 3	$ 2

Derivative Financial Instrume_3

Derivative Financial Instruments - Narrative (Details) MWh in Millions, $ in Millions	Jun. 30, 2022 MWh	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Derivative [Line Items]
Derivative, Notional Amount		$ 3,481	$ 4,018
Other		766	784
Commonwealth Edison Co [Member]
Derivative [Line Items]
Long-term Purchase Commitment, Minimum Energy Volume Required \| MWh	1.3
Other		133	143
PECO Energy Co [Member]
Derivative [Line Items]
Incremental collateral for loss of investment grade credit rating		37
Other		35	30
Baltimore Gas and Electric Company [Member]
Derivative [Line Items]
Incremental collateral for loss of investment grade credit rating		78
Other		48	91
Delmarva Power & Light Company [Member]
Derivative [Line Items]
Incremental collateral for loss of investment grade credit rating		14
Other		59	$ 20
Commodity Contract [Member] \| Commonwealth Edison Co [Member] \| External Counterparties \| Collateral [Member]
Derivative [Line Items]
Other		41
Commodity Contract [Member] \| Delmarva Power & Light Company [Member] \| External Counterparties \| Collateral [Member]
Derivative [Line Items]
Other		$ 43

Derivative Financial Instrume_4

Derivative Financial Instruments - Summary of Derivative Fair Value Balances (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Derivative [Line Items]
Mark-to-market derivative liabilities, current	$ (18)	$ (33)
Mark-to-market derivative liabilities, noncurrent	(201)	(268)
Total mark-to-market derivative net assets (liabilities)	(2)	1
Commonwealth Edison Co [Member]
Derivative [Line Items]
Mark-to-market derivative liabilities, current	(18)	(33)
Mark-to-market derivative liabilities, noncurrent	(201)	(268)
Commodity Contract [Member] \| Not Designated as Hedging Instrument, Economic Hedge [Member] \| Commonwealth Edison Co [Member]
Derivative [Line Items]
Mark-to-market derivative liabilities, current	(18)	(33)
Mark-to-market derivative liabilities, noncurrent	(201)	(268)
Total mark-to-market derivative liabilities	$ (219)	$ (301)

Derivative Financial Instrume_5

Derivative Financial Instruments - Summary of Economic Hedges (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Derivative [Line Items]
Unrealized Gain (Loss) on Derivatives	$ 568	$ 268	$ (222)
Derivative Liability, Current	(18)	(33)
Derivative Liability, Noncurrent	(201)	(268)
Commonwealth Edison Co [Member]
Derivative [Line Items]
Derivative Liability, Current	(18)	(33)
Derivative Liability, Noncurrent	(201)	(268)
Not Designated as Hedging Instrument, Economic Hedge [Member] \| Commodity Contract [Member] \| Commonwealth Edison Co [Member]
Derivative [Line Items]
Derivative Liability, Current	(18)	(33)
Derivative Liability, Noncurrent	(201)	(268)
Derivative Liability	$ (219)	$ (301)

Debt and Credit Agreements - Na

Debt and Credit Agreements - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Short-term Loan Agreements [Abstract]
Long-term Debt, Current Maturities	$ 2,153	$ 1,622
Nonrecourse Debt [Abstract]
Long-term Debt	32,655
Long-term debt, gross	$ 32,523	30,702
London Interbank Offered Rate (LIBOR) [Member] \| Minimum [Member]
Nonrecourse Debt [Abstract]
Debt Instrument, Basis Spread on Variable Rate	0.90%
London Interbank Offered Rate (LIBOR) [Member] \| Maximum [Member]
Nonrecourse Debt [Abstract]
Debt Instrument, Basis Spread on Variable Rate	1.275%
DOE Project Financing, 2.82% January 5, 2037 [Member] \| Non Recourse Debt [Member]
Nonrecourse Debt [Abstract]
Debt Instrument, Basis Spread on Variable Rate	0.375%
Corporate, Non-Segment [Member]
Short-term Loan Agreements [Abstract]
Long-term Debt, Current Maturities	$ 1,150	300
Notes Receivable, Related Parties	319	324
Nonrecourse Debt [Abstract]
Long-term Debt	7,289
Long-term debt, gross	7,289	7,589
Due from Affiliate, Noncurrent	$ 319	324
Corporate, Non-Segment [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Nonrecourse Debt [Abstract]
Debt Instrument, Basis Spread on Variable Rate	1.275%
Corporate, Non-Segment [Member] \| ShortTermDebt03232017 [Member]
Short-term Loan Agreements [Abstract]
Short-Term Loans	$ 500
Corporate, Non-Segment [Member] \| ShortTermDebt03232017 [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Short-term Loan Agreements [Abstract]
Short-Term Loans, Interest rate terms	0.65
Corporate, Non-Segment [Member] \| ShortTermDebt03242021 [Member]
Short-term Loan Agreements [Abstract]
Short-Term Loans	$ 200
Corporate, Non-Segment [Member] \| ShortTermDebt03242021 [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Short-term Loan Agreements [Abstract]
Short-Term Loans, Interest rate terms	0.65
Corporate, Non-Segment [Member] \| ShortTermDebt03312021.1 [Member]
Short-term Loan Agreements [Abstract]
Short-Term Loans	$ 150
Corporate, Non-Segment [Member] \| ShortTermDebt03312021.1 [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Short-term Loan Agreements [Abstract]
Short-Term Loans, Interest rate terms	0.65
Corporate, Non-Segment [Member] \| ShortTermDebt03312021.2 [Member]
Short-term Loan Agreements [Abstract]
Short-Term Loans	$ 150
Corporate, Non-Segment [Member] \| ShortTermDebt03312021.2 [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Short-term Loan Agreements [Abstract]
Short-Term Loans, Interest rate terms	0.65
Commonwealth Edison Co [Member]
Short-term Loan Agreements [Abstract]
Long-term Debt, Current Maturities	$ 0	350
Nonrecourse Debt [Abstract]
Long-term Debt	10,092
Long-term debt, gross	$ 9,887	9,087
Commonwealth Edison Co [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Nonrecourse Debt [Abstract]
Debt Instrument, Basis Spread on Variable Rate	1%
Commonwealth Edison Co [Member] \| ShortTermDebt01252021.1
Short-term Loan Agreements [Abstract]
Short-Term Loans	$ 125
Commonwealth Edison Co [Member] \| ShortTermDebt01252021.1 \| London Interbank Offered Rate (LIBOR) [Member]
Short-term Loan Agreements [Abstract]
Short-Term Loans, Interest rate terms	0.50
Commonwealth Edison Co [Member] \| ShortTermDebt01252021.2
Short-term Loan Agreements [Abstract]
Short-Term Loans	$ 125
Commonwealth Edison Co [Member] \| ShortTermDebt01252021.2 \| London Interbank Offered Rate (LIBOR) [Member]
Short-term Loan Agreements [Abstract]
Short-Term Loans, Interest rate terms	0.75
Delmarva Power & Light Company [Member]
Short-term Loan Agreements [Abstract]
Long-term Debt, Current Maturities	$ 79	79
Nonrecourse Debt [Abstract]
Long-term Debt	1,821
Long-term debt, gross	$ 1,821	$ 1,687
Delmarva Power & Light Company [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Nonrecourse Debt [Abstract]
Debt Instrument, Basis Spread on Variable Rate	1%

Debt and Credit Agreements - Co

Debt and Credit Agreements - Commercial Paper Borrowings (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Commercial Paper
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	$ 3,700	$ 3,700
Commercial Paper	$ 599	$ 691
Average interest rate on commercial paper borrowings	0.35%	0.24%
Revolving Credit Facility [Member]
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	$ 3,700
Letters of Credit Outstanding, Amount	8
Line of credit facility, remaining borrowing capacity	3,692
Revolving Credit Facility [Member] \| Community and Minority Facilities [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Current Borrowing Capacity	98	$ 97
Corporate, Non-Segment [Member] \| Commercial Paper
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	600	600
Commercial Paper	0	0
Corporate, Non-Segment [Member] \| Revolving Credit Facility [Member]
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	600
Letters of Credit Outstanding, Amount	6
Line of credit facility, remaining borrowing capacity	594
Commonwealth Edison Co [Member] \| Commercial Paper
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	1,000	1,000
Commercial Paper	$ 0	$ 323
Average interest rate on commercial paper borrowings	0%	0.23%
Commonwealth Edison Co [Member] \| Revolving Credit Facility [Member]
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	$ 1,000
Letters of Credit Outstanding, Amount	2
Line of credit facility, remaining borrowing capacity	998
Commonwealth Edison Co [Member] \| Revolving Credit Facility [Member] \| Community and Minority Facilities [Member]
Short-term Debt [Line Items]
Letters of Credit Outstanding, Amount	5
Line of Credit Facility, Current Borrowing Capacity	33	$ 32
PECO Energy Co [Member] \| Commercial Paper
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	600	600
Commercial Paper	$ 0	$ 0
Average interest rate on commercial paper borrowings	0%	0%
PECO Energy Co [Member] \| Revolving Credit Facility [Member]
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	$ 600
Letters of Credit Outstanding, Amount	0
Line of credit facility, remaining borrowing capacity	600
PECO Energy Co [Member] \| Revolving Credit Facility [Member] \| Community and Minority Facilities [Member]
Short-term Debt [Line Items]
Letters of Credit Outstanding, Amount	1
Line of Credit Facility, Current Borrowing Capacity	33	$ 33
Baltimore Gas and Electric Company [Member] \| Commercial Paper
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	600	600
Commercial Paper	$ 130	$ 0
Average interest rate on commercial paper borrowings	0.37%	0%
Baltimore Gas and Electric Company [Member] \| Revolving Credit Facility [Member]
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	$ 600
Letters of Credit Outstanding, Amount	0
Line of credit facility, remaining borrowing capacity	600
Baltimore Gas and Electric Company [Member] \| Revolving Credit Facility [Member] \| Community and Minority Facilities [Member]
Short-term Debt [Line Items]
Letters of Credit Outstanding, Amount	2
Line of Credit Facility, Current Borrowing Capacity	8	$ 8
Pepco Holdings LLC [Member] \| Commercial Paper
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	900	900
Commercial Paper	$ 469	$ 368
Average interest rate on commercial paper borrowings	0.35%	0.24%
Pepco Holdings LLC [Member] \| Revolving Credit Facility [Member]
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	$ 900
Letters of Credit Outstanding, Amount	0
Line of credit facility, remaining borrowing capacity	900
Pepco Holdings LLC [Member] \| Revolving Credit Facility [Member] \| Maximum [Member]
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	900
Potomac Electric Power Company [Member] \| Commercial Paper
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	300	$ 300
Commercial Paper	$ 175	$ 35
Average interest rate on commercial paper borrowings	0.33%	0.22%
Line of credit facility, remaining borrowing capacity	$ 500
Potomac Electric Power Company [Member] \| Revolving Credit Facility [Member]
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	300
Letters of Credit Outstanding, Amount	0
Line of credit facility, remaining borrowing capacity	300
Potomac Electric Power Company [Member] \| Revolving Credit Facility [Member] \| Community and Minority Facilities [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Current Borrowing Capacity	8	$ 8
Delmarva Power & Light Company [Member] \| Commercial Paper
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	300	300
Commercial Paper	$ 149	$ 146
Average interest rate on commercial paper borrowings	0.36%	0.24%
Line of credit facility, remaining borrowing capacity	$ 500
Delmarva Power & Light Company [Member] \| Revolving Credit Facility [Member]
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	300
Letters of Credit Outstanding, Amount	0
Line of credit facility, remaining borrowing capacity	300
Delmarva Power & Light Company [Member] \| Revolving Credit Facility [Member] \| Community and Minority Facilities [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Current Borrowing Capacity	8	$ 8
Atlantic City Electric Company [Member] \| Commercial Paper
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	300	300
Commercial Paper	$ 145	$ 187
Average interest rate on commercial paper borrowings	0.35%	0.25%
Line of credit facility, remaining borrowing capacity	$ 350
Atlantic City Electric Company [Member] \| Revolving Credit Facility [Member]
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	300
Letters of Credit Outstanding, Amount	0
Line of credit facility, remaining borrowing capacity	300
Atlantic City Electric Company [Member] \| Revolving Credit Facility [Member] \| Community and Minority Facilities [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Current Borrowing Capacity	$ 8	$ 8

Debt and Credit Agreements - Su

Debt and Credit Agreements - Summary of Bank Commitments, Credit Facility Borrowings and Available Capacity (Details) - Revolving Credit Facility [Member] - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	$ 3,700
Long-term line of credit/facility draws	0
Outstanding letters of credit	8
Actual available capacity	3,692
To support additional commercial paper	3,093
Community and Minority Facilities [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Current Borrowing Capacity	98	$ 97
Corporate, Non-Segment [Member]
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	600
Outstanding letters of credit	6
Actual available capacity	594
Commonwealth Edison Co [Member]
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	1,000
Long-term line of credit/facility draws	0
Outstanding letters of credit	2
Actual available capacity	998
To support additional commercial paper	998
Commonwealth Edison Co [Member] \| Community and Minority Facilities [Member]
Short-term Debt [Line Items]
Outstanding letters of credit	5
Line of Credit Facility, Current Borrowing Capacity	33	32
PECO Energy Co [Member]
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	600
Long-term line of credit/facility draws	0
Outstanding letters of credit	0
Actual available capacity	600
To support additional commercial paper	600
PECO Energy Co [Member] \| Community and Minority Facilities [Member]
Short-term Debt [Line Items]
Outstanding letters of credit	1
Line of Credit Facility, Current Borrowing Capacity	33	33
Baltimore Gas and Electric Company [Member]
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	600
Long-term line of credit/facility draws	0
Outstanding letters of credit	0
Actual available capacity	600
To support additional commercial paper	470
Baltimore Gas and Electric Company [Member] \| Community and Minority Facilities [Member]
Short-term Debt [Line Items]
Outstanding letters of credit	2
Line of Credit Facility, Current Borrowing Capacity	8	8
Pepco Holdings LLC [Member]
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	900
Long-term line of credit/facility draws	0
Outstanding letters of credit	0
Actual available capacity	900
To support additional commercial paper	431
Potomac Electric Power Company [Member]
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	300
Long-term line of credit/facility draws	0
Outstanding letters of credit	0
Actual available capacity	300
To support additional commercial paper	125
Potomac Electric Power Company [Member] \| Community and Minority Facilities [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Current Borrowing Capacity	8	8
Delmarva Power & Light Company [Member]
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	300
Long-term line of credit/facility draws	0
Outstanding letters of credit	0
Actual available capacity	300
To support additional commercial paper	151
Delmarva Power & Light Company [Member] \| Community and Minority Facilities [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Current Borrowing Capacity	8	8
Atlantic City Electric Company [Member]
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	300
Long-term line of credit/facility draws	0
Outstanding letters of credit	0
Actual available capacity	300
To support additional commercial paper	155
Atlantic City Electric Company [Member] \| Community and Minority Facilities [Member]
Short-term Debt [Line Items]
Line of Credit Facility, Current Borrowing Capacity	$ 8	$ 8

Debt and Credit Agreements - _2

Debt and Credit Agreements - Summary of Revolving Credit Agreements (Details) - Revolving Credit Facility [Member] - USD ($) $ in Millions	Feb. 01, 2022	Dec. 31, 2021
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 3,700
Commonwealth Edison Co [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		1,000
Commonwealth Edison Co [Member] \| Subsequent Event [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 1,000
Commonwealth Edison Co [Member] \| Subsequent Event [Member] \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Line of Credit Facility [Line Items]
Line of credit facility, interest rate at period end	1%
PECO Energy Co [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		600
PECO Energy Co [Member] \| Subsequent Event [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 600
PECO Energy Co [Member] \| Subsequent Event [Member] \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Line of Credit Facility [Line Items]
Line of credit facility, interest rate at period end	0.90%
Baltimore Gas and Electric Company [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		600
Baltimore Gas and Electric Company [Member] \| Subsequent Event [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 600
Baltimore Gas and Electric Company [Member] \| Subsequent Event [Member] \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Line of Credit Facility [Line Items]
Line of credit facility, interest rate at period end	0.90%
Potomac Electric Power Company [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		300
Potomac Electric Power Company [Member] \| Subsequent Event [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 300
Potomac Electric Power Company [Member] \| Subsequent Event [Member] \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Line of Credit Facility [Line Items]
Line of credit facility, interest rate at period end	1.075%
Delmarva Power & Light Company [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		300
Delmarva Power & Light Company [Member] \| Subsequent Event [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 300
Delmarva Power & Light Company [Member] \| Subsequent Event [Member] \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Line of Credit Facility [Line Items]
Line of credit facility, interest rate at period end	1%
Atlantic City Electric Company [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		300
Atlantic City Electric Company [Member] \| Subsequent Event [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 300
Atlantic City Electric Company [Member] \| Subsequent Event [Member] \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Line of Credit Facility [Line Items]
Line of credit facility, interest rate at period end	1.075%
Corporate, Non-Segment [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 600
Corporate, Non-Segment [Member] \| Subsequent Event [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 900
Corporate, Non-Segment [Member] \| Subsequent Event [Member] \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Line of Credit Facility [Line Items]
Line of credit facility, interest rate at period end	1.275%

Debt and Credit Agreements - _3

Debt and Credit Agreements - Summary of Basis Spread (Details)	12 Months Ended
	Dec. 31, 2021
Prime Rate [Member] \| Corporate, Non-Segment [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.275%
Prime Rate [Member] \| Minimum [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0%
Prime Rate [Member] \| Maximum [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.275%
Prime Rate [Member] \| Maximum [Member] \| External Credit Rating, Non Investment Grade
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.65%
London Interbank Offered Rate (LIBOR) [Member] \| Corporate, Non-Segment [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.275%
London Interbank Offered Rate (LIBOR) [Member] \| Minimum [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.90%
London Interbank Offered Rate (LIBOR) [Member] \| Maximum [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.275%
London Interbank Offered Rate (LIBOR) [Member] \| Maximum [Member] \| External Credit Rating, Non Investment Grade
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.65%
Commonwealth Edison Co [Member] \| Prime Rate [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0%
Commonwealth Edison Co [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1%
PECO Energy Co [Member] \| Prime Rate [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0%
PECO Energy Co [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.90%
Baltimore Gas and Electric Company [Member] \| Prime Rate [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0%
Baltimore Gas and Electric Company [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.90%
Potomac Electric Power Company [Member] \| Prime Rate [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.075%
Potomac Electric Power Company [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.075%
Delmarva Power & Light Company [Member] \| Prime Rate [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0%
Delmarva Power & Light Company [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1%
Atlantic City Electric Company [Member] \| Prime Rate [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.075%
Atlantic City Electric Company [Member] \| London Interbank Offered Rate (LIBOR) [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.075%

