Commonwealth Edison 10-Q9 May 222022 Q1 Quarterly reportFinancial data

Company Profile

Cover Page

Cover Page	3 Months Ended
Cover Page	Mar. 31, 2022shares
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2022
Document Transition Report	false
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 Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock Shares Outstanding	980,209,605
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31
Entity Central Index Key	0001109357
Amendment Flag	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, Address Line Two	49th Floor
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 Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock Shares Outstanding	127,021,391
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 Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock Shares Outstanding	170,478,507
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 Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock Shares Outstanding	1,000
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, District of Columbia
Entity Address, Postal Zip Code	20068-0001
City Area Code	(202)
Local Phone Number	872-2000
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
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, District of Columbia
Entity Address, Postal Zip Code	20068-001
City Area Code	(202)
Local Phone Number	872-2000
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock Shares Outstanding	100
Entity Central Index Key	0000079732
Delmarva Power and 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 Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock Shares Outstanding	1,000
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 Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Common Stock Shares Outstanding	8,546,017
Entity Central Index Key	0000008192
DISTRICT OF COLUMBIA \| Potomac Electric Power Company [Member]
Entity Incorporation, State or Country Code	DC
VIRGINIA \| Potomac Electric Power Company [Member]
Entity Incorporation, State or Country Code	VA
VIRGINIA \| Delmarva Power and Light Company [Member]
Entity Incorporation, State or Country Code	VA
DELAWARE \| Delmarva Power and Light Company [Member]
Entity Incorporation, State or Country Code	DE

Consolidated Statements of Oper

Consolidated Statements of Operations and Comprehensive Income (Unaudited) - USD ($) shares in Millions, $ in Millions		3 Months Ended
		Mar. 31, 2022	Mar. 31, 2021
Operating revenues
Revenues from alternative revenue programs		$ 29	$ 129
Operating revenues from affiliates		6	7
Total operating revenues		5,327	4,632
Operating expenses
Purchased power and/or fuel from affiliates		159	293
Operating and maintenance		1,178	1,083
Depreciation and amortization		817	757
Taxes other than income taxes		354	317
Total operating expenses		4,427	3,808
Operating income (loss)		900	824
Other income and (deductions)
Interest expense, net		(332)	(312)
Interest expense to affiliates		(6)	(6)
Other, net		137	58
Total other deductions		(201)	(260)
Income (Loss) before income taxes		699	564
Income taxes		218	39
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest		481	525
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest		117	(789)
Net income (loss)		598	(264)
Net income (loss) attributable to noncontrolling interests		1	25
Net Income (Loss) Available to Common Stockholders, Basic		597	(289)
Net Income (Loss) from Continuing Operations Available to Common Shareholders, Basic		481	525
Net Income (Loss) from Discontinued Operations Available to Common Shareholders, Basic		116	(814)
Other comprehensive income (loss), net of income taxes
Prior service benefit reclassified to periodic benefit cost		0	(1)
Actuarial loss reclassified to periodic benefit cost		14	56
Pension and non-pension postretirement benefit plan valuation adjustment		0	(2)
Unrealized gain (loss) on foreign currency translation		0	1
Other comprehensive income		14	54
Comprehensive income		612	(210)
Comprehensive income attributable to noncontrolling interests		1	25
Comprehensive income attributable to common shareholders/membership interest		$ 611	$ (235)
Average shares of common stock outstanding:
Basic average shares of common stock outstanding		981	977
Assumed exercise and/or distributions of stock-based awards		0	1
Diluted average shares of common stock outstanding	[1]	981	978
Earnings per average common share from continuing operations
Income (Loss) from Continuing Operations, Per Basic Share		$ 0.49	$ 0.53
Income (Loss) from Continuing Operations, Per Diluted Share		0.49	0.53
Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Basic Share		0.12	(0.83)
Discontinued Operation, Income (Loss) from Discontinued Operation, Net of Tax, Per Diluted Share		$ 0.12	$ (0.83)
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount			1
Commonwealth Edison Co [Member]
Operating revenues
Revenues from alternative revenue programs		$ 40	$ 54
Operating revenues from affiliates		6	6
Total operating revenues		1,734	1,535
Operating expenses
Purchased power and/or fuel from affiliates		59	85
Operating and maintenance		266	245
Related Party Transaction, Expenses from Transactions with Related Party		85	71
Depreciation and amortization		321	292
Taxes other than income taxes		96	75
Total operating expenses		1,406	1,210
Operating income (loss)		328	325
Other income and (deductions)
Interest expense, net		(97)	(93)
Interest expense to affiliates		(3)	(3)
Other, net		12	7
Total other deductions		(88)	(89)
Income (Loss) before income taxes		240	236
Income taxes		52	39
Net income (loss)		188	197
Other comprehensive income (loss), net of income taxes
Comprehensive income		188	197
PECO Energy Co [Member]
Operating revenues
Revenues from alternative revenue programs		6	10
Operating revenues from affiliates		1	2
Total operating revenues		1,047	889
Operating expenses
Purchased power and/or fuel from affiliates		33	41
Operating and maintenance		196	193
Related Party Transaction, Expenses from Transactions with Related Party		51	41
Depreciation and amortization		92	86
Taxes other than income taxes		47	43
Total operating expenses		793	679
Operating income (loss)		254	210
Other income and (deductions)
Interest expense, net		(38)	(35)
Interest expense to affiliates		(3)	(3)
Other, net		7	5
Total other deductions		(34)	(33)
Income (Loss) before income taxes		220	177
Income taxes		14	10
Net income (loss)		206	167
Other comprehensive income (loss), net of income taxes
Comprehensive income		206	167
Baltimore Gas and Electric Company [Member]
Operating revenues
Revenues from alternative revenue programs		(12)	18
Operating revenues from affiliates		7	6
Total operating revenues		1,154	974
Operating expenses
Purchased power and/or fuel from affiliates		18	70
Operating and maintenance		167	152
Related Party Transaction, Expenses from Transactions with Related Party		51	45
Depreciation and amortization		171	152
Taxes other than income taxes		76	72
Total operating expenses		919	752
Operating income (loss)		235	222
Other income and (deductions)
Interest expense, net		(35)	(34)
Other, net		7	8
Total other deductions		(28)	(26)
Income (Loss) before income taxes		207	196
Income taxes		9	(13)
Net income (loss)		198	209
Other comprehensive income (loss), net of income taxes
Comprehensive income		198	209
Pepco Holdings LLC [Member]
Operating revenues
Revenues from alternative revenue programs		(5)	46
Operating revenues from affiliates		3	3
Total operating revenues		1,404	1,244
Operating expenses
Purchased power and/or fuel from affiliates		50	98
Operating and maintenance		248	216
Related Party Transaction, Expenses from Transactions with Related Party		51	40
Depreciation and amortization		218	210
Taxes other than income taxes		119	113
Total operating expenses		1,215	1,058
Operating income (loss)		189	186
Other income and (deductions)
Interest expense, net		(69)	(67)
Other, net		17	17
Total other deductions		(52)	(50)
Income (Loss) before income taxes		137	136
Income taxes		7	8
Net income (loss)		130	128
Other comprehensive income (loss), net of income taxes
Comprehensive income attributable to common shareholders/membership interest		130	128
Potomac Electric Power Company [Member]
Operating revenues
Revenues from alternative revenue programs		(7)	26
Operating revenues from affiliates		1	1
Total operating revenues		614	553
Operating expenses
Purchased power and/or fuel from affiliates		39	74
Operating and maintenance		73	56
Related Party Transaction, Expenses from Transactions with Related Party		58	52
Depreciation and amortization		108	102
Taxes other than income taxes		95	90
Total operating expenses		547	466
Operating income (loss)		67	87
Other income and (deductions)
Interest expense, net		(36)	(34)
Other, net		13	12
Total other deductions		(23)	(22)
Income (Loss) before income taxes		44	65
Income taxes		(2)	6
Net income (loss)		46	59
Other comprehensive income (loss), net of income taxes
Comprehensive income		46	59
Delmarva Power and Light Company [Member]
Operating revenues
Revenues from alternative revenue programs		(1)	9
Operating revenues from affiliates		1	2
Total operating revenues		431	382
Operating expenses
Purchased power and/or fuel from affiliates		10	20
Operating and maintenance		51	44
Related Party Transaction, Expenses from Transactions with Related Party		42	39
Depreciation and amortization		57	53
Taxes other than income taxes		18	17
Total operating expenses		357	309
Operating income (loss)		74	73
Other income and (deductions)
Interest expense, net		(16)	(15)
Other, net		2	3
Total other deductions		(14)	(12)
Income (Loss) before income taxes		60	61
Income taxes		4	5
Net income (loss)		56	56
Other comprehensive income (loss), net of income taxes
Comprehensive income		56	56
Atlantic City Electric Company [Member]
Operating revenues
Revenues from alternative revenue programs		3	11
Operating revenues from affiliates		1	1
Total operating revenues		349	310
Operating expenses
Purchased power and/or fuel from affiliates		2	4
Operating and maintenance		47	42
Related Party Transaction, Expenses from Transactions with Related Party		37	34
Depreciation and amortization		47	47
Taxes other than income taxes		2	2
Total operating expenses		311	282
Operating income (loss)		38	28
Other income and (deductions)
Interest expense, net		(14)	(15)
Other, net		3	1
Total other deductions		(11)	(14)
Income (Loss) before income taxes		27	14
Income taxes		1	0
Net income (loss)		26	14
Other comprehensive income (loss), net of income taxes
Comprehensive income		26	14
Generation commodities and services
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		4,481	3,870
Operating expenses
Purchased power and/or fuel		1,581	1,140
Natural gas operating revenues
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		817	633
Operating expenses
Purchased power and/or fuel		338	218
Electricity, US Regulated
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		4,522	3,991
Electricity, US Regulated \| Commonwealth Edison Co [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		1,688	1,475
Operating expenses
Purchased power and/or fuel		579	442
Electricity, US Regulated \| PECO Energy Co [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		734	649
Operating expenses
Purchased power and/or fuel		229	189
Electricity, US Regulated \| Baltimore Gas and Electric Company [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		735	620
Operating expenses
Purchased power and/or fuel		285	162
Electricity, US Regulated \| Pepco Holdings LLC [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		1,323	1,124
Operating expenses
Purchased power and/or fuel		487	348
Electricity, US Regulated \| Potomac Electric Power Company [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		620	526
Operating expenses
Purchased power and/or fuel		174	92
Electricity, US Regulated \| Delmarva Power and Light Company [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		348	300
Operating expenses
Purchased power and/or fuel		137	103
Electricity, US Regulated \| Atlantic City Electric Company [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		345	298
Operating expenses
Purchased power and/or fuel		176	153
Natural Gas, US Regulated
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		805	641
Natural Gas, US Regulated \| PECO Energy Co [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		306	228
Operating expenses
Purchased power and/or fuel		145	86
Natural Gas, US Regulated \| Baltimore Gas and Electric Company [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		424	330
Operating expenses
Purchased power and/or fuel		151	99
Natural Gas, US Regulated \| Pepco Holdings LLC [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		83	71
Operating expenses
Purchased power and/or fuel		42	33
Natural Gas, US Regulated \| Delmarva Power and Light Company [Member]
Operating revenues
Revenue from Contract with Customer, Including Assessed Tax		83	71
Operating expenses
Purchased power and/or fuel		$ 42	$ 33

[1]	The number of stock options not included in the calculation of diluted common shares outstanding due to their antidilutive effect were none and less than 1 million for the three months ended March 31, 2022 and 2021, respectively

Consolidated Statements of Cash

Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash flows from operating activities
Net income (loss)	$ 598	$ (264)
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization	1,024	2,104
Asset impairments	0	1
Gain on sales of assets and businesses	(10)	(71)
Deferred income taxes and amortization of investment tax credits	110	(142)
Net fair value changes related to derivatives	(59)	(178)
Net realized and unrealized (gains) losses on NDT funds	205	(118)
Net unrealized (gains) losses on equity investments	16	23
Other non-cash operating activities	232	(170)
Changes in assets and liabilities:
Accounts receivable	(711)	(372)
Inventories	125	77
Accounts payable and accrued expenses	291	(176)
Option premiums (paid) received, net	(39)	16
Collateral received (posted), net	1,142	273
Income taxes	77	113
Pension and non-pension postretirement benefit contributions	(574)	(537)
Other assets and liabilities	(645)	(1,840)
Net Cash Provided by (Used in) Operating Activities, Total	1,782	(1,261)
Cash flows from investing activities
Capital expenditures	(1,922)	(2,140)
Proceeds from NDT fund sales	488	2,908
Investment in NDT funds	(516)	(2,939)
Collection of deferred purchase price	169	1,574
Proceeds from Sale of Property Held-for-sale	16	680
Other investing activities	(54)	12
Net Cash Provided by (Used in) Investing Activities, Total	(1,819)	95
Cash flows from financing activities
Changes in short-term borrowings	(700)	597
Proceeds from short-term borrowings with maturities greater than 90 days	1,150	500
Repayments on short-term borrowings with maturities greater than 90 days	(350)	0
Issuance of long-term debt	4,301	1,705
Retirement of long-term debt	(6)	(79)
Dividends paid on common stock	(332)	(374)
Proceeds from employee stock plans	9	31
Transfer of cash, restricted cash, and cash equivalents to Constellation	(2,594)	0
Other financing activities	(62)	(46)
Net cash flows provided by financing activities	1,416	2,334
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect, Total	1,379	1,168
Cash, restricted cash, and cash equivalents at beginning of period	1,619	1,166
Cash, restricted cash, and cash equivalents at end of period	2,998	2,334
Supplemental Cash Flow Information
Decrease in capital expenditures not paid	(322)	(324)
Increase in deferred purchase price	348	1,339
Increase in PPE related to ARO update	(335)	2
Exelon Generation Co L L C [Member]
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization	207	1,346
Gain on sales of assets and businesses	9	(71)
Deferred income taxes and amortization of investment tax credits	(143)	(234)
Net fair value changes related to derivatives	(59)	(178)
Net realized and unrealized (gains) losses on NDT funds	205	(118)
Net unrealized (gains) losses on equity investments	16	23
Other non-cash operating activities	(36)	332
Cash flows from investing activities
Capital expenditures	(227)	(394)
Collection of deferred purchase price	169	1,574
Supplemental Cash Flow Information
Decrease in capital expenditures not paid	(128)	(37)
Increase in deferred purchase price	348	1,339
Increase in PPE related to ARO update	335	0
Commonwealth Edison Co [Member]
Cash flows from operating activities
Net income (loss)	188	197
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization	321	292
Deferred income taxes and amortization of investment tax credits	54	63
Other non-cash operating activities	(9)	(9)
Changes in assets and liabilities:
Accounts receivable	(45)	23
Change in receivables from payables to affiliates, net	(42)	(15)
Inventories	3	(1)
Accounts payable and accrued expenses	(154)	(176)
Collateral received (posted), net	43	5
Income taxes	(2)	(23)
Pension and non-pension postretirement benefit contributions	(176)	(171)
Other assets and liabilities	(37)	(159)
Net Cash Provided by (Used in) Operating Activities, Total	144	26
Cash flows from investing activities
Capital expenditures	(617)	(613)
Other investing activities	7	7
Net Cash Provided by (Used in) Investing Activities, Total	(610)	(606)
Cash flows from financing activities
Changes in short-term borrowings	0	(188)
Issuance of long-term debt	750	700
Dividends paid on common stock	(144)	(127)
Contributions from parent	167	198
Other financing activities	(10)	(9)
Net cash flows provided by financing activities	763	574
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect, Total	297	(6)
Cash, restricted cash, and cash equivalents at beginning of period	384	405
Cash, restricted cash, and cash equivalents at end of period	681	399
Supplemental Cash Flow Information
Decrease in capital expenditures not paid	(50)	(107)
PECO Energy Co [Member]
Cash flows from operating activities
Net income (loss)	206	167
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization	92	86
Deferred income taxes and amortization of investment tax credits	14	6
Other non-cash operating activities	15	12
Changes in assets and liabilities:
Accounts receivable	(40)	(5)
Change in receivables from payables to affiliates, net	(31)	(2)
Inventories	27	13
Accounts payable and accrued expenses	(24)	(36)
Income taxes	0	3
Pension and non-pension postretirement benefit contributions	(12)	(16)
Other assets and liabilities	(106)	(103)
Net Cash Provided by (Used in) Operating Activities, Total	141	125
Cash flows from investing activities
Capital expenditures	(344)	(295)
Changes in Exelon/PHI intercompany money pool	0	(48)
Other investing activities	2	1
Net Cash Provided by (Used in) Investing Activities, Total	(342)	(342)
Cash flows from financing activities
Issuance of long-term debt	0	375
Increase (Decrease) in Due to Affiliates, Current	65	(40)
Dividends paid on common stock	(100)	(85)
Contributions from parent	227	0
Other financing activities	(1)	(4)
Net cash flows provided by financing activities	191	246
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect, Total	(10)	29
Cash, restricted cash, and cash equivalents at beginning of period	44	26
Cash, restricted cash, and cash equivalents at end of period	34	55
Supplemental Cash Flow Information
Decrease in capital expenditures not paid	(41)	(44)
Baltimore Gas and Electric Company [Member]
Cash flows from operating activities
Net income (loss)	198	209
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization	171	152
Deferred income taxes and amortization of investment tax credits	5	(4)
Other non-cash operating activities	44	2
Changes in assets and liabilities:
Accounts receivable	(80)	12
Change in receivables from payables to affiliates, net	(2)	(15)
Inventories	32	9
Accounts payable and accrued expenses	(30)	(59)
Income taxes	4	(9)
Pension and non-pension postretirement benefit contributions	(56)	(65)
Other assets and liabilities	(9)	(103)
Net Cash Provided by (Used in) Operating Activities, Total	277	129
Cash flows from investing activities
Capital expenditures	(303)	(336)
Other investing activities	3	2
Net Cash Provided by (Used in) Investing Activities, Total	(300)	(334)
Cash flows from financing activities
Changes in short-term borrowings	120	156
Dividends paid on common stock	(76)	(74)
Other financing activities	(1)	0
Net cash flows provided by financing activities	43	82
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect, Total	20	(123)
Cash, restricted cash, and cash equivalents at beginning of period	55	145
Cash, restricted cash, and cash equivalents at end of period	75	22
Supplemental Cash Flow Information
Decrease in capital expenditures not paid	(32)	(80)
Pepco Holdings LLC [Member]
Cash flows from operating activities
Net income (loss)	130	128
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization	218	210
Deferred income taxes and amortization of investment tax credits	2	4
Other non-cash operating activities	35	(25)
Changes in assets and liabilities:
Accounts receivable	(21)	56
Change in receivables from payables to affiliates, net	(51)	(18)
Inventories	7	5
Accounts payable and accrued expenses	(23)	(24)
Income taxes	5	3
Pension and non-pension postretirement benefit contributions	(67)	(36)
Other assets and liabilities	(3)	(94)
Net Cash Provided by (Used in) Operating Activities, Total	232	209
Cash flows from investing activities
Capital expenditures	(409)	(456)
Other investing activities	2	1
Net Cash Provided by (Used in) Investing Activities, Total	(407)	(455)
Cash flows from financing activities
Changes in short-term borrowings	(468)	(368)
Issuance of long-term debt	700	625
Retirement of long-term debt	0	(44)
Increase (Decrease) in Due to Affiliates, Current	39	3
Payments of Distributions to Affiliates	(102)	(81)
Proceeds from Contributions from Affiliates	704	560
Other financing activities	(9)	(5)
Net cash flows provided by financing activities	864	690
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect, Total	689	444
Cash, restricted cash, and cash equivalents at beginning of period	213	160
Cash, restricted cash, and cash equivalents at end of period	902	604
Supplemental Cash Flow Information
Decrease in capital expenditures not paid	(55)	(33)
Potomac Electric Power Company [Member]
Cash flows from operating activities
Net income (loss)	46	59
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization	108	102
Deferred income taxes and amortization of investment tax credits	(2)	4
Other non-cash operating activities	12	(25)
Changes in assets and liabilities:
Accounts receivable	(2)	26
Change in receivables from payables to affiliates, net	(25)	(9)
Inventories	0	1
Accounts payable and accrued expenses	5	0
Income taxes	1	2
Pension and non-pension postretirement benefit contributions	(5)	(5)
Other assets and liabilities	(18)	(58)
Net Cash Provided by (Used in) Operating Activities, Total	120	97
Cash flows from investing activities
Capital expenditures	(218)	(220)
Other investing activities	1	1
Net Cash Provided by (Used in) Investing Activities, Total	(217)	(219)
Cash flows from financing activities
Changes in short-term borrowings	(175)	(35)
Issuance of long-term debt	400	150
Dividends paid on common stock	(42)	(28)
Contributions from parent	387	138
Other financing activities	(5)	(1)
Net cash flows provided by financing activities	565	224
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect, Total	468	102
Cash, restricted cash, and cash equivalents at beginning of period	68	65
Cash, restricted cash, and cash equivalents at end of period	536	167
Supplemental Cash Flow Information
Decrease in capital expenditures not paid	(36)	(16)
Delmarva Power and Light Company [Member]
Cash flows from operating activities
Net income (loss)	56	56
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization	57	53
Deferred income taxes and amortization of investment tax credits	5	2
Other non-cash operating activities	9	(1)
Changes in assets and liabilities:
Accounts receivable	(17)	15
Change in receivables from payables to affiliates, net	(17)	(11)
Inventories	8	2
Accounts payable and accrued expenses	15	11
Income taxes	(1)	3
Pension and non-pension postretirement benefit contributions	(1)	0
Other assets and liabilities	33	(26)
Net Cash Provided by (Used in) Operating Activities, Total	147	104
Cash flows from investing activities
Capital expenditures	(103)	(112)
Other investing activities	1	0
Net Cash Provided by (Used in) Investing Activities, Total	(102)	(112)
Cash flows from financing activities
Changes in short-term borrowings	(149)	(146)
Issuance of long-term debt	125	125
Dividends paid on common stock	(41)	(40)
Contributions from parent	144	120
Other financing activities	(2)	(2)
Net cash flows provided by financing activities	77	57
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect, Total	122	49
Cash, restricted cash, and cash equivalents at beginning of period	71	15
Cash, restricted cash, and cash equivalents at end of period	193	64
Supplemental Cash Flow Information
Decrease in capital expenditures not paid	(8)	(15)
Atlantic City Electric Company [Member]
Cash flows from operating activities
Net income (loss)	26	14
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization	47	47
Deferred income taxes and amortization of investment tax credits	1	(1)
Other non-cash operating activities	2	(7)
Changes in assets and liabilities:
Accounts receivable	(1)	13
Change in receivables from payables to affiliates, net	(6)	1
Inventories	(1)	3
Accounts payable and accrued expenses	(17)	(11)
Income taxes	0	1
Pension and non-pension postretirement benefit contributions	(7)	(3)
Other assets and liabilities	0	(3)
Net Cash Provided by (Used in) Operating Activities, Total	44	54
Cash flows from investing activities
Capital expenditures	(87)	(123)
Net Cash Provided by (Used in) Investing Activities, Total	(87)	(123)
Cash flows from financing activities
Changes in short-term borrowings	(144)	(187)
Issuance of long-term debt	175	350
Retirement of long-term debt	0	(44)
Dividends paid on common stock	(19)	(14)
Contributions from parent	173	303
Other financing activities	(3)	(3)
Net cash flows provided by financing activities	182	405
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents, Period Increase (Decrease), Excluding Exchange Rate Effect, Total	139	336
Cash, restricted cash, and cash equivalents at beginning of period	29	30
Cash, restricted cash, and cash equivalents at end of period	168	366
Supplemental Cash Flow Information
Decrease in capital expenditures not paid	$ (10)	$ (2)