Debt and Credit Agreements - _4

Debt and Credit Agreements - Summary of Outstanding Long-term Debt (Details) - USD ($) $ in Millions	Jan. 24, 2022	Jan. 21, 2022	Feb. 15, 2022	Dec. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Long-term debt, gross				$ 32,523	$ 30,702
Unamortized debt discount and premium, net				(70)	(72)
Unamortized debt issuance costs				(220)	(202)
Fair value adjustment				669	721
Long-term Debt, Current Maturities				(2,153)	(1,622)
Long-term Debt, Excluding Current Maturities				30,749	29,527
Long-term debt to financing trusts				390	390
Corporate, Non-Segment [Member]
Debt Instrument [Line Items]
Long-term debt, gross				7,289	7,589
Unamortized debt discount and premium, net				10	10
Unamortized debt issuance costs				(39)	(47)
Fair value adjustment				175	186
Long-term Debt, Current Maturities				(1,150)	(300)
Long-term Debt, Excluding Current Maturities				6,265	7,418
First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 20,751	18,915
First Mortgage Bonds [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				0.14%
Long-term Debt, Maturity Date				Dec. 31, 2022
First Mortgage Bonds [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				7.90%
Long-term Debt, Maturity Date				Dec. 31, 2051
Senior unsecured notes [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 6,324	6,624
Senior unsecured notes [Member] \| Corporate, Non-Segment [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 6,139	6,439
Senior unsecured notes [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				3.40%
Long-term Debt, Maturity Date				Dec. 31, 2022
Senior unsecured notes [Member] \| Minimum [Member] \| Corporate, Non-Segment [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				3.40%
Long-term Debt, Maturity Date				Dec. 31, 2025
Senior unsecured notes [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				7.60%
Long-term Debt, Maturity Date				Dec. 31, 2050
Senior unsecured notes [Member] \| Maximum [Member] \| Corporate, Non-Segment [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				7.60%
Long-term Debt, Maturity Date				Dec. 31, 2050
Unsecured notes [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 4,000	3,700
Unsecured notes [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				2.25%
Long-term Debt, Maturity Date				Dec. 31, 2022
Unsecured notes [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				6.35%
Long-term Debt, Maturity Date				Dec. 31, 2050
Notes payable and other [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 86	59
Notes payable and other [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				1.64%
Long-term Debt, Maturity Date				Dec. 31, 2022
Notes payable and other [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				7.49%
Long-term Debt, Maturity Date				Dec. 31, 2053
Junior subordinated notes [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 1,150	1,150
Junior subordinated notes [Member] \| Corporate, Non-Segment [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 1,150	1,150
Junior subordinated notes [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				3.50%
Long-term Debt, Maturity Date				Dec. 31, 2022
Junior subordinated notes [Member] \| Maximum [Member] \| Corporate, Non-Segment [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				3.50%
Long-term Debt, Maturity Date				Dec. 31, 2022
Long-term software licensing agreement [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 9	30
Long-term software licensing agreement [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				3.62%
Long-term Debt, Maturity Date				Dec. 31, 2024
Long-term software licensing agreement [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				3.95%
Long-term Debt, Maturity Date				Dec. 31, 2025
Unsecured tax-exempt bonds [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 143	143
Unsecured tax-exempt bonds [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				0.12%
Long-term Debt, Maturity Date				Dec. 31, 2022
Unsecured tax-exempt bonds [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				1.70%
Long-term Debt, Maturity Date				Dec. 31, 2024
Medium-term notes [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 10	10
Medium-term notes [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage
Medium-term notes [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				7.72%
Long-term Debt, Maturity Date				Dec. 31, 2027
Transition bonds [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 0	21
Transition bonds [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				5.55%
Long-term Debt, Maturity Date				Dec. 31, 2021
Loan agreement [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 50	50
Loan agreement [Member] \| Subsequent Event [Member] \| Corporate, Non-Segment [Member]
Debt Instrument [Line Items]
Long-term debt, gross		$ 300
Loan agreement [Member] \| Subsequent Event [Member] \| Corporate, Non-Segment [Member] \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Debt Instrument [Line Items]
Subordinated Borrowing, Interest Rate		0.65%
Loan agreement [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				2%
Long-term Debt, Maturity Date				Dec. 31, 2023
Fixed rates [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturity Date				Dec. 31, 2031
Fixed rates [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturity Date				Dec. 31, 2037
Variable rates [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturity Date				Dec. 31, 2026
Variable rates [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturity Date				Dec. 31, 2027
Long-term debt to financing trusts [Member]
Debt Instrument [Line Items]
Long-term debt to financing trusts				$ 390	390
Loans Payable Two \| Subsequent Event [Member] \| Corporate, Non-Segment [Member]
Debt Instrument [Line Items]
Long-term debt, gross		$ 300
Loans Payable Two \| Subsequent Event [Member] \| Corporate, Non-Segment [Member] \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Debt Instrument [Line Items]
Subordinated Borrowing, Interest Rate		0.65%
Loans Payable Three \| Subsequent Event [Member] \| Corporate, Non-Segment [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 250
Loans Payable Three \| Subsequent Event [Member] \| Corporate, Non-Segment [Member] \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Debt Instrument [Line Items]
Subordinated Borrowing, Interest Rate	0.65%
ComEd Financing III Affiliate [Member]
Debt Instrument [Line Items]
Long-term debt to financing trusts				$ 206	206
ComEd Financing III Affiliate [Member] \| Long-term debt to financing trusts [Member]
Debt Instrument [Line Items]
Long-term debt to financing trusts					206
ComEd Financing III Affiliate [Member] \| Long-term debt to financing trusts [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				6.35%
Long-term Debt, Maturity Date				Dec. 31, 2033
PECO Trust III Affiliate [Member]
Debt Instrument [Line Items]
Long-term debt to financing trusts				$ 81	81
PECO Trust III Affiliate [Member] \| Long-term debt to financing trusts [Member]
Debt Instrument [Line Items]
Long-term debt to financing trusts				$ 81	81
PECO Trust III Affiliate [Member] \| Long-term debt to financing trusts [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				5.25%
PECO Trust III Affiliate [Member] \| Long-term debt to financing trusts [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				7.38%
Long-term Debt, Maturity Date				Dec. 31, 2028
PECO Trust IV Affiliate [Member]
Debt Instrument [Line Items]
Long-term debt to financing trusts				$ 103	103
PECO Trust IV Affiliate [Member] \| Long-term debt to financing trusts [Member]
Debt Instrument [Line Items]
Long-term debt to financing trusts				$ 103	103
PECO Trust IV Affiliate [Member] \| Long-term debt to financing trusts [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				5.75%
Long-term Debt, Maturity Date				Dec. 31, 2033
Commonwealth Edison Co [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 9,887	9,087
Unamortized debt discount and premium, net				(27)	(28)
Unamortized debt issuance costs				(87)	(76)
Long-term Debt, Current Maturities				0	(350)
Long-term Debt, Excluding Current Maturities				9,773	8,633
Long-term debt to financing trusts				205	205
Commonwealth Edison Co [Member] \| First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 9,879	9,079
Commonwealth Edison Co [Member] \| First Mortgage Bonds [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				2.20%
Long-term Debt, Maturity Date				Dec. 31, 2024
Commonwealth Edison Co [Member] \| First Mortgage Bonds [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				6.45%
Long-term Debt, Maturity Date				Dec. 31, 2051
Commonwealth Edison Co [Member] \| Notes payable and other [Member]
Debt Instrument [Line Items]
Finance lease, liability				$ 8	8
Commonwealth Edison Co [Member] \| Notes payable and other [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturity Date				Dec. 31, 2053
Lessee, finance lease, discount rate				7.49%
Commonwealth Edison Co [Member] \| Long-term debt to financing trusts [Member]
Debt Instrument [Line Items]
Long-term debt to financing trusts				$ 206	206
Commonwealth Edison Co [Member] \| ComEd Financing III Affiliate [Member]
Debt Instrument [Line Items]
Unamortized debt issuance costs				(1)	(1)
Long-term debt to financing trusts				205	205
Commonwealth Edison Co [Member] \| ComEd Financing III Affiliate [Member] \| Long-term debt to financing trusts [Member]
Debt Instrument [Line Items]
Long-term debt to financing trusts				$ 206	206
Commonwealth Edison Co [Member] \| ComEd Financing III Affiliate [Member] \| Long-term debt to financing trusts [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				6.35%
Long-term Debt, Maturity Date				Dec. 31, 2033
Commonwealth Edison Co [Member] \| PECO Trust III Affiliate [Member]
Debt Instrument [Line Items]
Long-term debt to financing trusts				$ 0	0
Commonwealth Edison Co [Member] \| PECO Trust IV Affiliate [Member]
Debt Instrument [Line Items]
Long-term debt to financing trusts				0	0
PECO Energy Co [Member]
Debt Instrument [Line Items]
Long-term debt, gross				4,250	3,800
Unamortized debt discount and premium, net				(20)	(20)
Unamortized debt issuance costs				(33)	(27)
Long-term Debt, Current Maturities				(350)	(300)
Long-term Debt, Excluding Current Maturities				3,847	3,453
Long-term debt to financing trusts				184	184
PECO Energy Co [Member] \| First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 4,200	3,750
PECO Energy Co [Member] \| First Mortgage Bonds [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				2.38%
Long-term Debt, Maturity Date				Dec. 31, 2022
PECO Energy Co [Member] \| First Mortgage Bonds [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				5.95%
Long-term Debt, Maturity Date				Dec. 31, 2051
PECO Energy Co [Member] \| Loan agreement [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 50	50
PECO Energy Co [Member] \| Loan agreement [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				2%
Long-term Debt, Maturity Date				Dec. 31, 2023
PECO Energy Co [Member] \| ComEd Financing III Affiliate [Member]
Debt Instrument [Line Items]
Long-term debt to financing trusts				$ 0	0
PECO Energy Co [Member] \| PECO Trust III Affiliate [Member]
Debt Instrument [Line Items]
Long-term debt to financing trusts				81	81
PECO Energy Co [Member] \| PECO Trust III Affiliate [Member] \| Long-term debt to financing trusts [Member]
Debt Instrument [Line Items]
Long-term debt to financing trusts				$ 81	81
PECO Energy Co [Member] \| PECO Trust III Affiliate [Member] \| Long-term debt to financing trusts [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				5.25%
PECO Energy Co [Member] \| PECO Trust III Affiliate [Member] \| Long-term debt to financing trusts [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				7.38%
Long-term Debt, Maturity Date				Dec. 31, 2028
PECO Energy Co [Member] \| PECO Trust IV Affiliate [Member]
Debt Instrument [Line Items]
Long-term debt to financing trusts				$ 103	103
PECO Energy Co [Member] \| PECO Trust IV Affiliate [Member] \| Long-term debt to financing trusts [Member]
Debt Instrument [Line Items]
Long-term debt to financing trusts				$ 103	103
PECO Energy Co [Member] \| PECO Trust IV Affiliate [Member] \| Long-term debt to financing trusts [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				5.75%
Long-term Debt, Maturity Date				Dec. 31, 2033
Baltimore Gas and Electric Company [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 4,000	3,700
Unamortized debt discount and premium, net				(12)	(12)
Unamortized debt issuance costs				(27)	(24)
Long-term Debt, Current Maturities				(250)	(300)
Long-term Debt, Excluding Current Maturities				3,711	3,364
Baltimore Gas and Electric Company [Member] \| Senior unsecured notes [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 4,000	3,700
Baltimore Gas and Electric Company [Member] \| Senior unsecured notes [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				2.25%
Long-term Debt, Maturity Date				Dec. 31, 2022
Baltimore Gas and Electric Company [Member] \| Senior unsecured notes [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				6.35%
Long-term Debt, Maturity Date				Dec. 31, 2050
Pepco Holdings LLC [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 7,084	6,496
Finance lease, liability				74	50
Unamortized debt discount and premium, net				4	4
Unamortized debt issuance costs				(36)	(28)
Fair value adjustment				495	534
Long-term debt due within one year				(399)	(347)
Long-term Debt, Excluding Current Maturities				7,148	6,659
Pepco Holdings LLC [Member] \| First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 6,672	6,086
Pepco Holdings LLC [Member] \| First Mortgage Bonds [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				0.14%
Long-term Debt, Maturity Date				Dec. 31, 2022
Pepco Holdings LLC [Member] \| First Mortgage Bonds [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				7.90%
Long-term Debt, Maturity Date				Dec. 31, 2051
Pepco Holdings LLC [Member] \| Senior unsecured notes [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturity Date				Dec. 31, 2032
Pepco Holdings LLC [Member] \| Unsecured notes [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 185	185
Pepco Holdings LLC [Member] \| Unsecured notes [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				7.45%
Pepco Holdings LLC [Member] \| Finance Leases \| Minimum [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturity Date				Dec. 31, 2022
Pepco Holdings LLC [Member] \| Finance Leases \| Maximum [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturity Date				Dec. 31, 2029
Pepco Holdings LLC [Member] \| Notes payable and other [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 0	1
Finance lease, liability				$ 74	50
Pepco Holdings LLC [Member] \| Notes payable and other [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				7.28%
Pepco Holdings LLC [Member] \| Notes payable and other [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				7.49%
Long-term Debt, Maturity Date				Dec. 31, 2022
Lessee, finance lease, discount rate				3.54%
Pepco Holdings LLC [Member] \| Unsecured tax-exempt bonds [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 143	143
Pepco Holdings LLC [Member] \| Unsecured tax-exempt bonds [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				0.12%
Long-term Debt, Maturity Date				Dec. 31, 2022
Pepco Holdings LLC [Member] \| Unsecured tax-exempt bonds [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				1.70%
Long-term Debt, Maturity Date				Dec. 31, 2024
Pepco Holdings LLC [Member] \| Medium-term notes [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 10	10
Pepco Holdings LLC [Member] \| Medium-term notes [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				7.72%
Long-term Debt, Maturity Date				Dec. 31, 2027
Pepco Holdings LLC [Member] \| Transition bonds [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 0	21
Pepco Holdings LLC [Member] \| Transition bonds [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				5.55%
Long-term Debt, Maturity Date				Dec. 31, 2021
Potomac Electric Power Company [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 3,486	3,203
Finance lease, liability				26	17
Unamortized debt discount and premium, net				2	2
Unamortized debt issuance costs				(43)	(40)
Long-term debt due within one year				(313)	(3)
Long-term Debt, Excluding Current Maturities				3,132	3,162
Potomac Electric Power Company [Member] \| First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 3,350	3,075
Potomac Electric Power Company [Member] \| First Mortgage Bonds [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				2.32%
Long-term Debt, Maturity Date				Dec. 31, 2022
Potomac Electric Power Company [Member] \| First Mortgage Bonds [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				7.90%
Long-term Debt, Maturity Date				Dec. 31, 2051
Potomac Electric Power Company [Member] \| Finance Leases \| Minimum [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturity Date				Dec. 31, 2025
Potomac Electric Power Company [Member] \| Finance Leases \| Maximum [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturity Date				Dec. 31, 2029
Potomac Electric Power Company [Member] \| Notes payable and other [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 0	1
Finance lease, liability				$ 26	17
Potomac Electric Power Company [Member] \| Notes payable and other [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				7.28%
Potomac Electric Power Company [Member] \| Notes payable and other [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				7.49%
Long-term Debt, Maturity Date				Dec. 31, 2022
Lessee, finance lease, discount rate				3.54%
Potomac Electric Power Company [Member] \| Unsecured tax-exempt bonds [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 110	110
Potomac Electric Power Company [Member] \| Unsecured tax-exempt bonds [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				1.70%
Long-term Debt, Maturity Date				Dec. 31, 2022
Delmarva Power & Light Company [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 1,821	1,687
Finance lease, liability				29	20
Unamortized debt discount and premium, net				0	1
Unamortized debt issuance costs				(11)	(11)
Long-term Debt, Current Maturities				(79)	(79)
Long-term debt due within one year				(83)	(82)
Long-term Debt, Excluding Current Maturities				1,727	1,595
Delmarva Power & Light Company [Member] \| First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 1,749	1,624
Delmarva Power & Light Company [Member] \| First Mortgage Bonds [Member] \| Subsequent Event [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			3.06%
Long-term debt, gross			$ 125
Delmarva Power & Light Company [Member] \| First Mortgage Bonds [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				0.14%
Long-term Debt, Maturity Date				Dec. 31, 2023
Delmarva Power & Light Company [Member] \| First Mortgage Bonds [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				4.27%
Long-term Debt, Maturity Date				Dec. 31, 2051
Delmarva Power & Light Company [Member] \| Finance Leases \| Minimum [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturity Date				Dec. 31, 2025
Delmarva Power & Light Company [Member] \| Finance Leases \| Maximum [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturity Date				Dec. 31, 2029
Delmarva Power & Light Company [Member] \| Notes payable and other [Member]
Debt Instrument [Line Items]
Finance lease, liability				$ 29	20
Delmarva Power & Light Company [Member] \| Notes payable and other [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Lessee, finance lease, discount rate				3.54%
Delmarva Power & Light Company [Member] \| Unsecured tax-exempt bonds [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 33	33
Delmarva Power & Light Company [Member] \| Unsecured tax-exempt bonds [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				0.12%
Delmarva Power & Light Company [Member] \| Unsecured tax-exempt bonds [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				0.13%
Long-term Debt, Maturity Date				Dec. 31, 2024
Delmarva Power & Light Company [Member] \| Medium-term notes [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 10	10
Delmarva Power & Light Company [Member] \| Medium-term notes [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				7.72%
Long-term Debt, Maturity Date				Dec. 31, 2027
Atlantic City Electric Company [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 1,592	1,421
Finance lease, liability				19	13
Unamortized debt discount and premium, net				(1)	(1)
Unamortized debt issuance costs				(9)	(7)
Long-term debt due within one year				(3)	(261)
Long-term Debt, Excluding Current Maturities				1,579	1,152
Atlantic City Electric Company [Member] \| First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 1,573	1,387
Atlantic City Electric Company [Member] \| First Mortgage Bonds [Member] \| Subsequent Event [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			2.27%
Long-term debt, gross			$ 25
Atlantic City Electric Company [Member] \| First Mortgage Bonds [Member] \| Minimum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				2.25%
Long-term Debt, Maturity Date				Dec. 31, 2024
Atlantic City Electric Company [Member] \| First Mortgage Bonds [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				5.80%
Long-term Debt, Maturity Date				Dec. 31, 2050
Atlantic City Electric Company [Member] \| Finance Leases \| Minimum [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturity Date				Dec. 31, 2022
Atlantic City Electric Company [Member] \| Finance Leases \| Maximum [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturity Date				Dec. 31, 2029
Atlantic City Electric Company [Member] \| Notes payable and other [Member]
Debt Instrument [Line Items]
Finance lease, liability				$ 19	13
Atlantic City Electric Company [Member] \| Notes payable and other [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Lessee, finance lease, discount rate				3.54%
Atlantic City Electric Company [Member] \| Transition bonds [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 0	$ 21
Atlantic City Electric Company [Member] \| Transition bonds [Member] \| Maximum [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				5.55%
Long-term Debt, Maturity Date				Dec. 31, 2021
Atlantic City Electric Company [Member] \| First Mortgage Bonds Two \| Subsequent Event [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			3.06%
Long-term debt, gross			$ 150

Debt and Credit Agreements - Sc

Debt and Credit Agreements - Schedule of Long-term Debt Maturities (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
2022	$ 2,153
2023	864
2024	817
2025	1,322
2026	1,611
Thereafter	25,888
Long-term Debt	32,655
Long-term debt to financing trusts	390	$ 390
Long-term debt to financing trusts [Member]
Debt Instrument [Line Items]
Long-term debt to financing trusts	390	390
ComEd Financing III Affiliate [Member]
Debt Instrument [Line Items]
Long-term debt to financing trusts	206	206
ComEd Financing III Affiliate [Member] \| Long-term debt to financing trusts [Member]
Debt Instrument [Line Items]
Long-term debt to financing trusts		206
Commonwealth Edison Co [Member]
Debt Instrument [Line Items]
2022	0
2023	0
2024	250
2025	0
2026	500
Thereafter	9,342
Long-term Debt	10,092
Long-term debt to financing trusts	205	205
Commonwealth Edison Co [Member] \| Long-term debt to financing trusts [Member]
Debt Instrument [Line Items]
Long-term debt to financing trusts	206	206
Commonwealth Edison Co [Member] \| ComEd Financing III Affiliate [Member]
Debt Instrument [Line Items]
Long-term debt to financing trusts	205	205
Commonwealth Edison Co [Member] \| ComEd Financing III Affiliate [Member] \| Long-term debt to financing trusts [Member]
Debt Instrument [Line Items]
Long-term debt to financing trusts	206	206
PECO Energy Co [Member]
Debt Instrument [Line Items]
2022	350
2023	50
2024	0
2025	350
2026	0
Thereafter	3,684
Long-term Debt	4,434
Long-term debt to financing trusts	184	184
PECO Energy Co [Member] \| ComEd Financing III Affiliate [Member]
Debt Instrument [Line Items]
Long-term debt to financing trusts	0	$ 0
PECO Energy Co [Member] \| PECO Financing Trusts [Member] \| Long-term debt to financing trusts [Member]
Debt Instrument [Line Items]
Long-term debt to financing trusts	184
Baltimore Gas and Electric Company [Member]
Debt Instrument [Line Items]
2022	250
2023	300
2024	0
2025	0
2026	350
Thereafter	3,100
Long-term Debt	4,000
Pepco Holdings LLC [Member]
Debt Instrument [Line Items]
2022	399
2023	512
2024	562
2025	162
2026	11
Thereafter	5,438
Long-term Debt	7,084
Potomac Electric Power Company [Member]
Debt Instrument [Line Items]
2022	313
2023	4
2024	404
2025	4
2026	4
Thereafter	2,757
Long-term Debt	3,486
Delmarva Power & Light Company [Member]
Debt Instrument [Line Items]
2022	83
2023	505
2024	5
2025	5
2026	4
Thereafter	1,219
Long-term Debt	1,821
Atlantic City Electric Company [Member]
Debt Instrument [Line Items]
2022	3
2023	3
2024	153
2025	153
2026	3
Thereafter	1,277
Long-term Debt	$ 1,592

Fair Value of Financial Asset_3

Fair Value of Financial Assets and Liabilities - Fair Value of Financial Liabilities Recorded at Amortized Cost(Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	$ 669	$ 721
Long-term debt to financing trusts	390	390
Estimate of Fair Value Measurement [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	37,114	37,272
Long-term debt to financing trusts	470	467
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	0	0
Long-term debt to financing trusts	0	0
Spent Nuclear Fuel Obligation, Noncurrent	0	0
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	34,897	35,416
Long-term debt to financing trusts	0	0
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	2,217	1,856
Long-term debt to financing trusts	470	467
Reported Value Measurement [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	32,902	31,149
Long-term debt to financing trusts	390	390
Commonwealth Edison Co [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt to financing trusts	205	205
Commonwealth Edison Co [Member] \| Estimate of Fair Value Measurement [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	11,305	11,117
Long-term debt to financing trusts	248	246
Commonwealth Edison Co [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	0	0
Long-term debt to financing trusts	0	0
Commonwealth Edison Co [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	11,305	11,117
Long-term debt to financing trusts	0	0
Commonwealth Edison Co [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	0	0
Long-term debt to financing trusts	248	246
Commonwealth Edison Co [Member] \| Reported Value Measurement [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	9,773	8,983
Long-term debt to financing trusts	205	205
PECO Energy Co [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt to financing trusts	184	184
PECO Energy Co [Member] \| Estimate of Fair Value Measurement [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	4,790	4,603
Long-term debt to financing trusts	222	221
PECO Energy Co [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	0	0
Long-term debt to financing trusts	0	0
PECO Energy Co [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	4,740	4,553
Long-term debt to financing trusts	0	0
PECO Energy Co [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	50	50
Long-term debt to financing trusts	222	221
PECO Energy Co [Member] \| Reported Value Measurement [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	4,197	3,753
Long-term debt to financing trusts	184	184
Baltimore Gas and Electric Company [Member] \| Estimate of Fair Value Measurement [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	4,406	4,366
Baltimore Gas and Electric Company [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	0	0
Baltimore Gas and Electric Company [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	4,406	4,366
Baltimore Gas and Electric Company [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	0	0
Baltimore Gas and Electric Company [Member] \| Reported Value Measurement [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	3,961	3,664
Pepco Holdings LLC [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	495	534
Pepco Holdings LLC [Member] \| Estimate of Fair Value Measurement [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	8,137	7,905
Pepco Holdings LLC [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	0	0
Pepco Holdings LLC [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	5,970	6,099
Pepco Holdings LLC [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	2,167	1,806
Pepco Holdings LLC [Member] \| Reported Value Measurement [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	7,547	7,006
Potomac Electric Power Company [Member] \| Estimate of Fair Value Measurement [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	4,176	4,084
Potomac Electric Power Company [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	0	0
Potomac Electric Power Company [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	3,201	3,336
Potomac Electric Power Company [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	975	748
Potomac Electric Power Company [Member] \| Reported Value Measurement [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	3,445	3,165
Delmarva Power & Light Company [Member] \| Estimate of Fair Value Measurement [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	1,978	1,939
Delmarva Power & Light Company [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	0	0
Delmarva Power & Light Company [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	1,426	1,484
Delmarva Power & Light Company [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	552	455
Delmarva Power & Light Company [Member] \| Reported Value Measurement [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	1,810	1,677
Atlantic City Electric Company [Member] \| Estimate of Fair Value Measurement [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	1,732	1,620
Atlantic City Electric Company [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	0	0
Atlantic City Electric Company [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	1,091	1,018
Atlantic City Electric Company [Member] \| Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	641	602
Atlantic City Electric Company [Member] \| Reported Value Measurement [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	$ 1,582	$ 1,413

Fair Value of Financial Asset_4

Fair Value of Financial Assets and Liabilities - Fair Value Measurement of Assets and Liabilities, Recurring (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Footnotes To Fair Value Assets And Liabilities Measured On Recurring Basis [Abstract]
Derivative, Notional Amount	$ 3,481	$ 4,018
Unrealized Gain (Loss) on Investments	(160)	186	$ 0
Market-to-market derivative liabilities, current	18	33
Derivative Liability, Noncurrent	201	268
Cash and Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	464	237
Restricted cash [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	49	39
Other assets
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	44	53
Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	524	558
Assets, Fair Value Disclosure	752	776
Deferred Compensation Liability, Current and Noncurrent	(131)	(121)
Total liabilities	(350)	(422)
Fair Value, Net Asset (Liability)	402	354
Fair Value, Recurring [Member] \| Economic Hedging Instrument Liabilites [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Total mark-to-market derivative liabilities	(219)	(301)
Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	228	218
Fair Value, Recurring [Member] \| Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	60	59
Fair Value, Recurring [Member] \| Mutual Fund [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	60	54
Fair Value, Recurring [Member] \| Fixed Income Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	10	11
Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	98	94
Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	524	558
Assets, Fair Value Disclosure	644	671
Deferred Compensation Liability, Current and Noncurrent	0	0
Total liabilities	0	0
Fair Value, Net Asset (Liability)	644	671
Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Economic Hedging Instrument Liabilites [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Total mark-to-market derivative liabilities	0	0
Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	120	113
Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	60	59
Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Mutual Fund [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	60	54
Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Fixed Income Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	71	71
Deferred Compensation Liability, Current and Noncurrent	(131)	(121)
Total liabilities	(131)	(121)
Fair Value, Net Asset (Liability)	(60)	(50)
Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Economic Hedging Instrument Liabilites [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Total mark-to-market derivative liabilities	0	0
Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	71	71
Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Mutual Fund [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Fixed Income Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	10	11
Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	61	60
Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	37	34
Deferred Compensation Liability, Current and Noncurrent	0	0
Total liabilities	(219)	(301)
Fair Value, Net Asset (Liability)	(182)	(267)
Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Economic Hedging Instrument Liabilites [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Total mark-to-market derivative liabilities	(219)	(301)
Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	37	34
Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Mutual Fund [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Fixed Income Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	37	34
Commonwealth Edison Co [Member]
Footnotes To Fair Value Assets And Liabilities Measured On Recurring Basis [Abstract]
Market-to-market derivative liabilities, current	18	33
Derivative Liability, Noncurrent	201	268
Commonwealth Edison Co [Member] \| Cash and Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	105	83
Commonwealth Edison Co [Member] \| Restricted cash [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	42	37
Commonwealth Edison Co [Member] \| Other assets
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	43	43
Commonwealth Edison Co [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	237	285
Assets, Fair Value Disclosure	237	285
Total mark-to-market derivative liabilities	(219)	(301)
Deferred Compensation Liability, Current and Noncurrent	(10)	(8)
Total liabilities	(229)	(309)
Fair Value, Net Asset (Liability)	8	(24)
Commonwealth Edison Co [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Commonwealth Edison Co [Member] \| Fair Value, Recurring [Member] \| Mutual Fund [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Commonwealth Edison Co [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Commonwealth Edison Co [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	237	285
Assets, Fair Value Disclosure	237	285
Total mark-to-market derivative liabilities	0	0
Deferred Compensation Liability, Current and Noncurrent	0	0
Total liabilities	0	0
Fair Value, Net Asset (Liability)	237	285
Commonwealth Edison Co [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Commonwealth Edison Co [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Mutual Fund [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Commonwealth Edison Co [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Commonwealth Edison Co [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	0	0
Total mark-to-market derivative liabilities	0	0
Deferred Compensation Liability, Current and Noncurrent	(10)	(8)
Total liabilities	(10)	(8)
Fair Value, Net Asset (Liability)	(10)	(8)
Commonwealth Edison Co [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Commonwealth Edison Co [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Mutual Fund [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Commonwealth Edison Co [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Commonwealth Edison Co [Member] \| Fair Value, Inputs, Level 3 [Member]
Footnotes To Fair Value Assets And Liabilities Measured On Recurring Basis [Abstract]
Market-to-market derivative liabilities, current	18	33
Derivative Liability, Noncurrent	201	268
Commonwealth Edison Co [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	0	0
Total mark-to-market derivative liabilities	(219)	(301)
Deferred Compensation Liability, Current and Noncurrent	0	0
Total liabilities	(219)	(301)
Fair Value, Net Asset (Liability)	(219)	(301)
Commonwealth Edison Co [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Commonwealth Edison Co [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Mutual Fund [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Commonwealth Edison Co [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
PECO Energy Co [Member] \| Cash and Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	35	18
PECO Energy Co [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	9	8
Assets, Fair Value Disclosure	36	30
Total mark-to-market derivative liabilities	0	0
Deferred Compensation Liability, Current and Noncurrent	(9)	(9)
Total liabilities	(9)	(9)
Fair Value, Net Asset (Liability)	27	21
PECO Energy Co [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	27	22
PECO Energy Co [Member] \| Fair Value, Recurring [Member] \| Mutual Fund [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	11	9
PECO Energy Co [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	16	13
PECO Energy Co [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	9	8
Assets, Fair Value Disclosure	20	17
Total mark-to-market derivative liabilities	0	0
Deferred Compensation Liability, Current and Noncurrent	0	0
Total liabilities	0	0
Fair Value, Net Asset (Liability)	20	17
PECO Energy Co [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	11	9
PECO Energy Co [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Mutual Fund [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	11	9
PECO Energy Co [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
PECO Energy Co [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	16	13
Total mark-to-market derivative liabilities	0	0
Deferred Compensation Liability, Current and Noncurrent	(9)	(9)
Total liabilities	(9)	(9)
Fair Value, Net Asset (Liability)	7	4
PECO Energy Co [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	16	13
PECO Energy Co [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Mutual Fund [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
PECO Energy Co [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	16	13
PECO Energy Co [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	0	0
Total mark-to-market derivative liabilities	0	0
Deferred Compensation Liability, Current and Noncurrent	0	0
Total liabilities	0	0
Fair Value, Net Asset (Liability)	0	0
PECO Energy Co [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
PECO Energy Co [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Mutual Fund [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
PECO Energy Co [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Baltimore Gas and Electric Company [Member] \| Cash and Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	51	24
Baltimore Gas and Electric Company [Member] \| Restricted cash [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	4	1
Baltimore Gas and Electric Company [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	0	120
Assets, Fair Value Disclosure	14	130
Total mark-to-market derivative liabilities	0	0
Deferred Compensation Liability, Current and Noncurrent	(7)	(5)
Total liabilities	(7)	(5)
Fair Value, Net Asset (Liability)	7	125
Baltimore Gas and Electric Company [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	14	10
Baltimore Gas and Electric Company [Member] \| Fair Value, Recurring [Member] \| Mutual Fund [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	14	10
Baltimore Gas and Electric Company [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Baltimore Gas and Electric Company [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	0	120
Assets, Fair Value Disclosure	14	130
Total mark-to-market derivative liabilities	0	0
Deferred Compensation Liability, Current and Noncurrent	0	0
Total liabilities	0	0
Fair Value, Net Asset (Liability)	14	130
Baltimore Gas and Electric Company [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	14	10
Baltimore Gas and Electric Company [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Mutual Fund [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	14	10
Baltimore Gas and Electric Company [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Baltimore Gas and Electric Company [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	0	0
Total mark-to-market derivative liabilities	0	0
Deferred Compensation Liability, Current and Noncurrent	(7)	(5)
Total liabilities	(7)	(5)
Fair Value, Net Asset (Liability)	(7)	(5)
Baltimore Gas and Electric Company [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Baltimore Gas and Electric Company [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Mutual Fund [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Baltimore Gas and Electric Company [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Baltimore Gas and Electric Company [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	0	0
Total mark-to-market derivative liabilities	0	0
Deferred Compensation Liability, Current and Noncurrent	0	0
Total liabilities	0	0
Fair Value, Net Asset (Liability)	0	0
Baltimore Gas and Electric Company [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Baltimore Gas and Electric Company [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Mutual Fund [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Baltimore Gas and Electric Company [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Pepco Holdings LLC [Member] \| Cash and Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	100	74
Pepco Holdings LLC [Member] \| Restricted cash [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	3	0
Pepco Holdings LLC [Member] \| Other assets
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	0	10
Pepco Holdings LLC [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	110	86
Assets, Fair Value Disclosure	255	226
Deferred Compensation Liability, Current and Noncurrent	(18)	(17)
Total liabilities	(18)	(17)
Fair Value, Net Asset (Liability)	237	209
Pepco Holdings LLC [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	145	140
Pepco Holdings LLC [Member] \| Fair Value, Recurring [Member] \| Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	59	55
Pepco Holdings LLC [Member] \| Fair Value, Recurring [Member] \| Mutual Fund [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	14	14
Pepco Holdings LLC [Member] \| Fair Value, Recurring [Member] \| Fixed Income Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	10	11
Pepco Holdings LLC [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	62	60
Pepco Holdings LLC [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	110	86
Assets, Fair Value Disclosure	183	155
Deferred Compensation Liability, Current and Noncurrent	0	0
Total liabilities	0	0
Fair Value, Net Asset (Liability)	183	155
Pepco Holdings LLC [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	73	69
Pepco Holdings LLC [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	59	55
Pepco Holdings LLC [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Mutual Fund [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	14	14
Pepco Holdings LLC [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Fixed Income Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Pepco Holdings LLC [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Pepco Holdings LLC [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	37	37
Deferred Compensation Liability, Current and Noncurrent	(18)	(17)
Total liabilities	(18)	(17)
Fair Value, Net Asset (Liability)	19	20
Pepco Holdings LLC [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	37	37
Pepco Holdings LLC [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Pepco Holdings LLC [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Mutual Fund [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Pepco Holdings LLC [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Fixed Income Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	10	11
Pepco Holdings LLC [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	27	26
Pepco Holdings LLC [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	35	34
Deferred Compensation Liability, Current and Noncurrent	0	0
Total liabilities	0	0
Fair Value, Net Asset (Liability)	35	34
Pepco Holdings LLC [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	35	34
Pepco Holdings LLC [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Pepco Holdings LLC [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Mutual Fund [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Pepco Holdings LLC [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Fixed Income Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Pepco Holdings LLC [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	35	34
Potomac Electric Power Company [Member] \| Cash and Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	34	30
Potomac Electric Power Company [Member] \| Restricted cash [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	3	0
Potomac Electric Power Company [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	31	35
Assets, Fair Value Disclosure	151	150
Deferred Compensation Liability, Current and Noncurrent	(2)	(2)
Total liabilities	(2)	(2)
Fair Value, Net Asset (Liability)	149	148
Potomac Electric Power Company [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	120	115
Potomac Electric Power Company [Member] \| Fair Value, Recurring [Member] \| Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	58	53
Potomac Electric Power Company [Member] \| Fair Value, Recurring [Member] \| Fixed Income Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure		2
Potomac Electric Power Company [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	62	60
Potomac Electric Power Company [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	31	35
Assets, Fair Value Disclosure	89	88
Deferred Compensation Liability, Current and Noncurrent	0	0
Total liabilities	0	0
Fair Value, Net Asset (Liability)	89	88
Potomac Electric Power Company [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	58	53
Potomac Electric Power Company [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	58	53
Potomac Electric Power Company [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Fixed Income Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure		0
Potomac Electric Power Company [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Potomac Electric Power Company [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	27	28
Deferred Compensation Liability, Current and Noncurrent	(2)	(2)
Total liabilities	(2)	(2)
Fair Value, Net Asset (Liability)	25	26
Potomac Electric Power Company [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	27	28
Potomac Electric Power Company [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Potomac Electric Power Company [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Fixed Income Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure		2
Potomac Electric Power Company [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	27	26
Potomac Electric Power Company [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	35	34
Deferred Compensation Liability, Current and Noncurrent	0	0
Total liabilities	0	0
Fair Value, Net Asset (Liability)	35	34
Potomac Electric Power Company [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	35	34
Potomac Electric Power Company [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Potomac Electric Power Company [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Fixed Income Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure		0
Potomac Electric Power Company [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	35	34
Delmarva Power & Light Company [Member] \| Cash and Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	28	15
Delmarva Power & Light Company [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	43	0
Assets, Fair Value Disclosure	43	0
Deferred Compensation Liability, Current and Noncurrent	0	0
Total liabilities	0	0
Fair Value, Net Asset (Liability)	43	0
Delmarva Power & Light Company [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Delmarva Power & Light Company [Member] \| Fair Value, Recurring [Member] \| Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Delmarva Power & Light Company [Member] \| Fair Value, Recurring [Member] \| Fixed Income Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure		0
Delmarva Power & Light Company [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Delmarva Power & Light Company [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	43	0
Assets, Fair Value Disclosure	43	0
Deferred Compensation Liability, Current and Noncurrent	0	0
Total liabilities	0	0
Fair Value, Net Asset (Liability)	43	0
Delmarva Power & Light Company [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Delmarva Power & Light Company [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Delmarva Power & Light Company [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Fixed Income Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure		0
Delmarva Power & Light Company [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Delmarva Power & Light Company [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	0	0
Deferred Compensation Liability, Current and Noncurrent	0	0
Total liabilities	0	0
Fair Value, Net Asset (Liability)	0	0
Delmarva Power & Light Company [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Delmarva Power & Light Company [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Delmarva Power & Light Company [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Fixed Income Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure		0
Delmarva Power & Light Company [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Delmarva Power & Light Company [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	0	0
Deferred Compensation Liability, Current and Noncurrent	0	0
Total liabilities	0	0
Fair Value, Net Asset (Liability)	0	0
Delmarva Power & Light Company [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Delmarva Power & Light Company [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Delmarva Power & Light Company [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Fixed Income Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure		0
Delmarva Power & Light Company [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Atlantic City Electric Company [Member] \| Cash and Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	29	17
Atlantic City Electric Company [Member] \| Other assets
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	0	10
Atlantic City Electric Company [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	0	13
Assets, Fair Value Disclosure	0	13
Deferred Compensation Liability, Current and Noncurrent	0	0
Total liabilities	0	0
Fair Value, Net Asset (Liability)	0	13
Atlantic City Electric Company [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Atlantic City Electric Company [Member] \| Fair Value, Recurring [Member] \| Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Atlantic City Electric Company [Member] \| Fair Value, Recurring [Member] \| Fixed Income Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure		0
Atlantic City Electric Company [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Atlantic City Electric Company [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	0	13
Assets, Fair Value Disclosure	0	13
Deferred Compensation Liability, Current and Noncurrent	0	0
Total liabilities	0	0
Fair Value, Net Asset (Liability)	0	13
Atlantic City Electric Company [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Atlantic City Electric Company [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Atlantic City Electric Company [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Fixed Income Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure		0
Atlantic City Electric Company [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Atlantic City Electric Company [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	0	0
Deferred Compensation Liability, Current and Noncurrent	0	0
Total liabilities	0	0
Fair Value, Net Asset (Liability)	0	0
Atlantic City Electric Company [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Atlantic City Electric Company [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Atlantic City Electric Company [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Fixed Income Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure		0
Atlantic City Electric Company [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Atlantic City Electric Company [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash and Cash Equivalents, Fair Value Disclosure	0	0
Assets, Fair Value Disclosure	0	0
Deferred Compensation Liability, Current and Noncurrent	0	0
Total liabilities	0	0
Fair Value, Net Asset (Liability)	0	0
Atlantic City Electric Company [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Atlantic City Electric Company [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0	0
Atlantic City Electric Company [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Fixed Income Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure		0
Atlantic City Electric Company [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	$ 0	$ 0