Consolidated Balance Sheets (Un

Consolidated Balance Sheets (Unaudited) - USD ($) shares in Millions, $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Current Assets
Cash and cash equivalents	$ 2,476	$ 672
Restricted cash and cash equivalents	430	321
Accounts receivable
Customer accounts receivable	2,365	2,189
Customer allowance for credit losses	(389)	(320)
Customer accounts receivable, net	1,976	1,869
Other accounts receivable	1,148	1,068
Other allowance for credit losses	(81)	(72)
Other accounts receivable, net	1,067	996
Inventories, net
Fossil fuel and emission allowances	39	105
Materials and supplies	473	476
Regulatory assets, current	1,221	1,296
Current assets of discontinued operations	0	7,835
Other	463	387
Total current assets	8,145	13,957
Accumulated depreciation and amortization	14,878	14,430
Property, plant and equipment, net	65,465	64,558
Deferred debits and other assets
Regulatory assets, noncurrent	8,200	8,224
Investments	244	250
Goodwill	6,630	6,630
Receivable related to Regulatory Agreement Units	2,969	0
Property, plant, and equipment, deferred debits, and other assets of discontinued operations	0	38,509
Other	1,045	885
Total deferred debits and other assets	19,088	54,498
Total assets	92,698	133,013
Current Liabilities
Short-term borrowings	1,900	1,248
Long-term debt due within one year	2,154	2,153
Accounts payable	2,175	2,379
Accrued expenses	1,029	1,137
Payables to affiliates, current	6	5
Regulatory liabilities, current	394	376
Mark-to-market derivative liabilities, current	0	18
Unamortized energy contract liabilities, current	13	89
Current liabilities of discontinued operations	0	7,940
Other	964	766
Total current liabilities	8,635	16,111
Long-term debt	35,008	30,749
Long-term debt to financing trusts	390	390
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits	11,089	10,611
Asset retirement obligations, noncurrent	273	271
Pension obligations	1,447	2,051
Non-pension postretirement benefit obligations	800	811
Regulatory liabilities, noncurrent	9,192	9,628
Mark-to-market derivative liabilities, noncurrent	144	201
Unamortized energy contract liabilities, noncurrent	42	146
Long-term debt, deferred credits, and other liabilities of discontinued operations	0	25,676
Other	2,187	1,573
Total deferred credits and other liabilities	25,174	50,968
Liabilities	69,207	98,218
Commitments and contingencies
Shareholders' equity
Common Stock, No Par Value	$ 0	$ 0
Common stock, shares authorized	2,000	2,000
Common stock, shares outstanding	980	979
Common stock	$ 20,299	$ 20,324
Treasury stock, shares	2	2
Treasury stock, at cost	$ (123)	$ (123)
Retained earnings/Undistributed earnings (losses)	4,028	16,942
Accumulated other comprehensive loss, net	(713)	(2,750)
Total shareholders’ equity	23,491	34,393
Members' Equity [Abstract]
Noncontrolling interests	0	402
Total equity	23,491	34,795
Total liabilities and shareholders’ equity	92,698	133,013
Commonwealth Edison Co [Member]
Current Assets
Cash and cash equivalents	343	131
Restricted cash and cash equivalents	246	210
Accounts receivable
Customer accounts receivable	702	647
Customer allowance for credit losses	(92)	(73)
Customer accounts receivable, net	610	574
Other accounts receivable	219	227
Other allowance for credit losses	(20)	(17)
Other accounts receivable, net	199	210
Receivables from affiliates, current	3	16
Inventories, net
Inventories, net	167	170
Regulatory assets, current	316	335
Other	80	76
Total current assets	1,964	1,722
Accumulated depreciation and amortization	6,267	6,099
Property, plant and equipment, net	26,325	25,995
Deferred debits and other assets
Regulatory assets, noncurrent	1,883	1,870
Investments	6	6
Goodwill	2,625	2,625
Receivables from affiliates, noncurrent	0	2,761
Receivable related to Regulatory Agreement Units	2,484	0
Prepaid pension asset	1,245	1,086
Other	481	405
Total deferred debits and other assets	8,724	8,753
Total assets	37,013	36,470
Current Liabilities
Accounts payable	553	647
Accrued expenses	275	384
Payables to affiliates, current	66	121
Customer deposits	98	99
Regulatory liabilities, current	190	185
Mark-to-market derivative liabilities, current	0	18
Other	161	133
Total current liabilities	1,343	1,587
Long-term debt	10,515	9,773
Long-term debt to financing trusts	205	205
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits	4,761	4,685
Asset retirement obligations, noncurrent	145	144
Non-pension postretirement benefit obligations	168	169
Regulatory liabilities, noncurrent	6,551	6,759
Mark-to-market derivative liabilities, noncurrent	144	201
Other	615	592
Total deferred credits and other liabilities	12,384	12,550
Liabilities	24,447	24,115
Commitments and contingencies
Shareholders' equity
Common stock	1,588	1,588
Retained earnings/Undistributed earnings (losses)	1,735	1,691
Other paid-in capital	9,243	9,076
Total shareholders’ equity	12,566	12,355
Members' Equity [Abstract]
Total liabilities and shareholders’ equity	37,013	36,470
PECO Energy Co [Member]
Current Assets
Cash and cash equivalents	26	36
Restricted cash and cash equivalents	8	8
Accounts receivable
Customer accounts receivable	528	489
Customer allowance for credit losses	(125)	(105)
Customer accounts receivable, net	403	384
Other accounts receivable	129	116
Other allowance for credit losses	(9)	(7)
Other accounts receivable, net	120	109
Receivables from affiliates, current	0	1
Inventories, net
Fossil fuel and emission allowances	23	51
Materials and supplies	46	45
Prepaid utility taxes	117	1
Regulatory assets, current	57	48
Other	30	28
Total current assets	830	711
Accumulated depreciation and amortization	4,004	3,964
Property, plant and equipment, net	11,334	11,117
Deferred debits and other assets
Regulatory assets, noncurrent	1,000	943
Investments	33	34
Receivables from affiliates, noncurrent	0	597
Receivable related to Regulatory Agreement Units	486	0
Prepaid pension asset	401	386
Other	29	36
Total deferred debits and other assets	1,949	1,996
Total assets	14,113	13,824
Current Liabilities
Long-term debt due within one year	350	350
Accounts payable	477	494
Accrued expenses	105	136
Payables to affiliates, current	38	70
Borrowings from Exelon/PHI intercompany money pool	65	0
Customer deposits	50	48
Regulatory liabilities, current	94	94
Other	41	35
Total current liabilities	1,220	1,227
Long-term debt	3,848	3,847
Long-term debt to financing trusts	184	184
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits	2,495	2,421
Asset retirement obligations, noncurrent	29	29
Non-pension postretirement benefit obligations	287	286
Regulatory liabilities, noncurrent	523	635
Other	82	83
Total deferred credits and other liabilities	3,416	3,454
Liabilities	8,668	8,712
Commitments and contingencies
Shareholders' equity
Common stock	3,655	3,428
Retained earnings/Undistributed earnings (losses)	1,790	1,684
Total shareholders’ equity	5,445	5,112
Members' Equity [Abstract]
Total liabilities and shareholders’ equity	14,113	13,824
Baltimore Gas and Electric Company [Member]
Current Assets
Cash and cash equivalents	41	51
Restricted cash and cash equivalents	34	4
Accounts receivable
Customer accounts receivable	519	436
Customer allowance for credit losses	(59)	(38)
Customer accounts receivable, net	460	398
Other accounts receivable	126	124
Other allowance for credit losses	(11)	(9)
Other accounts receivable, net	115	115
Receivables from affiliates, current	0	1
Inventories, net
Fossil fuel and emission allowances	12	42
Materials and supplies	51	53
Prepaid utility taxes	46	49
Regulatory assets, current	175	215
Other	11	8
Total current assets	945	936
Accumulated depreciation and amortization	4,376	4,299
Property, plant and equipment, net	10,736	10,577
Deferred debits and other assets
Regulatory assets, noncurrent	467	477
Investments	6	14
Prepaid pension asset	315	276
Other	40	44
Total deferred debits and other assets	828	811
Total assets	12,509	12,324
Current Liabilities
Short-term borrowings	250	130
Long-term debt due within one year	250	250
Accounts payable	299	349
Accrued expenses	168	176
Payables to affiliates, current	37	48
Customer deposits	98	97
Regulatory liabilities, current	35	26
Other	61	48
Total current liabilities	1,198	1,124
Long-term debt	3,711	3,711
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits	1,755	1,686
Asset retirement obligations, noncurrent	26	26
Non-pension postretirement benefit obligations	170	175
Regulatory liabilities, noncurrent	872	934
Other	85	98
Total deferred credits and other liabilities	2,908	2,919
Liabilities	7,817	7,754
Commitments and contingencies
Shareholders' equity
Common stock	2,575	2,575
Retained earnings/Undistributed earnings (losses)	2,117	1,995
Total shareholders’ equity	4,692	4,570
Members' Equity [Abstract]
Total liabilities and shareholders’ equity	12,509	12,324
Pepco Holdings LLC [Member]
Current Assets
Cash and cash equivalents	796	136
Restricted cash and cash equivalents	106	77
Accounts receivable
Customer accounts receivable	618	616
Customer allowance for credit losses	(113)	(104)
Customer accounts receivable, net	505	512
Other accounts receivable	288	283
Other allowance for credit losses	(41)	(39)
Other accounts receivable, net	247	244
Receivables from affiliates, current	0	2
Inventories, net
Fossil fuel and emission allowances	4	11
Materials and supplies	209	209
Regulatory assets, current	432	432
Other	69	69
Total current assets	2,368	1,692
Accumulated depreciation and amortization	2,256	2,108
Property, plant and equipment, net	16,701	16,498
Deferred debits and other assets
Regulatory assets, noncurrent	1,770	1,794
Investments	142	145
Goodwill	4,005	4,005
Prepaid pension asset	392	344
Deferred income taxes	5	8
Other	253	258
Total deferred debits and other assets	6,567	6,554
Total assets	25,636	24,744
Current Liabilities
Short-term borrowings	0	468
Long-term debt due within one year	400	399
Accounts payable	522	578
Accrued expenses	264	281
Payables to affiliates, current	51	104
Borrowings from Exelon/PHI intercompany money pool	46	7
Customer deposits	80	81
Regulatory liabilities, current	72	68
Unamortized energy contract liabilities, current	13	89
PPA termination obligation	85	0
Other	215	171
Total current liabilities	1,748	2,246
Long-term debt	7,833	7,148
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits	2,723	2,675
Asset retirement obligations, noncurrent	70	70
Non-pension postretirement benefit obligations	60	66
Regulatory liabilities, noncurrent	1,182	1,238
Unamortized energy contract liabilities, noncurrent	42	146
Other	661	570
Total deferred credits and other liabilities	4,738	4,765
Liabilities	14,319	14,159
Commitments and contingencies
Shareholders' equity
Retained earnings/Undistributed earnings (losses)	(182)	(210)
Members' Equity [Abstract]
Membership interest	11,499	10,795
Total members' equity	11,317	10,585
Total liabilities and shareholders’ equity	25,636	24,744
Potomac Electric Power Company [Member]
Current Assets
Cash and cash equivalents	502	34
Restricted cash and cash equivalents	34	34
Accounts receivable
Customer accounts receivable	278	277
Customer allowance for credit losses	(40)	(37)
Customer accounts receivable, net	238	240
Other accounts receivable	157	160
Other allowance for credit losses	(18)	(16)
Other accounts receivable, net	139	144
Receivables from affiliates, current	0	0
Inventories, net
Inventories, net	119	119
Regulatory assets, current	216	213
Other	29	25
Total current assets	1,277	809
Accumulated depreciation and amortization	3,929	3,875
Property, plant and equipment, net	8,229	8,104
Deferred debits and other assets
Regulatory assets, noncurrent	496	532
Investments	119	120
Prepaid pension asset	279	279
Other	58	59
Total deferred debits and other assets	952	990
Total assets	10,458	9,903
Current Liabilities
Short-term borrowings	0	175
Long-term debt due within one year	314	313
Accounts payable	246	272
Accrued expenses	158	160
Payables to affiliates, current	34	59
Customer deposits	36	35
Regulatory liabilities, current	18	14
Merger related obligation	27	27
Other	64	55
Total current liabilities	897	1,110
Long-term debt	3,527	3,132
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits	1,293	1,275
Asset retirement obligations, noncurrent	45	45
Non-pension postretirement benefit obligations	0	3
Regulatory liabilities, noncurrent	533	549
Other	297	314
Total deferred credits and other liabilities	2,168	2,186
Liabilities	6,592	6,428
Commitments and contingencies
Shareholders' equity
Common stock	2,689	2,302
Retained earnings/Undistributed earnings (losses)	1,177	1,173
Total shareholders’ equity	3,866	3,475
Members' Equity [Abstract]
Total liabilities and shareholders’ equity	10,458	9,903
Delmarva Power and Light Company [Member]
Current Assets
Cash and cash equivalents	120	28
Restricted cash and cash equivalents	73	43
Accounts receivable
Customer accounts receivable	164	149
Customer allowance for credit losses	(24)	(18)
Customer accounts receivable, net	140	131
Other accounts receivable	62	58
Other allowance for credit losses	(9)	(8)
Other accounts receivable, net	53	50
Receivables from affiliates, current	0	1
Inventories, net
Fossil fuel and emission allowances	4	11
Materials and supplies	53	54
Prepaid utility taxes	10	20
Regulatory assets, current	66	68
Other	19	16
Total current assets	538	422
Accumulated depreciation and amortization	1,671	1,635
Property, plant and equipment, net	4,612	4,560
Deferred debits and other assets
Regulatory assets, noncurrent	208	212
Prepaid pension asset	157	157
Other	58	61
Total deferred debits and other assets	423	430
Total assets	5,573	5,412
Current Liabilities
Short-term borrowings	0	149
Long-term debt due within one year	83	83
Accounts payable	128	131
Accrued expenses	50	40
Payables to affiliates, current	15	33
Customer deposits	27	28
Regulatory liabilities, current	33	25
Other	88	59
Total current liabilities	424	548
Long-term debt	1,852	1,727
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits	825	803
Asset retirement obligations, noncurrent	16	16
Non-pension postretirement benefit obligations	10	11
Regulatory liabilities, noncurrent	423	441
Other	87	89
Total deferred credits and other liabilities	1,361	1,360
Liabilities	3,637	3,635
Commitments and contingencies
Shareholders' equity
Common stock	1,353	1,209
Retained earnings/Undistributed earnings (losses)	583	568
Total shareholders’ equity	1,936	1,777
Members' Equity [Abstract]
Total liabilities and shareholders’ equity	5,573	5,412
Atlantic City Electric Company [Member]
Current Assets
Cash and cash equivalents	168	29
Restricted cash and cash equivalents	0	0
Accounts receivable
Customer accounts receivable	177	190
Customer allowance for credit losses	(49)	(49)
Customer accounts receivable, net	128	141
Other accounts receivable	79	76
Other allowance for credit losses	(14)	(15)
Other accounts receivable, net	65	61
Receivables from affiliates, current	0	2
Inventories, net
Inventories, net	37	36
Regulatory assets, current	137	61
Other	5	3
Total current assets	540	333
Accumulated depreciation and amortization	1,458	1,420
Property, plant and equipment, net	3,763	3,729
Deferred debits and other assets
Regulatory assets, noncurrent	559	430
Prepaid pension asset	30	27
Other	37	37
Total deferred debits and other assets	626	494
Total assets	4,929	4,556
Current Liabilities
Short-term borrowings	0	144
Long-term debt due within one year	3	3
Accounts payable	139	165
Accrued expenses	43	44
Payables to affiliates, current	23	31
Customer deposits	18	18
Regulatory liabilities, current	20	28
PPA termination obligation	85	0
Other	18	12
Total current liabilities	349	445
Long-term debt	1,754	1,579
Deferred credits and other liabilities
Deferred income taxes and unamortized investment tax credits	692	682
Non-pension postretirement benefit obligations	11	12
Regulatory liabilities, noncurrent	203	214
Other	165	49
Total deferred credits and other liabilities	1,071	957
Liabilities	3,174	2,981
Commitments and contingencies
Shareholders' equity
Common stock	1,763	1,590
Retained earnings/Undistributed earnings (losses)	(8)	(15)
Total shareholders’ equity	1,755	1,575
Members' Equity [Abstract]
Total liabilities and shareholders’ equity	$ 4,929	$ 4,556

Consolidated Statements of Chan

Consolidated Statements of Changes in Shareholders Equity (Unaudited) - USD ($) shares in Thousands, $ in Millions	Total	Correcting Adjustment [Member]	Common Stock [Member]	Common Stock [Member]Correcting Adjustment [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Noncontrolling Interest [Member]	Commonwealth Edison Co [Member]	Commonwealth Edison Co [Member]Common Stock [Member]	Commonwealth Edison Co [Member]Retained Earnings [Member]	Commonwealth Edison Co [Member]Other Paid-in-Capital [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]Retained Earnings [Member]	Pepco Holdings LLC [Member]Membership Interest [Member]	Potomac Electric Power Company [Member]	Potomac Electric Power Company [Member]Common Stock [Member]	Potomac Electric Power Company [Member]Retained Earnings [Member]	Delmarva Power and Light Company [Member]	Delmarva Power and Light Company [Member]Common Stock [Member]	Delmarva Power and 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, 2020	977,466
Beginning balance at Dec. 31, 2020	$ 34,868		$ 19,373		$ (123)	$ 16,735	$ (3,400)	$ 2,283
Beginning Balance at Dec. 31, 2020																			$ 10,044	$ (68)	$ 10,112
Beginning Balance at Dec. 31, 2020									$ 11,329	$ 1,588	$ 1,456	$ 8,285	$ 4,533	$ 3,014	$ 1,519	$ 4,197	$ 2,318	$ 1,879				$ 3,203	$ 2,058	$ 1,145	$ 1,676	$ 1,089	$ 587	$ 1,398	$ 1,271	$ 127
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ (264)					(289)		25	197		197		167		167	209		209	128	128		59		59	56		56	14		14
Long -Term Incentive Plan Activity (shares)	640
Long-Term Incentive Plan Activity		$ 5		$ 5
Employee stock purchase plan issuances (shares)	902
Employee stock purchase plan issuances	$ 34		34
Changes in equity of noncontrolling interests	$ (10)							(10)
Common Stock, Dividends, Per Share, Declared	$ 0.38
Common stock dividends	$ (374)					(374)			(127)		(127)		(85)		(85)	(74)		(74)				(28)		(28)	(40)		(40)	(14)		(14)
Distributions to member																			(81)	(81)
Contributions from parent									198			198							560		560	138	138		120	120		303	303
Other comprehensive income (loss), net of income taxes	$ 54						54
Ending balance (in shares) at Mar. 31, 2021	979,008
Ending balance at Mar. 31, 2021	$ 34,313		19,412		(123)	16,072	(3,346)	2,298
Ending Balance at Mar. 31, 2021																			10,651	(21)	10,672
Ending Balance at Mar. 31, 2021									11,597	1,588	1,526	8,483	4,615	3,014	1,601	4,332	2,318	2,014				3,372	2,196	1,176	1,812	1,209	603	1,701	1,574	127
Beginning balance (in shares) at Dec. 31, 2021	981,291
Beginning balance at Dec. 31, 2021	$ 34,795		20,324		(123)	16,942	(2,750)	402
Beginning Balance at Dec. 31, 2021																			10,585	(210)	10,795
Beginning Balance at Dec. 31, 2021	34,393								12,355	1,588	1,691	9,076	5,112	3,428	1,684	4,570	2,575	1,995				3,475	2,302	1,173	1,777	1,209	568	1,575	1,590	(15)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 598					597		1	188		188		206		206	198		198	130	130		46		46	56		56	26		26
Long -Term Incentive Plan Activity (shares)	540
Long-Term Incentive Plan Activity	$ (13)		(13)
Employee stock purchase plan issuances (shares)	211
Employee stock purchase plan issuances	$ 9		9
Changes in equity of noncontrolling interests	$ (7)							(7)
Common Stock, Dividends, Per Share, Declared	$ 0.34
Distribution of Constellation	$ (11,573)		(21)			(13,179)	2,023	(396)
Common stock dividends	(332)					(332)			(144)		(144)		(100)		(100)	(76)		(76)				(42)		(42)	(41)		(41)	(19)		(19)
Distributions to member																			(102)	(102)
Contributions from parent									167			167	227	227					704		704	387	387		144	144		173	173
Other comprehensive income (loss), net of income taxes	$ 14						14
Ending balance (in shares) at Mar. 31, 2022	982,042
Ending balance at Mar. 31, 2022	$ 23,491		$ 20,299		$ (123)	$ 4,028	$ (713)	$ 0
Ending Balance at Mar. 31, 2022																			$ 11,317	$ (182)	$ 11,499
Ending Balance at Mar. 31, 2022	$ 23,491								$ 12,566	$ 1,588	$ 1,735	$ 9,243	$ 5,445	$ 3,655	$ 1,790	$ 4,692	$ 2,575	$ 2,117				$ 3,866	$ 2,689	$ 1,177	$ 1,936	$ 1,353	$ 583	$ 1,755	$ 1,763	$ (8)

Significant Accounting Policies

Significant Accounting Policies (All Registrants)	3 Months Ended
Significant Accounting Policies (All Registrants)	Mar. 31, 2022
Accounting Policies [Abstract]
Significant Accounting Policies (All Registrants)	Significant Accounting Policies (All Registrants) Description of Business Exelon is a utility services holding company engaged in 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. The separation was completed on February 1, 2022, creating two publicly traded companies, Exelon and Constellation. 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 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 & 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 This is a combined quarterly 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” in the consolidated financial statements and include intercompany eliminations unless otherwise disclosed. The accompanying consolidated financial statements as of March 31, 2022 and for the three months ended March 31, 2022 and 2021 are unaudited but, in the opinion of the management of each Registrant include all adjustments that are considered necessary for a fair statement of the Registrants’ respective financial statements in accordance with GAAP. All adjustments are of a normal, recurring nature, except as otherwise disclosed. The December 31, 2021 Consolidated Balance Sheets were derived from audited financial statements. The interim financial statements are to be read in conjunction with prior annual financial statements and notes. Additionally, financial results for interim periods are not necessarily indicative of results that may be expected for any other interim period or for the fiscal year ending December 31, 2022. These Combined Notes to Consolidated Financial Statements have been prepared pursuant to the rules and regulations of the SEC for Quarterly Reports on Form 10-Q. Certain information and note disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. The separation of Constellation, 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, shareholders' equity, and cash flows related to Constellation 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. Prior Period Adjustments and Reclassifications (Exelon, PHI, ACE) In the first quarter of 2022, management identified an error related to an overstatement of the regulatory liability associated with ACE’s mechanism to recover the cost of Transition Bonds issued in 2002 and 2003 by ACE Funding. Management has concluded that the error was not material to previously issued financial statements for Exelon, PHI or ACE. The error was corrected through a revision to ACE’s financial statements contained herein. The impact of the error correction was an $8 million increase to ACE’s opening Retained earnings as of January 1, 2021 with a corresponding reduction to Regulatory liabilities of $11 million and an increase to Deferred income taxes and unamortized investment tax credits of $3 million. The impact of the error to ACE’s Total operating revenues and Net income was less than $1 million for the three months ended March 31, 2021. The error did not impact net cash flows provided by operating activities, net cash flows used in investing activities or net cash flows provided by financing activities for the three months ended March 31, 2021. The error was corrected in the Exelon and PHI financial statements for the three months ended March 31, 2022 as it was not material, resulting in an increase to Net income of $8 million.