Fair Value of Financial Asset_5

Fair Value of Financial Assets and Liabilities - Fair Value Reconciliation of Level 3 Assets and Liabilities Measured on a Recurring Basis (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	$ (267)	$ (260)
Total realized / unrealized gains (losses)
Included in net income	3	3
Included in regulatory assets/liabilities	82	0
Purchases, sales, issuances and settlements
Settlements	(2)	(10)
Transfers into Level 3	2
Ending Balance	(182)	(267)
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)	3	3
Commonwealth Edison Co [Member] \| Derivative [Member] \| Interest Rate Swap [Member]
Purchases, sales, issuances and settlements
Realized Investment Gains (Losses)	20	33
Commonwealth Edison Co [Member] \| Derivative [Member] \| Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	(301)	(301)
Total realized / unrealized gains (losses)
Included in net income	0	0
Included in regulatory assets/liabilities	82	0
Purchases, sales, issuances and settlements
Settlements	0	0
Transfers into Level 3	0
Ending Balance	(219)	(301)
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)	0	0
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Period Increase (Decrease)	(62)	33
Pepco Holdings LLC [Member] \| 6311 Life Insurance [Member] \| Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	34	41
Total realized / unrealized gains (losses)
Included in net income	3	3
Included in regulatory assets/liabilities	0	0
Purchases, sales, issuances and settlements
Settlements	(2)	(10)
Transfers into Level 3	0
Ending Balance	35	34
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)	3	3
Potomac Electric Power Company [Member] \| 6311 Life Insurance [Member] \| Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning Balance	34	41
Total realized / unrealized gains (losses)
Included in net income	3	3
Included in regulatory assets/liabilities	0	0
Purchases, sales, issuances and settlements
Settlements	(2)	(10)
Transfers into Level 3	0
Ending Balance	35	34
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)	$ 3	$ 3

Fair Value of Financial Asset_6

Fair Value of Financial Assets and Liabilities - Fair Value Assets and Liabilities Measure on a Recurring Basis Gain Loss Included in Earnings (Details) - Fair Value, Inputs, Level 3 [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Fair Value Assets and Liabilities Measured on a Recurring Basis Gain Loss Included in Earnings [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings	$ (3)	$ (3)
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)	$ 3	$ 3

Fair Value of Financial Asset_7

Fair Value of Financial Assets and Liabilities - Fair Value Inputs Assets Quantitative Information (Details) - Derivative [Member] - Fair Value, Inputs, Level 3 [Member] $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	$ (219)	$ (301)
Minimum [Member] \| Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative Asset (Liability) Net, Measurement Input	0.03	0.03
Fair Value Inputs Forward Heat Rate	900%	800%
Renewable factor	92%	91%
Maximum [Member] \| Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative Asset (Liability) Net, Measurement Input	0.07	0.08
Fair Value Inputs Forward Heat Rate	1,000%	900%
Renewable factor	120%	123%
Arithmetic Average [Member] \| Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative Asset (Liability) Net, Measurement Input	0.0477	0.0493
Fair Value Inputs Forward Heat Rate	913%	885%
Renewable factor	97%	99%
Commonwealth Edison Co [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	$ (219)	$ (301)
Commonwealth Edison Co [Member] \| Minimum [Member] \| Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative Asset (Liability) Net, Measurement Input	0.03	0.03
Fair Value Inputs Forward Heat Rate	900%	800%
Renewable factor	92%	91%
Commonwealth Edison Co [Member] \| Maximum [Member] \| Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative Asset (Liability) Net, Measurement Input	0.07	0.08
Fair Value Inputs Forward Heat Rate	1,000%	900%
Renewable factor	120%	123%
Commonwealth Edison Co [Member] \| Arithmetic Average [Member] \| Discounted Cash Flow [Member]
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative Asset (Liability) Net, Measurement Input	0.0477	0.0493
Fair Value Inputs Forward Heat Rate	913%	885%
Renewable factor	97%	99%

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) $ in Millions		12 Months Ended
	Mar. 23, 2016 MW	Dec. 31, 2022 MW	Dec. 31, 2021 USD ($) MGPSite	Dec. 31, 2018 MW	Dec. 31, 2017 MW	Dec. 31, 2020 USD ($)
Commitments and Contingencies [Line Items]
Other Commitment			$ 535
Accrual for Environmental Loss Contingencies, Gross			352			$ 366
Deferred Prosecution Payment			200
Commonwealth Edison Co [Member]
Commitments and Contingencies [Line Items]
Other Commitment			$ 224
Sites under study/remediation \| MGPSite			21
Accrual for Environmental Loss Contingencies, Gross			$ 279			293
Deferred Prosecution Payment			200
PECO Energy Co [Member]
Commitments and Contingencies [Line Items]
Other Commitment			$ 181
Sites under study/remediation \| MGPSite			6
Accrual for Environmental Loss Contingencies, Gross			$ 22			23
Baltimore Gas and Electric Company [Member]
Commitments and Contingencies [Line Items]
Other Commitment			$ 5
Sites under study/remediation \| MGPSite			4
Accrual for Environmental Loss Contingencies, Gross			$ 6			2
Banking Regulation, Common Equity Tier One Risk-Based Capital Ratio, Actual			0.48
Pepco Holdings LLC [Member]
Commitments and Contingencies [Line Items]
Other Commitment			$ 54
Accrual for Environmental Loss Contingencies, Gross			42			44
Potomac Electric Power Company [Member]
Commitments and Contingencies [Line Items]
Other Commitment			24
Accrual for Environmental Loss Contingencies, Gross			$ 40			42
Banking Regulation, Common Equity Tier One Risk-Based Capital Ratio, Actual			0.48
Delmarva Power & Light Company [Member]
Commitments and Contingencies [Line Items]
Other Commitment			$ 18
Sites under study/remediation \| MGPSite			1
Accrual for Environmental Loss Contingencies, Gross			$ 1			1
Banking Regulation, Common Equity Tier One Risk-Based Capital Ratio, Actual			0.48
Atlantic City Electric Company [Member]
Commitments and Contingencies [Line Items]
Other Commitment			$ 12
Accrual for Environmental Loss Contingencies, Gross			$ 1			$ 1
Banking Regulation, Common Equity Tier One Risk-Based Capital Ratio, Actual			0.48
Atlantic City Electric Company [Member] \| Minimum [Member]
Commitments and Contingencies [Line Items]
Banking Regulation, Common Equity Tier One Risk-Based Capital Ratio, Actual			0.30
PEPCO Holdings Inc [Member]
Commitments and Contingencies [Line Items]
Other Commitment			$ 513
PEPCO Holdings Inc [Member] \| Pepco Holdings LLC [Member]
Commitments and Contingencies [Line Items]
Other Commitment			320
PEPCO Holdings Inc [Member] \| Potomac Electric Power Company [Member]
Commitments and Contingencies [Line Items]
Other Commitment			120
PEPCO Holdings Inc [Member] \| Delmarva Power & Light Company [Member]
Commitments and Contingencies [Line Items]
Other Commitment			89
PEPCO Holdings Inc [Member] \| Atlantic City Electric Company [Member]
Commitments and Contingencies [Line Items]
Other Commitment			$ 111
PEPCO Holdings Inc [Member] \| Wind Assets [Member]
Commitments and Contingencies [Line Items]
OtherNonFinancialCommitment1 \| MW	100
PEPCO Holdings Inc [Member] \| Wind Assets [Member] \| Delmarva Power & Light Company [Member]
Commitments and Contingencies [Line Items]
Purchase Commitment \| MW	120			40	40
PEPCO Holdings Inc [Member] \| Wind Assets [Member] \| Delmarva Power & Light Company [Member] \| Subsequent Event [Member]
Commitments and Contingencies [Line Items]
Purchase Commitment \| MW		40

Commitments and Contingencies_3

Commitments and Contingencies - Schedule of PHI Merger Commitments (Details) $ in Millions	Dec. 31, 2021 USD ($)
PHI Merger Commitments [Line Items]
Other Commitment	$ 535
PEPCO Holdings Inc [Member]
PHI Merger Commitments [Line Items]
Other Commitment	513
Pepco Holdings LLC [Member]
PHI Merger Commitments [Line Items]
Other Commitment	54
Pepco Holdings LLC [Member] \| PEPCO Holdings Inc [Member]
PHI Merger Commitments [Line Items]
Other Commitment	320
Potomac Electric Power Company [Member]
PHI Merger Commitments [Line Items]
Other Commitment	24
Potomac Electric Power Company [Member] \| PEPCO Holdings Inc [Member]
PHI Merger Commitments [Line Items]
Other Commitment	120
Delmarva Power & Light Company [Member]
PHI Merger Commitments [Line Items]
Other Commitment	18
Delmarva Power & Light Company [Member] \| PEPCO Holdings Inc [Member]
PHI Merger Commitments [Line Items]
Other Commitment	89
Atlantic City Electric Company [Member]
PHI Merger Commitments [Line Items]
Other Commitment	12
Atlantic City Electric Company [Member] \| PEPCO Holdings Inc [Member]
PHI Merger Commitments [Line Items]
Other Commitment	111
Remaining Commitment [Member] \| PEPCO Holdings Inc [Member]
PHI Merger Commitments [Line Items]
Other Commitment	68
Remaining Commitment [Member] \| Pepco Holdings LLC [Member] \| PEPCO Holdings Inc [Member]
PHI Merger Commitments [Line Items]
Other Commitment	58
Remaining Commitment [Member] \| Potomac Electric Power Company [Member] \| PEPCO Holdings Inc [Member]
PHI Merger Commitments [Line Items]
Other Commitment	48
Remaining Commitment [Member] \| Delmarva Power & Light Company [Member] \| PEPCO Holdings Inc [Member]
PHI Merger Commitments [Line Items]
Other Commitment	6
Remaining Commitment [Member] \| Atlantic City Electric Company [Member] \| PEPCO Holdings Inc [Member]
PHI Merger Commitments [Line Items]
Other Commitment	$ 4

Commitments and Contingencies_4

Commitments and Contingencies - Schedule of Commercial Commitments (Details) $ in Millions	Dec. 31, 2021 USD ($)
Guarantor Obligations [Line Items]
Other Commitment	$ 535
Other Commitments, Due in Next Twelve Months	124
Other Commitment, to be Paid, Year Two	5
Other Commitment, to be Paid, Year Three	8
Other Commitment, to be Paid, Year Four	6
Other Commitment, to be Paid, Year Five	5
Other Commitment, to be Paid, after Year Five	387
Guarantee obligations maximum exposure	75
Commonwealth Edison Co [Member]
Guarantor Obligations [Line Items]
Other Commitment	224
Other Commitments, Due in Next Twelve Months	22
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	2
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five	0
Other Commitment, to be Paid, after Year Five	200
PECO Energy Co [Member]
Guarantor Obligations [Line Items]
Other Commitment	181
Other Commitments, Due in Next Twelve Months	3
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five	0
Other Commitment, to be Paid, after Year Five	178
Baltimore Gas and Electric Company [Member]
Guarantor Obligations [Line Items]
Other Commitment	5
Other Commitments, Due in Next Twelve Months	5
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five	0
Other Commitment, to be Paid, after Year Five	0
Pepco Holdings LLC [Member]
Guarantor Obligations [Line Items]
Other Commitment	54
Other Commitments, Due in Next Twelve Months	23
Other Commitment, to be Paid, Year Two	5
Other Commitment, to be Paid, Year Three	6
Other Commitment, to be Paid, Year Four	6
Other Commitment, to be Paid, Year Five	5
Other Commitment, to be Paid, after Year Five	9
Guarantee obligations maximum exposure	75
Potomac Electric Power Company [Member]
Guarantor Obligations [Line Items]
Other Commitment	24
Other Commitments, Due in Next Twelve Months	14
Other Commitment, to be Paid, Year Two	1
Other Commitment, to be Paid, Year Three	2
Other Commitment, to be Paid, Year Four	2
Other Commitment, to be Paid, Year Five	2
Other Commitment, to be Paid, after Year Five	3
Guarantee obligations maximum exposure	25
Delmarva Power & Light Company [Member]
Guarantor Obligations [Line Items]
Other Commitment	18
Other Commitments, Due in Next Twelve Months	5
Other Commitment, to be Paid, Year Two	2
Other Commitment, to be Paid, Year Three	3
Other Commitment, to be Paid, Year Four	2
Other Commitment, to be Paid, Year Five	2
Other Commitment, to be Paid, after Year Five	4
Guarantee obligations maximum exposure	31
Atlantic City Electric Company [Member]
Guarantor Obligations [Line Items]
Other Commitment	12
Other Commitments, Due in Next Twelve Months	4
Other Commitment, to be Paid, Year Two	2
Other Commitment, to be Paid, Year Three	1
Other Commitment, to be Paid, Year Four	2
Other Commitment, to be Paid, Year Five	1
Other Commitment, to be Paid, after Year Five	2
Guarantee obligations maximum exposure	19
Financial Standby Letter of Credit [Member]
Guarantor Obligations [Line Items]
Other Commitment	17
Other Commitments, Due in Next Twelve Months	17
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five	0
Other Commitment, to be Paid, after Year Five	0
Financial Standby Letter of Credit [Member] \| Commonwealth Edison Co [Member]
Guarantor Obligations [Line Items]
Other Commitment	7
Other Commitments, Due in Next Twelve Months	7
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five	0
Other Commitment, to be Paid, after Year Five	0
Financial Standby Letter of Credit [Member] \| PECO Energy Co [Member]
Guarantor Obligations [Line Items]
Other Commitment	1
Other Commitments, Due in Next Twelve Months	1
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five	0
Other Commitment, to be Paid, after Year Five	0
Financial Standby Letter of Credit [Member] \| Baltimore Gas and Electric Company [Member]
Guarantor Obligations [Line Items]
Other Commitment	2
Other Commitments, Due in Next Twelve Months	2
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five	0
Other Commitment, to be Paid, after Year Five	0
Surety Bond [Member]
Guarantor Obligations [Line Items]
Other Commitment	109
Other Commitments, Due in Next Twelve Months	107
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	2
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five	0
Other Commitment, to be Paid, after Year Five	0
Surety Bond [Member] \| Commonwealth Edison Co [Member]
Guarantor Obligations [Line Items]
Other Commitment	17
Other Commitments, Due in Next Twelve Months	15
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	2
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five	0
Other Commitment, to be Paid, after Year Five	0
Surety Bond [Member] \| PECO Energy Co [Member]
Guarantor Obligations [Line Items]
Other Commitment	2
Other Commitments, Due in Next Twelve Months	2
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five	0
Other Commitment, to be Paid, after Year Five	0
Surety Bond [Member] \| Baltimore Gas and Electric Company [Member]
Guarantor Obligations [Line Items]
Other Commitment	3
Other Commitments, Due in Next Twelve Months	3
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five	0
Other Commitment, to be Paid, after Year Five	0
Surety Bond [Member] \| Pepco Holdings LLC [Member]
Guarantor Obligations [Line Items]
Other Commitment	23
Other Commitments, Due in Next Twelve Months	23
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five	0
Other Commitment, to be Paid, after Year Five	0
Surety Bond [Member] \| Potomac Electric Power Company [Member]
Guarantor Obligations [Line Items]
Other Commitment	14
Other Commitments, Due in Next Twelve Months	14
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five	0
Other Commitment, to be Paid, after Year Five	0
Surety Bond [Member] \| Delmarva Power & Light Company [Member]
Guarantor Obligations [Line Items]
Other Commitment	5
Other Commitments, Due in Next Twelve Months	5
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five	0
Other Commitment, to be Paid, after Year Five	0
Surety Bond [Member] \| Atlantic City Electric Company [Member]
Guarantor Obligations [Line Items]
Other Commitment	4
Other Commitments, Due in Next Twelve Months	4
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five	0
Other Commitment, to be Paid, after Year Five	0
Guarantee of Indebtedness of Others [Member]
Guarantor Obligations [Line Items]
Other Commitment	378
Other Commitments, Due in Next Twelve Months	0
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five	0
Other Commitment, to be Paid, after Year Five	378
Guarantee of Indebtedness of Others [Member] \| Commonwealth Edison Co [Member]
Guarantor Obligations [Line Items]
Other Commitment	200
Other Commitments, Due in Next Twelve Months	0
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five	0
Other Commitment, to be Paid, after Year Five	200
Guarantee of Indebtedness of Others [Member] \| PECO Energy Co [Member]
Guarantor Obligations [Line Items]
Other Commitment	178
Other Commitments, Due in Next Twelve Months	0
Other Commitment, to be Paid, Year Two	0
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five	0
Other Commitment, to be Paid, after Year Five	178
Guarantee Obligations [Member]
Guarantor Obligations [Line Items]
Other Commitment	31
Other Commitments, Due in Next Twelve Months	0
Other Commitment, to be Paid, Year Two	5
Other Commitment, to be Paid, Year Three	6
Other Commitment, to be Paid, Year Four	6
Other Commitment, to be Paid, Year Five	5
Other Commitment, to be Paid, after Year Five	9
Guarantee Obligations [Member] \| Pepco Holdings LLC [Member]
Guarantor Obligations [Line Items]
Other Commitment	31
Other Commitments, Due in Next Twelve Months	0
Other Commitment, to be Paid, Year Two	5
Other Commitment, to be Paid, Year Three	6
Other Commitment, to be Paid, Year Four	6
Other Commitment, to be Paid, Year Five	5
Other Commitment, to be Paid, after Year Five	9
Guarantee Obligations [Member] \| Potomac Electric Power Company [Member]
Guarantor Obligations [Line Items]
Other Commitment	10
Other Commitments, Due in Next Twelve Months	0
Other Commitment, to be Paid, Year Two	1
Other Commitment, to be Paid, Year Three	2
Other Commitment, to be Paid, Year Four	2
Other Commitment, to be Paid, Year Five	2
Other Commitment, to be Paid, after Year Five	3
Guarantee Obligations [Member] \| Delmarva Power & Light Company [Member]
Guarantor Obligations [Line Items]
Other Commitment	13
Other Commitments, Due in Next Twelve Months	0
Other Commitment, to be Paid, Year Two	2
Other Commitment, to be Paid, Year Three	3
Other Commitment, to be Paid, Year Four	2
Other Commitment, to be Paid, Year Five	2
Other Commitment, to be Paid, after Year Five	4
Guarantee Obligations [Member] \| Atlantic City Electric Company [Member]
Guarantor Obligations [Line Items]
Other Commitment	8
Other Commitments, Due in Next Twelve Months	0
Other Commitment, to be Paid, Year Two	2
Other Commitment, to be Paid, Year Three	1
Other Commitment, to be Paid, Year Four	2
Other Commitment, to be Paid, Year Five	1
Other Commitment, to be Paid, after Year Five	$ 2
Minimum [Member]
Guarantor Obligations [Line Items]
Lessor, Operating Lease, Term of Contract	1 year
Minimum [Member] \| Commonwealth Edison Co [Member]
Guarantor Obligations [Line Items]
Lessor, Operating Lease, Term of Contract	1 year
Minimum [Member] \| PECO Energy Co [Member]
Guarantor Obligations [Line Items]
Lessor, Operating Lease, Term of Contract	1 year
Minimum [Member] \| Baltimore Gas and Electric Company [Member]
Guarantor Obligations [Line Items]
Lessor, Operating Lease, Term of Contract	21 years
Minimum [Member] \| Pepco Holdings LLC [Member]
Guarantor Obligations [Line Items]
Lessor, Operating Lease, Term of Contract	1 year
Minimum [Member] \| Potomac Electric Power Company [Member]
Guarantor Obligations [Line Items]
Lessor, Operating Lease, Term of Contract	1 year
Minimum [Member] \| Delmarva Power & Light Company [Member]
Guarantor Obligations [Line Items]
Lessor, Operating Lease, Term of Contract	10 years
Minimum [Member] \| Guarantee Obligations [Member]
Guarantor Obligations [Line Items]
Lessor, Operating Lease, Term of Contract	1 year
Maximum [Member]
Guarantor Obligations [Line Items]
Lessor, Operating Lease, Term of Contract	81 years
Maximum [Member] \| Commonwealth Edison Co [Member]
Guarantor Obligations [Line Items]
Lessor, Operating Lease, Term of Contract	15 years
Maximum [Member] \| PECO Energy Co [Member]
Guarantor Obligations [Line Items]
Lessor, Operating Lease, Term of Contract	81 years
Maximum [Member] \| Baltimore Gas and Electric Company [Member]
Guarantor Obligations [Line Items]
Lessor, Operating Lease, Term of Contract	21 years
Maximum [Member] \| Pepco Holdings LLC [Member]
Guarantor Obligations [Line Items]
Lessor, Operating Lease, Term of Contract	11 years
Maximum [Member] \| Potomac Electric Power Company [Member]
Guarantor Obligations [Line Items]
Lessor, Operating Lease, Term of Contract	4 years
Maximum [Member] \| Delmarva Power & Light Company [Member]
Guarantor Obligations [Line Items]
Lessor, Operating Lease, Term of Contract	11 years
Maximum [Member] \| Guarantee Obligations [Member]
Guarantor Obligations [Line Items]
Lessor, Operating Lease, Term of Contract	8 years