Discontinued Operations (Exelon

Discontinued Operations (Exelon)	3 Months Ended
Discontinued Operations (Exelon)	Mar. 31, 2022
Discontinued Operations and Disposal Groups [Abstract]
Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]	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"). Exelon completed the separation on February 1, 2022, through the distribution of 326,663,937 common stock shares of Constellation, 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 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 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 to Constellation and for general corporate purposes. See Note 10 — Debt and Credit Agreements for additional information. • Exelon made a cash payment of $1.75 billion to Constellation on January 31, 2022. • Exelon contributed its equity ownership interest in Generation to Constellation. Exelon no longer retains any equity ownership interest in Generation or Constellation. • Exelon transferred certain corporate assets and employee-related obligations to Constellation. • Exelon received cash from Generation of $258 million to settle the intercompany loan on January 31, 2022. See Note 10 — Debt and Credit Agreements for additional information. Continuing Involvement In order to govern the ongoing relationships between Exelon and Constellation after the separation, and to facilitate an orderly transition, Exelon and Constellation have entered into several agreements, including the following: • Separation Agreement – governs the rights and obligations between Exelon and Constellation regarding certain actions to be taken in connection with the separation, among others, including the allocation of assets and liabilities between Exelon and Constellation. • Transition Services Agreement (TSA) – governs the terms and conditions of the services that Exelon will provide to Constellation and Constellation 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. For the period from February 1, 2022 to March 31, 2022, the amounts Exelon billed Constellation and Constellation billed Exelon for these services were $56 million recorded in Other income, net and $9 million recorded in Operating and maintenance expense, respectively. • Tax Matters Agreement (TMA) – governs the respective rights, responsibilities and obligations of Exelon and Constellation 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. See Note 7. Income Taxes for additional information. 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. After the separation, such expenses are primarily recorded as Purchased power and an immaterial amount recorded as Operating and maintenance expense 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 10 — Asset Retirement Obligations of the Combined Notes to Consolidated Financial Statements of the Exelon 2021 Form 10-K and Note 15 — Related Party Transactions 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 Constellation that have been reclassified from continuing operations and included in discontinued operations within Exelon’s Consolidated Statements of Operations and Comprehensive Income for the three months ended March 31, 2022 and March 31, 2021. 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. Three Months Ended 2022 2021 Operating revenues Competitive business revenues $ 1,855 $ 5,265 Competitive business revenues from affiliates 161 294 Total operating revenues 2,016 5,559 Operating expenses Competitive businesses purchased power and fuel 1,138 4,610 Operating and maintenance (a) 371 904 Depreciation and amortization 94 940 Taxes other than income taxes 44 121 Total operating expenses 1,647 6,575 Gain on sales of assets and businesses 10 71 Operating income (loss) 379 (945) Other income and (deductions) Interest expense, net (20) (68) Other, net (281) 167 Total other income and (deductions) (301) 99 Income (loss) before income taxes 78 (846) Income taxes (40) (58) Equity in losses of unconsolidated affiliates (1) (1) Net income (loss) 117 (789) Net income attributable to noncontrolling interests 1 25 Net income (loss) from discontinued operations $ 116 $ (814) __________ (a) Includes transaction and transition costs related to the separation of $52 million and $3 million for the three months ended March 31, 2022 and 2021, respectively. $50 million and $2 million of transaction costs and $2 million and less than $1 million of transition costs are included in the results of discontinued operations in the table presented above for the three months ended March 31, 2022 and March 31, 2021, respectively. See discussion above for additional information. There were no assets and liabilities of discontinued operations included in Exelon’s Consolidated Balance Sheet as of March 31, 2022. Constellation had net assets of $11,573 million that separated on February 1, 2022 that resulted in a reduction to Exelon’s equity during the three months ended March 31, 2022. Refer to the Distribution of Constellation line in Exelon’s Consolidated Statement of Changes in Shareholders’ Equity for further information. The following table presents the assets and liabilities of discontinued operations in Exelon’s Consolidated Balance Sheet as of December 31, 2021: December 31, 2021 ASSETS Current assets Cash and cash equivalents $ 510 Restricted cash and cash equivalents 72 Accounts receivable Customer accounts receivable 1,724 Customer allowance for credit losses (55) Customer accounts receivable, net 1,669 Other accounts receivable 596 Other allowance for credit losses (4) Other accounts receivable, net 592 Mark-to-market derivative assets 2,169 Inventories, net Fossil fuel and emission allowances 284 Materials and supplies 1,004 Renewable energy credits 529 Assets held for sale 13 Other 993 Total current assets of discontinued operations 7,835 Property, plant, and equipment (net of accumulated depreciation and amortization of $15,888) 19,661 Deferred debits and other assets Nuclear decommissioning trust funds 15,938 Investments 193 Mark-to-market derivative assets 949 Other 1,768 Total property, plant, and equipment, deferred debits, and other assets of discontinued operations 38,509 Total assets of discontinued operations $ 46,344 December 31, 2021 LIABILITIES AND SHAREHOLDERS’ EQUITY Current liabilities Short-term borrowings $ 2,082 Long-term debt due within one year 1,220 Accounts payable 1,757 Accrued expenses 818 Mark-to-market derivative liabilities 981 Renewable energy credit obligation 779 Liabilities held for sale 3 Other 300 Total current liabilities of discontinued operations 7,940 Long-term debt 4,575 Deferred credits and other liabilities Deferred income taxes and unamortized investment tax credits 3,583 Asset retirement obligations 12,819 Pension obligations 939 Non-pension postretirement benefit obligations 876 Spent nuclear fuel obligation 1,210 Mark-to-market derivative liabilities 513 Other 1,161 Total long-term debt, deferred credits, and other liabilities of discontinued operations 25,676 Total liabilities of discontinued operations $ 33,616 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 three months ended March 31, 2022 and March 31, 2021. Three Months Ended March 31, 2022 2022 2021 Non-cash items included in net income (loss) from discontinued operations: Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization $ 207 $ 1,346 Gain on sales of assets and businesses 9 (71) Deferred income taxes and amortization of investment tax credits (143) (234) Net fair value changes related to derivatives (59) (178) Net realized and unrealized losses (gains) on NDT fund investments 205 (118) Net unrealized losses on equity investments 16 23 Other decommissioning-related activity 36 (332) Cash flows from investing activities: Capital expenditures (227) (394) Collection of DPP 169 1,574 Supplemental cash flow information: Decrease in capital expenditures not paid (128) (37) Increase in DPP 348 1,339 Increase in PP&E related to ARO update 335 —

Mergers, Acquisitions, and Disp

Mergers, Acquisitions, and Dispositions (Exelon and Generation)	3 Months Ended
	Mar. 31, 2022
Mergers, Acquisitions, and Dispositions [Abstract]
Mergers, Acquisitions, and Dispositions (Exelon and Generation)	Mergers, Acquisitions, and Dispositions (Exelon)

Regulatory Matters (All Registr

Regulatory Matters (All Registrants)	3 Months Ended
Regulatory Matters (All Registrants)	Mar. 31, 2022
Regulated Operations [Abstract]
Regulatory Matters (All Registrants)	Regulatory Matters (All Registrants) As discussed in Note 3 — Regulatory Matters of the Exelon 2021 Form 10-K, the Registrants are involved in rate and regulatory proceedings at FERC and their state commissions. The following discusses developments in 2022 and updates to the 2021 Form 10-K. Distribution Base Rate Case Proceedings The following tables show the completed and pending distribution base rate case proceedings in 2022. Completed Distribution Base Rate Case Proceedings Registrant/Jurisdiction Filing Date Service Requested Revenue Requirement Increase Approved Revenue Requirement Increase Approved ROE Approval Date Rate Effective Date ComEd - Illinois (a) April 16, 2021 Electric $ 51 $ 46 7.36 % December 1, 2021 January 1, 2022 PECO - Pennsylvania 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 - Maryland (f) September 1, 2021 (amended December 23, 2021) Electric 27 13 9.60 % March 2, 2022 March 2, 2022 ACE - New Jersey (g) December 9, 2020 (amended February 26, 2021) Electric 67 41 9.60 % July 14, 2021 January 1, 2022 __________ (a) ComEd's 2022 approved revenue requirement 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 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 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 for the 12-month period ending March 31, 2023. Whether certain tax benefits will be used to offset the customer rate increases for the 12-month period ending March 31, 2024 has not been decided, and Pepco cannot predict the outcome. (f) The approved settlement reflects a 9.60% ROE, which is solely for the purposes of calculating AFUDC and regulatory asset carrying costs. (g) 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 ComEd - Illinois (a) April 15, 2022 Electric $ 199 7.85 % Fourth quarter of 2022 PECO - Pennsylvania March 31, 2022 Natural Gas 82 10.95 % Fourth quarter of 2022 DPL - Delaware (b) January 14, 2022 (amended February 28, 2022) Natural Gas 15 10.30 % First quarter of 2023 __________ (a) ComEd's 2023 requested revenue requirement reflects an increase of $144 million for the initial year revenue requirement for 2023 and an increase of $55 million related to the annual reconciliation for 2021. The revenue requirement for 2023 provides for a weighted average debt and equity return on distribution rate base of 5.94%, inclusive of an allowed ROE of 7.85%, reflecting the average monthly yields for 30-year treasury bonds plus 580 basis points. The reconciliation revenue requirement for 2021 provides for a weighted average debt and equity return on distribution rate base of 5.91%, inclusive of an allowed ROE of 7.78%, reflecting the average monthly yields for 30-year treasury bonds plus 580 basis points less a performance metrics penalty of 7 basis points. This is ComEd's last performance-based electric distribution formula rate update filing under EIMA as a result of the law authorizing the rate setting process sunsetting at the end of 2022. See Note 3. - Regulatory Matters of the Exelon 2021 Form 10-K for additional information on ComEd's transition away from the electric distribution formula rate. (b) The rates will go into effect on August 14, 2022, subject to refund. 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 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 annual update for BGE 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 BGE also reconciles any differences between the actual costs and actual revenues for the calendar year (annual reconciliation). For 2022, the following total increases were included in ComEd’s and BGE's electric transmission formula rate update. PECO, Pepco, DPL, and ACE intend to file by the required deadline for the annual update. Registrant (a) Initial Revenue Requirement Increase Annual Reconciliation Decrease Total Revenue Requirement Increase Allowed Return on Rate Base (c) Allowed ROE (d) ComEd $ 24 $ (24) $ — 8.11 % 11.50 % BGE 25 (4) 16 (b) 7.30 % 10.50 % (a) All rates are effective June 1, 2022 - May 31, 2023, subject to review by interested parties pursuant to review protocols of ComEd's and BGE's tariff. (b) The increase in BGE's transmission revenue requirement includes a $5 million reduction related to a FERC-approved dedicated facilities charge to recover the costs of providing transmission service to specifically designated load by BGE. (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 transmission rate case, the rate of return on common equity is 11.50%, 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%. As part of the FERC-approved settlement of the ROE complaint against BGE, 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 CEJA (Exelon and ComEd). On September 15, 2021, the Governor of Illinois signed into law CEJA. CEJA 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 ("EDIT") 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 CEJA are possible and Exelon and ComEd cannot reasonably predict the outcome of any such challenges. The ICC initiated a docket to accelerate and fully credit to customers TCJA unprotected property-related EDIT no later than December 31, 2025. On April 13, 2022, a stipulation and agreement on the schedule for the acceleration of EDIT amortization was submitted by ComEd, the Illinois Attorney General's Office, and the Citizens Utility Board. At this time, ComEd cannot predict an outcome of these proceedings. See Note 3 — Regulatory Matters of the Exelon 2021 Form 10-K for additional information on CEJA (referred to as Clean Energy Law). New Jersey Regulatory Matters Termination of Energy Procurement Provisions of PPAs (Exelon, PHI, and ACE). On December 22, 2021, ACE filed with the NJBPU a petition to terminate the provisions in the PPAs to purchase electricity from two coal-powered generation facilities located in the state of New Jersey. The petition was approved by the NJBPU on March 23, 2022. Upon closing of the transaction on March 31, 2022, ACE recognized a liability of $203 million for the contract termination fee, which is to be paid by the end of 2024, and recognized a corresponding regulatory asset of $203 million. As of March 31, 2022, the $203 million liability for the contract termination fee consists of $85 million and $118 million included in Other current liabilities and Other deferred credits and other liabilities, respectively, in Exelon's Consolidated Balance Sheet. As of March 31, 2022, the current and noncurrent liability is included in PPA termination obligation and Other deferred credits and other liabilities, respectively, in PHI's and ACE's Consolidated Balance Sheets. Regulatory Assets and Liabilities The Utility Registrants' regulatory assets and liabilities have not changed materially since December 31, 2021, unless noted below. See Note 3 — Regulatory Matters of the Exelon 2021 Form 10-K for additional information on the specific regulatory assets and liabilities. PECO. Regulatory assets increased $66 million primarily due to an increase of $60 million in the Deferred Income Taxes regulatory asset. Regulatory liabilities decreased by $112 million primarily due to a decrease of $111 million in the Nuclear Decommissioning regulatory liability. BGE. Regulatory assets decreased $50 million primarily due to a decrease of $19 million in the Electric Energy and Natural Gas Costs regulatory asset and $16 million in the Energy Efficiency and Demand Response Programs regulatory asset. Regulatory liabilities decreased $53 million primarily due to a decrease of $65 million in the Deferred Income Taxes regulatory liability. ACE. Regulatory assets increased $205 million primarily due to an increase in the Electric Energy Costs regulatory asset as a result of the PPA termination. Regulatory liabilities decreased $19 million primarily due to a decrease of $9 million in the Deferred Income Taxes regulatory liability and $5 million in the Electric Energy Costs regulatory liability. Capitalized Ratemaking Amounts Not Recognized 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 March 31, 2022 $ 49 $ 2 $ — $ 34 $ 13 $ 11 $ 2 $ — December 31, 2021 43 1 — 37 5 3 2 — __________ (a) Reflects ComEd's unrecognized equity returns earned for ratemaking purposes on its energy efficiency and electric distribution formula rate regulatory assets. (b) BGE's authorized amounts capitalized for ratemaking purposes primarily relate to earnings on shareholder's investment on its AMI programs. (c) Pepco's and DPL's authorized amounts capitalized for ratemaking purposes relate to earnings on shareholder's investment on their respective AMI Programs and Energy Efficiency and Demand Response Programs, and for Pepco District of Columbia revenue decoupling program. The earnings on energy efficiency are on Pepco District of Columbia and DPL Delaware programs only.

Revenue from Contracts with Cus

Revenue from Contracts with Customers (All Registrants)	3 Months Ended
Revenue from Contracts with Customers (All Registrants)	Mar. 31, 2022
Revenue from Contract with Customer [Abstract]
Revenue from Contracts with Customers (All Registrants)	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. See Note 4 — Revenue from Contracts with Customers of the Exelon 2021 Form 10-K for additional information regarding the primary sources of revenue for the Registrants. 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 their Consolidated Balance Sheets. For PHI, Pepco, DPL, and ACE these contract liabilities primarily relate to upfront consideration received in the third quarter of 2020 for a collaborative arrangement with an unrelated owner and manager of communication infrastructure. The revenue attributable to this arrangement will be recognized as operating revenue over the 35 years under the collaborative arrangement. Revenues recognized were immaterial for Exelon, PHI, Pepco, DPL, and ACE for the three months ended March 31, 2022 and 2021. As of March 31, 2022 and December 31, 2021, ComEd's, PECO's, and BGE's contract liabilities were immaterial. 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 March 31, 2022. 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 $ 6 $ 8 $ 6 $ 5 $ 82 $ 107 PHI 6 8 6 5 82 107 Pepco 4 6 5 5 65 85 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)	3 Months Ended
Segment Information (All Registrants)	Mar. 31, 2022
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. Exelon has six reportable segments, which include 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. An analysis and reconciliation of the Registrants’ reportable segment information to the respective information in the consolidated financial statements for the three months ended March 31, 2022 and 2021 is as follows: Three Months Ended March 31, 2022 and 2021 ComEd PECO BGE PHI Other (a) Intersegment Exelon Operating revenues (b) : 2022 Electric revenues $ 1,734 $ 741 $ 736 $ 1,318 $ — $ (7) $ 4,522 Natural gas revenues — 306 418 83 — (2) $ 805 Shared service and other revenues — — — 3 576 (579) $ — Total operating revenues $ 1,734 $ 1,047 $ 1,154 $ 1,404 $ 576 $ (588) $ 5,327 2021 Electric revenues $ 1,535 $ 661 $ 632 $ 1,170 $ — $ (7) $ 3,991 Natural gas revenues — 228 342 71 — — 641 Shared service and other revenues — — — 3 491 (494) — Total operating revenues $ 1,535 $ 889 $ 974 $ 1,244 $ 491 $ (501) $ 4,632 Intersegment revenues (c) : 2022 $ 6 $ 1 $ 7 $ 3 $ 576 $ (587) $ 6 2021 6 2 6 3 487 (497) 7 Depreciation and amortization: 2022 $ 321 $ 92 $ 171 $ 218 $ 15 $ — $ 817 2021 292 86 152 210 17 — 757 Operating expenses: 2022 $ 1,406 $ 793 $ 919 $ 1,215 $ 625 $ (531) $ 4,427 2021 1,210 679 752 1,058 448 (339) 3,808 Interest expense, net: 2022 $ 100 $ 41 $ 35 $ 69 $ 93 $ — $ 338 2021 96 38 34 67 83 — 318 Income (loss) from continuing operations before income taxes: 2022 $ 240 $ 220 $ 207 $ 137 $ (62) $ (43) $ 699 2021 236 177 196 136 (32) (149) 564 Income Taxes: 2022 $ 52 $ 14 $ 9 $ 7 $ 146 $ (10) $ 218 2021 39 10 (13) 8 7 (12) 39 Net income (loss) from continuing operations: 2022 $ 188 $ 206 $ 198 $ 130 $ (208) $ (33) $ 481 2021 197 167 209 128 (39) (137) 525 Capital Expenditures: 2022 $ 617 $ 344 $ 303 $ 409 $ 22 $ — $ 1,695 2021 613 295 336 456 46 — 1,746 Total assets: March 31, 2022 $ 37,013 $ 14,113 $ 12,509 $ 25,636 $ 7,583 $ (4,156) $ 92,698 December 31, 2021 36,470 13,824 12,324 24,744 7,634 (8,319) 86,677 __________ (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 14 — Supplemental Financial Information for additional information on total utility taxes. (c) See Note 15 — Related Party Transactions for additional information on intersegment revenues. PHI: Pepco DPL ACE Other (a) Intersegment PHI Operating revenues (b) : 2022 Electric revenues $ 614 $ 348 $ 349 $ — $ 7 $ 1,318 Natural gas revenues — 83 — — — 83 Shared service and other revenues — — — 107 (104) 3 Total operating revenues $ 614 $ 431 $ 349 $ 107 $ (97) $ 1,404 2021 Electric revenues $ 553 $ 311 $ 310 $ — $ (4) $ 1,170 Natural gas revenues — 71 — — — 71 Shared service and other revenues — — — 95 (92) 3 Total operating revenues $ 553 $ 382 $ 310 $ 95 $ (96) $ 1,244 Intersegment revenues (c) : 2022 $ 1 $ 1 $ 1 $ 97 $ (97) $ 3 2021 1 2 1 95 (96) 3 Depreciation and amortization: 2022 $ 108 $ 57 $ 47 $ 6 $ — $ 218 2021 102 53 47 8 — 210 Operating expenses: 2022 $ 547 $ 357 $ 311 $ 97 $ (97) $ 1,215 2021 466 309 282 97 (96) 1,058 Interest expense, net: 2022 $ 36 $ 16 $ 14 $ 3 $ — $ 69 2021 34 15 15 3 — 67 Income (loss) before income taxes: 2022 $ 44 $ 60 $ 27 $ 6 $ — $ 137 2021 65 61 14 (4) — 136 Income Taxes: 2022 $ (2) $ 4 $ 1 $ 4 $ — $ 7 2021 6 5 — (3) — 8 Net income (loss): 2022 $ 46 $ 56 $ 26 $ 2 $ — $ 130 2021 59 56 14 (1) — 128 Capital Expenditures: 2022 $ 218 $ 103 $ 87 $ 1 $ — $ 409 2021 220 112 123 1 — 456 Total assets: March 31, 2022 $ 10,458 $ 5,573 $ 4,929 $ 4,720 $ (44) $ 25,636 December 31, 2021 9,903 5,412 4,556 4,933 (60) 24,744 __________ (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 14 — 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 Registrants' 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. Three Months Ended March 31, 2022 Revenues from contracts with customers ComEd PECO BGE PHI Pepco DPL ACE Electric revenues Residential $ 857 $ 487 $ 417 $ 652 $ 275 $ 207 $ 170 Small commercial & industrial 423 111 81 141 38 56 47 Large commercial & industrial 153 64 131 323 253 26 44 Public authorities & electric railroads 14 8 7 16 8 4 4 Other (a) 239 62 97 193 46 56 81 Total electric revenues (b) $ 1,686 $ 732 $ 733 $ 1,325 $ 620 $ 349 $ 346 Natural gas revenues Residential $ — $ 218 $ 282 $ 51 $ — $ 51 $ — Small commercial & industrial — 76 45 21 — 21 — Large commercial & industrial — — 65 3 — 3 — Transportation — 8 — 4 — 4 — Other (c) — 3 35 4 — 4 — Total natural gas revenues (d) $ — $ 305 $ 427 $ 83 $ — $ 83 $ — Total revenues from contracts with customers $ 1,686 $ 1,037 $ 1,160 $ 1,408 $ 620 $ 432 $ 346 Other revenues Revenues from alternative revenue programs $ 40 $ 6 $ (12) $ (5) $ (7) $ (1) $ 3 Other electric revenues (e) 8 3 4 1 1 — — Other natural gas revenues (e) — 1 2 — — — — Total other revenues $ 48 $ 10 $ (6) $ (4) $ (6) $ (1) $ 3 Total revenues for reportable segments $ 1,734 $ 1,047 $ 1,154 $ 1,404 $ 614 $ 431 $ 349 Three Months Ended March 31, 2021 Revenues from contracts with customers ComEd PECO BGE PHI Pepco DPL ACE Electric revenues Residential $ 741 $ 433 $ 362 $ 605 $ 253 $ 190 $ 162 Small commercial & industrial 367 100 69 118 33 46 39 Large commercial & industrial 134 57 105 248 184 21 43 Public authorities & electric railroads 11 9 7 13 6 4 3 Other (a) 220 52 77 143 51 41 52 Total electric revenues (b) $ 1,473 $ 651 $ 620 $ 1,127 $ 527 $ 302 $ 299 Natural gas revenues Residential $ — $ 160 $ 216 $ 46 $ — $ 46 $ — Small commercial & industrial — 59 35 18 — 18 — Large commercial & industrial — — 54 2 — 2 — Transportation — 7 — 4 — 4 — Other (c) — 2 31 1 — 1 — Total natural gas revenues (d) $ — $ 228 $ 336 $ 71 $ — $ 71 $ — Total revenues from contracts with customers $ 1,473 $ 879 $ 956 $ 1,198 $ 527 $ 373 $ 299 Other revenues Revenues from alternative revenue programs $ 54 $ 10 $ 18 $ 46 $ 26 $ 9 $ 11 Other electric revenues (e) 8 — — — — — — Total other revenues $ 62 $ 10 $ 18 $ 46 $ 26 $ 9 $ 11 Total revenues for reportable segments $ 1,535 $ 889 $ 974 $ 1,244 $ 553 $ 382 $ 310 __________ (a) Includes revenues from transmission revenue from PJM, wholesale electric revenue and mutual assistance revenue. (b) Includes operating revenues from affiliates in 2022 and 2021 respectively of: • $6 million, $6 million at ComEd • $1 million, $1 million at PECO • $2 million, $2 million at BGE • $3 million, $3 million at PHI • $1 million, $1 million at Pepco • $2 million, $2 million at DPL • $1 million, $1 million at ACE (c) Includes revenues from off-system natural gas sales. (d) Includes operating revenues from affiliates in 2022 and 2021 respectively of: • less than $1 million, less than $1 million at PECO • $6 million, $4 million at BGE (e) Includes late payment charge revenues.