Commitments and Contingencies_5

Commitments and Contingencies - Schedule of Environmental Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	$ 352	$ 366
Commonwealth Edison Co [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	279	293
PECO Energy Co [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	22	23
Baltimore Gas and Electric Company [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	6	2
Pepco Holdings LLC [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	42	44
Potomac Electric Power Company [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	40	42
Delmarva Power & Light Company [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	1	1
Atlantic City Electric Company [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	1	1
Accrual For MGP Investigation And Remediation [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	303	314
Accrual For MGP Investigation And Remediation [Member] \| Commonwealth Edison Co [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	279	293
Accrual For MGP Investigation And Remediation [Member] \| PECO Energy Co [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	20	21
Accrual For MGP Investigation And Remediation [Member] \| Baltimore Gas and Electric Company [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	4	0
Accrual For MGP Investigation And Remediation [Member] \| Pepco Holdings LLC [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	0	0
Accrual For MGP Investigation And Remediation [Member] \| Potomac Electric Power Company [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	0	0
Accrual For MGP Investigation And Remediation [Member] \| Delmarva Power & Light Company [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	0	0
Accrual For MGP Investigation And Remediation [Member] \| Atlantic City Electric Company [Member]
Loss Contingencies [Line Items]
Accrual for Environmental Loss Contingencies, Gross	$ 0	$ 0

Shareholders' Equity - Narrativ

Shareholders' Equity - Narrative (Details)	Dec. 31, 2021 shares
Schedule of Capitalization, Equity [Line Items]
Stock Repurchase Program, Number of Shares Authorized to be Repurchased	0

Shareholders' Equity - Schedule

Shareholders' Equity - Schedule of Common Stock Warrants (Details) - Commonwealth Edison Co [Member] - shares	Dec. 31, 2021	Dec. 31, 2020
Class of Warrant or Right [Line Items]
Class of Warrant or Right, Outstanding	60,061	60,143
Common Stock [Member]
Class of Warrant or Right [Line Items]
Common Stock Shares Reserved For Warrant Conversion	20,020	20,048

Shareholders' Equity - Schedu_2

Shareholders' Equity - Schedule of Preferred Stock (Details) - shares	Dec. 31, 2021	Dec. 31, 2020
Preferred Stock [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Outstanding	0	0
Preferred Stock, Shares Authorized	100,000,000	100,000,000
Preferred Stock [Member] \| Commonwealth Edison Co [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Outstanding	0	0
Preferred Stock, Shares Authorized	850,000	850,000
Preferred Stock [Member] \| PECO Energy Co [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Outstanding	0	0
Preferred Stock, Shares Authorized	15,000,000	15,000,000
Preferred Stock [Member] \| Baltimore Gas and Electric Company [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Outstanding	0	0
Preferred Stock, Shares Authorized	1,000,000	1,000,000
Preferred Stock [Member] \| Potomac Electric Power Company [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Outstanding	0	0
Preferred Stock, Shares Authorized	6,000,000	6,000,000
Preferred Stock [Member] \| Atlantic City Electric Company [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Outstanding	0	0
Preferred Stock, Shares Authorized	2,799,979	2,799,979
Preferred Stock [Member] \| Delmarva Power & Light Company [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Authorized	0
Cumulative Preferred Stock [Member] \| Atlantic City Electric Company [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Authorized	799,979	799,979
No-Par Preferred Stock [Member] \| Atlantic City Electric Company [Member]
Class of Stock [Line Items]
Preferred Stock, Shares Authorized	2,000,000	2,000,000

Shareholders' Equity - Schedu_3

Shareholders' Equity - Schedule of Preference Stock (Details) - shares	Dec. 31, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Preference Stock, Shares Authorized	0
Commonwealth Edison Co [Member]
Class of Stock [Line Items]
Preference Stock, Shares Outstanding	0	0
Preference Stock, Shares Authorized	6,810,451	6,810,451
Baltimore Gas and Electric Company [Member]
Class of Stock [Line Items]
Preference Stock, Shares Outstanding	0	0
Preference Stock, Shares Authorized	6,500,000	6,500,000
Atlantic City Electric Company [Member]
Class of Stock [Line Items]
Preference Stock, Shares Outstanding	0	0
Preference Stock, Shares Authorized	3,000,000	3,000,000
PECO Energy Co [Member]
Class of Stock [Line Items]
Preference Stock, Shares Authorized	0
Potomac Electric Power Company [Member]
Class of Stock [Line Items]
Preference Stock, Shares Authorized	0
Delmarva Power & Light Company [Member]
Class of Stock [Line Items]
Preference Stock, Shares Authorized	0
Unclassified Preference Stock [Member] \| Baltimore Gas and Electric Company [Member]
Class of Stock [Line Items]
Preference Stock, Shares Authorized	4,600,000	4,600,000
Preference Stock Redeemed [Member] \| Baltimore Gas and Electric Company [Member]
Class of Stock [Line Items]
Preference Stock, Shares Authorized	1,900,000	1,900,000

Stock-Based Compensation Plan_3

Stock-Based Compensation Plans - Narrative (Details) shares in Millions	12 Months Ended
	Dec. 31, 2021 shares
Performance Shares [Member]
Common Stock Narrative Information [Line Items]
Percentage to be settled as common stock	50%
Percentage to be settled as cash	50%
Percentage to be settled as cash if ownership requirements are met	100%
Vesting period	3 years
Minimum [Member] \| Restricted Stock Units (RSUs) [Member]
Common Stock Narrative Information [Line Items]
Requisite service period	3 years
Maximum [Member] \| Restricted Stock Units (RSUs) [Member]
Common Stock Narrative Information [Line Items]
Requisite service period	5 years
LTIP [Member]
Common Stock Narrative Information [Line Items]
Shares authorized	33

Stock-Based Compensation Plan_4

Stock-Based Compensation Plans - Schedule of Stock-based Compensation Expense (Details) - Share-based Payment Arrangement [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Expense	$ 95	$ 37	$ 40
Share-based Payment Arrangement, Expense, Tax Benefit	(25)	(9)	(10)
Share-based Payment Arrangement, Expense, after Tax	$ 70	$ 28	$ 30

Stock-Based Compensation Plan_5

Stock-Based Compensation Plans - Components of Tax Benefits from Stock-based Compensation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Performance Shares [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Tax benefit on stock compensation	$ 6	$ 15	$ 27
Restricted Stock Units (RSUs) [Member]
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Tax benefit on stock compensation	$ 6	$ 8	$ 12

Stock-Based Compensation Plan_6

Stock-Based Compensation Plans - Summary of Performance Share Awards Activity (Details) - Performance Shares [Member] - $ / shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Beginning Balance	930,392
Granted	1,131,788
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Period Increase (Decrease)	713,202
Vested	(327,551)
Forfeited	(157,552)
Undistributed vested awards	(1,067,763)
Ending Balance	1,222,516	930,392
Nonvested, Weighted Average Exercise Price (in usd per share)	$ 44.96	$ 43.67
Granted, Weighted Average Grant Date Fair Value (in usd per share)	43.37	$ 46.61	$ 47.37
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Change in Performance, Weighted Average Grant Date Fair Value	45.59
Vested, Weighted Average Exercise Price (in usd per share)	38.66
Forfeited, Weighted Average Exercise Price (in usd per share)	44.45
Undistributed Vested Awards, Weighted Average Grant Date Fair Value (in usd per share)	$ 44.58
Fully Vested Stock Based Compensation Issued To Retirement Eligible Employees	1,934,238	1,414,661

Stock-Based Compensation Plan_7

Stock-Based Compensation Plans - Summary of Weighted Average Fair Value (Details) - Performance Shares [Member] - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, Weighted Average Grant Date Fair Value (in usd per share)	$ 43.37	$ 46.61	$ 47.37
Fair Value Of Settled Performance Share Awards	$ 44	$ 39	$ 158
Performance Share Awards Obligations Settled In Cash	28	$ 63	$ 131
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount	$ 26
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition	1 year 9 months 18 days

Stock-Based Compensation Plan_8

Stock-Based Compensation Plans - Summary of Nonvested Restricted Stock Unit Activity (Details) - Restricted Stock Units (RSUs) [Member] - $ / shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Beginning Balance	1,114,130
Granted	879,606
Vested	(397,526)
Forfeited	(57,646)
Undistributed vested awards	(396,515)
Ending Balance	1,142,049	1,114,130
Nonvested, Weighted Average Exercise Price (in usd per share)	$ 43.52	$ 43.67
Granted, Weighted Average Grant Date Fair Value (in usd per share)	44.21	$ 46.33	$ 45.65
Vested, Weighted Average Exercise Price (in usd per share)	44.39
Forfeited, Weighted Average Exercise Price (in usd per share)	44.98
Undistributed Vested Awards, Weighted Average Grant Date Fair Value (in usd per share)	$ 43.66
Fully Vested Stock Based Compensation Issued To Retirement Eligible Employees	609,934	748,165

Stock-Based Compensation Plan_9

Stock-Based Compensation Plans - Summary of Weighted Average Restricted Stock Unit Activity (Details) - Restricted Stock Units (RSUs) [Member] - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted, Weighted Average Grant Date Fair Value (in usd per share)	$ 44.21	$ 46.33	$ 45.65
Fair Value Of Settled Restricted Stock Units	$ 34	$ 54	$ 92
Share-based Payment Arrangement, Nonvested Award, Excluding Option, Cost Not yet Recognized, Amount	$ 22
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition	2 years 3 months 18 days

Stock-Based Compensation Pla_10

Stock-Based Compensation Plans - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Aggregate value	$ 11	$ 5	$ 9
Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning Balance	1,265,410
Options exercised	(928,003)
Options expired	(310,400)
Ending Balance	27,007	1,265,410
Exercisable at December 31, 2020	27,007
Weighted Average Exercise Price (in usd per share)	$ 46.47	$ 40.57
Options Exercised, Weighted Average Exercise Price (in usd per share)	39.45
Options Expired, Weighted Average Exercise Price (in usd per share)	43.40
Shares Exercisable, Weighted Average Exercise Price (in usd per share)	$ 46.47
Shares Outstanding, Weighted Average Remaining Contractual Life	1 month 24 days	10 months 28 days
Shares Exercisable, Weighted Average Remaining Contractual Life	1 month 24 days
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value	$ 0	$ 3
Aggregate value	11
Shares Exercisable, Aggregate Intrinsic Value	$ 0

Stock-Based Compensation Pla_11

Stock-Based Compensation Plans - Summary of Stock Option Exercised (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate value	$ 11	$ 5	$ 9
Cash received for exercise price	$ 37	$ 18	$ 59

Changes in Accumulated Other _3

Changes in Accumulated Other Comprehensive Income - Schedule of Changes in AOCI (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Movement in Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	$ 34,868	$ 34,573	$ 33,047
Other comprehensive income (loss)	650	(206)	(198)
Ending Balance	34,795	34,868	34,573
Losses on Cash Flow Hedges
Movement in Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	(5)	(2)	(2)
OCI before reclassifications	(1)	(3)	0
Amounts reclassified from AOCI	0	0	0
Other comprehensive income (loss)	(1)	(3)	0
Ending Balance	(6)	(5)	(2)
Pension and Non-Pension Postretirement Benefit Plan Items (a)
Movement in Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	(3,372)	(3,165)	(2,960)
OCI before reclassifications	432	(357)	(289)
Amounts reclassified from AOCI	219	150	84
Other comprehensive income (loss)	651	(207)	(205)
Ending Balance	(2,721)	(3,372)	(3,165)
Foreign Currency Items
Movement in Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	(23)	(27)	(33)
OCI before reclassifications	0	4	6
Amounts reclassified from AOCI	0	0	0
Other comprehensive income (loss)	0	4	6
Ending Balance	(23)	(23)	(27)
AOCI of Investments Unconsolidated Affiliates (b)
Movement in Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	0	0	0
OCI before reclassifications	0	0	(2)
Amounts reclassified from AOCI	0	0	2
Other comprehensive income (loss)	0	0	0
Ending Balance	0	0	0
Total
Movement in Accumulated Other Comprehensive Income [Roll Forward]
Beginning Balance	(3,400)	(3,194)	(2,995)
OCI before reclassifications	431	(356)	(285)
Amounts reclassified from AOCI	219	150	86
Other comprehensive income (loss)	650	(206)	(199)
Ending Balance	$ (2,750)	$ (3,400)	$ (3,194)

Changes in Accumulated Other _4

Changes in Accumulated Other Comprehensive Income - Income Taxes Allocated to Other Comprehensive Income (Loss) Components (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Prior service costs
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), Tax	$ 4	$ 16	$ 23
Actuarial losses
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), Tax	(76)	(66)	(52)
Pension and Non-Pension Postretirement Benefit Plan Items (a)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), Tax	$ (153)	$ 122	$ 100

Variable Interest Entities - Na

Variable Interest Entities - Narrative (Details) $ in Millions	Dec. 31, 2021 USD ($)
Variable Interest Entity [Line Items]
Guarantee obligations maximum exposure	$ 75

Variable Interest Entities - As

Variable Interest Entities - Assets and Liabilities of Consolidated VIEs (Details) - USD ($) $ in Millions		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current assets
Cash and cash equivalents		$ 672	$ 432	$ 587	$ 1,349
Restricted cash		321	349	358	247
Accounts Receivable, net
Customer		1,869	1,932
Inventories, net
Materials and supplies		476	447
Currents assets of discontinued operations		7,835	6,841
Other current assets		387	223
Total current assets		13,957	12,562
Property, plant and equipment, net		64,558	60,332
Other Assets, Noncurrent		885	1,143
Total assets	[1]	133,013	129,317
Current liabilities
Long-term debt due within one year		2,153	1,622
Accounts payable		2,379	2,309
Accrued expenses		1,137	1,230
Market-to-market derivative liabilities, current		18	33
Unamortized energy contract liabilities		89	93
Liabilities held for sale		7,940	4,923
Other current liabilities		766	784
Total current liabilities		16,111	12,771
Long-term debt		30,749	29,527
Asset retirement obligations		271	246
Other deferred credits and other liabilities		1,573	1,642
Total liabilities	[1]	98,218	94,449
Pepco Holdings LLC [Member]
Current assets
Cash and cash equivalents		136	111	131	124
Restricted cash		77	39	36	43
Accounts Receivable, net
Customer		512	525
Inventories, net
Materials and supplies		209	198
Other current assets		69	45
Total current assets		1,692	1,599
Property, plant and equipment, net		16,498	15,377
Other Assets, Noncurrent		258	307
Total assets	[2]	24,744	23,736
Current liabilities
Long-term debt due within one year		399	347
Accounts payable		578	539
Accrued expenses		281	299
Unamortized energy contract liabilities		89	92
Other current liabilities		171	141
Total current liabilities		2,246	2,154
Long-term debt		7,148	6,659
Asset retirement obligations		70	59
Other deferred credits and other liabilities		570	622
Total liabilities	[2]	14,159	13,692
Pepco Holdings LLC [Member] \| Variable Interest Entity, Primary Beneficiary [Member]
Current assets
Restricted cash			3
Inventories, net
Other current assets			5
Total current assets			8
Other Assets, Noncurrent			10
Total noncurrent assets			10
Total assets			18
Current liabilities
Long-term debt due within one year			26
Total current liabilities			26
Total liabilities			26
Atlantic City Electric Company [Member]
Current assets
Cash and cash equivalents		29	17	12	7
Restricted cash		0	3	$ 2	$ 4
Accounts Receivable, net
Customer		141	124
Inventories, net
Other current assets		3	3
Total current assets		333	326
Property, plant and equipment, net		3,729	3,475
Other Assets, Noncurrent		37	50
Total assets	[3]	4,556	4,286
Current liabilities
Long-term debt due within one year		3	261
Accounts payable		165	177
Accrued expenses		44	46
Other current liabilities		12	11
Total current liabilities		445	780
Long-term debt		1,579	1,152
Other deferred credits and other liabilities		49	48
Total liabilities	[3]	$ 2,988	2,895
Atlantic City Electric Company [Member] \| Variable Interest Entity, Primary Beneficiary [Member]
Current assets
Restricted cash			3
Inventories, net
Other current assets			0
Total current assets			3
Other Assets, Noncurrent			10
Total noncurrent assets			10
Total assets			13
Current liabilities
Long-term debt due within one year			21
Total current liabilities			21
Total liabilities			$ 21

[1]Exelon’s consolidated assets include $18 million as of December 31, 2020, of certain VIEs that can only be used to settle the liabilities of the VIE. Exelon’s consolidated liabilities include $26 million as of December 31, 2020, of certain VIEs for which the VIE creditors do not have recourse to Exelon. See Note 21–Variable Interest Entities for additional information.[2]PHI’s consolidated total assets include $0 million and $18 million as of December 31, 2021 and 2020, respectively, of PHI's consolidated VIE that can only be used to settle the liabilities of the VIE. PHI’s consolidated total liabilities include $0 million and $26 million as of December 31, 2021 and 2020, respectively, of PHI's consolidated VIE for which the VIE creditors do not have recourse to PHI. See Note 21 - Variable Interest Entities for additional information.[3] ACE’s consolidated assets include $0 million and $13 million as of December 31, 2021 and 2020, respectively, of ACE’s consolidated VIE that can only be used to settle the liabilities of the VIE. ACE’s consolidated liabilities include $0 million and $21 million as of December 31, 2021 and 2020, respectively, of ACE’s consolidated VIE for which the VIE creditors do not have recourse to ACE. See Note 21 - Variable Interest Entities for additional information.

Variable Interest Entities - Su

Variable Interest Entities - Summary of Significant Unconsolidated VIEs (Details) - USD ($) $ in Millions		Dec. 31, 2021	Dec. 31, 2020
Variable Interest Entity [Line Items]
Total assets	[1]	$ 133,013	$ 129,317
Total liabilities	[1]	$ 98,218	$ 94,449

[1]Exelon’s consolidated assets include $18 million as of December 31, 2020, of certain VIEs that can only be used to settle the liabilities of the VIE. Exelon’s consolidated liabilities include $26 million as of December 31, 2020, of certain VIEs for which the VIE creditors do not have recourse to Exelon. See Note 21–Variable Interest Entities for additional information.