Accounts Receivable (All Regist

Accounts Receivable (All Registrants)	3 Months Ended
Accounts Receivable (All Registrants)	Mar. 31, 2022
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. Three Months Ended March 31, 2022 Exelon ComEd PECO BGE PHI Pepco DPL ACE Balance as of December 31, 2021 $ 320 $ 73 $ 105 $ 38 $ 104 $ 37 $ 18 $ 49 Plus: Current period provision for expected credit losses (a) 110 26 31 26 27 11 7 9 Less: Write-offs, net of recoveries (b)(c) 41 7 11 5 18 8 1 9 Balance as of March 31, 2022 $ 389 $ 92 $ 125 $ 59 $ 113 $ 40 $ 24 $ 49 Three Months Ended March 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 (d) 70 21 20 9 20 11 6 3 Less: Write-offs, net of recoveries (b) 27 15 6 1 5 2 3 — Balance as of March 31, 2021 $ 377 $ 103 $ 130 $ 43 $ 101 $ 41 $ 25 $ 35 __________ (a) For PECO, BGE and ACE, the increase is primarily as a result of increased receivable balances due to the increased aging of receivables. For BGE, also reflects increased receivable balance due to colder weather. (b) Recoveries were not material to the Registrants. (c) For ACE, the increase in 2022 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 January 2022, write-offs of aging accounts receivable increased throughout the year. (d) The increase is primarily as a result of increased receivable balances due to the colder weather and the increased aging of receivables, the temporary suspension of customer disconnections for non-payment, temporary cessation of new late payment fees, and reconnection of service for customers previously disconnected due to COVID-19. The following tables present the rollforward of Allowance for Credit Losses on Other Accounts Receivable. Three Months Ended March 31, 2022 Exelon ComEd PECO BGE PHI Pepco DPL ACE Balance as of December 31, 2021 $ 72 $ 17 $ 7 $ 9 $ 39 $ 16 $ 8 $ 15 Plus: Current period provision for expected credit losses 14 4 3 3 4 2 1 1 Less: Write-offs, net of recoveries (a) 5 1 1 1 2 — — 2 Balance as of March 31, 2022 $ 81 $ 20 $ 9 $ 11 $ 41 $ 18 $ 9 $ 14 Three Months Ended March 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 10 1 4 1 4 2 1 1 Less: Write-offs, net of recoveries (a) 2 — 1 1 — — — — Balance as of March 31, 2021 $ 79 $ 22 $ 11 $ 9 $ 37 $ 15 $ 10 $ 12 __________ (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 March 31, 2022 and December 31, 2021. Unbilled customer revenues (a) Exelon ComEd PECO BGE PHI Pepco DPL ACE March 31, 2022 $ 629 $ 189 $ 127 $ 139 $ 174 $ 89 $ 50 $ 35 December 31, 2021 747 240 161 171 175 82 53 40 __________ (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, Delaware, 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. Total receivables purchased Exelon (a) ComEd PECO BGE (a) PHI Pepco DPL ACE Three months ended March 31, 2022 $ 1,044 $ 248 $ 292 $ 222 $ 282 $ 174 $ 57 $ 51 Three months ended March 31, 2021 1,023 266 290 199 268 166 56 46 __________

Nuclear Decommissioning (Exelon

Nuclear Decommissioning (Exelon and Generation)	3 Months Ended
Nuclear Decommissioning (Exelon and Generation)	Mar. 31, 2022
Asset Retirement Obligation Disclosure [Abstract]
Nuclear Decommissioning (Exelon and Generation)	Nuclear Decommissioning (Exelon) Accounting Implications of the Regulatory Agreements with ComEd and PECO Based on the regulatory agreements with the ICC and PAPUC that dictate Generation’s obligations related to the shortfall or excess of NDT funds necessary for decommissioning the former ComEd units on a unit-by-unit basis and the former PECO units in total, decommissioning-related activities net of applicable taxes, including realized and unrealized gains and losses on the NDT funds, depreciation of the ARC, and accretion of the decommissioning obligation, are generally offset within Exelon’s and Generation’s Consolidated Statements of Operations and Comprehensive Income and are recorded by Generation and the corresponding regulated utility as a component of the intercompany and regulatory balances on the balance sheet. For the purposes of making this determination, the decommissioning obligation referred to is different from the calculation used in the NRC minimum funding obligation filings based on NRC guidelines. For the former ComEd units, given no further recovery from ComEd customers is permitted and Generation retains an obligation to ultimately return any unused NDTs to ComEd customers (on a unit-by-unit basis), to the extent the related NDT investment balances are expected to exceed the total estimated decommissioning obligation for each unit, the offset of decommissioning-related activities within the Consolidated Statements of Operations and Comprehensive Income results with Generation recognizing an intercompany payable to ComEd while ComEd records an intercompany receivable from Generation with a corresponding regulatory liability. However, given the asymmetric settlement provision that does not allow for continued recovery from ComEd customers in the event of a shortfall, recognition of a regulatory asset at ComEd is not permissible and accounting for decommissioning-related activities at Generation for that unit would not be offset, and the impact to Exelon’s and Generation’s Consolidated Statements of Operations and Comprehensive Income could be material during such periods. During the second quarter of 2022, a pre-tax charge of $53 million was recorded in Exelon’s and Generation’s Consolidated Statements of Operations and Comprehensive Income for decommissioning-related activities that were not offset for the Byron units due to contractual offset being suspended. Generation believes that additional growth of the NDT funds for the Byron units will ultimately be sufficient to cover the future costs of decommissioning. As of March 31, 2022, decommissioning-related activities for all of the former ComEd units, except for Byron (see discussion above) and Zion (see Note 10 – Asset Retirement Obligations of the Exelon 2021 Form 10-K), are currently offset within Exelon’s and Generation’s Consolidated Statements of Operations and Comprehensive Income. The decommissioning-related activities related to the Non-Regulatory Agreement Units are reflected in Exelon’s and Generation’s Consolidated Statements of Operations and Comprehensive Income. See Note 10 – Asset Retirement Obligations of the Exelon 2021 Form 10-K for additional information, including the former PECO units.

Income Taxes (All Registrants)

Income Taxes (All Registrants)	3 Months Ended
Income Taxes (All Registrants)	Mar. 31, 2022
Income Tax Disclosure [Abstract]
Income Taxes (All Registrants)	Income Taxes (All Registrants) Rate Reconciliation The effective income tax rate from continuing operations varies from the U.S. federal statutory rate principally due to the following: Three Months Ended March 31, 2022 (a) Exelon ComEd PECO (b) BGE (b) PHI Pepco (b) DPL 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 (c) 21.1 8.0 (0.1) 2.4 3.7 (4.5) 6.2 6.8 Plant basis differences (3.6) (0.6) (11.3) (0.9) (1.6) (2.6) (0.7) (1.3) Excess deferred tax amortization (11.5) (6.3) (3.2) (17.6) (17.7) (17.4) (19.4) (22.2) Amortization of investment tax credit, including deferred taxes on basis difference (0.1) (0.1) — (0.1) (0.1) — (0.2) (0.2) Tax credits (d) 1.7 (0.3) — (0.4) (0.4) (0.4) (0.3) (0.3) Other (e) 2.6 — — (0.1) 0.2 (0.6) 0.1 (0.1) Effective income tax rate 31.2 % 21.7 % 6.4 % 4.3 % 5.1 % (4.5) % 6.7 % 3.7 % Three Months Ended March 31, 2021 (a) Exelon ComEd PECO (f) BGE (f) PHI Pepco DPL ACE (f) 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 2.8 6.8 (1.6) (10.1) 6.1 5.5 6.4 6.9 Plant basis differences (3.4) (0.6) (10.5) (1.4) (1.5) (2.1) (0.7) (0.9) Excess deferred tax amortization (12.0) (6.9) (3.2) (15.5) (19.3) (15.1) (18.5) (28.7) Amortization of investment tax credit, including deferred taxes on basis difference (0.1) (0.1) — (0.1) (0.1) — (0.2) (0.2) Tax credits (0.3) (0.2) — (0.4) (0.2) (0.2) (0.1) (0.3) Other (1.1) (3.5) (0.1) (0.1) (0.1) 0.1 0.3 2.2 Effective income tax rate 6.9 % 16.5 % 5.6 % (6.6) % 5.9 % 9.2 % 8.2 % — % __________ (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 lower effective tax rate is primarily due to the Maryland multi-year plan which resulted in the acceleration of certain income tax benefits. For Pepco, the income tax benefit is primarily due to the Maryland and Washington, D.C. multi-year plans which resulted in the acceleration of certain income tax benefits. For ACE, the lower effective tax rate is primarily due to the acceleration of certain income tax benefits due to distribution rate case settlements. (c) For Exelon, the higher state income taxes, net of federal income tax benefit, is primarily due to the long-term marginal state income tax rate change of approximately $67 million and the recognition of a valuation allowance of approximately $40 million against the net deferred tax asset position for certain standalone state filing jurisdictions as a result of the separation. (d) For Exelon, reflects the income tax expense related to the write-off of federal tax credits subject to recapture of approximately $15 million as a result of the separation. (e) For Exelon, primarily reflects the nondeductible transaction costs of approximately $19 million arising as part of the separation. (f) 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 ACE, the lower effective tax rate is primarily due to the acceleration of certain income tax benefits due to distribution rate case settlements. Unrecognized Tax Benefits Exelon, PHI and ACE have the following unrecognized tax benefits as of March 31, 2022 and December 31, 2021. ComEd's, PECO's, BGE's, Pepco's, and DPL's amounts are not material. Exelon PHI ACE March 31, 2022 $ 146 $ 56 $ 16 December 31, 2021 143 56 16 __________ (a) As of March 31, 2022, Exelon recorded a receivable of approximately $50 million in Noncurrent other assets in the Consolidated Balance Sheet for Constellation’s share of unrecognized tax benefits for periods prior to the separation. Reasonably possible the total amount of unrecognized tax benefits could significantly increase or decrease within 12 months after the reporting date As of March 31, 2022, 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. Other Tax Matters Separation (Exelon) In connection with the separation, Exelon recorded an income tax expense related to continuing operations of approximately $148 million primarily due to the long-term marginal state income tax rate change of approximately $67 million discussed further below, the recognition of valuation allowances of approximately $40 million against the net deferred tax assets positions for certain standalone state filing jurisdictions, the write-off of federal and state tax credits subject to recapture of approximately $17 million, and nondeductible transaction costs for federal and state taxes of approximately $24 million. Tax Matters Agreement (Exelon) In connection with the separation, Exelon entered into a TMA with Constellation. The TMA governs the respective rights, responsibilities, and obligations between Exelon and Constellation after the separation with respect to tax liabilities, refunds and attributes for open tax years that Constellation was part of Exelon’s consolidated group for U.S. federal, state, and local tax purposes. Indemnification for Taxes. As a former subsidiary of Exelon, Constellation has joint and several liability with Exelon to the IRS and certain state jurisdictions relating to the taxable periods prior to the separation. The TMA specifies that Constellation is liable for their share of taxes required to be paid by Exelon with respect to taxable periods prior to the separation to the extent Constellation would have been responsible for such taxes under the existing Exelon tax sharing agreement. As of March 31, 2022, Exelon recorded a receivable of approximately $55 million in Current other assets in the Consolidated Balance Sheet for Constellation’s share of taxes for periods prior to the separation. Tax Refunds. The TMA specifies that Constellation is entitled to their share of any future tax refunds claimed by Exelon with respect to taxable periods prior to the separation to the extent that Constellation would have received such tax refunds under the existing Exelon tax sharing agreement. Tax Attributes . At the date of separation certain tax attributes, primarily pre-closing tax credit carryforwards, that were generated by Constellation were required by law to be allocated to Exelon. The TMA also provides that Exelon will reimburse Constellation when those allocated tax credit carryforwards are utilized. As of March 31, 2022, Exelon recorded a payable of approximately $11 million and $484 million in Current other liabilities and Noncurrent other liabilities, respectively, in the Consolidated Balance Sheet for tax credit carryforwards that are expected to be utilized and reimbursed to Constellation.

Retirement Benefits (All Regist

Retirement Benefits (All Registrants)	3 Months Ended
Retirement Benefits (All Registrants)	Mar. 31, 2022
Retirement Benefits [Abstract]
Retirement Benefits (All Registrants)	Retirement Benefits (All Registrants) Defined Benefit Pension and OPEB Effective February 1, 2022, in connection with the separation, pension and OPEB obligations and assets for current and former employees of the Constellation business and certain other former employees of Exelon and its subsidiaries transferred to pension and OPEB plans and trusts maintained by Constellation or its subsidiaries. The Exelon New England Union Employees Pension Plan and Constellation Mystic Power, LLC Union Employees Pension Plan Including Plan A and Plan B were transferred. The following OPEB plans were also transferred: Constellation Mystic Power, LLC Post-Employment Medical Account Savings Plan, Exelon New England Union Post-Employment Medical Savings Account Plan, and the Nine Mile Point Nuclear Station, LLC Medical Care and Prescription Drug Plan for Retired Employees. As a result of the separation, Exelon restructured certain of its qualified pension plans. Pension obligations and assets for current and former employees continuing with Exelon and who are participants in the Exelon Employee Pension Plan for Clinton, TMI, and Oyster Creek, Pension Plan of Constellation Energy Nuclear Group, LLC, and Nine Mile Point Pension Plan were merged into the Pension Plan of Constellation Energy Group, Inc, which was subsequently renamed, Exelon Pension Plan (EPP). Exelon employees who participated in these plans prior to the separation now participate in the EPP. The merging of the plans did not change the benefits offered to the plan participants and, thus, had no impact on Exelon's pension obligations. The tables below show the pension and OPEB plans in which employees of each operating company participated as of March 31, 2022: Operating Company (a) Name of Plan: ComEd PECO BGE PHI Pepco DPL ACE Qualified Pension Plans: Exelon Corporation Retirement Program X X X X X X X Exelon Corporation Pension Plan for Bargaining Unit Employees X Exelon Pension Plan X X X X X X X Pepco Holdings LLC Retirement Plan X X X X X X X Non-Qualified Pension Plans: Exelon Corporation Supplemental Pension Benefit Plan and 2000 Excess Benefit Plan X X X Exelon Corporation Supplemental Management Retirement Plan X X X X X Constellation Energy Group, Inc. Senior Executive Supplemental Plan X X Constellation Energy Group, Inc. Supplemental Pension Plan X X Constellation Energy Group, Inc. Benefits Restoration Plan X X X Baltimore Gas & Electric Company Executive Benefit Plan X Baltimore Gas & Electric Company Manager Benefit Plan X X Pepco Holdings LLC 2011 Supplemental Executive Retirement Plan X X X X Conectiv Supplemental Executive Retirement Plan X X X Pepco Holdings LLC Combined Executive Retirement Plan X X Atlantic City Electric Director Retirement Plan X X Operating Company (a) Name of Plan: ComEd PECO BGE PHI Pepco DPL ACE OPEB Plans: PECO Energy Company Retiree Medical Plan X X X X X X X Exelon Corporation Health Care Program X X X X X X X Exelon Corporation Employees’ Life Insurance Plan X X X Exelon Corporation Health Reimbursement Arrangement Plan X X X BGE Retiree Medical Plan X X X X X X BGE Retiree Dental Plan X Exelon Employee Life Insurance Plan and Family Life Insurance Plan X X X X X Exelon Retiree Medical Plan of Constellation Energy Nuclear Group, LLC X X X Exelon Retiree Dental Plan of Constellation Energy Nuclear Group, LLC X X X Pepco Holdings LLC Welfare Plan for Retirees X X X X X X X __________ (a) Employees generally remain in their legacy benefit plans when transferring between operating companies. As of February 1, 2022, in connection with the separation, Exelon's pension and OPEB plans were remeasured. The remeasurement and separation resulted in a decrease to the pension obligation, net of plan assets, of $921 million and a decrease to the OPEB obligation of $893 million. Additionally, accumulated other comprehensive loss, decreased by $1,994 million (after-tax) and regulatory assets and liabilities increased by $14 million and $5 million respectively. Key assumptions were held consistent with the year end December 31, 2021 assumptions with the exception of the discount rate. The majority of the 2022 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 3.24%. The majority of the 2022 OPEB cost is calculated using an expected long-term rate of return on plan assets of 6.44% for funded plans and a discount rate of 3.20%. During the first quarter of 2022, Exelon received an updated valuation of its pension and OPEB to reflect actual census data as of February 1, 2022. This valuation resulted in a decrease to the pension obligation of $24 million and an increase to the OPEB obligation of $5 million. Additionally, accumulated other comprehensive loss increased by $5 million (after-tax) and regulatory assets and liabilities decreased by $30 million and $3 million, respectively. A portion of the net periodic benefit cost for all plans is capitalized within the Consolidated Balance Sheets. The following table presents the components of Exelon's net periodic benefit costs, prior to capitalization, for the three months ended March 31, 2022 and 2021. Pension Benefits OPEB Three Months Ended March 31, Three Months Ended March 31, 2022 2021 2022 2021 Components of net periodic benefit cost: Service cost $ 61 $ 74 $ 10 $ 14 Interest cost 110 102 19 17 Expected return on assets (209) (213) (25) (26) Amortization of: Prior service cost (credit) 1 1 (5) (6) Actuarial loss 76 100 4 7 Curtailment benefits — — — (1) Net periodic benefit cost $ 39 $ 64 $ 3 $ 5 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. Three Months Ended March 31, Pension and OPEB Costs 2022 2021 Exelon $ 42 $ 69 ComEd 16 32 PECO (2) 2 BGE 11 15 PHI 13 12 Pepco 2 2 DPL 1 1 ACE 3 3 Defined Contribution Savings Plan The Registrants participate in a 401(k) defined contribution savings plan that is sponsored by Exelon. The plan is 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 the matching contributions to the savings plans for the three months ended March 31, 2022 and 2021, respectively. Three Months Ended March 31, Savings Plans Matching Contributions 2022 2021 Exelon $ 20 $ 20 ComEd 8 8 PECO 3 3 BGE 2 2 PHI 3 3 Pepco 1 1 DPL 1 1 ACE — —

Derivative Financial Instrument

Derivative Financial Instruments (All Registrants)	3 Months Ended
Derivative Financial Instruments (All Registrants)	Mar. 31, 2022
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 receivable or accounts payable are recorded when derivatives settle and revenue or expense is recognized in earnings as the underlying physical commodity is sold or 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 of the 2021 Form 10-K for additional information. (b) The fair value of the DPL economic hedge is not material as of March 31, 2022 and December 31, 2021. The fair value of derivative economic hedges is presented in current and noncurrent Mark-to-market derivative liabilities in Exelon's and ComEd's Consolidated Balance Sheets. 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 March 31, 2022, the amount of cash collateral held with external counterparties by Exelon, ComEd, PHI, and DPL was $192 million, $72 million, $86 million, and $73 million, respectively, which is recorded in Other current liabilities in Exelon's, ComEd's, PHI's, and DPL's Consolidated Balance Sheets. The amounts for PECO, BGE, Pepco, and ACE were not material as of March 31, 2022. As of December 31, 2021, the amounts for ComEd and DPL were $41 million and $43 million, respectively. The amounts for Exelon, PECO, BGE, PHI, Pepco, and ACE were not material as of December 31, 2021.

Debt and Credit Agreements (All

Debt and Credit Agreements (All Registrants)	3 Months Ended
Debt and Credit Agreements (All Registrants)	Mar. 31, 2022
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 their 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 as of March 31, 2022 and December 31, 2021. PECO and ComEd had no commercial paper borrowings as of March 31, 2022 and December 31, 2021. Outstanding Commercial Average Interest Rate on Commercial Paper Issuer March 31, 2022 December 31, 2021 March 31, 2022 December 31, 2021 Exelon (a) $ 250 $ 599 0.87 % 0.35 % BGE 250 130 0.87 % 0.37 % PHI (b) — 469 — % 0.35 % Pepco — 175 — % 0.33 % DPL — 149 — % 0.36 % ACE — 145 — % 0.35 % __________ (a) Exelon Corporate had no outstanding commercial paper borrowings as of March 31, 2022 and December 31, 2021. (b) 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 % See Note 17 — Debt and Credit Agreements of the Exelon 2021 Form 10-K for additional information on the Registrants' credit facilities. 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 14, 2022 and will expire on March 16, 2023. Pursuant to the loan agreement, loans made thereunder bear interest at a variable rate equal to SOFR plus 0.65% and all indebtedness thereunder is unsecured. The loan agreement is reflected in Exelon's Consolidated Balance Sheets within Short-term borrowings. On March 31, 2021, Exelon Corporate entered into a 364-day term loan agreement for $150 million with a variable interest rate of LIBOR plus 0.65% and an expiration date of March 30, 2022. Exelon Corporate repaid the term loan on March 30, 2022. 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% with a 22.5 basis point increase commencing on July 24, 2022. All indebtedness pursuant to the loan agreement is unsecured. Long-Term Debt Issuance of Long-Term Debt During the three months ended March 31, 2022, the following long-term debt was issued: Company Type Interest Rate Maturity Amount Use of Proceeds Exelon SMBC Term Loan Agreement SOFR plus 0.65% July 21, 2023 $300 Fund a cash payment to Constellation and for general corporate purposes. Exelon U.S. Bank Term Loan Agreement SOFR plus 0.65% July 21, 2023 300 Fund a cash payment to Constellation and for general corporate purposes. Exelon PNC Term Loan Agreement SOFR plus 0.65% July 24, 2023 250 Fund a cash payment to Constellation and for general corporate purposes. Exelon Notes 2.75% March 15, 2027 650 Repay existing indebtedness and for general corporate purposes. Exelon Notes 3.35% March 15, 2032 650 Repay existing indebtedness and for general corporate purposes. Exelon Notes 4.10% March 15, 2052 700 Repay existing indebtedness and for general corporate purposes. ComEd First Mortgage Bonds, Series 132 3.15% March 15, 2032 300 Repay outstanding commercial paper obligations and to fund other general corporate purposes. ComEd First Mortgage Bonds, Series 133 3.85% March 15, 2052 450 Repay outstanding commercial paper obligations and to fund other general corporate purposes. Pepco (a) First Mortgage Bonds 3.97% March 24, 2052 400 Repay existing indebtedness and for general corporate purposes. DPL First Mortgage Bonds 3.06% February 15, 2052 125 Repay existing indebtedness and for general corporate purposes. ACE First Mortgage Bonds 2.27% February 15, 2032 25 Repay existing indebtedness and for general corporate purposes. ACE First Mortgage Bonds 3.06% February 15, 2052 150 Repay existing indebtedness and for general corporate purposes. __________ (a) On March 24, 2022, Pepco entered into a purchase agreement of First Mortgage Bonds of $225 million at 3.35% due on September 15, 2032. The closing date of the issuance is expected to occur in September 2022. Long-Term Debt to Affiliates As of December 31, 2021, Exelon Corporate had $319 million recorded to intercompany notes receivable from Generation. See Note 17 — Debt and Credit Agreements of the Exelon 2021 Form 10-K for additional information. 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 March 31, 2022, the Registrants are in compliance with debt covenants.

Fair Value of Financial Assets

Fair Value of Financial Assets and Liabilities (All Registrants)	3 Months Ended
	Mar. 31, 2022
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 March 31, 2022 and December 31, 2021. 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. March 31, 2022 December 31, 2021 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 $ 37,162 $ 35,174 $ 2,645 $ 37,819 $ 32,902 $ 34,897 $ 2,217 $ 37,114 ComEd 10,515 10,894 — 10,894 9,773 11,305 — 11,305 PECO 4,198 4,244 50 4,294 4,197 4,740 50 4,790 BGE 3,961 3,969 — 3,969 3,961 4,406 — 4,406 PHI 8,233 5,453 2,595 8,048 7,547 5,970 2,167 8,137 Pepco 3,841 2,901 1,272 4,173 3,445 3,201 975 4,176 DPL 1,935 1,300 592 1,892 1,810 1,426 552 1,978 ACE 1,757 1,007 732 1,739 1,582 1,091 641 1,732 Long-Term Debt to Financing Trusts Exelon $ 390 $ — $ 435 $ 435 $ 390 $ — $ 470 $ 470 ComEd 205 — 228 228 205 — 248 248 PECO 184 — 207 207 184 — 222 222 __________ (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 17 - Debt and Credit Agreements of the Exelon 2021 Form 10-K for unamortized debt issuance costs, unamortized debt discount and premium, net, and purchase accounting fair value adjustments and Note 11 - Leases of the Exelon 2021 Form 10-K for finance lease liabilities. 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 March 31, 2022 and December 31, 2021: Exelon As of March 31, 2022 As of December 31, 2021 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets Cash equivalents (a) $ 2,418 $ — $ — $ 2,418 $ 524 $ — $ — $ 524 Rabbi trust investments Cash equivalents 65 — — 65 60 — — 60 Mutual funds 55 — — 55 60 — — 60 Fixed income — 9 — 9 — 10 — 10 Life insurance contracts — 63 37 100 — 61 37 98 Rabbi trust investments subtotal 120 72 37 229 120 71 37 228 Total assets 2,538 72 37 2,647 644 71 37 752 Liabilities Mark-to-market derivative liabilities — — (144) (144) — — (219) (219) Deferred compensation obligation — (84) — (84) — (131) — (131) Total liabilities — (84) (144) (228) — (131) (219) (350) Total net assets (liabilities) $ 2,538 $ (12) $ (107) $ 2,419 $ 644 $ (60) $ (182) $ 402 __________ (a) Exelon excludes cash of $470 million and $464 million as of March 31, 2022 and December 31, 2021, respectively, and restricted cash of $110 million and $49 million as of March 31, 2022 and December 31, 2021, respectively, and includes long-term restricted cash of $92 million and $44 million as of March 31, 2022 and December 31, 2021, respectively, which is reported in Other deferred debits in the Consolidated Balance Sheets. ComEd, PECO, and BGE ComEd PECO BGE As of March 31, 2022 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) $ 537 $ — $ — $ 537 $ 9 $ — $ — $ 9 $ — $ — $ — $ — Rabbi trust investments Cash equivalents — — — — 1 — — 1 — — — — Mutual funds — — — — 9 — — 9 7 — — 7 Life insurance contracts — — — — — 17 — 17 — — — — Rabbi trust investments subtotal — — — — 10 17 — 27 7 — — 7 Total assets 537 — — 537 19 17 — 36 7 — — 7 Liabilities Mark-to-market derivative liabilities (b) — — (144) (144) — — — — — — — — Deferred compensation obligation — (9) — (9) — (8) — (8) — (5) — (5) Total liabilities — (9) (144) (153) — (8) — (8) — (5) — (5) Total net assets (liabilities) $ 537 $ (9) $ (144) $ 384 $ 19 $ 9 $ — $ 28 $ 7 $ (5) $ — $ 2 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 __________ (a) ComEd excludes cash of $71 million and $105 million as of March 31, 2022 and December 31, 2021, respectively, and restricted cash of $73 million and $42 million as of March 31, 2022 and December 31, 2021, respectively, and includes long-term restricted cash of $92 million and $43 million as of March 31, 2022 and December 31, 2021, respectively, which is reported in Other deferred debits in the Consolidated Balance Sheets. PECO excludes cash of $25 million and $35 million as of March 31, 2022 and December 31, 2021, respectively. BGE excludes cash of $41 million and $51 million as of March 31, 2022 and December 31, 2021, respectively, and restricted cash of $34 million and $4 million as of March 31, 2022 and December 31, 2021, respectively. (b) The Level 3 balance consists of the current and noncurrent liability of none and $144 million, respectively, as of March 31, 2022 and $18 million and $201 million, respectively, as of December 31, 2021 related to floating-to-fixed energy swap contracts with unaffiliated suppliers. PHI, Pepco, DPL, and ACE As of March 31, 2022 As of December 31, 2021 PHI Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets Cash equivalents (a) $ 599 $ — $ — $ 599 $ 110 $ — $ — $ 110 Rabbi trust investments Cash equivalents 61 — — 61 59 — — 59 Mutual funds 12 — — 12 14 — — 14 Fixed income — 9 — 9 — 10 — 10 Life insurance contracts — 24 36 60 — 27 35 62 Rabbi trust investments subtotal 73 33 36 142 73 37 35 145 Total assets 672 33 36 741 183 37 35 255 Liabilities Deferred compensation obligation — (17) — (17) — (18) — (18) Total liabilities — (17) — (17) — (18) — (18) Total net assets $ 672 $ 16 $ 36 $ 724 $ 183 $ 19 $ 35 $ 237 Pepco DPL ACE As of March 31, 2022 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) $ 294 $ — $ — $ 294 $ 152 $ — $ — $ 152 $ 153 $ — $ — $ 153 Rabbi trust investments Cash equivalents 59 — — 59 — — — — — — — — Life insurance contracts — 24 36 60 — — — — — — — — Rabbi trust investments subtotal 59 24 36 119 — — — — — — — — Total assets 353 24 36 413 152 — — 152 153 — — 153 Liabilities Deferred compensation obligation — (2) — (2) — — — — — — — — Total liabilities — (2) — (2) — — — — — — — — Total net assets $ 353 $ 22 $ 36 $ 411 $ 152 $ — $ — $ 152 $ 153 $ — $ — $ 153 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 $ — $ — $ — $ — __________ (a) PHI excludes cash of $300 million and $100 million as of March 31, 2022 and December 31, 2021, respectively, and restricted cash of $3 million as of both March 31, 2022 and December 31, 2021. Pepco excludes cash of $239 million and $34 million as of March 31, 2022 and December 31, 2021, respectively, and restricted cash of $3 million as of both March 31, 2022 and December 31, 2021. DPL excludes cash of $41 million and $28 million as of March 31, 2022 and December 31, 2021, respectively. ACE excludes cash of $15 million and $29 million as of March 31, 2022 and December 31, 2021, respectively. 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 three months ended March 31, 2022 and 2021: Exelon ComEd PHI and Pepco Three months ended March 31, 2022 Total Mark-to-Market Life Insurance Contracts Balance as of January 1, 2022 $ (182) $ (219) $ 35 Total realized / unrealized gains Included in net income (a) 1 — 1 Included in regulatory assets 75 75 (b) — Transfers out of Level 3 (1) — — Balance as of March 31, 2022 $ (107) $ (144) $ 36 The amount of total gains included in income attributed to the change in unrealized gains related to assets and liabilities as of March 31, 2022 $ 1 $ — $ 1 Exelon ComEd PHI and Pepco Three Months Ended March 31, 2021 Total Mark-to-Market Life Insurance Contracts Balance as of January 1, 2021 $ (267) $ (301) $ 34 Total realized / unrealized gains Included in net income (a) 1 — 1 Included in regulatory assets 6 6 (b) — Balance as of March 31, 2021 $ (260) $ (295) $ 35 The amount of total gains included in income attributed to the change in unrealized gain related to assets and liabilities as of March 31, 2021 $ 1 $ — $ 1 __________ (a) Classified in Operating and maintenance expense in the Consolidated Statements of Operations and Comprehensive Income. (b) Includes $69 million of increases in fair value and an increase for realized losses due to settlements of $6 million recorded in purchased power expense associated with floating-to-fixed energy swap contracts with unaffiliated suppliers for the three months ended March 31, 2022. Includes $2 million of decreases in fair value and an increase for realized losses due to settlements of $8 million recorded in purchased power expense associated with floating-to-fixed energy swap contracts with unaffiliated suppliers for the three months ended March 31, 2021. Valuation Techniques Used to Determine Fair Value Exelon’s valuation techniques used to measure the fair value of the assets and liabilities shown in the tables below are in accordance with the policies discussed in Note 18 — Fair Value of Financial Assets and Liabilities of the Exelon 2021 Form 10-K. Mark-to-Market Derivatives (Exelon and ComEd) The table below discloses the significant inputs to the forward curve used to value mark-to-market derivatives. Type of trade Fair Value as of March 31, 2022 Fair Value as of December 31, 2021 Valuation Unobservable 2022 Range & Arithmetic Average 2021 Range & Arithmetic Average Mark-to-market derivatives $ (144) $ (219) Discounted Forward heat (a) 8.90x - 9.10x 9.00x 9x - 10x 9.13x Marketability 4% - 5% 4.35% 3% - 7% 4.77% Renewable 92% - 120% 98% 92% - 120% 97% __________ (a) Quoted forward natural gas rates are utilized to project the forward power curve for the delivery of energy at specified future dates.

Commitments and Contingencies (

Commitments and Contingencies (All Registrants)	3 Months Ended
Commitments and Contingencies (All Registrants)	Mar. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies (All Registrants)	Commitments and Contingencies (All Registrants) The following is an update to the current status of commitments and contingencies set forth in Note 19 — Commitments and Contingencies of the Exelon 2021 Form 10-K. 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 March 31, 2022: Description Exelon PHI Pepco DPL ACE Total commitments $ 513 $ 320 $ 120 $ 89 $ 111 Remaining commitments (a) 65 55 46 6 3 __________ (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 March 31, 2022, representing commitments potentially triggered by future events were as follows: Expiration within Total 2022 2023 2024 2025 2026 2027 and beyond Exelon Letters of credit $ 14 $ 12 $ 2 $ — $ — $ — $ — Surety bonds (a) 201 188 11 2 — — — Financing trust guarantees 378 — — — — — 378 Guaranteed lease residual values (b) 30 1 3 6 5 5 10 Total commercial commitments $ 623 $ 201 $ 16 $ 8 $ 5 $ 5 $ 388 ComEd Letters of credit $ 7 $ 7 $ — $ — $ — $ — $ — Surety bonds (a) 17 12 3 2 — — — Financing trust guarantees 200 — — — — — 200 Total commercial commitments $ 224 $ 19 $ 3 $ 2 $ — $ — $ 200 PECO Letters of credit $ 1 $ 1 $ — $ — $ — $ — $ — Surety bonds (a) 3 2 1 — — — — Financing trust guarantees 178 — — — — — 178 Total commercial commitments $ 182 $ 3 $ 1 $ — $ — $ — $ 178 BGE Letters of credit $ 2 $ 2 $ — $ — $ — $ — $ — Surety bonds (a) 4 3 1 — — — — Total commercial commitments $ 6 $ 5 $ 1 $ — $ — $ — $ — PHI Surety bonds (a) $ 94 $ 91 $ 3 $ — $ — $ — $ — Guaranteed lease residual values (b) 30 1 3 6 5 5 10 Total commercial commitments $ 124 $ 92 $ 6 $ 6 $ 5 $ 5 $ 10 Pepco Surety bonds (a) $ 84 $ 84 $ — $ — $ — $ — $ — Guaranteed lease residual values (b) 10 — 1 2 2 2 3 Total commercial commitments $ 94 $ 84 $ 1 $ 2 $ 2 $ 2 $ 3 DPL Surety bonds (a) $ 6 $ 3 $ 3 $ — $ — $ — $ — Guaranteed lease residual values (b) 13 1 1 3 2 2 4 Total commercial commitments $ 19 $ 4 $ 4 $ 3 $ 2 $ 2 $ 4 ACE Surety bonds (a) $ 4 $ 4 $ — $ — $ — $ — $ — Guaranteed lease residual values (b) 7 — 1 1 1 1 3 Total commercial commitments $ 11 $ 4 $ 1 $ 1 $ 1 $ 1 $ 3 __________ (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 $73 million guaranteed by Exelon and PHI, of which $25 million, $30 million, and $18 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 2031. • PECO has 6 sites 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 site 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 a PAPUC order, 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 March 31, 2022 and December 31, 2021, 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: March 31, 2022 December 31, 2021 Total environmental Portion of total related to Total environmental Portion of total related to Exelon $ 354 $ 305 $ 352 $ 303 ComEd 279 279 279 279 PECO 21 20 22 20 BGE 7 6 6 4 PHI 42 — 42 — Pepco 40 — 40 — 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 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 transferred any of the potential remaining remediation liability, if any, of PES/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 entered into negotiations with the Trustees to evaluate possible incorporation of NRD assessment and restoration as part of its remedial activities associated with the Benning site to accelerate the NRD benefits for that portion of the Anacostia River Sediment Project ("ARSP") assessment. 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 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. Similarly, any potential future liability associated with the ARSP was also assumed by this entity. Litigation and Regulatory Matters 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 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 appealed dismissal of the federal law claim to the Seventh Circuit Court of Appeals. Plaintiffs and CUB also refiled their state law claims in state court and moved to consolidate them with the already pending consumer state court class action, discussed below. Plaintiffs' opening appeal brief in the Seventh Circuit was filed on January 14, 2022. Exelon and ComEd filed their response brief on March 7, 2022, and plaintiffs filed their reply brief on April 6, 2022. The court has scheduled oral argument for May 17, 2022. • 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 CUB's 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 asserted in their motion to dismiss the original state court plaintiffs' complaint. The court granted dismissal of the refiled state claims on February 16, 2022. The original federal plaintiffs appealed that dismissal on February 18, 2022. The two state appeals were consolidated on March 21, 2022. Plaintiffs' opening appellate briefs are currently due June 3, 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. 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. • Several shareholders have sent letters to the Exelon Board of Directors from 2020 through May 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 responded to both requests and both shareholders have since sent formal shareholder demands to the Exelon Board, as discussed above. No loss contingencies have been reflec ted 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. The testimony supports the calculation of the refund amount and proposes a refund mechanism (one-time bill credit in April 2023) and also addresses other topics outlined by statute and the ICC orders initiating the investigation. On April 14, 2022, in response to rebuttal testimony from ICC staff and the Illinois Attorney General, City of Chicago, and CUB, ComEd filed surrebuttal testimony, in which ComEd proposed to increase its voluntary customer refund to $38 million of ICC and FERC jurisdictional amounts, and estimated interest to resolve the issue of the potential expenditure of customer monies on activities identified in the DPA in this matter. An accrual for the amount of the voluntary customer refund has been recorded in Other deferred credits and other liabilities in Exelon’s and ComEd’s Consolidated Balance Sheets as of March 31, 2022. The voluntary customer refund will not be recovered in rates or charged to customers and ComEd will not seek or accept reimbursement or indemnification from any source other than Exelon. The evidentiary hearing on the remaining contested issue was held on April 28, 2022. A final order is expected by September 9, 2022. 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 filed a motion to dismiss the complaint on February 25, 2022. The plaintiffs filed their response brief on March 28, 2022 and the defendants filed their reply on April 11, 2022. On March 4, 2022, the Chamber of Commerce filed a brief of amicus curiae in support of the defendants' motion to dismiss. 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

Changes in Accumulated Other Co

Changes in Accumulated Other Comprehensive Income (Exelon)	3 Months Ended
Changes in Accumulated Other Comprehensive Income (Exelon)	Mar. 31, 2022
Changes in Accumulated Other Comprehensive Income [Abstract]
Changes in Accumulated Other Comprehensive Income	Changes in Accumulated Other Comprehensive Income (Exelon) The following tables present changes in Exelon's AOCI, net of tax, by component: Three Months Ended March 31, 2022 Cash Flow Hedges Pension and Non-Pension Postretirement Benefit Plan Items (a) Foreign Total Balance at December 31, 2021 $ (6) $ (2,721) $ (23) $ (2,750) Separation of Constellation 6 1,994 23 2,023 Amounts reclassified from AOCI — 14 — 14 Net current-period OCI — 14 — 14 Balance at March 31, 2022 $ — $ (713) $ — $ (713) Three Months Ended March 31, 2021 Losses on Cash Flow Hedges Pension and Non-Pension Postretirement Benefit Plan Items (a) Foreign Total Balance at December 31, 2020 $ (5) $ (3,372) $ (23) $ (3,400) OCI before reclassifications — (2) 1 (1) Amounts reclassified from AOCI — 55 — 55 Net current-period OCI — 53 1 54 Balance at March 31, 2021 $ (5) $ (3,319) $ (22) $ (3,346) ______ (a) This AOCI component is included in the computation of net periodic pension and OPEB cost. Additionally, as of February 1, 2022, in connection with the separation, Exelon's pension and OPEB plans were remeasured. See Note 8 — Retirement Benefits for additional information. See Exelon's Statements of Operations and Comprehensive Income for individual components of AOCI. The following table presents income tax benefit (expense) allocated to each component of Exelon's other comprehensive income (loss): Three Months Ended March 31, 2022 2021 Pension and non-pension postretirement benefit plans: Prior service benefit reclassified to periodic benefit cost $ — $ 1 Actuarial loss reclassified to periodic benefit cost (5) (19)

Supplemental Financial Informat

Supplemental Financial Information (All Registrants)	3 Months Ended
Supplemental Financial Information (All Registrants)	Mar. 31, 2022
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 Three Months Ended March 31, 2022 Utility taxes (a) $ 221 $ 78 $ 38 $ 27 $ 78 $ 70 $ 7 $ 1 Property 94 10 4 46 34 23 10 1 Payroll 37 7 4 4 7 2 1 1 Three Months Ended March 31, 2021 Utility taxes (a) $ 193 $ 59 $ 35 $ 25 $ 74 $ 67 $ 6 $ 1 Property 86 8 4 42 32 21 10 1 Payroll 33 7 4 5 7 2 1 — _________ (a) The Registrants' utility taxes represent 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 Three Months Ended March 31, 2022 AFUDC — Equity $ 36 $ 8 $ 7 $ 6 $ 15 $ 11 $ 2 $ 2 Non-service net periodic benefit cost 17 — — — — — — — Three Months Ended March 31, 2021 AFUDC — Equity $ 28 $ 4 $ 6 $ 7 $ 11 $ 9 $ 1 $ 1 Non-service net periodic benefit cost 20 — — — — — — — Supplemental Cash Flow Information The following tables provide additional information about material items recorded in the Registrants' Consolidated Statements of Cash Flows. Depreciation and amortization Exelon (a) ComEd PECO BGE PHI Pepco DPL ACE Three Months Ended March 31, 2022 Property, plant, and equipment (b) $ 726 $ 254 $ 88 $ 117 $ 164 $ 72 $ 45 $ 41 Amortization of regulatory assets (b) 179 67 4 54 54 36 12 6 Amortization of intangible assets, net (b) 6 — — — — — — — Amortization of energy contract assets and liabilities (c) 3 — — — — — — — Nuclear fuel (d) 66 — — — — — — — ARO accretion (e) 44 — — — — — — — Total depreciation, amortization, and accretion $ 1,024 $ 321 $ 92 $ 171 $ 218 $ 108 $ 57 $ 47 Three Months Ended March 31, 2021 Property, plant, and equipment (b) $ 1,522 $ 239 $ 82 $ 106 $ 154 $ 67 $ 42 $ 37 Amortization of regulatory assets (b) 160 53 4 46 56 35 11 10 Amortization of intangible assets, net (b) 15 — — — — — — — Amortization of energy contract assets and liabilities (c) 4 — — — — — — — Nuclear fuel (d) 276 — — — — — — — ARO accretion (e) 127 — — — — — — — Total depreciation, amortization, and accretion $ 2,104 $ 292 $ 86 $ 152 $ 210 $ 102 $ 53 $ 47 __________ (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 the Registrants’ Consolidated Statements of Operations and Comprehensive Income. (d) Included in Purchased fuel expense in Exelon's Consolidated Statement of Operations and Comprehensive Income. (e) Included in Operating and maintenance expense in Exelon's Consolidated Statement of Operations and Comprehensive Income. Other non-cash operating activities Exelon (a) ComEd PECO BGE PHI Pepco DPL ACE Three Months Ended March 31, 2022 Pension and non-pension postretirement benefit costs $ 44 $ 16 $ (2) $ 12 $ 13 $ 2 $ 1 $ 3 Allowance for credit losses 78 17 27 18 18 9 6 3 Other decommissioning-related activity 36 — — — — — — — Energy-related options 60 — — — — — — — True-up adjustments to decoupling mechanisms and formula rates (b) (29) (40) (6) 12 5 7 1 (3) Long-term incentive plan 25 — — — — — — — Amortization of operating ROU asset 23 1 — 7 7 2 2 1 AFUDC — Equity (36) (8) (7) (6) (15) (11) (2) (2) Three Months Ended March 31, 2021 Pension and non-pension postretirement benefit costs $ 95 $ 32 $ 2 $ 14 $ 12 $ 2 $ 1 $ 3 Allowance for credit losses 85 13 24 4 10 5 4 1 Other decommissioning-related activity (322) — — — — — — — Energy-related options 17 — — — — — — — True-up adjustments to decoupling mechanisms and formula rates (b) (129) (54) (10) (18) (46) (26) (9) (11) Long-term incentive plan 32 — — — — — — — Amortization of operating ROU asset 37 — — 7 7 1 3 1 AFUDC — Equity (28) (4) (6) (7) (11) (9) (1) (1) __________ (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 rates. See Note 3 — Regulatory Matters of the Exelon Form 10-K for additional information. The following tables provide a reconciliation of cash, cash equivalents, and restricted cash 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 March 31, 2022 Cash and cash equivalents $ 2,476 $ 343 $ 26 $ 41 $ 796 $ 502 $ 120 $ 168 Restricted cash and cash equivalents 430 246 8 34 106 34 73 — Restricted cash included in other long-term assets 92 92 — — — — — — Total cash, restricted cash, and cash equivalents $ 2,998 $ 681 $ 34 $ 75 $ 902 $ 536 $ 193 $ 168 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 from discontinued operations 582 — — — — — — — Total cash, restricted cash, and cash equivalents $ 1,619 $ 384 $ 44 $ 55 $ 213 $ 68 $ 71 $ 29 March 31, 2021 Cash and cash equivalents $ 1,908 $ 86 $ 48 $ 21 $ 558 $ 134 $ 64 $ 353 Restricted cash and cash equivalents 374 270 7 1 37 33 — 4 Restricted cash included in other long-term assets 52 43 — — 9 — — 9 Total cash, restricted cash, and cash equivalents (a) $ 2,334 $ 399 $ 55 $ 22 $ 604 $ 167 $ 64 $ 366 December 31, 2020 Cash and cash equivalents $ 663 $ 83 $ 19 $ 144 $ 111 $ 30 $ 15 $ 17 Restricted cash and cash equivalents 438 279 7 1 39 35 — 3 Restricted cash included in other long-term assets 53 43 — — 10 — — 10 Cash, restricted cash, and cash equivalents - Held for Sale 12 — — — — — — — Total cash, restricted cash, and cash equivalents (a) $ 1,166 $ 405 $ 26 $ 145 $ 160 $ 65 $ 15 $ 30 __________ (a) Exelon's amounts include amounts related to Generation prior to the separation. See Note 2 — Discontinued Operations for additional information. For additional information on restricted cash see Note 1 — Significant Accounting Policies of the Exelon 2021 Form 10-K. Supplemental Balance Sheet Information The following table provides additional information about material items recorded in the Registrants' Consolidated Balance Sheets. Accrued expenses Exelon ComEd PECO BGE PHI Pepco DPL ACE March 31, 2022 Compensation-related accruals (a) $ 370 $ 95 $ 51 $ 48 $ 73 $ 26 $ 15 $ 12 Taxes accrued 258 95 15 78 94 85 10 9 Interest accrued 346 66 36 39 77 37 21 17 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 __________ (a) Primarily includes accrued payroll, bonuses and other incentives, vacation, and benefits.

Related Party Transactions (All

Related Party Transactions (All Registrants)	3 Months Ended
Related Party Transactions (All Registrants)	Mar. 31, 2022
Related Party Transactions [Abstract]
Related Party Transactions (All Registrants)	Related Party Transactions (All Registrants) Utility Registrants' expense with Generation The Utility Registrants incurred expenses from transactions with the Generation affiliate as described in the footnotes to the table below prior to separation on February 1, 2022. 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 : Three Months Ended March 31, 2022 2021 ComEd (a) $ 59 $ 85 PECO (b) 33 42 BGE (c) 18 72 PHI 51 100 Pepco (d) 39 75 DPL (e) 10 21 ACE (f) 2 4 __________ (a) 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. (b) 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. (c) BGE received a portion of its energy requirements from Generation under its MDPSC-approved market-based SOS and gas commodity programs. (d) Pepco received electric supply from Generation under contracts executed through Pepco's competitive procurement process approved by the MDPSC and DCPSC. (e) DPL received a portion of its energy requirements from Generation under its MDPSC and DEPSC approved market-based SOS commodity programs. (f) ACE received electric supply from Generation under contracts executed through ACE's competitive procurement process approved by the NJBPU. 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 Three Months Ended March 31, Three Months Ended March 31, 2022 2021 2022 2021 Exelon BSC $ 205 $ 114 PHISCO 19 17 ComEd BSC $ 85 $ 71 85 45 PECO BSC 49 39 36 17 BGE BSC 51 43 38 20 PHI BSC 50 39 46 32 PHISCO 19 17 Pepco BSC 29 22 17 13 PHISCO 29 30 8 7 DPL BSC 18 14 14 10 PHISCO 24 25 6 5 ACE BSC 15 12 15 8 PHISCO 21 22 5 5 Current Receivables from/Payables to affiliates The following tables present current receivables from affiliates and current payables to affiliates: March 31, 2022 Receivables from affiliates: Payables to affiliates: ComEd PECO BGE Pepco DPL ACE BSC PHISCO Other Total ComEd $ — $ — $ — $ — $ — $ 64 $ — $ 2 $ 66 PECO $ — — — — — 33 — 5 38 BGE — — — — — 35 — 2 37 PHI — — — — — — 7 1 10 18 Pepco — — — — — 19 15 — 34 DPL — — — — — 3 12 — 15 ACE — — — — — 12 11 — 23 Other 3 — — — — — — — 3 Total $ 3 $ — $ — $ — $ — $ — $ 173 $ 39 $ 19 $ 234 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 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. The receivables are recorded in Receivable related to Regulatory Agreement Units as of March 31, 2022 and in noncurrent Receivables from affiliates as of December 31, 2021. See Note 10 — Asset Retirement Obligations of the Combined Notes to Consolidated Financial Statements of the Exelon 2021 Form 10-K for additional information. Long-term debt to financing trusts The following table presents Long-term debt to financing trusts: March 31, 2022 December 31, 2021 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