Supplemental Financial Inform_3

Supplemental Financial Information - Summary of Taxes other than income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Supplemental Statement of Operations Information [Line Items]
Utility	$ 774	$ 759	$ 768
Property	364	336	321
Payroll	124	121	117
Commonwealth Edison Co [Member]
Supplemental Statement of Operations Information [Line Items]
Utility	246	238	242
Property	39	30	29
Payroll	27	27	27
PECO Energy Co [Member]
Supplemental Statement of Operations Information [Line Items]
Utility	139	135	132
Property	18	16	17
Payroll	16	16	15
Baltimore Gas and Electric Company [Member]
Supplemental Statement of Operations Information [Line Items]
Utility	88	87	90
Property	176	164	153
Payroll	18	17	17
Pepco Holdings LLC [Member]
Supplemental Statement of Operations Information [Line Items]
Utility	301	299	304
Property	131	126	122
Payroll	27	25	24
Potomac Electric Power Company [Member]
Supplemental Statement of Operations Information [Line Items]
Utility	278	275	286
Property	88	84	85
Payroll	7	7	7
Delmarva Power & Light Company [Member]
Supplemental Statement of Operations Information [Line Items]
Utility	22	21	18
Property	40	39	34
Payroll	5	5	4
Atlantic City Electric Company [Member]
Supplemental Statement of Operations Information [Line Items]
Utility	3	3	0
Property	3	3	2
Payroll	$ 3	$ 3	$ 2

Supplemental Financial Inform_4

Supplemental Financial Information - Summary of Other Income (Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Decommissioning-Related Activities [Abstract]
AFUDC—Equity	$ 136	$ 104	$ 85
Non-service net periodic benefit cost	91	53	13
Unrealized Gain (Loss) on Investments	(160)	186	0
Commonwealth Edison Co [Member]
Decommissioning-Related Activities [Abstract]
AFUDC—Equity	34	29	17
Non-service net periodic benefit cost	0	0	0
PECO Energy Co [Member]
Decommissioning-Related Activities [Abstract]
AFUDC—Equity	26	17	13
Non-service net periodic benefit cost	0	0	0
Baltimore Gas and Electric Company [Member]
Decommissioning-Related Activities [Abstract]
AFUDC—Equity	27	22	21
Non-service net periodic benefit cost	0	0	0
Pepco Holdings LLC [Member]
Decommissioning-Related Activities [Abstract]
AFUDC—Equity	49	36	34
Non-service net periodic benefit cost	0	0	0
Potomac Electric Power Company [Member]
Decommissioning-Related Activities [Abstract]
AFUDC—Equity	40	28	25
Non-service net periodic benefit cost	0	0	0
Delmarva Power & Light Company [Member]
Decommissioning-Related Activities [Abstract]
AFUDC—Equity	6	4	4
Non-service net periodic benefit cost	0	0	0
Atlantic City Electric Company [Member]
Decommissioning-Related Activities [Abstract]
AFUDC—Equity	3	4	5
Non-service net periodic benefit cost	$ 0	$ 0	$ 0

Supplemental Financial Inform_5

Supplemental Financial Information - Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Depreciation, amortization and accretion
Depreciation	$ 5,384	$ 4,364	$ 3,665
Amortization of Regulatory Asset	594	588	528
Amortization of Intangible Assets	(83)	(98)	(102)
Amortization of Nuclear Fuel Lease	992	983	1,016
Accretion expense	514	500	491
Total depreciation, amortization and accretion	7,573	6,527	5,780
Cash paid (refunded) during the year:
Interest (net of amount capitalized)	1,505	1,521	1,470
Income taxes (net of refunds)	281	10	265
Other non-cash operating activities:
Pension and non-pension postretirement benefit costs	411	411	438
Provision for uncollectible accounts	160	150	120
Other decommissioning related-activity	(946)	(659)	(506)
Energy-related options	125	104	22
True-up Adjustments to Decoupling Mechanisms and Formula Rate	(171)	(6)	155
Restructuring Costs	(57)	105
Long-term incentive plan	137	56	10
Operating Leases, Income Statement, Depreciation Expense on Property Subject to or Held-for-lease	183	222	244
Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity	(136)	(104)	(85)
Inventory Write-down		131
Asset impairments	552	591	201
Change in environmental liabilities			23
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	672	432	587	$ 1,349
Restricted cash	321	349	358	247
Restricted cash included in other long-term assets	44	53	177	185
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Disposal Group, Including Discontinued Operations	582	332
Total cash, cash equivalents and restricted cash	1,619	1,166	1,122	1,781
Other Non-Cash [Member]
Other non-cash operating activities:
True-up Adjustments to Decoupling Mechanisms and Formula Rate	(171)	(6)	124
Asset impairments		0
Return on borrowed funds
Other non-cash operating activities:
Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity	(136)	(104)	(85)
Commonwealth Edison Co [Member]
Depreciation, amortization and accretion
Depreciation	970	922	886
Amortization of Regulatory Asset	235	211	147
Amortization of Nuclear Fuel Lease	0	0	0
Accretion expense	0	0	0
Total depreciation, amortization and accretion	1,205	1,133	1,033
Cash paid (refunded) during the year:
Interest (net of amount capitalized)	372	371	343
Income taxes (net of refunds)	(72)	(61)	(42)
Other non-cash operating activities:
Pension and non-pension postretirement benefit costs	129	114	96
Provision for uncollectible accounts	47	32	33
Other decommissioning related-activity	0	0	0
Energy-related options	0	0	0
True-up Adjustments to Decoupling Mechanisms and Formula Rate	(42)	47	133
Restructuring Costs	2	1
Long-term incentive plan	0	0	0
Operating Leases, Income Statement, Depreciation Expense on Property Subject to or Held-for-lease	1	2	3
Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity	(34)	(29)	(17)
Inventory Write-down		2
Change in environmental liabilities			0
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	131	83	90	135
Restricted cash	210	279	150	29
Restricted cash included in other long-term assets	43	43	163	166
Total cash, cash equivalents and restricted cash	384	405	403	330
Commonwealth Edison Co [Member] \| Other Non-Cash [Member]
Other non-cash operating activities:
True-up Adjustments to Decoupling Mechanisms and Formula Rate	(42)	47	128
Asset impairments		15
Commonwealth Edison Co [Member] \| Return on borrowed funds
Other non-cash operating activities:
Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity	(34)	(29)	(17)
PECO Energy Co [Member]
Depreciation, amortization and accretion
Depreciation	336	319	303
Amortization of Regulatory Asset	12	28	30
Amortization of Nuclear Fuel Lease	0	0	0
Accretion expense	0	0	0
Total depreciation, amortization and accretion	348	347	333
Cash paid (refunded) during the year:
Interest (net of amount capitalized)	152	144	129
Income taxes (net of refunds)	(4)	(37)	82
Other non-cash operating activities:
Pension and non-pension postretirement benefit costs	8	5	12
Provision for uncollectible accounts	39	42	31
Other decommissioning related-activity	0	0	0
Energy-related options	0	0	0
True-up Adjustments to Decoupling Mechanisms and Formula Rate	(26)	(16)	21
Restructuring Costs	0	1
Long-term incentive plan	0	0	0
Operating Leases, Income Statement, Depreciation Expense on Property Subject to or Held-for-lease	0	1	0
Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity	(26)	(17)	(13)
Inventory Write-down		1
Change in environmental liabilities			0
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	36	19	21	130
Restricted cash	8	7	6	5
Restricted cash included in other long-term assets	0	0	0	0
Total cash, cash equivalents and restricted cash	44	26	27	135
PECO Energy Co [Member] \| Other Non-Cash [Member]
Other non-cash operating activities:
True-up Adjustments to Decoupling Mechanisms and Formula Rate	(26)	(16)	0
Asset impairments		0
PECO Energy Co [Member] \| Return on borrowed funds
Other non-cash operating activities:
Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity	(26)	(17)	(13)
Baltimore Gas and Electric Company [Member]
Depreciation, amortization and accretion
Depreciation	439	397	359
Amortization of Regulatory Asset	152	153	143
Amortization of Nuclear Fuel Lease	0	0	0
Accretion expense	0	0	0
Total depreciation, amortization and accretion	591	550	502
Cash paid (refunded) during the year:
Interest (net of amount capitalized)	134	125	106
Income taxes (net of refunds)	(38)	(57)	17
Other non-cash operating activities:
Pension and non-pension postretirement benefit costs	61	62	61
Provision for uncollectible accounts	17	15	8
Other decommissioning related-activity	0	0	0
Energy-related options	0	0	0
True-up Adjustments to Decoupling Mechanisms and Formula Rate	(12)	(16)	(12)
Restructuring Costs	0	0
Long-term incentive plan	0	0	0
Operating Leases, Income Statement, Depreciation Expense on Property Subject to or Held-for-lease	29	31	30
Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity	(27)	(22)	(21)
Inventory Write-down		0
Change in environmental liabilities			0
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	51	144	24	7
Restricted cash	4	1	1	6
Restricted cash included in other long-term assets	0	0	0	0
Total cash, cash equivalents and restricted cash	55	145	25	13
Baltimore Gas and Electric Company [Member] \| Other Non-Cash [Member]
Other non-cash operating activities:
True-up Adjustments to Decoupling Mechanisms and Formula Rate	(12)	(16)	0
Asset impairments		0
Baltimore Gas and Electric Company [Member] \| Return on borrowed funds
Other non-cash operating activities:
Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity	(27)	(22)	(21)
Pepco Holdings LLC [Member]
Depreciation, amortization and accretion
Depreciation	627	586	547
Amortization of Regulatory Asset	194	196	207
Amortization of Intangible Assets	(92)	(115)	(119)
Amortization of Nuclear Fuel Lease	0	0	0
Accretion expense	0	0	0
Total depreciation, amortization and accretion	821	782	754
Cash paid (refunded) during the year:
Interest (net of amount capitalized)	255	257	255
Income taxes (net of refunds)	0	46	29
Other non-cash operating activities:
Pension and non-pension postretirement benefit costs	49	70	95
Provision for uncollectible accounts	24	43	17
Other decommissioning related-activity	0	0	0
Energy-related options	0	0	0
True-up Adjustments to Decoupling Mechanisms and Formula Rate	(91)	(21)	14
Restructuring Costs	1	0
Long-term incentive plan	0	0	0
Operating Leases, Income Statement, Depreciation Expense on Property Subject to or Held-for-lease	28	28	33
Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity	(49)	(36)	(34)
Inventory Write-down		0
Change in environmental liabilities			23
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	136	111	131	124
Restricted cash	77	39	36	43
Restricted cash included in other long-term assets	0	10	14	19
Total cash, cash equivalents and restricted cash	213	160	181	186
Pepco Holdings LLC [Member] \| Other Non-Cash [Member]
Other non-cash operating activities:
True-up Adjustments to Decoupling Mechanisms and Formula Rate	(91)	(21)	(4)
Asset impairments		13
Pepco Holdings LLC [Member] \| Return on borrowed funds
Other non-cash operating activities:
Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity	(49)	(36)	(34)
Potomac Electric Power Company [Member]
Depreciation, amortization and accretion
Depreciation	274	257	239
Amortization of Regulatory Asset	129	120	135
Amortization of Nuclear Fuel Lease	0	0	0
Accretion expense	0	0	0
Total depreciation, amortization and accretion	403	377	374
Cash paid (refunded) during the year:
Interest (net of amount capitalized)	132	129	130
Income taxes (net of refunds)	12	40	7
Other non-cash operating activities:
Pension and non-pension postretirement benefit costs	6	15	25
Provision for uncollectible accounts	9	24	7
Other decommissioning related-activity	0	0	0
Energy-related options	0	0	0
True-up Adjustments to Decoupling Mechanisms and Formula Rate	(53)	(40)	3
Restructuring Costs	0	0
Long-term incentive plan	0	0	0
Operating Leases, Income Statement, Depreciation Expense on Property Subject to or Held-for-lease	6	7	8
Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity	(40)	(28)	(25)
Inventory Write-down		0
Change in environmental liabilities			23
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	34	30	30	16
Restricted cash	34	35	33	37
Restricted cash included in other long-term assets	0	0	0	0
Total cash, cash equivalents and restricted cash	68	65	63	53
Potomac Electric Power Company [Member] \| Other Non-Cash [Member]
Other non-cash operating activities:
True-up Adjustments to Decoupling Mechanisms and Formula Rate	(53)	(40)	(4)
Asset impairments		0
Potomac Electric Power Company [Member] \| Return on borrowed funds
Other non-cash operating activities:
Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity	(40)	(28)	(25)
Delmarva Power & Light Company [Member]
Depreciation, amortization and accretion
Depreciation	169	155	146
Amortization of Regulatory Asset	41	36	38
Amortization of Nuclear Fuel Lease	0	0	0
Accretion expense	0	0	0
Total depreciation, amortization and accretion	210	191	184
Cash paid (refunded) during the year:
Interest (net of amount capitalized)	59	61	59
Income taxes (net of refunds)	(9)	12	19
Other non-cash operating activities:
Pension and non-pension postretirement benefit costs	2	7	15
Provision for uncollectible accounts	5	16	4
Other decommissioning related-activity	0	0	0
Energy-related options	0	0	0
True-up Adjustments to Decoupling Mechanisms and Formula Rate	(14)	7	11
Restructuring Costs	0	0
Long-term incentive plan	0	0	0
Operating Leases, Income Statement, Depreciation Expense on Property Subject to or Held-for-lease	8	8	8
Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity	(6)	(4)	(4)
Inventory Write-down		0
Change in environmental liabilities			0
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	28	15	13	23
Restricted cash	43	0	0	1
Restricted cash included in other long-term assets	0	0	0	0
Total cash, cash equivalents and restricted cash	71	15	13	24
Delmarva Power & Light Company [Member] \| Other Non-Cash [Member]
Other non-cash operating activities:
True-up Adjustments to Decoupling Mechanisms and Formula Rate	(14)	7	0
Asset impairments		7
Delmarva Power & Light Company [Member] \| Return on borrowed funds
Other non-cash operating activities:
Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity	(6)	(4)	(4)
Atlantic City Electric Company [Member]
Depreciation, amortization and accretion
Depreciation	155	140	123
Amortization of Regulatory Asset	24	40	34
Amortization of Nuclear Fuel Lease	0	0	0
Accretion expense	0	0	0
Total depreciation, amortization and accretion	179	180	157
Cash paid (refunded) during the year:
Interest (net of amount capitalized)	56	57	55
Income taxes (net of refunds)	2	(3)	(5)
Other non-cash operating activities:
Pension and non-pension postretirement benefit costs	11	14	16
Provision for uncollectible accounts	10	2	5
Other decommissioning related-activity	0	0	0
Energy-related options	0	0	0
True-up Adjustments to Decoupling Mechanisms and Formula Rate	(24)	12	0
Restructuring Costs	0	0
Long-term incentive plan	0	0	0
Operating Leases, Income Statement, Depreciation Expense on Property Subject to or Held-for-lease	4	3	4
Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity	(3)	(4)	(5)
Inventory Write-down		0
Change in environmental liabilities			0
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	29	17	12	7
Restricted cash	0	3	2	4
Restricted cash included in other long-term assets	0	10	14	19
Total cash, cash equivalents and restricted cash	29	30	28	$ 30
Atlantic City Electric Company [Member] \| Other Non-Cash [Member]
Other non-cash operating activities:
True-up Adjustments to Decoupling Mechanisms and Formula Rate	(24)	12	0
Asset impairments		6
Atlantic City Electric Company [Member] \| Return on borrowed funds
Other non-cash operating activities:
Public Utilities, Allowance for Funds Used During Construction, Capitalized Cost of Equity	(3)	(4)	(5)
Other Intangible Assets [Member]
Depreciation, amortization and accretion
Amortization of Intangible Assets	58	62	59
Other Intangible Assets [Member] \| Commonwealth Edison Co [Member]
Depreciation, amortization and accretion
Amortization of Intangible Assets	0	0	0
Other Intangible Assets [Member] \| PECO Energy Co [Member]
Depreciation, amortization and accretion
Amortization of Intangible Assets	0	0	0
Other Intangible Assets [Member] \| Baltimore Gas and Electric Company [Member]
Depreciation, amortization and accretion
Amortization of Intangible Assets	0	0	0
Other Intangible Assets [Member] \| Pepco Holdings LLC [Member]
Depreciation, amortization and accretion
Amortization of Intangible Assets	0	0	0
Other Intangible Assets [Member] \| Potomac Electric Power Company [Member]
Depreciation, amortization and accretion
Amortization of Intangible Assets	0	0	0
Other Intangible Assets [Member] \| Delmarva Power & Light Company [Member]
Depreciation, amortization and accretion
Amortization of Intangible Assets	0	0	0
Other Intangible Assets [Member] \| Atlantic City Electric Company [Member]
Depreciation, amortization and accretion
Amortization of Intangible Assets	0	0	0
Unamortized Energy Contracts [Member]
Depreciation, amortization and accretion
Amortization of Power Contracts Emission Credits	31	30	21
Unamortized Energy Contracts [Member] \| Commonwealth Edison Co [Member]
Depreciation, amortization and accretion
Amortization of Power Contracts Emission Credits	0	0	0
Unamortized Energy Contracts [Member] \| PECO Energy Co [Member]
Depreciation, amortization and accretion
Amortization of Power Contracts Emission Credits	0	0	0
Unamortized Energy Contracts [Member] \| Baltimore Gas and Electric Company [Member]
Depreciation, amortization and accretion
Amortization of Power Contracts Emission Credits	0	0	0
Unamortized Energy Contracts [Member] \| Pepco Holdings LLC [Member]
Depreciation, amortization and accretion
Amortization of Power Contracts Emission Credits	0	0	0
Unamortized Energy Contracts [Member] \| Potomac Electric Power Company [Member]
Depreciation, amortization and accretion
Amortization of Power Contracts Emission Credits	0	0	0
Unamortized Energy Contracts [Member] \| Delmarva Power & Light Company [Member]
Depreciation, amortization and accretion
Amortization of Power Contracts Emission Credits	0	0	0
Unamortized Energy Contracts [Member] \| Atlantic City Electric Company [Member]
Depreciation, amortization and accretion
Amortization of Power Contracts Emission Credits	$ 0	$ 0	$ 0

Supplemental Financial Inform_6

Supplemental Financial Information - Supplemental Balance Sheet Information (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Investments [Abstract]
Equity investments without readily determinable fair values		$ 5
Total Investments	$ 250	238
Accrued Expenses [Abstract]
Compensation-related accruals	596	594
Taxes accrued	253	291
Interest accrued	297	289
Other Equity Method Investments
Investments [Abstract]
Equity Method Investments	15	15
Employee benefit trusts and investments
Investments [Abstract]
Employee benefit trusts and investments	235	218
Commonwealth Edison Co [Member]
Investments [Abstract]
Equity investments without readily determinable fair values		0
Total Investments	6	6
Accrued Expenses [Abstract]
Compensation-related accruals	155	170
Taxes accrued	94	94
Interest accrued	116	109
Commonwealth Edison Co [Member] \| Other Equity Method Investments
Investments [Abstract]
Equity Method Investments	6	6
Commonwealth Edison Co [Member] \| Employee benefit trusts and investments
Investments [Abstract]
Employee benefit trusts and investments	0	0
PECO Energy Co [Member]
Investments [Abstract]
Equity investments without readily determinable fair values		0
Total Investments	34	30
Accrued Expenses [Abstract]
Compensation-related accruals	77	73
Taxes accrued	14	16
Interest accrued	41	37
PECO Energy Co [Member] \| Other Equity Method Investments
Investments [Abstract]
Equity Method Investments	7	8
PECO Energy Co [Member] \| Employee benefit trusts and investments
Investments [Abstract]
Employee benefit trusts and investments	27	22
Baltimore Gas and Electric Company [Member]
Investments [Abstract]
Equity investments without readily determinable fair values		0
Total Investments	14	10
Accrued Expenses [Abstract]
Compensation-related accruals	78	84
Taxes accrued	53	73
Interest accrued	44	46
Baltimore Gas and Electric Company [Member] \| Other Equity Method Investments
Investments [Abstract]
Equity Method Investments	0	0
Baltimore Gas and Electric Company [Member] \| Employee benefit trusts and investments
Investments [Abstract]
Employee benefit trusts and investments	14	10
Pepco Holdings LLC [Member]
Investments [Abstract]
Equity investments without readily determinable fair values		0
Total Investments	145	140
Accrued Expenses [Abstract]
Compensation-related accruals	113	109
Taxes accrued	96	117
Interest accrued	52	51
Pepco Holdings LLC [Member] \| Other Equity Method Investments
Investments [Abstract]
Equity Method Investments	0	0
Pepco Holdings LLC [Member] \| Employee benefit trusts and investments
Investments [Abstract]
Employee benefit trusts and investments	145	140
Potomac Electric Power Company [Member]
Investments [Abstract]
Equity investments without readily determinable fair values		0
Total Investments	120	115
Accrued Expenses [Abstract]
Compensation-related accruals	35	36
Taxes accrued	88	90
Interest accrued	28	26
Potomac Electric Power Company [Member] \| Other Equity Method Investments
Investments [Abstract]
Equity Method Investments	0	0
Potomac Electric Power Company [Member] \| Employee benefit trusts and investments
Investments [Abstract]
Employee benefit trusts and investments	120	115
Delmarva Power & Light Company [Member]
Accrued Expenses [Abstract]
Compensation-related accruals	20	18
Taxes accrued	9	18
Interest accrued	8	7
Atlantic City Electric Company [Member]
Accrued Expenses [Abstract]
Compensation-related accruals	17	17
Taxes accrued	11	12
Interest accrued	$ 11	$ 12