Planned Separation

Planned Separation	3 Months Ended
Planned Separation	Mar. 31, 2022
Discontinued Operations and Disposal Groups [Abstract]
Disposal Groups, Including Discontinued Operations, Disclosure [Text Block]	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"). Exelon completed the separation on February 1, 2022, through the distribution of 326,663,937 common stock shares of Constellation, 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 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 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 to Constellation and for general corporate purposes. See Note 10 — Debt and Credit Agreements for additional information. • Exelon made a cash payment of $1.75 billion to Constellation on January 31, 2022. • Exelon contributed its equity ownership interest in Generation to Constellation. Exelon no longer retains any equity ownership interest in Generation or Constellation. • Exelon transferred certain corporate assets and employee-related obligations to Constellation. • Exelon received cash from Generation of $258 million to settle the intercompany loan on January 31, 2022. See Note 10 — Debt and Credit Agreements for additional information. Continuing Involvement In order to govern the ongoing relationships between Exelon and Constellation after the separation, and to facilitate an orderly transition, Exelon and Constellation have entered into several agreements, including the following: • Separation Agreement – governs the rights and obligations between Exelon and Constellation regarding certain actions to be taken in connection with the separation, among others, including the allocation of assets and liabilities between Exelon and Constellation. • Transition Services Agreement (TSA) – governs the terms and conditions of the services that Exelon will provide to Constellation and Constellation 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. For the period from February 1, 2022 to March 31, 2022, the amounts Exelon billed Constellation and Constellation billed Exelon for these services were $56 million recorded in Other income, net and $9 million recorded in Operating and maintenance expense, respectively. • Tax Matters Agreement (TMA) – governs the respective rights, responsibilities and obligations of Exelon and Constellation 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. See Note 7. Income Taxes for additional information. 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. After the separation, such expenses are primarily recorded as Purchased power and an immaterial amount recorded as Operating and maintenance expense 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 10 — Asset Retirement Obligations of the Combined Notes to Consolidated Financial Statements of the Exelon 2021 Form 10-K and Note 15 — Related Party Transactions 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 Constellation that have been reclassified from continuing operations and included in discontinued operations within Exelon’s Consolidated Statements of Operations and Comprehensive Income for the three months ended March 31, 2022 and March 31, 2021. 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. Three Months Ended 2022 2021 Operating revenues Competitive business revenues $ 1,855 $ 5,265 Competitive business revenues from affiliates 161 294 Total operating revenues 2,016 5,559 Operating expenses Competitive businesses purchased power and fuel 1,138 4,610 Operating and maintenance (a) 371 904 Depreciation and amortization 94 940 Taxes other than income taxes 44 121 Total operating expenses 1,647 6,575 Gain on sales of assets and businesses 10 71 Operating income (loss) 379 (945) Other income and (deductions) Interest expense, net (20) (68) Other, net (281) 167 Total other income and (deductions) (301) 99 Income (loss) before income taxes 78 (846) Income taxes (40) (58) Equity in losses of unconsolidated affiliates (1) (1) Net income (loss) 117 (789) Net income attributable to noncontrolling interests 1 25 Net income (loss) from discontinued operations $ 116 $ (814) __________ (a) Includes transaction and transition costs related to the separation of $52 million and $3 million for the three months ended March 31, 2022 and 2021, respectively. $50 million and $2 million of transaction costs and $2 million and less than $1 million of transition costs are included in the results of discontinued operations in the table presented above for the three months ended March 31, 2022 and March 31, 2021, respectively. See discussion above for additional information. There were no assets and liabilities of discontinued operations included in Exelon’s Consolidated Balance Sheet as of March 31, 2022. Constellation had net assets of $11,573 million that separated on February 1, 2022 that resulted in a reduction to Exelon’s equity during the three months ended March 31, 2022. Refer to the Distribution of Constellation line in Exelon’s Consolidated Statement of Changes in Shareholders’ Equity for further information. The following table presents the assets and liabilities of discontinued operations in Exelon’s Consolidated Balance Sheet as of December 31, 2021: December 31, 2021 ASSETS Current assets Cash and cash equivalents $ 510 Restricted cash and cash equivalents 72 Accounts receivable Customer accounts receivable 1,724 Customer allowance for credit losses (55) Customer accounts receivable, net 1,669 Other accounts receivable 596 Other allowance for credit losses (4) Other accounts receivable, net 592 Mark-to-market derivative assets 2,169 Inventories, net Fossil fuel and emission allowances 284 Materials and supplies 1,004 Renewable energy credits 529 Assets held for sale 13 Other 993 Total current assets of discontinued operations 7,835 Property, plant, and equipment (net of accumulated depreciation and amortization of $15,888) 19,661 Deferred debits and other assets Nuclear decommissioning trust funds 15,938 Investments 193 Mark-to-market derivative assets 949 Other 1,768 Total property, plant, and equipment, deferred debits, and other assets of discontinued operations 38,509 Total assets of discontinued operations $ 46,344 December 31, 2021 LIABILITIES AND SHAREHOLDERS’ EQUITY Current liabilities Short-term borrowings $ 2,082 Long-term debt due within one year 1,220 Accounts payable 1,757 Accrued expenses 818 Mark-to-market derivative liabilities 981 Renewable energy credit obligation 779 Liabilities held for sale 3 Other 300 Total current liabilities of discontinued operations 7,940 Long-term debt 4,575 Deferred credits and other liabilities Deferred income taxes and unamortized investment tax credits 3,583 Asset retirement obligations 12,819 Pension obligations 939 Non-pension postretirement benefit obligations 876 Spent nuclear fuel obligation 1,210 Mark-to-market derivative liabilities 513 Other 1,161 Total long-term debt, deferred credits, and other liabilities of discontinued operations 25,676 Total liabilities of discontinued operations $ 33,616 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 three months ended March 31, 2022 and March 31, 2021. Three Months Ended March 31, 2022 2022 2021 Non-cash items included in net income (loss) from discontinued operations: Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization $ 207 $ 1,346 Gain on sales of assets and businesses 9 (71) Deferred income taxes and amortization of investment tax credits (143) (234) Net fair value changes related to derivatives (59) (178) Net realized and unrealized losses (gains) on NDT fund investments 205 (118) Net unrealized losses on equity investments 16 23 Other decommissioning-related activity 36 (332) Cash flows from investing activities: Capital expenditures (227) (394) Collection of DPP 169 1,574 Supplemental cash flow information: Decrease in capital expenditures not paid (128) (37) Increase in DPP 348 1,339 Increase in PP&E related to ARO update 335 —

Significant Accounting Polici_2

Significant Accounting Policies (Policies)	3 Months Ended
Significant Accounting Policies (Policies)	Mar. 31, 2022
Accounting Policies [Abstract]
Description of Business and Basis of Presentation (All Registrants)	Description of Business Exelon is a utility services holding company engaged in 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. The separation was completed on February 1, 2022, creating two publicly traded companies, Exelon and Constellation. 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 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 & 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 This is a combined quarterly 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” in the consolidated financial statements and include intercompany eliminations unless otherwise disclosed. The accompanying consolidated financial statements as of March 31, 2022 and for the three months ended March 31, 2022 and 2021 are unaudited but, in the opinion of the management of each Registrant include all adjustments that are considered necessary for a fair statement of the Registrants’ respective financial statements in accordance with GAAP. All adjustments are of a normal, recurring nature, except as otherwise disclosed. The December 31, 2021 Consolidated Balance Sheets were derived from audited financial statements. The interim financial statements are to be read in conjunction with prior annual financial statements and notes. Additionally, financial results for interim periods are not necessarily indicative of results that may be expected for any other interim period or for the fiscal year ending December 31, 2022. These Combined Notes to Consolidated Financial Statements have been prepared pursuant to the rules and regulations of the SEC for Quarterly Reports on Form 10-Q. Certain information and note disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations. The separation of Constellation, 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, shareholders' equity, and cash flows related to Constellation 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. Prior Period Adjustments and Reclassifications (Exelon, PHI, ACE) In the first quarter of 2022, management identified an error related to an overstatement of the regulatory liability associated with ACE’s mechanism to recover the cost of Transition Bonds issued in 2002 and 2003 by ACE Funding. Management has concluded that the error was not material to previously issued financial statements for Exelon, PHI or ACE. The error was corrected through a revision to ACE’s financial statements contained herein. The impact of the error correction was an $8 million increase to ACE’s opening Retained earnings as of January 1, 2021 with a corresponding reduction to Regulatory liabilities of $11 million and an increase to Deferred income taxes and unamortized investment tax credits of $3 million. The impact of the error to ACE’s Total operating revenues and Net income was less than $1 million for the three months ended March 31, 2021. The error did not impact net cash flows provided by operating activities, net cash flows used in investing activities or net cash flows provided by financing activities for the three months ended March 31, 2021. The error was corrected in the Exelon and PHI financial statements for the three months ended March 31, 2022 as it was not material, resulting in an increase to Net income of $8 million.

Discontinued Operations (Tables

Discontinued Operations (Tables) - Exelon Generation Co L L C [Member]	3 Months Ended	12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021
Discontinued Operations - Income Statement
Discontinued Operations - Income Statement	The following table presents the results of Constellation that have been reclassified from continuing operations and included in discontinued operations within Exelon’s Consolidated Statements of Operations and Comprehensive Income for the three months ended March 31, 2022 and March 31, 2021. 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. Three Months Ended 2022 2021 Operating revenues Competitive business revenues $ 1,855 $ 5,265 Competitive business revenues from affiliates 161 294 Total operating revenues 2,016 5,559 Operating expenses Competitive businesses purchased power and fuel 1,138 4,610 Operating and maintenance (a) 371 904 Depreciation and amortization 94 940 Taxes other than income taxes 44 121 Total operating expenses 1,647 6,575 Gain on sales of assets and businesses 10 71 Operating income (loss) 379 (945) Other income and (deductions) Interest expense, net (20) (68) Other, net (281) 167 Total other income and (deductions) (301) 99 Income (loss) before income taxes 78 (846) Income taxes (40) (58) Equity in losses of unconsolidated affiliates (1) (1) Net income (loss) 117 (789) Net income attributable to noncontrolling interests 1 25 Net income (loss) from discontinued operations $ 116 $ (814) __________ (a) Includes transaction and transition costs related to the separation of $52 million and $3 million for the three months ended March 31, 2022 and 2021, respectively. $50 million and $2 million of transaction costs and $2 million and less than $1 million of transition costs are included in the results of discontinued operations in the table presented above for the three months ended March 31, 2022 and March 31, 2021, respectively. See discussion above for additional information.
Discontinued Operations - Balance Sheet [Table Text Block]		The following table presents the assets and liabilities of discontinued operations in Exelon’s Consolidated Balance Sheet as of December 31, 2021: December 31, 2021 ASSETS Current assets Cash and cash equivalents $ 510 Restricted cash and cash equivalents 72 Accounts receivable Customer accounts receivable 1,724 Customer allowance for credit losses (55) Customer accounts receivable, net 1,669 Other accounts receivable 596 Other allowance for credit losses (4) Other accounts receivable, net 592 Mark-to-market derivative assets 2,169 Inventories, net Fossil fuel and emission allowances 284 Materials and supplies 1,004 Renewable energy credits 529 Assets held for sale 13 Other 993 Total current assets of discontinued operations 7,835 Property, plant, and equipment (net of accumulated depreciation and amortization of $15,888) 19,661 Deferred debits and other assets Nuclear decommissioning trust funds 15,938 Investments 193 Mark-to-market derivative assets 949 Other 1,768 Total property, plant, and equipment, deferred debits, and other assets of discontinued operations 38,509 Total assets of discontinued operations $ 46,344 December 31, 2021 LIABILITIES AND SHAREHOLDERS’ EQUITY Current liabilities Short-term borrowings $ 2,082 Long-term debt due within one year 1,220 Accounts payable 1,757 Accrued expenses 818 Mark-to-market derivative liabilities 981 Renewable energy credit obligation 779 Liabilities held for sale 3 Other 300 Total current liabilities of discontinued operations 7,940 Long-term debt 4,575 Deferred credits and other liabilities Deferred income taxes and unamortized investment tax credits 3,583 Asset retirement obligations 12,819 Pension obligations 939 Non-pension postretirement benefit obligations 876 Spent nuclear fuel obligation 1,210 Mark-to-market derivative liabilities 513 Other 1,161 Total long-term debt, deferred credits, and other liabilities of discontinued operations 25,676 Total liabilities of discontinued operations $ 33,616
Discontinued Operations - Cash Flows [Table Text Block]	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 three months ended March 31, 2022 and March 31, 2021. Three Months Ended March 31, 2022 2022 2021 Non-cash items included in net income (loss) from discontinued operations: Depreciation, amortization, and accretion, including nuclear fuel and energy contract amortization $ 207 $ 1,346 Gain on sales of assets and businesses 9 (71) Deferred income taxes and amortization of investment tax credits (143) (234) Net fair value changes related to derivatives (59) (178) Net realized and unrealized losses (gains) on NDT fund investments 205 (118) Net unrealized losses on equity investments 16 23 Other decommissioning-related activity 36 (332) Cash flows from investing activities: Capital expenditures (227) (394) Collection of DPP 169 1,574 Supplemental cash flow information: Decrease in capital expenditures not paid (128) (37) Increase in DPP 348 1,339 Increase in PP&E related to ARO update 335 —

Regulatory Matters (Tables)

Regulatory Matters (Tables)	3 Months Ended
Regulatory Matters (Tables)	Mar. 31, 2022
Regulated Operations [Abstract]
Public Utilities Distribution Rate Cases [Table Text Block]	The following tables show the completed and pending distribution base rate case proceedings in 2022. Completed Distribution Base Rate Case Proceedings Registrant/Jurisdiction Filing Date Service Requested Revenue Requirement Increase Approved Revenue Requirement Increase Approved ROE Approval Date Rate Effective Date ComEd - Illinois (a) April 16, 2021 Electric $ 51 $ 46 7.36 % December 1, 2021 January 1, 2022 PECO - Pennsylvania 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 - Maryland (f) September 1, 2021 (amended December 23, 2021) Electric 27 13 9.60 % March 2, 2022 March 2, 2022 ACE - New Jersey (g) December 9, 2020 (amended February 26, 2021) Electric 67 41 9.60 % July 14, 2021 January 1, 2022 __________ (a) ComEd's 2022 approved revenue requirement 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 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 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 for the 12-month period ending March 31, 2023. Whether certain tax benefits will be used to offset the customer rate increases for the 12-month period ending March 31, 2024 has not been decided, and Pepco cannot predict the outcome. (f) The approved settlement reflects a 9.60% ROE, which is solely for the purposes of calculating AFUDC and regulatory asset carrying costs. (g) 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 ComEd - Illinois (a) April 15, 2022 Electric $ 199 7.85 % Fourth quarter of 2022 PECO - Pennsylvania March 31, 2022 Natural Gas 82 10.95 % Fourth quarter of 2022 DPL - Delaware (b) January 14, 2022 (amended February 28, 2022) Natural Gas 15 10.30 % First quarter of 2023 __________ (a) ComEd's 2023 requested revenue requirement reflects an increase of $144 million for the initial year revenue requirement for 2023 and an increase of $55 million related to the annual reconciliation for 2021. The revenue requirement for 2023 provides for a weighted average debt and equity return on distribution rate base of 5.94%, inclusive of an allowed ROE of 7.85%, reflecting the average monthly yields for 30-year treasury bonds plus 580 basis points. The reconciliation revenue requirement for 2021 provides for a weighted average debt and equity return on distribution rate base of 5.91%, inclusive of an allowed ROE of 7.78%, reflecting the average monthly yields for 30-year treasury bonds plus 580 basis points less a performance metrics penalty of 7 basis points. This is ComEd's last performance-based electric distribution formula rate update filing under EIMA as a result of the law authorizing the rate setting process sunsetting at the end of 2022. See Note 3. - Regulatory Matters of the Exelon 2021 Form 10-K for additional information on ComEd's transition away from the electric distribution formula rate. (b) The rates will go into effect on August 14, 2022, subject to refund.
Public Utilities Transmission Rate Filings [Table Text Block]	For 2022, the following total increases were included in ComEd’s and BGE's electric transmission formula rate update. PECO, Pepco, DPL, and ACE intend to file by the required deadline for the annual update. Registrant (a) Initial Revenue Requirement Increase Annual Reconciliation Decrease Total Revenue Requirement Increase Allowed Return on Rate Base (c) Allowed ROE (d) ComEd $ 24 $ (24) $ — 8.11 % 11.50 % BGE 25 (4) 16 (b) 7.30 % 10.50 % (a) All rates are effective June 1, 2022 - May 31, 2023, subject to review by interested parties pursuant to review protocols of ComEd's and BGE's tariff. (b) The increase in BGE's transmission revenue requirement includes a $5 million reduction related to a FERC-approved dedicated facilities charge to recover the costs of providing transmission service to specifically designated load by BGE. (c) Represents the weighted average debt and equity return on transmission rate bases.
Capitalized Ratemaking Amounts Not Recognized [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 March 31, 2022 $ 49 $ 2 $ — $ 34 $ 13 $ 11 $ 2 $ — December 31, 2021 43 1 — 37 5 3 2 — __________ (a) Reflects ComEd's unrecognized equity returns earned for ratemaking purposes on its energy efficiency and electric distribution formula rate regulatory assets. (b) BGE's authorized amounts capitalized for ratemaking purposes primarily relate to earnings on shareholder's investment on its AMI programs. (c) Pepco's and DPL's authorized amounts capitalized for ratemaking purposes relate to earnings on shareholder's investment on their respective AMI Programs and Energy Efficiency and Demand Response Programs, and for Pepco District of Columbia revenue decoupling program. The earnings on energy efficiency are on Pepco District of Columbia and DPL Delaware programs only.

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	3 Months Ended
Revenue from Contracts with Customers (Tables)	Mar. 31, 2022
Contracts with Customers [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction	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 March 31, 2022. 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 $ 6 $ 8 $ 6 $ 5 $ 82 $ 107 PHI 6 8 6 5 82 107 Pepco 4 6 5 5 65 85 DPL 1 1 — — 9 11 ACE 1 1 1 — 8 11

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
Segment Information (Tables)	Mar. 31, 2022
Segment Tables [Line Items]
Analysis and reconciliation of reportable segment information	An analysis and reconciliation of the Registrants’ reportable segment information to the respective information in the consolidated financial statements for the three months ended March 31, 2022 and 2021 is as follows: Three Months Ended March 31, 2022 and 2021 ComEd PECO BGE PHI Other (a) Intersegment Exelon Operating revenues (b) : 2022 Electric revenues $ 1,734 $ 741 $ 736 $ 1,318 $ — $ (7) $ 4,522 Natural gas revenues — 306 418 83 — (2) $ 805 Shared service and other revenues — — — 3 576 (579) $ — Total operating revenues $ 1,734 $ 1,047 $ 1,154 $ 1,404 $ 576 $ (588) $ 5,327 2021 Electric revenues $ 1,535 $ 661 $ 632 $ 1,170 $ — $ (7) $ 3,991 Natural gas revenues — 228 342 71 — — 641 Shared service and other revenues — — — 3 491 (494) — Total operating revenues $ 1,535 $ 889 $ 974 $ 1,244 $ 491 $ (501) $ 4,632 Intersegment revenues (c) : 2022 $ 6 $ 1 $ 7 $ 3 $ 576 $ (587) $ 6 2021 6 2 6 3 487 (497) 7 Depreciation and amortization: 2022 $ 321 $ 92 $ 171 $ 218 $ 15 $ — $ 817 2021 292 86 152 210 17 — 757 Operating expenses: 2022 $ 1,406 $ 793 $ 919 $ 1,215 $ 625 $ (531) $ 4,427 2021 1,210 679 752 1,058 448 (339) 3,808 Interest expense, net: 2022 $ 100 $ 41 $ 35 $ 69 $ 93 $ — $ 338 2021 96 38 34 67 83 — 318 Income (loss) from continuing operations before income taxes: 2022 $ 240 $ 220 $ 207 $ 137 $ (62) $ (43) $ 699 2021 236 177 196 136 (32) (149) 564 Income Taxes: 2022 $ 52 $ 14 $ 9 $ 7 $ 146 $ (10) $ 218 2021 39 10 (13) 8 7 (12) 39 Net income (loss) from continuing operations: 2022 $ 188 $ 206 $ 198 $ 130 $ (208) $ (33) $ 481 2021 197 167 209 128 (39) (137) 525 Capital Expenditures: 2022 $ 617 $ 344 $ 303 $ 409 $ 22 $ — $ 1,695 2021 613 295 336 456 46 — 1,746 Total assets: March 31, 2022 $ 37,013 $ 14,113 $ 12,509 $ 25,636 $ 7,583 $ (4,156) $ 92,698 December 31, 2021 36,470 13,824 12,324 24,744 7,634 (8,319) 86,677 __________ (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 14 — Supplemental Financial Information for additional information on total utility taxes. (c) See Note 15 — Related Party Transactions for additional information on intersegment revenues. PHI: Pepco DPL ACE Other (a) Intersegment PHI Operating revenues (b) : 2022 Electric revenues $ 614 $ 348 $ 349 $ — $ 7 $ 1,318 Natural gas revenues — 83 — — — 83 Shared service and other revenues — — — 107 (104) 3 Total operating revenues $ 614 $ 431 $ 349 $ 107 $ (97) $ 1,404 2021 Electric revenues $ 553 $ 311 $ 310 $ — $ (4) $ 1,170 Natural gas revenues — 71 — — — 71 Shared service and other revenues — — — 95 (92) 3 Total operating revenues $ 553 $ 382 $ 310 $ 95 $ (96) $ 1,244 Intersegment revenues (c) : 2022 $ 1 $ 1 $ 1 $ 97 $ (97) $ 3 2021 1 2 1 95 (96) 3 Depreciation and amortization: 2022 $ 108 $ 57 $ 47 $ 6 $ — $ 218 2021 102 53 47 8 — 210 Operating expenses: 2022 $ 547 $ 357 $ 311 $ 97 $ (97) $ 1,215 2021 466 309 282 97 (96) 1,058 Interest expense, net: 2022 $ 36 $ 16 $ 14 $ 3 $ — $ 69 2021 34 15 15 3 — 67 Income (loss) before income taxes: 2022 $ 44 $ 60 $ 27 $ 6 $ — $ 137 2021 65 61 14 (4) — 136 Income Taxes: 2022 $ (2) $ 4 $ 1 $ 4 $ — $ 7 2021 6 5 — (3) — 8 Net income (loss): 2022 $ 46 $ 56 $ 26 $ 2 $ — $ 130 2021 59 56 14 (1) — 128 Capital Expenditures: 2022 $ 218 $ 103 $ 87 $ 1 $ — $ 409 2021 220 112 123 1 — 456 Total assets: March 31, 2022 $ 10,458 $ 5,573 $ 4,929 $ 4,720 $ (44) $ 25,636 December 31, 2021 9,903 5,412 4,556 4,933 (60) 24,744 __________ (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 14 — Supplemental Financial Information for additional information on total utility taxes. (c) Includes intersegment revenues with ComEd, BGE, and PECO, which are eliminated at Exelon.
Schedule of Revenue by Major Customers by Reporting Segments [Table Text Block]	The following tables disaggregate the Registrants' 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. Three Months Ended March 31, 2022 Revenues from contracts with customers ComEd PECO BGE PHI Pepco DPL ACE Electric revenues Residential $ 857 $ 487 $ 417 $ 652 $ 275 $ 207 $ 170 Small commercial & industrial 423 111 81 141 38 56 47 Large commercial & industrial 153 64 131 323 253 26 44 Public authorities & electric railroads 14 8 7 16 8 4 4 Other (a) 239 62 97 193 46 56 81 Total electric revenues (b) $ 1,686 $ 732 $ 733 $ 1,325 $ 620 $ 349 $ 346 Natural gas revenues Residential $ — $ 218 $ 282 $ 51 $ — $ 51 $ — Small commercial & industrial — 76 45 21 — 21 — Large commercial & industrial — — 65 3 — 3 — Transportation — 8 — 4 — 4 — Other (c) — 3 35 4 — 4 — Total natural gas revenues (d) $ — $ 305 $ 427 $ 83 $ — $ 83 $ — Total revenues from contracts with customers $ 1,686 $ 1,037 $ 1,160 $ 1,408 $ 620 $ 432 $ 346 Other revenues Revenues from alternative revenue programs $ 40 $ 6 $ (12) $ (5) $ (7) $ (1) $ 3 Other electric revenues (e) 8 3 4 1 1 — — Other natural gas revenues (e) — 1 2 — — — — Total other revenues $ 48 $ 10 $ (6) $ (4) $ (6) $ (1) $ 3 Total revenues for reportable segments $ 1,734 $ 1,047 $ 1,154 $ 1,404 $ 614 $ 431 $ 349 Three Months Ended March 31, 2021 Revenues from contracts with customers ComEd PECO BGE PHI Pepco DPL ACE Electric revenues Residential $ 741 $ 433 $ 362 $ 605 $ 253 $ 190 $ 162 Small commercial & industrial 367 100 69 118 33 46 39 Large commercial & industrial 134 57 105 248 184 21 43 Public authorities & electric railroads 11 9 7 13 6 4 3 Other (a) 220 52 77 143 51 41 52 Total electric revenues (b) $ 1,473 $ 651 $ 620 $ 1,127 $ 527 $ 302 $ 299 Natural gas revenues Residential $ — $ 160 $ 216 $ 46 $ — $ 46 $ — Small commercial & industrial — 59 35 18 — 18 — Large commercial & industrial — — 54 2 — 2 — Transportation — 7 — 4 — 4 — Other (c) — 2 31 1 — 1 — Total natural gas revenues (d) $ — $ 228 $ 336 $ 71 $ — $ 71 $ — Total revenues from contracts with customers $ 1,473 $ 879 $ 956 $ 1,198 $ 527 $ 373 $ 299 Other revenues Revenues from alternative revenue programs $ 54 $ 10 $ 18 $ 46 $ 26 $ 9 $ 11 Other electric revenues (e) 8 — — — — — — Total other revenues $ 62 $ 10 $ 18 $ 46 $ 26 $ 9 $ 11 Total revenues for reportable segments $ 1,535 $ 889 $ 974 $ 1,244 $ 553 $ 382 $ 310 __________ (a) Includes revenues from transmission revenue from PJM, wholesale electric revenue and mutual assistance revenue. (b) Includes operating revenues from affiliates in 2022 and 2021 respectively of: • $6 million, $6 million at ComEd • $1 million, $1 million at PECO • $2 million, $2 million at BGE • $3 million, $3 million at PHI • $1 million, $1 million at Pepco • $2 million, $2 million at DPL • $1 million, $1 million at ACE (c) Includes revenues from off-system natural gas sales. (d) Includes operating revenues from affiliates in 2022 and 2021 respectively of: • less than $1 million, less than $1 million at PECO • $6 million, $4 million at BGE (e) Includes late payment charge revenues.

Accounts Receivable (Tables)

Accounts Receivable (Tables)	3 Months Ended
Accounts Receivable (Tables)	Mar. 31, 2022
Accounts, Notes, Loans and Financing Receivable, Gross, Allowance, and Net [Abstract]
Allowance for credit loss rollforward	The following tables present the rollforward of Allowance for Credit Losses on Customer Accounts Receivable. Three Months Ended March 31, 2022 Exelon ComEd PECO BGE PHI Pepco DPL ACE Balance as of December 31, 2021 $ 320 $ 73 $ 105 $ 38 $ 104 $ 37 $ 18 $ 49 Plus: Current period provision for expected credit losses (a) 110 26 31 26 27 11 7 9 Less: Write-offs, net of recoveries (b)(c) 41 7 11 5 18 8 1 9 Balance as of March 31, 2022 $ 389 $ 92 $ 125 $ 59 $ 113 $ 40 $ 24 $ 49 Three Months Ended March 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 (d) 70 21 20 9 20 11 6 3 Less: Write-offs, net of recoveries (b) 27 15 6 1 5 2 3 — Balance as of March 31, 2021 $ 377 $ 103 $ 130 $ 43 $ 101 $ 41 $ 25 $ 35 __________ (a) For PECO, BGE and ACE, the increase is primarily as a result of increased receivable balances due to the increased aging of receivables. For BGE, also reflects increased receivable balance due to colder weather. (b) Recoveries were not material to the Registrants. (c) For ACE, the increase in 2022 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 January 2022, write-offs of aging accounts receivable increased throughout the year. (d) The increase is primarily as a result of increased receivable balances due to the colder weather and the increased aging of receivables, the temporary suspension of customer disconnections for non-payment, temporary cessation of new late payment fees, and reconnection of service for customers previously disconnected due to COVID-19. The following tables present the rollforward of Allowance for Credit Losses on Other Accounts Receivable. Three Months Ended March 31, 2022 Exelon ComEd PECO BGE PHI Pepco DPL ACE Balance as of December 31, 2021 $ 72 $ 17 $ 7 $ 9 $ 39 $ 16 $ 8 $ 15 Plus: Current period provision for expected credit losses 14 4 3 3 4 2 1 1 Less: Write-offs, net of recoveries (a) 5 1 1 1 2 — — 2 Balance as of March 31, 2022 $ 81 $ 20 $ 9 $ 11 $ 41 $ 18 $ 9 $ 14 Three Months Ended March 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 10 1 4 1 4 2 1 1 Less: Write-offs, net of recoveries (a) 2 — 1 1 — — — — Balance as of March 31, 2021 $ 79 $ 22 $ 11 $ 9 $ 37 $ 15 $ 10 $ 12 __________ (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 March 31, 2022 and December 31, 2021. Unbilled customer revenues (a) Exelon ComEd PECO BGE PHI Pepco DPL ACE March 31, 2022 $ 629 $ 189 $ 127 $ 139 $ 174 $ 89 $ 50 $ 35 December 31, 2021 747 240 161 171 175 82 53 40 __________ (a) Unbilled customer revenues are classified in Customer accounts receivables, net in the Registrants' Consolidated Balance Sheets.
Purchases and sales of accounts receivable	The Utility Registrants are required, under separate legislation and regulations in Illinois, Pennsylvania, Maryland, District of Columbia, Delaware, 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. Total receivables purchased Exelon (a) ComEd PECO BGE (a) PHI Pepco DPL ACE Three months ended March 31, 2022 $ 1,044 $ 248 $ 292 $ 222 $ 282 $ 174 $ 57 $ 51 Three months ended March 31, 2021 1,023 266 290 199 268 166 56 46 __________

Income Taxes (Tables)

Income Taxes (Tables)	3 Months Ended
Income Taxes (Tables)	Mar. 31, 2022
Income Tax Disclosure [Abstract]
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	The effective income tax rate from continuing operations varies from the U.S. federal statutory rate principally due to the following: Three Months Ended March 31, 2022 (a) Exelon ComEd PECO (b) BGE (b) PHI Pepco (b) DPL 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 (c) 21.1 8.0 (0.1) 2.4 3.7 (4.5) 6.2 6.8 Plant basis differences (3.6) (0.6) (11.3) (0.9) (1.6) (2.6) (0.7) (1.3) Excess deferred tax amortization (11.5) (6.3) (3.2) (17.6) (17.7) (17.4) (19.4) (22.2) Amortization of investment tax credit, including deferred taxes on basis difference (0.1) (0.1) — (0.1) (0.1) — (0.2) (0.2) Tax credits (d) 1.7 (0.3) — (0.4) (0.4) (0.4) (0.3) (0.3) Other (e) 2.6 — — (0.1) 0.2 (0.6) 0.1 (0.1) Effective income tax rate 31.2 % 21.7 % 6.4 % 4.3 % 5.1 % (4.5) % 6.7 % 3.7 % Three Months Ended March 31, 2021 (a) Exelon ComEd PECO (f) BGE (f) PHI Pepco DPL ACE (f) 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 2.8 6.8 (1.6) (10.1) 6.1 5.5 6.4 6.9 Plant basis differences (3.4) (0.6) (10.5) (1.4) (1.5) (2.1) (0.7) (0.9) Excess deferred tax amortization (12.0) (6.9) (3.2) (15.5) (19.3) (15.1) (18.5) (28.7) Amortization of investment tax credit, including deferred taxes on basis difference (0.1) (0.1) — (0.1) (0.1) — (0.2) (0.2) Tax credits (0.3) (0.2) — (0.4) (0.2) (0.2) (0.1) (0.3) Other (1.1) (3.5) (0.1) (0.1) (0.1) 0.1 0.3 2.2 Effective income tax rate 6.9 % 16.5 % 5.6 % (6.6) % 5.9 % 9.2 % 8.2 % — % __________ (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 lower effective tax rate is primarily due to the Maryland multi-year plan which resulted in the acceleration of certain income tax benefits. For Pepco, the income tax benefit is primarily due to the Maryland and Washington, D.C. multi-year plans which resulted in the acceleration of certain income tax benefits. For ACE, the lower effective tax rate is primarily due to the acceleration of certain income tax benefits due to distribution rate case settlements. (c) For Exelon, the higher state income taxes, net of federal income tax benefit, is primarily due to the long-term marginal state income tax rate change of approximately $67 million and the recognition of a valuation allowance of approximately $40 million against the net deferred tax asset position for certain standalone state filing jurisdictions as a result of the separation. (d) For Exelon, reflects the income tax expense related to the write-off of federal tax credits subject to recapture of approximately $15 million as a result of the separation. (e) For Exelon, primarily reflects the nondeductible transaction costs of approximately $19 million arising as part of the separation. (f) 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
Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block]	Exelon, PHI and ACE have the following unrecognized tax benefits as of March 31, 2022 and December 31, 2021. ComEd's, PECO's, BGE's, Pepco's, and DPL's amounts are not material. Exelon PHI ACE March 31, 2022 $ 146 $ 56 $ 16 December 31, 2021 143 56 16 __________

Retirement Benefits (Tables)

Retirement Benefits (Tables)	3 Months Ended
Retirement Benefits (Tables)	Mar. 31, 2022
Retirement Benefits [Abstract]
Calculation of Net Periodic Benefit Costs	A portion of the net periodic benefit cost for all plans is capitalized within the Consolidated Balance Sheets. The following table presents the components of Exelon's net periodic benefit costs, prior to capitalization, for the three months ended March 31, 2022 and 2021. Pension Benefits OPEB Three Months Ended March 31, Three Months Ended March 31, 2022 2021 2022 2021 Components of net periodic benefit cost: Service cost $ 61 $ 74 $ 10 $ 14 Interest cost 110 102 19 17 Expected return on assets (209) (213) (25) (26) Amortization of: Prior service cost (credit) 1 1 (5) (6) Actuarial loss 76 100 4 7 Curtailment benefits — — — (1) Net periodic benefit cost $ 39 $ 64 $ 3 $ 5
Allocated Portion of Pension and 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. Three Months Ended March 31, Pension and OPEB Costs 2022 2021 Exelon $ 42 $ 69 ComEd 16 32 PECO (2) 2 BGE 11 15 PHI 13 12 Pepco 2 2 DPL 1 1 ACE 3 3
Defined Contribution Savings Plans	The Registrants participate in a 401(k) defined contribution savings plan that is sponsored by Exelon. The plan is 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 the matching contributions to the savings plans for the three months ended March 31, 2022 and 2021, respectively. Three Months Ended March 31, Savings Plans Matching Contributions 2022 2021 Exelon $ 20 $ 20 ComEd 8 8 PECO 3 3 BGE 2 2 PHI 3 3 Pepco 1 1 DPL 1 1 ACE — —

Debt and Credit Agreements (Tab

Debt and Credit Agreements (Tables)	3 Months Ended
Debt and Credit Agreements (Tables)	Mar. 31, 2022
Debt Instrument [Line Items]
Schedule of Commercial Paper Borrowings	The following table reflects the Registrants' commercial paper programs as of March 31, 2022 and December 31, 2021. PECO and ComEd had no commercial paper borrowings as of March 31, 2022 and December 31, 2021. Outstanding Commercial Average Interest Rate on Commercial Paper Issuer March 31, 2022 December 31, 2021 March 31, 2022 December 31, 2021 Exelon (a) $ 250 $ 599 0.87 % 0.35 % BGE 250 130 0.87 % 0.37 % PHI (b) — 469 — % 0.35 % Pepco — 175 — % 0.33 % DPL — 149 — % 0.36 % ACE — 145 — % 0.35 % __________ (a) Exelon Corporate had no outstanding commercial paper borrowings as of March 31, 2022 and December 31, 2021. (b) Represents the consolidated amounts of Pepco, DPL, and ACE.
Schedule of 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 %
Schedule of Long-term Debt Instruments [Table Text Block]	During the three months ended March 31, 2022, the following long-term debt was issued: Company Type Interest Rate Maturity Amount Use of Proceeds Exelon SMBC Term Loan Agreement SOFR plus 0.65% July 21, 2023 $300 Fund a cash payment to Constellation and for general corporate purposes. Exelon U.S. Bank Term Loan Agreement SOFR plus 0.65% July 21, 2023 300 Fund a cash payment to Constellation and for general corporate purposes. Exelon PNC Term Loan Agreement SOFR plus 0.65% July 24, 2023 250 Fund a cash payment to Constellation and for general corporate purposes. Exelon Notes 2.75% March 15, 2027 650 Repay existing indebtedness and for general corporate purposes. Exelon Notes 3.35% March 15, 2032 650 Repay existing indebtedness and for general corporate purposes. Exelon Notes 4.10% March 15, 2052 700 Repay existing indebtedness and for general corporate purposes. ComEd First Mortgage Bonds, Series 132 3.15% March 15, 2032 300 Repay outstanding commercial paper obligations and to fund other general corporate purposes. ComEd First Mortgage Bonds, Series 133 3.85% March 15, 2052 450 Repay outstanding commercial paper obligations and to fund other general corporate purposes. Pepco (a) First Mortgage Bonds 3.97% March 24, 2052 400 Repay existing indebtedness and for general corporate purposes. DPL First Mortgage Bonds 3.06% February 15, 2052 125 Repay existing indebtedness and for general corporate purposes. ACE First Mortgage Bonds 2.27% February 15, 2032 25 Repay existing indebtedness and for general corporate purposes. ACE First Mortgage Bonds 3.06% February 15, 2052 150 Repay existing indebtedness and for general corporate purposes. __________ (a) On March 24, 2022, Pepco entered into a purchase agreement of First Mortgage Bonds of $225 million at 3.35% due on September 15, 2032. The closing date of the issuance is expected to occur in September 2022.

Fair Value of Financial Asset_2

Fair Value of Financial Assets and Liabilities (Tables)	3 Months Ended
Fair Value of Financial Assets and Liabilities (Tables)	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Fair Value of Financial Liabilities Recorded at Amortized Cost	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 March 31, 2022 and December 31, 2021. 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. March 31, 2022 December 31, 2021 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 $ 37,162 $ 35,174 $ 2,645 $ 37,819 $ 32,902 $ 34,897 $ 2,217 $ 37,114 ComEd 10,515 10,894 — 10,894 9,773 11,305 — 11,305 PECO 4,198 4,244 50 4,294 4,197 4,740 50 4,790 BGE 3,961 3,969 — 3,969 3,961 4,406 — 4,406 PHI 8,233 5,453 2,595 8,048 7,547 5,970 2,167 8,137 Pepco 3,841 2,901 1,272 4,173 3,445 3,201 975 4,176 DPL 1,935 1,300 592 1,892 1,810 1,426 552 1,978 ACE 1,757 1,007 732 1,739 1,582 1,091 641 1,732 Long-Term Debt to Financing Trusts Exelon $ 390 $ — $ 435 $ 435 $ 390 $ — $ 470 $ 470 ComEd 205 — 228 228 205 — 248 248 PECO 184 — 207 207 184 — 222 222 __________
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	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 March 31, 2022 and December 31, 2021: Exelon As of March 31, 2022 As of December 31, 2021 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets Cash equivalents (a) $ 2,418 $ — $ — $ 2,418 $ 524 $ — $ — $ 524 Rabbi trust investments Cash equivalents 65 — — 65 60 — — 60 Mutual funds 55 — — 55 60 — — 60 Fixed income — 9 — 9 — 10 — 10 Life insurance contracts — 63 37 100 — 61 37 98 Rabbi trust investments subtotal 120 72 37 229 120 71 37 228 Total assets 2,538 72 37 2,647 644 71 37 752 Liabilities Mark-to-market derivative liabilities — — (144) (144) — — (219) (219) Deferred compensation obligation — (84) — (84) — (131) — (131) Total liabilities — (84) (144) (228) — (131) (219) (350) Total net assets (liabilities) $ 2,538 $ (12) $ (107) $ 2,419 $ 644 $ (60) $ (182) $ 402 __________ (a) Exelon excludes cash of $470 million and $464 million as of March 31, 2022 and December 31, 2021, respectively, and restricted cash of $110 million and $49 million as of March 31, 2022 and December 31, 2021, respectively, and includes long-term restricted cash of $92 million and $44 million as of March 31, 2022 and December 31, 2021, respectively, which is reported in Other deferred debits in the Consolidated Balance Sheets. ComEd, PECO, and BGE ComEd PECO BGE As of March 31, 2022 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) $ 537 $ — $ — $ 537 $ 9 $ — $ — $ 9 $ — $ — $ — $ — Rabbi trust investments Cash equivalents — — — — 1 — — 1 — — — — Mutual funds — — — — 9 — — 9 7 — — 7 Life insurance contracts — — — — — 17 — 17 — — — — Rabbi trust investments subtotal — — — — 10 17 — 27 7 — — 7 Total assets 537 — — 537 19 17 — 36 7 — — 7 Liabilities Mark-to-market derivative liabilities (b) — — (144) (144) — — — — — — — — Deferred compensation obligation — (9) — (9) — (8) — (8) — (5) — (5) Total liabilities — (9) (144) (153) — (8) — (8) — (5) — (5) Total net assets (liabilities) $ 537 $ (9) $ (144) $ 384 $ 19 $ 9 $ — $ 28 $ 7 $ (5) $ — $ 2 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 __________ (a) ComEd excludes cash of $71 million and $105 million as of March 31, 2022 and December 31, 2021, respectively, and restricted cash of $73 million and $42 million as of March 31, 2022 and December 31, 2021, respectively, and includes long-term restricted cash of $92 million and $43 million as of March 31, 2022 and December 31, 2021, respectively, which is reported in Other deferred debits in the Consolidated Balance Sheets. PECO excludes cash of $25 million and $35 million as of March 31, 2022 and December 31, 2021, respectively. BGE excludes cash of $41 million and $51 million as of March 31, 2022 and December 31, 2021, respectively, and restricted cash of $34 million and $4 million as of March 31, 2022 and December 31, 2021, respectively. (b) The Level 3 balance consists of the current and noncurrent liability of none and $144 million, respectively, as of March 31, 2022 and $18 million and $201 million, respectively, as of December 31, 2021 related to floating-to-fixed energy swap contracts with unaffiliated suppliers. PHI, Pepco, DPL, and ACE As of March 31, 2022 As of December 31, 2021 PHI Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets Cash equivalents (a) $ 599 $ — $ — $ 599 $ 110 $ — $ — $ 110 Rabbi trust investments Cash equivalents 61 — — 61 59 — — 59 Mutual funds 12 — — 12 14 — — 14 Fixed income — 9 — 9 — 10 — 10 Life insurance contracts — 24 36 60 — 27 35 62 Rabbi trust investments subtotal 73 33 36 142 73 37 35 145 Total assets 672 33 36 741 183 37 35 255 Liabilities Deferred compensation obligation — (17) — (17) — (18) — (18) Total liabilities — (17) — (17) — (18) — (18) Total net assets $ 672 $ 16 $ 36 $ 724 $ 183 $ 19 $ 35 $ 237 Pepco DPL ACE As of March 31, 2022 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) $ 294 $ — $ — $ 294 $ 152 $ — $ — $ 152 $ 153 $ — $ — $ 153 Rabbi trust investments Cash equivalents 59 — — 59 — — — — — — — — Life insurance contracts — 24 36 60 — — — — — — — — Rabbi trust investments subtotal 59 24 36 119 — — — — — — — — Total assets 353 24 36 413 152 — — 152 153 — — 153 Liabilities Deferred compensation obligation — (2) — (2) — — — — — — — — Total liabilities — (2) — (2) — — — — — — — — Total net assets $ 353 $ 22 $ 36 $ 411 $ 152 $ — $ — $ 152 $ 153 $ — $ — $ 153 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 $ — $ — $ — $ — __________ (a) PHI excludes cash of $300 million and $100 million as of March 31, 2022 and December 31, 2021, respectively, and restricted cash of $3 million as of both March 31, 2022 and December 31, 2021. Pepco excludes cash of $239 million and $34 million as of March 31, 2022 and December 31, 2021, respectively, and restricted cash of $3 million as of both March 31, 2022 and December 31, 2021. DPL excludes cash of $41 million and $28 million as of March 31, 2022 and December 31, 2021, respectively. ACE excludes cash of $15 million and $29 million as of March 31, 2022 and December 31, 2021, respectively.
Fair Value Reconciliation of Level 3 Assets and Liabilities Measured at Fair Value on a Recurring Basis	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 three months ended March 31, 2022 and 2021: Exelon ComEd PHI and Pepco Three months ended March 31, 2022 Total Mark-to-Market Life Insurance Contracts Balance as of January 1, 2022 $ (182) $ (219) $ 35 Total realized / unrealized gains Included in net income (a) 1 — 1 Included in regulatory assets 75 75 (b) — Transfers out of Level 3 (1) — — Balance as of March 31, 2022 $ (107) $ (144) $ 36 The amount of total gains included in income attributed to the change in unrealized gains related to assets and liabilities as of March 31, 2022 $ 1 $ — $ 1 Exelon ComEd PHI and Pepco Three Months Ended March 31, 2021 Total Mark-to-Market Life Insurance Contracts Balance as of January 1, 2021 $ (267) $ (301) $ 34 Total realized / unrealized gains Included in net income (a) 1 — 1 Included in regulatory assets 6 6 (b) — Balance as of March 31, 2021 $ (260) $ (295) $ 35 The amount of total gains included in income attributed to the change in unrealized gain related to assets and liabilities as of March 31, 2021 $ 1 $ — $ 1 __________ (a) Classified in Operating and maintenance expense in the Consolidated Statements of Operations and Comprehensive Income.
Fair Value Reconciliation of Level 3 Assets and Liabilities Measured at Fair Value on a Recurring Basis, Valuation Technique	Mark-to-Market Derivatives (Exelon and ComEd) The table below discloses the significant inputs to the forward curve used to value mark-to-market derivatives. Type of trade Fair Value as of March 31, 2022 Fair Value as of December 31, 2021 Valuation Unobservable 2022 Range & Arithmetic Average 2021 Range & Arithmetic Average Mark-to-market derivatives $ (144) $ (219) Discounted Forward heat (a) 8.90x - 9.10x 9.00x 9x - 10x 9.13x Marketability 4% - 5% 4.35% 3% - 7% 4.77% Renewable 92% - 120% 98% 92% - 120% 97% __________ (a) Quoted forward natural gas rates are utilized to project the forward power curve for the delivery of energy at specified future dates.

Commitments and Contingencies_2

Commitments and Contingencies (Tables)	3 Months Ended
Commitments and Contingencies (Tables)	Mar. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
PHI Merger 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 March 31, 2022: Description Exelon PHI Pepco DPL ACE Total commitments $ 513 $ 320 $ 120 $ 89 $ 111 Remaining commitments (a) 65 55 46 6 3 __________ (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 March 31, 2022, representing commitments potentially triggered by future events were as follows: Expiration within Total 2022 2023 2024 2025 2026 2027 and beyond Exelon Letters of credit $ 14 $ 12 $ 2 $ — $ — $ — $ — Surety bonds (a) 201 188 11 2 — — — Financing trust guarantees 378 — — — — — 378 Guaranteed lease residual values (b) 30 1 3 6 5 5 10 Total commercial commitments $ 623 $ 201 $ 16 $ 8 $ 5 $ 5 $ 388 ComEd Letters of credit $ 7 $ 7 $ — $ — $ — $ — $ — Surety bonds (a) 17 12 3 2 — — — Financing trust guarantees 200 — — — — — 200 Total commercial commitments $ 224 $ 19 $ 3 $ 2 $ — $ — $ 200 PECO Letters of credit $ 1 $ 1 $ — $ — $ — $ — $ — Surety bonds (a) 3 2 1 — — — — Financing trust guarantees 178 — — — — — 178 Total commercial commitments $ 182 $ 3 $ 1 $ — $ — $ — $ 178 BGE Letters of credit $ 2 $ 2 $ — $ — $ — $ — $ — Surety bonds (a) 4 3 1 — — — — Total commercial commitments $ 6 $ 5 $ 1 $ — $ — $ — $ — PHI Surety bonds (a) $ 94 $ 91 $ 3 $ — $ — $ — $ — Guaranteed lease residual values (b) 30 1 3 6 5 5 10 Total commercial commitments $ 124 $ 92 $ 6 $ 6 $ 5 $ 5 $ 10 Pepco Surety bonds (a) $ 84 $ 84 $ — $ — $ — $ — $ — Guaranteed lease residual values (b) 10 — 1 2 2 2 3 Total commercial commitments $ 94 $ 84 $ 1 $ 2 $ 2 $ 2 $ 3 DPL Surety bonds (a) $ 6 $ 3 $ 3 $ — $ — $ — $ — Guaranteed lease residual values (b) 13 1 1 3 2 2 4 Total commercial commitments $ 19 $ 4 $ 4 $ 3 $ 2 $ 2 $ 4 ACE Surety bonds (a) $ 4 $ 4 $ — $ — $ — $ — $ — Guaranteed lease residual values (b) 7 — 1 1 1 1 3 Total commercial commitments $ 11 $ 4 $ 1 $ 1 $ 1 $ 1 $ 3 __________ (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 $73 million guaranteed by Exelon and PHI, of which $25 million, $30 million, and $18 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 March 31, 2022 and December 31, 2021, 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: March 31, 2022 December 31, 2021 Total environmental Portion of total related to Total environmental Portion of total related to Exelon $ 354 $ 305 $ 352 $ 303 ComEd 279 279 279 279 PECO 21 20 22 20 BGE 7 6 6 4 PHI 42 — 42 — Pepco 40 — 40 — DPL 1 — 1 — ACE 1 — 1 —

Changes in Accumulated Other _2

Changes in Accumulated Other Comprehensive Income (Tables)	3 Months Ended
Changes in Accumulated Other Comprehensive Income (Tables)	Mar. 31, 2022
Changes in Accumulated Other Comprehensive Income [Abstract]
Schedule of Changes in Accumulated Other Comprehensive Income (Loss)	The following tables present changes in Exelon's AOCI, net of tax, by component: Three Months Ended March 31, 2022 Cash Flow Hedges Pension and Non-Pension Postretirement Benefit Plan Items (a) Foreign Total Balance at December 31, 2021 $ (6) $ (2,721) $ (23) $ (2,750) Separation of Constellation 6 1,994 23 2,023 Amounts reclassified from AOCI — 14 — 14 Net current-period OCI — 14 — 14 Balance at March 31, 2022 $ — $ (713) $ — $ (713) Three Months Ended March 31, 2021 Losses on Cash Flow Hedges Pension and Non-Pension Postretirement Benefit Plan Items (a) Foreign Total Balance at December 31, 2020 $ (5) $ (3,372) $ (23) $ (3,400) OCI before reclassifications — (2) 1 (1) Amounts reclassified from AOCI — 55 — 55 Net current-period OCI — 53 1 54 Balance at March 31, 2021 $ (5) $ (3,319) $ (22) $ (3,346) ______
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): Three Months Ended March 31, 2022 2021 Pension and non-pension postretirement benefit plans: Prior service benefit reclassified to periodic benefit cost $ — $ 1 Actuarial loss reclassified to periodic benefit cost (5) (19)