Related Party Transactions - Op

Related Party Transactions - Operating Revenues and Purchased Power and Fuel From Affiliates (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Related Party Transaction [Line Items]
Related Party Transaction, Purchases from Related Party	$ (1,178)	$ (1,209)	$ (1,171)
Exelon Generation Co L L C [Member] \| Commonwealth Edison Co Affiliate [Member]
Related Party Transaction [Line Items]
Revenue from Related Parties	376	330	369
Exelon Generation Co L L C [Member] \| PECO Energy Co Affiliate [Member]
Related Party Transaction [Line Items]
Revenue from Related Parties	196	190	158
Exelon Generation Co L L C [Member] \| Baltimore Gas And Electric Company Affiliate [Member]
Related Party Transaction [Line Items]
Revenue from Related Parties	236	315	289
Exelon Generation Co L L C [Member] \| Pepco Holdings LLC Affiliate [Member]
Related Party Transaction [Line Items]
Revenue from Related Parties	366	367	353
Exelon Generation Co L L C [Member] \| Potomac Electric Power Co Affiliate [Member]
Related Party Transaction [Line Items]
Revenue from Related Parties	270	279	264
Exelon Generation Co L L C [Member] \| Delmarva Power and Light Co Affiliate [Member]
Related Party Transaction [Line Items]
Revenue from Related Parties	79	75	70
Exelon Generation Co L L C [Member] \| Atlantic City Electric Co Affiliate [Member]
Related Party Transaction [Line Items]
Revenue from Related Parties	17	13	19
Commonwealth Edison Co [Member]
Related Party Transaction [Line Items]
Revenue from Related Parties	41	37	30
Related Party Transaction, Purchases from Related Party	$ (383)	$ (345)	$ (376)

Related Party Transactions - BS

Related Party Transactions - BSC and PHISCO Service Companies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Exelon Business Services Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction Capitalized Costs Support Services	$ 508	$ 531	$ 450
PHI Service Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction Capitalized Costs Support Services	72	61	72
Commonwealth Edison Co [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	307	289	264
Commonwealth Edison Co [Member] \| Exelon Business Services Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	304	283	263
Related Party Transaction Capitalized Costs Support Services	207	186	148
PECO Energy Co [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	177	159	154
PECO Energy Co [Member] \| Exelon Business Services Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	169	150	149
Related Party Transaction Capitalized Costs Support Services	81	76	88
Baltimore Gas and Electric Company [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	193	172	160
Baltimore Gas and Electric Company [Member] \| Exelon Business Services Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	189	170	157
Related Party Transaction Capitalized Costs Support Services	92	132	126
Pepco Holdings LLC [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	179	159	143
Pepco Holdings LLC [Member] \| Exelon Business Services Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	168	152	139
Related Party Transaction Capitalized Costs Support Services	128	149	88
Pepco Holdings LLC [Member] \| PHI Service Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	0	0	0
Related Party Transaction Capitalized Costs Support Services	72	61	72
Potomac Electric Power Company [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	213	205	209
Potomac Electric Power Company [Member] \| Exelon Business Services Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	96	85	85
Related Party Transaction Capitalized Costs Support Services	50	55	38
Potomac Electric Power Company [Member] \| PHI Service Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	114	120	124
Related Party Transaction Capitalized Costs Support Services	31	27	33
Delmarva Power & Light Company [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	162	153	152
Delmarva Power & Light Company [Member] \| Exelon Business Services Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	61	54	52
Related Party Transaction Capitalized Costs Support Services	43	51	25
Delmarva Power & Light Company [Member] \| PHI Service Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	99	97	100
Related Party Transaction Capitalized Costs Support Services	22	18	20
Atlantic City Electric Company [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	141	134	133
Atlantic City Electric Company [Member] \| Exelon Business Services Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	53	45	42
Related Party Transaction Capitalized Costs Support Services	33	40	19
Atlantic City Electric Company [Member] \| PHI Service Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	86	87	90
Related Party Transaction Capitalized Costs Support Services	$ 19	$ 16	$ 19

Related Party Transactions - Cu

Related Party Transactions - Current Receivables From/Payables To Affiliates (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Related Party Transaction [Line Items]
Accounts Payable, Related Parties, Current	$ 5	$ 5
Related Party Transaction, Due from (to) Related Party, Current	523	494
Exelon Generation Co L L C [Member]
Related Party Transaction [Line Items]
Receivables from affiliates, current	117	103
Accounts Payable, Related Parties, Current	131	107
Exelon Generation Co L L C [Member] \| Commonwealth Edison Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	41	28
Exelon Generation Co L L C [Member] \| PECO Energy Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	30	17
Exelon Generation Co L L C [Member] \| Baltimore Gas And Electric Company Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	4	11
Exelon Generation Co L L C [Member] \| Pepco Holdings LLC Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Exelon Generation Co L L C [Member] \| Potomac Electric Power Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	20	13
Exelon Generation Co L L C [Member] \| Delmarva Power and Light Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	4	3
Exelon Generation Co L L C [Member] \| Atlantic City Electric Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	7	6
Exelon Generation Co L L C [Member] \| Other Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	11	25
Commonwealth Edison Co [Member]
Related Party Transaction [Line Items]
Receivables from affiliates, current	16	22
Accounts Payable, Related Parties, Current	121	96
Commonwealth Edison Co [Member] \| Exelon Generation Co LLC Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	13	13
Commonwealth Edison Co [Member] \| PECO Energy Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	1
Commonwealth Edison Co [Member] \| Baltimore Gas And Electric Company Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Commonwealth Edison Co [Member] \| Pepco Holdings LLC Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Commonwealth Edison Co [Member] \| Potomac Electric Power Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	2
Commonwealth Edison Co [Member] \| Delmarva Power and Light Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	1
Commonwealth Edison Co [Member] \| Atlantic City Electric Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Commonwealth Edison Co [Member] \| Other Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	3	5
Commonwealth Edison Co [Member] \| Affiliated Entities [Member]
Related Party Transaction [Line Items]
Accounts Payable, Related Parties, Current	121	96
PECO Energy Co [Member]
Related Party Transaction [Line Items]
Receivables from affiliates, current	1	2
Accounts Payable, Related Parties, Current	70	50
PECO Energy Co [Member] \| Exelon Generation Co LLC Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
PECO Energy Co [Member] \| Commonwealth Edison Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
PECO Energy Co [Member] \| Baltimore Gas And Electric Company Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
PECO Energy Co [Member] \| Pepco Holdings LLC Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	1	0
PECO Energy Co [Member] \| Potomac Electric Power Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
PECO Energy Co [Member] \| Delmarva Power and Light Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
PECO Energy Co [Member] \| Atlantic City Electric Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
PECO Energy Co [Member] \| Other Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	2
Baltimore Gas and Electric Company [Member]
Related Party Transaction [Line Items]
Receivables from affiliates, current	1	3
Accounts Payable, Related Parties, Current	48	61
Baltimore Gas and Electric Company [Member] \| Exelon Generation Co LLC Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Baltimore Gas and Electric Company [Member] \| Commonwealth Edison Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Baltimore Gas and Electric Company [Member] \| PECO Energy Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Baltimore Gas and Electric Company [Member] \| Pepco Holdings LLC Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Baltimore Gas and Electric Company [Member] \| Potomac Electric Power Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	1	1
Baltimore Gas and Electric Company [Member] \| Delmarva Power and Light Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Baltimore Gas and Electric Company [Member] \| Atlantic City Electric Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Baltimore Gas and Electric Company [Member] \| Other Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	2
Pepco Holdings LLC [Member]
Related Party Transaction [Line Items]
Receivables from affiliates, current	2	8
Accounts Payable, Related Parties, Current	104	104
Pepco Holdings LLC [Member] \| Affiliated Entities [Member]
Related Party Transaction [Line Items]
Accounts Payable, Related Parties, Current	16	15
Potomac Electric Power Company [Member]
Related Party Transaction [Line Items]
Receivables from affiliates, current	0	2
Accounts Payable, Related Parties, Current	59	55
Potomac Electric Power Company [Member] \| Exelon Generation Co LLC Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Potomac Electric Power Company [Member] \| Commonwealth Edison Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Potomac Electric Power Company [Member] \| PECO Energy Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Potomac Electric Power Company [Member] \| Baltimore Gas And Electric Company Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Potomac Electric Power Company [Member] \| Pepco Holdings LLC Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Potomac Electric Power Company [Member] \| Delmarva Power and Light Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Potomac Electric Power Company [Member] \| Atlantic City Electric Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Potomac Electric Power Company [Member] \| Other Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	2
Delmarva Power & Light Company [Member]
Related Party Transaction [Line Items]
Receivables from affiliates, current	1	1
Accounts Payable, Related Parties, Current	33	36
Atlantic City Electric Company [Member]
Related Party Transaction [Line Items]
Receivables from affiliates, current	2	6
Accounts Payable, Related Parties, Current	31	31
Atlantic City Electric Company [Member] \| Exelon Generation Co LLC Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Atlantic City Electric Company [Member] \| Commonwealth Edison Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Atlantic City Electric Company [Member] \| PECO Energy Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Atlantic City Electric Company [Member] \| Baltimore Gas And Electric Company Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Atlantic City Electric Company [Member] \| Pepco Holdings LLC Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	1	0
Atlantic City Electric Company [Member] \| Potomac Electric Power Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	1	0
Atlantic City Electric Company [Member] \| Delmarva Power and Light Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Atlantic City Electric Company [Member] \| Other Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	6
Business Services Company [Member]
Related Party Transaction [Line Items]
Receivables from affiliates, current	306	271
Business Services Company [Member] \| Exelon Generation Co LLC Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	102	72
Business Services Company [Member] \| Commonwealth Edison Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	71	59
Business Services Company [Member] \| PECO Energy Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	36	28
Business Services Company [Member] \| Baltimore Gas And Electric Company Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	41	47
Business Services Company [Member] \| Pepco Holdings LLC Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	5	4
Business Services Company [Member] \| Potomac Electric Power Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	21	25
Business Services Company [Member] \| Delmarva Power and Light Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	17	21
Business Services Company [Member] \| Atlantic City Electric Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	13	15
Business Services Company [Member] \| Other Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
PHI Service Company [Member]
Related Party Transaction [Line Items]
Receivables from affiliates, current	32	33
PHI Service Company [Member] \| Exelon Generation Co LLC Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
PHI Service Company [Member] \| Commonwealth Edison Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
PHI Service Company [Member] \| PECO Energy Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
PHI Service Company [Member] \| Baltimore Gas And Electric Company Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
PHI Service Company [Member] \| Pepco Holdings LLC Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
PHI Service Company [Member] \| Potomac Electric Power Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	12	14
PHI Service Company [Member] \| Delmarva Power and Light Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	11	10
PHI Service Company [Member] \| Atlantic City Electric Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	9	9
PHI Service Company [Member] \| Other Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Other Legal Entities [Member]
Related Party Transaction [Line Items]
Receivables from affiliates, current	47	51
Accounts Payable, Related Parties, Current	14	43
Other Legal Entities [Member] \| Exelon Generation Co LLC Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	16	22
Other Legal Entities [Member] \| Commonwealth Edison Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	9	9
Other Legal Entities [Member] \| PECO Energy Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	4	4
Other Legal Entities [Member] \| Baltimore Gas And Electric Company Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	3	3
Other Legal Entities [Member] \| Pepco Holdings LLC Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	9	11
Other Legal Entities [Member] \| Potomac Electric Power Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	3	0
Other Legal Entities [Member] \| Delmarva Power and Light Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	1	1
Other Legal Entities [Member] \| Atlantic City Electric Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	2	1
Delmarva Power & Light Co
Related Party Transaction [Line Items]
Receivables from affiliates, current	1	1
Accounts Payable, Related Parties, Current	33
Delmarva Power & Light Co \| Exelon Generation Co LLC Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Delmarva Power & Light Co \| Commonwealth Edison Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Delmarva Power & Light Co \| PECO Energy Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Delmarva Power & Light Co \| Baltimore Gas And Electric Company Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Delmarva Power & Light Co \| Pepco Holdings LLC Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Delmarva Power & Light Co \| Potomac Electric Power Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	1	0
Delmarva Power & Light Co \| Atlantic City Electric Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Delmarva Power & Light Co \| Other Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	$ 0	$ 1

Related Party Transactions - Lo

Related Party Transactions - Long Term Debt to Financing Trusts (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Related Party Transaction [Line Items]
Long-term debt to financing trusts	$ 390	$ 390
ComEd Financing III Affiliate [Member]
Related Party Transaction [Line Items]
Long-term debt to financing trusts	206	206
PECO Trust III Affiliate [Member]
Related Party Transaction [Line Items]
Long-term debt to financing trusts	81	81
PECO Trust IV Affiliate [Member]
Related Party Transaction [Line Items]
Long-term debt to financing trusts	103	103
Commonwealth Edison Co [Member]
Related Party Transaction [Line Items]
Long-term debt to financing trusts	205	205
Commonwealth Edison Co [Member] \| ComEd Financing III Affiliate [Member]
Related Party Transaction [Line Items]
Long-term debt to financing trusts	205	205
Commonwealth Edison Co [Member] \| PECO Trust III Affiliate [Member]
Related Party Transaction [Line Items]
Long-term debt to financing trusts	0	0
Commonwealth Edison Co [Member] \| PECO Trust IV Affiliate [Member]
Related Party Transaction [Line Items]
Long-term debt to financing trusts	0	0
PECO Energy Co [Member]
Related Party Transaction [Line Items]
Long-term debt to financing trusts	184	184
PECO Energy Co [Member] \| ComEd Financing III Affiliate [Member]
Related Party Transaction [Line Items]
Long-term debt to financing trusts	0	0
PECO Energy Co [Member] \| PECO Trust III Affiliate [Member]
Related Party Transaction [Line Items]
Long-term debt to financing trusts	81	81
PECO Energy Co [Member] \| PECO Trust IV Affiliate [Member]
Related Party Transaction [Line Items]
Long-term debt to financing trusts	$ 103	$ 103

Schedule I - Condensed Financ_2

Schedule I - Condensed Financial Information of Parent (Exelon Corporate) - Condensed Statements of Operations and Other Comprehensive Income (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating Expenses [Abstract]
Total operating expenses	$ 15,256	$ 14,485	$ 14,073
Operating Loss	2,682	2,191	2,656
Other income and (deductions)
Interest Expense, net	(1,264)	(1,282)	(1,197)
Other, net	261	208	204
Total other income	(1,028)	(1,099)	(1,018)
Income taxes	38	(7)	153
Net income (loss)	1,829	1,954	3,028
Other comprehensive income (loss), net of income taxes
Prior service benefit reclassified to periodic cost	(4)	(40)	(65)
Actuarial loss reclassified to periodic cost	(223)	(190)	(149)
Pension and non-pension postretirement benefit plan valuation adjustment	432	(357)	(289)
Unrealized (loss) gain on cash flow hedges	(1)	(3)	0
Other comprehensive income (loss)	650	(206)	(198)
Comprehensive Income	2,356	1,757	2,737
Corporate, Non-Segment [Member]
Operating Expenses [Abstract]
Operating and maintenance	(9)	(2)	33
Operating and maintenance from affiliates	14	10	9
Other	2	2	1
Total operating expenses	7	10	43
Operating Loss	(7)	(10)	(43)
Other income and (deductions)
Interest Expense, net	(333)	(378)	(321)
Equity in earnings of unconsolidated affiliates	1,908	1,482	1,844
Interest income from affiliates, net	0	1	3
Other, net	0	15	14
Total other income	1,575	1,120	1,540
Income before income taxes	1,568	1,110	1,497
Income taxes	(48)	11	11
Net income (loss)	1,706	1,963	2,936
Other comprehensive income (loss), net of income taxes
Prior service benefit reclassified to periodic cost	(4)	(40)	(64)
Actuarial loss reclassified to periodic cost	223	190	148
Pension and non-pension postretirement benefit plan valuation adjustment	431	(357)	(289)
Unrealized (loss) gain on cash flow hedges	0	(1)	1
Other comprehensive income (loss)	650	(208)	(204)
Comprehensive Income	$ 2,356	$ 1,755	$ 2,732

Schedule I - Condensed Financ_3

Schedule I - Condensed Financial Information of Parent (Exelon Corporate) - Condensed Statements of Cash Flows (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Net cash flows provided by operating activities	$ 3,012	$ 4,235	$ 6,659
Cash flows from investing activities
Payments for (Proceeds from) Other Investing Activities	26	18	12
Net cash flows used in investing activities	(3,317)	(4,336)	(7,260)
Cash flows from financing activities
Changes in short-term borrowings	269	161	781
Proceeds from short-term borrowings with maturities greater than 90 days	1,380	500	0
Repayments on short-term borrowings with maturities greater than 90 days	(350)	0	(125)
Issuance of long-term debt	3,481	7,507	1,951
Retirement of long-term debt	(1,640)	(6,440)	(1,287)
Dividends paid on common stock	(1,497)	(1,492)	(1,408)
Proceeds from employee stock plans	80	45	112
Other financing activities	(80)	(136)	(82)
Net cash flows provided by (used in) financing activities	758	145	(58)
Increase (decrease) in cash, restricted cash, and cash equivalents	453	44	(659)
Cash, restricted cash, and cash equivalents at beginning of period	1,166	1,122	1,781
Cash, restricted cash, and cash equivalents at end of period	1,619	1,166	1,122
Corporate, Non-Segment [Member]
Net cash flows provided by operating activities	3,629	3,018	1,948
Cash flows from investing activities
Changes in Exelon/PHI intercompany money pool	381	(477)	95
Notes receivable from affiliates	0	550	0
Investment in affiliates	(2,231)	(1,969)	(1,071)
Payments for (Proceeds from) Other Investing Activities	1	0	0
Net cash flows used in investing activities	(1,849)	(1,896)	(976)
Cash flows from financing activities
Changes in short-term borrowings	0	(136)	136
Proceeds from short-term borrowings with maturities greater than 90 days	500	0	0
Repayments on short-term borrowings with maturities greater than 90 days	(350)	0	0
Issuance of long-term debt	0	2,000	0
Retirement of long-term debt	(300)	(1,450)	0
Dividends paid on common stock	(1,497)	(1,492)	(1,408)
Proceeds from employee stock plans	80	45	112
Other financing activities	19	(27)	0
Net cash flows provided by (used in) financing activities	(1,548)	(1,060)	(1,160)
Increase (decrease) in cash, restricted cash, and cash equivalents	232	62	(188)
Cash, restricted cash, and cash equivalents at beginning of period	63	1	189
Cash, restricted cash, and cash equivalents at end of period	$ 295	$ 63	$ 1

Schedule I - Condensed Financ_4

Schedule I - Condensed Financial Information of Parent (Exelon Corporate) - Condensed Balance Sheet (Details) - USD ($) shares in Millions, $ / shares in Millions, $ in Millions		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Current assets
Cash and cash equivalents		$ 672	$ 432	$ 587	$ 1,349
Accounts receivable
Other accounts receivable, net		996	1,046
Regulatory assets, current		1,296	1,228
Other		387	223
Total current assets		13,957	12,562
Property, plant and equipment, net		64,558	60,332
Deferred debits and other assets
Regulatory assets, noncurrent		8,224	8,759
Other		885	1,143
Total deferred debits and other assets		54,498	56,423
Total assets	[1]	133,013	129,317
Current liabilities
Short-term borrowings		1,248	1,191
Long-term debt due within one year		2,153	1,622
Accounts payable		2,379	2,309
Accrued expenses		1,137	1,230
Payables to affiliates, current		5	5
Regulatory liabilities, current		376	581
Other		766	784
Total current liabilities		16,111	12,771
Long-term debt		30,749	29,527
Deferred credits and other liabilities
Regulatory liabilities, noncurrent		9,628	9,485
Pension obligations		2,051	2,946
Non-pension postretirement benefits obligations		811	1,002
Other		1,573	1,642
Total deferred credits and other liabilities		50,968	51,761
Total liabilities	[1]	98,218	94,449
Commitments and contingencies
Shareholders’ equity
Common Stock, No Par Value		$ 0	$ 0
Common Stock, Shares Authorized		2,000	2,000
Common Stock, Shares, Outstanding		979	976
Common stock		$ 20,324	$ 19,373
Treasury Stock, Shares		2	2
Treasury stock, at cost		$ (123)	$ (123)
Retained earnings		16,942	16,735
Accumulated other comprehensive loss, net		(2,750)	(3,400)
Total shareholders’ equity		34,393	32,585
Total liabilities and equity		133,013	129,317
Corporate, Non-Segment [Member]
Current assets
Cash and cash equivalents		295	63
Accounts receivable
Other accounts receivable, net		318	354
Accounts receivable from affiliates, current		35	11
Note receivable from affiliates, current		217	598
Regulatory assets, current		266	315
Other		41	(23)
Total current assets		1,172	1,318
Property, plant and equipment, net		45	46
Deferred debits and other assets
Regulatory assets, noncurrent		3,164	3,816
Investments in affiliates		29,563	27,140
Deferred income taxes		1,351	1,436
Notes receivable from affiliates, noncurrent		319	324
Other		42	312
Total deferred debits and other assets		46,772	45,977
Total assets		47,989	47,341
Current liabilities
Short-term borrowings		650	500
Long-term debt due within one year		1,150	300
Accounts payable		0	1
Accrued expenses		47	66
Payables to affiliates, current		360	457
Regulatory liabilities, current		3	4
Pension obligations		49	61
Other		40	(1)
Total current liabilities		2,299	1,388
Long-term debt		6,265	7,418
Deferred credits and other liabilities
Regulatory liabilities, noncurrent		63	32
Pension obligations		4,416	5,236
Non-pension postretirement benefits obligations		87	236
Deferred income taxes		362	360
Other		104	86
Total deferred credits and other liabilities		5,032	5,950
Total liabilities		13,596	14,756
Commitments and contingencies
Shareholders’ equity
Common Stock, No Par Value		$ 0	$ 0
Common Stock, Shares Authorized		2,000	2,000
Common Stock, Shares, Outstanding		979	976
Common stock		$ 20,324	$ 19,373
Treasury Stock, Shares		2	2
Treasury stock, at cost		$ (123)	$ (123)
Retained earnings		16,942	16,735
Accumulated other comprehensive loss, net		(2,750)	(3,400)
Total shareholders’ equity		34,393	32,585
Total liabilities and equity		$ 47,989	$ 47,341

[1]Exelon’s consolidated assets include $18 million as of December 31, 2020, of certain VIEs that can only be used to settle the liabilities of the VIE. Exelon’s consolidated liabilities include $26 million as of December 31, 2020, of certain VIEs for which the VIE creditors do not have recourse to Exelon. See Note 21–Variable Interest Entities for additional information.

Schedule I - Condensed Financ_5

Schedule I - Condensed Financial Information of Parent (Exelon Corporate) - Basis of Presentation - Narrative (Details) - Corporate, Non-Segment [Member]	12 Months Ended
	Dec. 31, 2021
Exelon significant subsidiaries
Schedule of Equity Method Investments [Line Items]
Percentage ownership of consolidated subsidiaries	100%
Commonwealth Edison Co [Member]
Schedule of Equity Method Investments [Line Items]
Percentage ownership of consolidated subsidiaries	99%

Schedule I - Condensed Financ_6

Schedule I - Condensed Financial Information of Parent (Exelon Corporate) - Debt and Credit Agreements - Narrative (Details) - USD ($) $ in Millions		12 Months Ended
	Jan. 24, 2022	Dec. 31, 2021	Feb. 01, 2022	Dec. 31, 2020
Line of Credit Facility [Line Items]
Long-term debt, gross		$ 32,523		$ 30,702
Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity		3,700
Line of credit facility, remaining borrowing capacity		3,692
Commercial Paper
Line of Credit Facility [Line Items]
Commercial Paper		599		691
Line of credit facility, maximum borrowing capacity		3,700		3,700
Corporate, Non-Segment [Member]
Line of Credit Facility [Line Items]
Long-term debt, gross		7,289		7,589
Corporate, Non-Segment [Member] \| Revolving Credit Facility [Member]
Line of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity		600
Line of credit facility, remaining borrowing capacity		594
Corporate, Non-Segment [Member] \| Revolving Credit Facility [Member] \| Subsequent Event [Member]
Line of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity			$ 900
Corporate, Non-Segment [Member] \| ShortTermDebt03232017 [Member]
Line of Credit Facility [Line Items]
Short-Term Loans		500
Corporate, Non-Segment [Member] \| ShortTermDebt03242021 [Member]
Line of Credit Facility [Line Items]
Short-Term Loans		200
Corporate, Non-Segment [Member] \| ShortTermDebt03312021.2 [Member]
Line of Credit Facility [Line Items]
Short-Term Loans		150
Corporate, Non-Segment [Member] \| ShortTermDebt03312021.1 [Member]
Line of Credit Facility [Line Items]
Short-Term Loans		150
Corporate, Non-Segment [Member] \| ShortTermDebt01242022 \| Subsequent Event [Member]
Line of Credit Facility [Line Items]
Short-Term Loans	$ 1,150
Corporate, Non-Segment [Member] \| Commercial Paper
Line of Credit Facility [Line Items]
Commercial Paper		0		0
Line of credit facility, maximum borrowing capacity		$ 600		$ 600
Corporate, Non-Segment [Member] \| London Interbank Offered Rate (LIBOR) [Member] \| ShortTermDebt03232017 [Member]
Line of Credit Facility [Line Items]
Short-Term Loans, Interest rate terms		0.65
Corporate, Non-Segment [Member] \| London Interbank Offered Rate (LIBOR) [Member] \| ShortTermDebt03242021 [Member]
Line of Credit Facility [Line Items]
Short-Term Loans, Interest rate terms		0.65
Corporate, Non-Segment [Member] \| London Interbank Offered Rate (LIBOR) [Member] \| ShortTermDebt03312021.2 [Member]
Line of Credit Facility [Line Items]
Short-Term Loans, Interest rate terms		0.65
Corporate, Non-Segment [Member] \| London Interbank Offered Rate (LIBOR) [Member] \| ShortTermDebt03312021.1 [Member]
Line of Credit Facility [Line Items]
Short-Term Loans, Interest rate terms		0.65
Corporate, Non-Segment [Member] \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate \| Revolving Credit Facility [Member] \| Subsequent Event [Member]
Line of Credit Facility [Line Items]
Line of credit facility, interest rate at period end			1.275%
Corporate, Non-Segment [Member] \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate \| ShortTermDebt01242022 \| Subsequent Event [Member]
Line of Credit Facility [Line Items]
Short-Term Loans, Interest rate terms	0.75

Schedule I - Condensed Financ_7

Schedule I - Condensed Financial Information of Parent (Exelon Corporate) - Debt and Credit Agreements - Schedule of Outstanding Long-term Debt (Details) - USD ($) $ in Millions	Jan. 24, 2022	Jan. 21, 2022	Jan. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Long-term debt, gross				$ 32,523	$ 30,702
Unamortized debt discount and premium, net				70	72
Unamortized debt issuance costs				(220)	(202)
Long-term debt (including amounts due within one year)				669	721
Long-term Debt, Current Maturities				(2,153)	(1,622)
Long-term debt				30,749	29,527
Exelon Corporate [Member] \| Exelon Generation Co L L C [Member]
Debt Instrument [Line Items]
Due from Affiliate, Noncurrent			$ 258	319	324
Junior subordinated notes [Member]
Debt Instrument [Line Items]
Long-term debt, gross				1,150	1,150
Senior unsecured notes [Member]
Debt Instrument [Line Items]
Long-term debt, gross				6,324	6,624
Loan agreement [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 50	50
Minimum [Member] \| Senior unsecured notes [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				3.40%
Long-term Debt, Maturity Date				Dec. 31, 2022
Maximum [Member] \| Junior subordinated notes [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				3.50%
Long-term Debt, Maturity Date				Dec. 31, 2022
Maximum [Member] \| Senior unsecured notes [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				7.60%
Long-term Debt, Maturity Date				Dec. 31, 2050
Maximum [Member] \| Loan agreement [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				2%
Long-term Debt, Maturity Date				Dec. 31, 2023
Corporate, Non-Segment [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 7,289	7,589
Unamortized debt discount and premium, net				(10)	(10)
Unamortized debt issuance costs				(39)	(47)
Long-term debt (including amounts due within one year)				175	186
Long-term Debt, Current Maturities				(1,150)	(300)
Long-term debt				6,265	7,418
Due from Affiliate, Noncurrent				319	324
Corporate, Non-Segment [Member] \| Junior subordinated notes [Member]
Debt Instrument [Line Items]
Long-term debt, gross				1,150	1,150
Corporate, Non-Segment [Member] \| Senior unsecured notes [Member]
Debt Instrument [Line Items]
Long-term debt, gross				$ 6,139	$ 6,439
Corporate, Non-Segment [Member] \| Loan agreement [Member] \| Subsequent Event [Member]
Debt Instrument [Line Items]
Long-term debt, gross		$ 300
Corporate, Non-Segment [Member] \| Loan agreement [Member] \| Subsequent Event [Member] \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Debt Instrument [Line Items]
Subordinated Borrowing, Interest Rate		0.65%
Corporate, Non-Segment [Member] \| Loans Payable Two \| Subsequent Event [Member]
Debt Instrument [Line Items]
Long-term debt, gross		$ 300
Corporate, Non-Segment [Member] \| Loans Payable Two \| Subsequent Event [Member] \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Debt Instrument [Line Items]
Subordinated Borrowing, Interest Rate		0.65%
Corporate, Non-Segment [Member] \| Loans Payable Three \| Subsequent Event [Member]
Debt Instrument [Line Items]
Long-term debt, gross	$ 250
Corporate, Non-Segment [Member] \| Loans Payable Three \| Subsequent Event [Member] \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Debt Instrument [Line Items]
Subordinated Borrowing, Interest Rate	0.65%
Corporate, Non-Segment [Member] \| Minimum [Member] \| Senior unsecured notes [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				3.40%
Long-term Debt, Maturity Date				Dec. 31, 2025
Corporate, Non-Segment [Member] \| Maximum [Member] \| Junior subordinated notes [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				3.50%
Long-term Debt, Maturity Date				Dec. 31, 2022
Corporate, Non-Segment [Member] \| Maximum [Member] \| Senior unsecured notes [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				7.60%
Long-term Debt, Maturity Date				Dec. 31, 2050

Schedule I - Condensed Financ_8

Schedule I - Condensed Financial Information of Parent (Exelon Corporate) - Debt and Credit Agreements - Schedule of Debt Maturities (Details) $ in Millions	Dec. 31, 2021 USD ($)
Debt Instrument [Line Items]
2022	$ 2,153
2023	864
2024	817
2025	1,322
2026	1,611
Thereafter	25,888
Total	32,655
Corporate, Non-Segment [Member]
Debt Instrument [Line Items]
2022	1,150
2023	0
2024	0
2025	807
2026	750
Thereafter	4,582
Total	$ 7,289

Schedule I - Condensed Financ_9

Schedule I - Condensed Financial Information of Parent (Exelon Corporate) - Related Party Transactions - Summary of Related Party Transactions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Jan. 31, 2022
Related Party Transaction [Line Items]
Payables to affiliates, current	$ 5	$ 5
Exelon Corporate [Member]
Related Party Transaction [Line Items]
Operating and maintenance from affiliates	14	10	$ 9
Interest income from affiliates, net	0	1	3
Equity in earnings of unconsolidated affiliates	1,908	1,482	1,844
Contributions from member	1,842	1,638	1,615
Accounts receivable from affiliates, current	35	11
Note receivable from affiliates, current	217	598
Investments in affiliates	29,563	27,140
Payables to affiliates, current	360	457
Exelon Corporate [Member] \| Exelon Business Services Co Affiliate [Member]
Related Party Transaction [Line Items]
Operating and maintenance from affiliates	14	10	9
Interest income from affiliates, net	0	1	3
Equity in earnings of unconsolidated affiliates	(301)	(273)	(281)
Accounts receivable from affiliates, current	4	0
Note receivable from affiliates, current	210	252
Investments in affiliates	146	183
Payables to affiliates, current	0	91
Exelon Corporate [Member] \| Other Affiliate [Member]
Related Party Transaction [Line Items]
Equity in earnings of unconsolidated affiliates	2	27	(3)
Investments in affiliates	(3,663)	(3,599)
Exelon Corporate [Member] \| Exelon Generation Co L L C [Member]
Related Party Transaction [Line Items]
Accounts receivable from affiliates, current	13	3
Note receivable from affiliates, current	0	285
Notes receivable from affiliates, noncurrent	319	324		$ 258
Payables to affiliates, current	0	2
Exelon Corporate [Member] \| Exelon Energy Delivery Company LLC [Member]
Related Party Transaction [Line Items]
Equity in earnings of unconsolidated affiliates	2,215	1,729	2,054
Investments in affiliates	32,621	30,103
Payables to affiliates, current	0	4
Exelon Corporate [Member] \| UII LLC [Member]
Related Party Transaction [Line Items]
Equity in earnings of unconsolidated affiliates	0	0	97
Investments in affiliates	365	365
Payables to affiliates, current	360	360
Exelon Corporate [Member] \| Potomac Capital Investment Affiliate [Member]
Related Party Transaction [Line Items]
Equity in earnings of unconsolidated affiliates	(1)	0	1
Investments in affiliates	62	62
Exelon Corporate [Member] \| Exelon Enterprise [Member]
Related Party Transaction [Line Items]
Equity in earnings of unconsolidated affiliates	0	0	(16)
Accounts receivable from affiliates, current	1	1
Investments in affiliates	3	3
Exelon Corporate [Member] \| Exelon INQB8R, LLC [Member] [Member]
Related Party Transaction [Line Items]
Equity in earnings of unconsolidated affiliates	(7)	(1)	(6)
Investments in affiliates	26	23
Exelon Corporate [Member] \| Exelon Transmission Company LLC [Member]
Related Party Transaction [Line Items]
Equity in earnings of unconsolidated affiliates	0	0	$ (2)
Exelon Corporate [Member] \| Commonwealth Edison Co [Member]
Related Party Transaction [Line Items]
Accounts receivable from affiliates, current	5	0
Exelon Corporate [Member] \| PECO Energy Co [Member]
Related Party Transaction [Line Items]
Accounts receivable from affiliates, current	4	1
Note receivable from affiliates, current	0	40
Exelon Corporate [Member] \| Baltimore Gas and Electric Company [Member]
Related Party Transaction [Line Items]
Accounts receivable from affiliates, current	2	0
Exelon Corporate [Member] \| PHI Service Co Affiliate [Member]
Related Party Transaction [Line Items]
Accounts receivable from affiliates, current	6	6
Exelon Corporate [Member] \| Pepco Holdings LLC Affiliate [Member]
Related Party Transaction [Line Items]
Note receivable from affiliates, current	7	21
Exelon Corporate [Member] \| VEBA [Member]
Related Party Transaction [Line Items]
Investments in affiliates	$ 3	$ 0

Schedule II - Valuation and Q_2

Schedule II - Valuation and Qualifying Accounts Schedule (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
SEC Schedule, 12-09, Allowance, Credit Loss [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	$ 405	$ 213	$ 215
Charged to Costs and Expenses	107	228	92
Charged to Other Accounts	0	38	37
Deductions	120	74	131
Balance at End of Period	392	405	213
Deferred Tax Valuation Allowance [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	4	2	9
Charged to Costs and Expenses	0	0	0
Charged to Other Accounts	33	2	(7)
Deductions	0	0	0
Balance at End of Period	37	4	2
Reserve for Obsolete Materials [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	11	12	11
Charged to Costs and Expenses	5	5	6
Charged to Other Accounts	0	0	0
Deductions	3	6	5
Balance at End of Period	13	11	12
SEC Schedule, 12-09, Allowance, Notes Receivable [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	5	9
Balance at End of Period	14	5	9
Commonwealth Edison Co [Member] \| SEC Schedule, 12-09, Allowance, Credit Loss [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	118	79	81
Charged to Costs and Expenses	18	54	35
Charged to Other Accounts	1	13	20
Deductions	47	28	57
Balance at End of Period	90	118	79
Commonwealth Edison Co [Member] \| Reserve for Obsolete Materials [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	6	7	6
Charged to Costs and Expenses	3	3	6
Charged to Other Accounts	0	0	0
Deductions	2	4	5
Balance at End of Period	7	6	7
PECO Energy Co [Member] \| SEC Schedule, 12-09, Allowance, Credit Loss [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	124	62	61
Charged to Costs and Expenses	32	76	31
Charged to Other Accounts	(6)	6	3
Deductions	38	20	33
Balance at End of Period	112	124	62
PECO Energy Co [Member] \| Deferred Tax Valuation Allowance [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	1	0
Charged to Costs and Expenses	0	0
Charged to Other Accounts	2	1
Deductions	0	0
Balance at End of Period	3	1	0
PECO Energy Co [Member] \| Reserve for Obsolete Materials [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	2	2	2
Charged to Costs and Expenses	1	1	0
Charged to Other Accounts	0	0	0
Deductions	1	1	0
Balance at End of Period	2	2	2
PECO Energy Co [Member] \| SEC Schedule, 12-09, Allowance, Notes Receivable [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	5	9
Balance at End of Period	14	5	9
Baltimore Gas and Electric Company [Member] \| SEC Schedule, 12-09, Allowance, Credit Loss [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	44	17	20
Charged to Costs and Expenses	16	31	8
Charged to Other Accounts	3	6	7
Deductions	16	10	18
Balance at End of Period	47	44	17
Baltimore Gas and Electric Company [Member] \| Deferred Tax Valuation Allowance [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	0	1	1
Charged to Costs and Expenses		0	0
Charged to Other Accounts		(1)	0
Deductions		0	0
Balance at End of Period		0	1
Baltimore Gas and Electric Company [Member] \| Reserve for Obsolete Materials [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	1	1	1
Charged to Costs and Expenses	0	0	0
Charged to Other Accounts	0	0	0
Deductions	0	0	0
Balance at End of Period	1	1	1
Pepco Holdings LLC [Member] \| SEC Schedule, 12-09, Allowance, Credit Loss [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	119	53	53
Charged to Costs and Expenses	41	69	17
Charged to Other Accounts	2	13	7
Deductions	19	16	24
Balance at End of Period	143	119	53
Pepco Holdings LLC [Member] \| Deferred Tax Valuation Allowance [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	0	0	8
Charged to Costs and Expenses	0		0
Charged to Other Accounts	31		(8)
Deductions	0		0
Balance at End of Period	31	0	0
Pepco Holdings LLC [Member] \| Reserve for Obsolete Materials [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	2	3	2
Charged to Costs and Expenses	1	0	1
Charged to Other Accounts	0	0	0
Deductions	0	1	0
Balance at End of Period	3	2	3
Potomac Electric Power Company [Member] \| SEC Schedule, 12-09, Allowance, Credit Loss [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	45	20	21
Charged to Costs and Expenses	14	25	7
Charged to Other Accounts	2	5	2
Deductions	8	5	10
Balance at End of Period	53	45	20
Potomac Electric Power Company [Member] \| Reserve for Obsolete Materials [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	1	1	1
Charged to Costs and Expenses	0	0	0
Charged to Other Accounts	0	0	0
Deductions	0	0	0
Balance at End of Period	1	1	1
Delmarva Power & Light Company [Member] \| SEC Schedule, 12-09, Allowance, Credit Loss [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	31	15	13
Charged to Costs and Expenses	6	16	4
Charged to Other Accounts	(1)	4	3
Deductions	10	4	5
Balance at End of Period	26	31	15
Delmarva Power & Light Company [Member] \| Deferred Tax Valuation Allowance [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	0
Charged to Costs and Expenses	0
Charged to Other Accounts	31
Deductions	0
Balance at End of Period	31	0
Atlantic City Electric Company [Member] \| SEC Schedule, 12-09, Allowance, Credit Loss [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	43	18	19
Charged to Costs and Expenses	21	28	5
Charged to Other Accounts	1	4	2
Deductions	1	7	8
Balance at End of Period	64	43	18
Atlantic City Electric Company [Member] \| Reserve for Obsolete Materials [Member]
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period	0	1	1
Charged to Costs and Expenses	1	0	0
Charged to Other Accounts	0	0	0
Deductions	0	1	0
Balance at End of Period	$ 1	$ 0	$ 1