Supplemental Financial Inform_2

Supplemental Financial Information (Tables)	3 Months Ended
Supplemental Financial Information (Tables)	Mar. 31, 2022
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 Three Months Ended March 31, 2022 Utility taxes (a) $ 221 $ 78 $ 38 $ 27 $ 78 $ 70 $ 7 $ 1 Property 94 10 4 46 34 23 10 1 Payroll 37 7 4 4 7 2 1 1 Three Months Ended March 31, 2021 Utility taxes (a) $ 193 $ 59 $ 35 $ 25 $ 74 $ 67 $ 6 $ 1 Property 86 8 4 42 32 21 10 1 Payroll 33 7 4 5 7 2 1 — _________ (a) The Registrants' utility taxes represent 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 Three Months Ended March 31, 2022 AFUDC — Equity $ 36 $ 8 $ 7 $ 6 $ 15 $ 11 $ 2 $ 2 Non-service net periodic benefit cost 17 — — — — — — — Three Months Ended March 31, 2021 AFUDC — Equity $ 28 $ 4 $ 6 $ 7 $ 11 $ 9 $ 1 $ 1 Non-service net periodic benefit cost 20 — — — — — — —
Cash Flow Supplemental Disclosures	The following tables provide additional information about material items recorded in the Registrants' Consolidated Statements of Cash Flows. Depreciation and amortization Exelon (a) ComEd PECO BGE PHI Pepco DPL ACE Three Months Ended March 31, 2022 Property, plant, and equipment (b) $ 726 $ 254 $ 88 $ 117 $ 164 $ 72 $ 45 $ 41 Amortization of regulatory assets (b) 179 67 4 54 54 36 12 6 Amortization of intangible assets, net (b) 6 — — — — — — — Amortization of energy contract assets and liabilities (c) 3 — — — — — — — Nuclear fuel (d) 66 — — — — — — — ARO accretion (e) 44 — — — — — — — Total depreciation, amortization, and accretion $ 1,024 $ 321 $ 92 $ 171 $ 218 $ 108 $ 57 $ 47 Three Months Ended March 31, 2021 Property, plant, and equipment (b) $ 1,522 $ 239 $ 82 $ 106 $ 154 $ 67 $ 42 $ 37 Amortization of regulatory assets (b) 160 53 4 46 56 35 11 10 Amortization of intangible assets, net (b) 15 — — — — — — — Amortization of energy contract assets and liabilities (c) 4 — — — — — — — Nuclear fuel (d) 276 — — — — — — — ARO accretion (e) 127 — — — — — — — Total depreciation, amortization, and accretion $ 2,104 $ 292 $ 86 $ 152 $ 210 $ 102 $ 53 $ 47 __________ (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 the Registrants’ Consolidated Statements of Operations and Comprehensive Income. (d) Included in Purchased fuel expense in Exelon's Consolidated Statement of Operations and Comprehensive Income. (e) Included in Operating and maintenance expense in Exelon's Consolidated Statement of Operations and Comprehensive Income. Other non-cash operating activities Exelon (a) ComEd PECO BGE PHI Pepco DPL ACE Three Months Ended March 31, 2022 Pension and non-pension postretirement benefit costs $ 44 $ 16 $ (2) $ 12 $ 13 $ 2 $ 1 $ 3 Allowance for credit losses 78 17 27 18 18 9 6 3 Other decommissioning-related activity 36 — — — — — — — Energy-related options 60 — — — — — — — True-up adjustments to decoupling mechanisms and formula rates (b) (29) (40) (6) 12 5 7 1 (3) Long-term incentive plan 25 — — — — — — — Amortization of operating ROU asset 23 1 — 7 7 2 2 1 AFUDC — Equity (36) (8) (7) (6) (15) (11) (2) (2) Three Months Ended March 31, 2021 Pension and non-pension postretirement benefit costs $ 95 $ 32 $ 2 $ 14 $ 12 $ 2 $ 1 $ 3 Allowance for credit losses 85 13 24 4 10 5 4 1 Other decommissioning-related activity (322) — — — — — — — Energy-related options 17 — — — — — — — True-up adjustments to decoupling mechanisms and formula rates (b) (129) (54) (10) (18) (46) (26) (9) (11) Long-term incentive plan 32 — — — — — — — Amortization of operating ROU asset 37 — — 7 7 1 3 1 AFUDC — Equity (28) (4) (6) (7) (11) (9) (1) (1) __________ (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 rates. See Note 3 — Regulatory Matters of the Exelon Form 10-K for additional information. The following tables provide a reconciliation of cash, cash equivalents, and restricted cash 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 March 31, 2022 Cash and cash equivalents $ 2,476 $ 343 $ 26 $ 41 $ 796 $ 502 $ 120 $ 168 Restricted cash and cash equivalents 430 246 8 34 106 34 73 — Restricted cash included in other long-term assets 92 92 — — — — — — Total cash, restricted cash, and cash equivalents $ 2,998 $ 681 $ 34 $ 75 $ 902 $ 536 $ 193 $ 168 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 from discontinued operations 582 — — — — — — — Total cash, restricted cash, and cash equivalents $ 1,619 $ 384 $ 44 $ 55 $ 213 $ 68 $ 71 $ 29 March 31, 2021 Cash and cash equivalents $ 1,908 $ 86 $ 48 $ 21 $ 558 $ 134 $ 64 $ 353 Restricted cash and cash equivalents 374 270 7 1 37 33 — 4 Restricted cash included in other long-term assets 52 43 — — 9 — — 9 Total cash, restricted cash, and cash equivalents (a) $ 2,334 $ 399 $ 55 $ 22 $ 604 $ 167 $ 64 $ 366 December 31, 2020 Cash and cash equivalents $ 663 $ 83 $ 19 $ 144 $ 111 $ 30 $ 15 $ 17 Restricted cash and cash equivalents 438 279 7 1 39 35 — 3 Restricted cash included in other long-term assets 53 43 — — 10 — — 10 Cash, restricted cash, and cash equivalents - Held for Sale 12 — — — — — — — Total cash, restricted cash, and cash equivalents (a) $ 1,166 $ 405 $ 26 $ 145 $ 160 $ 65 $ 15 $ 30 __________ (a) Exelon's amounts include amounts related to Generation prior to the separation. See Note 2 — Discontinued Operations for additional information. For additional information on restricted cash see Note 1 — Significant Accounting Policies of the Exelon 2021 Form 10-K.
Supplemental Balance Sheet Disclosures	The following table provides additional information about material items recorded in the Registrants' Consolidated Balance Sheets. Accrued expenses Exelon ComEd PECO BGE PHI Pepco DPL ACE March 31, 2022 Compensation-related accruals (a) $ 370 $ 95 $ 51 $ 48 $ 73 $ 26 $ 15 $ 12 Taxes accrued 258 95 15 78 94 85 10 9 Interest accrued 346 66 36 39 77 37 21 17 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 __________ (a) Primarily includes accrued payroll, bonuses and other incentives, vacation, and benefits.

Related Party Transactions (Tab

Related Party Transactions (Tables)	3 Months Ended
Related Party Transactions (Tables)	Mar. 31, 2022
Related Party Transactions [Abstract]
Operating Revenues and Purchased Power and Fuel	The Utility Registrants incurred expenses from transactions with the Generation affiliate as described in the footnotes to the table below prior to separation on February 1, 2022. 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 : Three Months Ended March 31, 2022 2021 ComEd (a) $ 59 $ 85 PECO (b) 33 42 BGE (c) 18 72 PHI 51 100 Pepco (d) 39 75 DPL (e) 10 21 ACE (f) 2 4 __________ (a) 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. (b) 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. (c) BGE received a portion of its energy requirements from Generation under its MDPSC-approved market-based SOS and gas commodity programs. (d) Pepco received electric supply from Generation under contracts executed through Pepco's competitive procurement process approved by the MDPSC and DCPSC. (e) DPL received a portion of its energy requirements from Generation under its MDPSC and DEPSC approved market-based SOS commodity programs. (f) ACE received electric supply from Generation under contracts executed through ACE's competitive procurement process approved by the NJBPU.
BSC and PHISCO Service Companies	The following table presents the service company costs allocated to the Registrants: Operating and maintenance from affiliates Capitalized costs Three Months Ended March 31, Three Months Ended March 31, 2022 2021 2022 2021 Exelon BSC $ 205 $ 114 PHISCO 19 17 ComEd BSC $ 85 $ 71 85 45 PECO BSC 49 39 36 17 BGE BSC 51 43 38 20 PHI BSC 50 39 46 32 PHISCO 19 17 Pepco BSC 29 22 17 13 PHISCO 29 30 8 7 DPL BSC 18 14 14 10 PHISCO 24 25 6 5 ACE BSC 15 12 15 8 PHISCO 21 22 5 5
Current Receivables From/Payables To Affiliates	The following tables present current receivables from affiliates and current payables to affiliates: March 31, 2022 Receivables from affiliates: Payables to affiliates: ComEd PECO BGE Pepco DPL ACE BSC PHISCO Other Total ComEd $ — $ — $ — $ — $ — $ 64 $ — $ 2 $ 66 PECO $ — — — — — 33 — 5 38 BGE — — — — — 35 — 2 37 PHI — — — — — — 7 1 10 18 Pepco — — — — — 19 15 — 34 DPL — — — — — 3 12 — 15 ACE — — — — — 12 11 — 23 Other 3 — — — — — — — 3 Total $ 3 $ — $ — $ — $ — $ — $ 173 $ 39 $ 19 $ 234 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
Long Term Debt to Financing Trusts	The following table presents Long-term debt to financing trusts: March 31, 2022 December 31, 2021 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 (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Jan. 01, 2021
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Retained earnings/Undistributed earnings (losses)	$ 4,028		$ 16,942
Deferred income taxes and unamortized investment tax credits	11,089		10,611
Net income (loss)	598	$ (264)
Atlantic City Electric Company [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Retained earnings/Undistributed earnings (losses)	(8)		(15)
Deferred income taxes and unamortized investment tax credits	692		682
Net income (loss)	26	14
Pepco Holdings LLC [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Retained earnings/Undistributed earnings (losses)	(182)		(210)
Deferred income taxes and unamortized investment tax credits	2,723		$ 2,675
Net income (loss)	130	128
Atlantic City Electric Company [Member] \| Atlantic City Electric Company [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Retained earnings/Undistributed earnings (losses)				$ 8
Regulatory Liabilities				11
Deferred income taxes and unamortized investment tax credits				$ 3
Net income (loss)		$ 1
Pepco Holdings LLC [Member] \| Pepco Holdings LLC [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Net income (loss)	$ 8

Discontinued Operations and Dis

Discontinued Operations and Disposal Groups (Details) - USD ($) $ in Millions	2 Months Ended	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2022	Feb. 01, 2022	Jan. 31, 2022
Discontinued Operations - Income Statement
Discontinued Operation, Intra-Entity Amounts, Discontinued Operation after Disposal, Expense	$ 56
Exelon Generation Co L L C [Member]
Discontinued Operations - Income Statement
Net assets			$ (11,573)
Discontinued Operation, Intra-Entity Amounts, Discontinued Operation after Disposal, Expense	9
Corporate, Non-Segment [Member]
Discontinued Operations - Income Statement
Common Stock, Shares, Issued			326,663,937
Separation Cash Payment				$ 1,750
Proceeds from Sale and Collection of Notes Receivable		$ 258
Corporate, Non-Segment [Member] \| ShortTermDebtSOFRplus0.75Jan2023
Discontinued Operations - Income Statement
Short-term Bank Loans and Notes Payable	1,150	1,150
Corporate, Non-Segment [Member] \| SMBCTermLoanJuly2023 \| Notes Payable to Banks [Member]
Discontinued Operations - Income Statement
Debt Instrument, Face Amount	300	300
Corporate, Non-Segment [Member] \| USBTermLoanJuly2023 \| Notes Payable to Banks [Member]
Discontinued Operations - Income Statement
Debt Instrument, Face Amount	300	300
Corporate, Non-Segment [Member] \| PNCTermLoanJuly2023 \| Notes Payable to Banks [Member]
Discontinued Operations - Income Statement
Debt Instrument, Face Amount	$ 250	$ 250

Discontinued Operations and D_2

Discontinued Operations and Disposal Groups (Details) - Income Statement - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Discontinued Operations - Income Statement
Revenue from Related Parties	$ 6	$ 7
Operating and maintenance	1,178	1,083
Cost, Depreciation and Amortization	817	757
Taxes, Miscellaneous	354	317
Costs and Expenses	4,427	3,808
Other, net	137	58
Nonoperating Income (Expense)	(201)	(260)
Income taxes	218	39
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	117	(789)
Net income (loss) attributable to noncontrolling interests	1	25
Net Income (Loss) from Discontinued Operations Available to Common Shareholders, Basic	116	(814)
Total transaction and transition costs incurred related to the Separation	52	3
Total transaction costs relating to the Separation	19
Exelon Generation Co L L C [Member]
Discontinued Operations - Income Statement
Revenue from Contract with Customer, Including Assessed Tax	1,855	5,265
Revenue from Related Parties	161	294
Disposal Group, Including Discontinued Operation, Revenue	2,016	5,559
Purchased power and/or fuel	1,138	4,610
Operating and maintenance	371	904
Cost, Depreciation and Amortization	94	940
Taxes, Miscellaneous	44	121
Costs and Expenses	1,647	6,575
Gain (Loss) on Disposition of Assets	10	71
Disposal Group, Including Discontinued Operation, Operating Income (Loss)	379	(945)
Disposal Group, Including Discontinued Operation, Interest Expense	(20)	(68)
Other, net	(281)	167
Nonoperating Income (Expense)	(301)	99
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax	78	(846)
Income taxes	(40)	(58)
Income (Loss) from Equity Method Investments	(1)	(1)
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	117	(789)
Net income (loss) attributable to noncontrolling interests	1	25
Net Income (Loss) from Discontinued Operations Available to Common Shareholders, Basic	116	(814)
Total transition costs relating to the Separation	2	1
Total transaction costs relating to the Separation	$ 50	$ 2

Discontinued Operations and D_3

Discontinued Operations and Disposal Groups (Details) - Balance Sheet - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Discontinued Operations - Income Statement
Restricted cash	$ 430	$ 321	$ 374	$ 438
Customer accounts receivable	2,365	2,189
Accounts Receivable, Allowance for Credit Loss, Current	(389)	(320)
Other accounts receivable	1,148	1,068
Allowance for Credit Loss, Receivable, Other, Current	(81)	(72)
Other Receivables, Net, Current	1,067	996
Fossil fuel and emission allowances	39	105
Materials and supplies inventory, net	473	476
Current assets of discontinued operations	0	7,835
Accumulated depreciation and amortization	14,878	14,430
Investments	244	250
Other Assets, Noncurrent	1,045	885
Property, plant, and equipment, deferred debits, and other assets of discontinued operations	0	38,509
Assets	92,698	133,013
Short-term Debt	1,900	1,248
Long-term Debt and Lease Obligation, Current	2,154	2,153
Mark-to-market derivative liabilities (current liabilities)	0	18
Current liabilities of discontinued operations	0	7,940
Long-term Debt, Excluding Current Maturities	35,008	30,749
Deferred income taxes and unamortized investment tax credits	11,089	10,611
Asset retirement obligations, noncurrent	273	271
Derivative Liability, Noncurrent	144	201
Other	2,187	1,573
Long-term debt, deferred credits, and other liabilities of discontinued operations	0	25,676
Liabilities	$ 69,207	98,218
Exelon Generation Co L L C [Member]
Discontinued Operations - Income Statement
Disposal Group, Including Discontinued Operation, Cash and Cash Equivalents		510
Restricted cash		72
Customer accounts receivable		1,724
Accounts Receivable, Allowance for Credit Loss, Current		(55)
Disposal Group, Including Discontinued Operation, Accounts, Notes and Loans Receivable, Net		1,669
Other accounts receivable		596
Allowance for Credit Loss, Receivable, Other, Current		(4)
Other Receivables, Net, Current		592
Mark-to-market derivative assets, current		2,169
Fossil fuel and emission allowances		284
Materials and supplies inventory, net		1,004
Renewable energy credits, current		529
Disposal Group, Including Discontinued Operations, Assets, Current - Assets held for sale		13
Disposal Group, Including Discontinued Operation, Other Assets, Current		993
Current assets of discontinued operations		7,835
Accumulated depreciation and amortization		15,888
Disposal Group, Including Discontinued Operation, Property, Plant and Equipment, Noncurrent		19,661
Nuclear decommissioning trust funds		15,938
Investments		193
Derivative Asset, Noncurrent		949
Other Assets, Noncurrent		1,768
Property, plant, and equipment, deferred debits, and other assets of discontinued operations		38,509
Assets		46,344
Short-term Debt		2,082
Long-term Debt and Lease Obligation, Current		1,220
Disposal Group, Including Discontinued Operation, Accounts Payable, Current		1,757
Disposal Group, Including Discontinued Operation, Accrued Liabilities, Current		818
Mark-to-market derivative liabilities (current liabilities)		981
Energy Marketing Accounts Payable		779
Disposal Group, Including Discontinued Operations, Assets, Current - Liabilities held for sale		3
Disposal Group, Including Discontinued Operation, Other Liabilities, Current		300
Current liabilities of discontinued operations		7,940
Long-term Debt, Excluding Current Maturities		4,575
Deferred income taxes and unamortized investment tax credits		3,583
Asset retirement obligations, noncurrent		12,819
Disposal Group, Including Discontinued Operation, Pension Plan Benefit Obligation, Noncurrent		939
Disposal Group, Including Discontinued Operation, Postretirement Plan Benefit Obligation, Noncurrent		876
Spent Nuclear Fuel Obligation, Noncurrent		1,210
Derivative Liability, Noncurrent		513
Other		1,161
Long-term debt, deferred credits, and other liabilities of discontinued operations		25,676
Liabilities		$ 33,616

Discontinued Operations and D_4

Discontinued Operations and Disposal Groups (Details) - Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Discontinued Operations - Income Statement
Depreciation, Amortization and Accretion, Net	$ 1,024	$ 2,104
Gain (Loss) on Sale of Assets and Asset Impairment Charges	(10)	(71)
Deferred income taxes and amortization of investment tax credits	110	(142)
Net fair value changes related to derivatives	(59)	(178)
Net realized and unrealized (gains) losses on NDT funds	205	(118)
Net unrealized (gains) losses on equity investments	16	23
Other non-cash operating activities	(232)	170
Payments to Acquire Property, Plant, and Equipment	(1,922)	(2,140)
Collection of deferred purchase price	169	1,574
Decrease in capital expenditures not paid	(322)	(324)
Increase in deferred purchase price	348	1,339
Increase in PPE related to ARO update	(335)	2
Exelon Generation Co L L C [Member]
Discontinued Operations - Income Statement
Depreciation, Amortization and Accretion, Net	207	1,346
Gain (Loss) on Sale of Assets and Asset Impairment Charges	9	(71)
Deferred income taxes and amortization of investment tax credits	(143)	(234)
Net fair value changes related to derivatives	(59)	(178)
Net realized and unrealized (gains) losses on NDT funds	205	(118)
Net unrealized (gains) losses on equity investments	16	23
Other non-cash operating activities	36	(332)
Payments to Acquire Property, Plant, and Equipment	(227)	(394)
Collection of deferred purchase price	169	1,574
Decrease in capital expenditures not paid	(128)	(37)
Increase in deferred purchase price	348	1,339
Increase in PPE related to ARO update	$ 335	$ 0

Mergers, Acquisitions, and Di_2

Mergers, Acquisitions, and Dispositions - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Business Dispositions
Gain (Loss) on Sale of Assets and Asset Impairment Charges	$ 10	$ 71

Regulatory Matters - Narrative

Regulatory Matters - Narrative (Details) $ in Millions	3 Months Ended
Regulatory Matters - Narrative (Details) $ in Millions	Mar. 31, 2022USD ($)
PECO Energy Co [Member]
Regulatory Matters Additional Narrative Information [Line Items]
Increase (Decrease) in Regulatory Assets	$ 66
Increase (Decrease) in Regulatory Liabilities	(112)
PECO Energy Co [Member] \| Nuclear Decommissioning [Member]
Regulatory Matters Additional Narrative Information [Line Items]
Increase (Decrease) in Regulatory Liabilities	(111)
PECO Energy Co [Member] \| Deferred Income Tax Charge [Member]
Regulatory Matters Additional Narrative Information [Line Items]
Increase (Decrease) in Regulatory Assets	60
Baltimore Gas and Electric Company [Member]
Regulatory Matters Additional Narrative Information [Line Items]
Increase (Decrease) in Regulatory Assets	(50)
Increase (Decrease) in Regulatory Liabilities	(53)
Baltimore Gas and Electric Company [Member] \| Deferred Income Tax Charge [Member]
Regulatory Matters Additional Narrative Information [Line Items]
Increase (Decrease) in Regulatory Liabilities	(65)
Baltimore Gas and Electric Company [Member] \| Electric Energy and Natural Gas Cost [Member]
Regulatory Matters Additional Narrative Information [Line Items]
Increase (Decrease) in Regulatory Assets	(19)
Baltimore Gas and Electric Company [Member] \| Energy Efficiency and Demand Response Programs
Regulatory Matters Additional Narrative Information [Line Items]
Increase (Decrease) in Regulatory Assets	(16)
Atlantic City Electric Company [Member]
Regulatory Matters Additional Narrative Information [Line Items]
Contract Termination Liability	203
Increase (Decrease) in Regulatory Assets	205
Increase (Decrease) in Regulatory Liabilities	(19)
Atlantic City Electric Company [Member] \| Other Current Liabilities
Regulatory Matters Additional Narrative Information [Line Items]
Contract Termination Liability	85
Atlantic City Electric Company [Member] \| Other Noncurrent Liabilities
Regulatory Matters Additional Narrative Information [Line Items]
Contract Termination Liability	118
Atlantic City Electric Company [Member] \| Deferred Income Tax Charge [Member]
Regulatory Matters Additional Narrative Information [Line Items]
Increase (Decrease) in Regulatory Liabilities	(9)
Atlantic City Electric Company [Member] \| Electric Transmission Formula Rate Annual Reconciliations [Member]
Regulatory Matters Additional Narrative Information [Line Items]
Increase (Decrease) in Regulatory Liabilities	$ (5)

Regulatory Matters - Schedule o

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

Mar. 02, 2022

Feb. 23, 2022

Dec. 23, 2021

Dec. 22, 2021

Dec. 01, 2021

Nov. 18, 2021

Jul. 14, 2021

Jun. 28, 2021

Jun. 08, 2021

Apr. 16, 2021

Mar. 31, 2021

Mar. 30, 2021

Feb. 26, 2021

Dec. 16, 2020

Sep. 11, 2020

Jun. 01, 2020

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

Regulatory Matters Completed Rate Cases [Line Items]

Requested Revenue Requirement Increase (Decrease)

$ 51

Approved Revenue Requirement Increase (Decrease)

$ 46

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]

Approved Revenue Requirement Increase (Decrease)

$ 37

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 Reconciliation | 2020

Regulatory Matters Completed Rate Cases [Line Items]

Approved Return on Equity, Percentage

7.29%

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

$ 9

Public Utilities, Approved Equity Capital Structure, Percentage

5.69%

Basis points for ComEd's Revenue Requirement

580

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

Regulatory Matters Completed Rate Cases [Line Items]

Basis points for ComEd's Revenue Requirement

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

Regulatory Matters Completed Rate Cases [Line Items]

Requested Revenue Requirement Increase (Decrease)

$ 246

Approved Revenue Requirement Increase (Decrease)

$ 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

Approved Revenue Requirement Increase (Decrease)

$ 140

Approved Return on Equity, Percentage

9.50%

Baltimore Gas and Electric Company [Member] | Maryland 2020 Electric Distribution Base Rate Case [Member] | 2021

Regulatory Matters Completed Rate Cases [Line Items]

Approved Revenue Requirement Increase (Decrease)

$ 59

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

Regulatory Matters Completed Rate Cases [Line Items]

Approved Revenue Requirement Increase (Decrease)

Baltimore Gas and Electric Company [Member] | Maryland 2020 Electric Distribution Base Rate Case [Member] | 2023

Regulatory Matters Completed Rate Cases [Line Items]

Approved Revenue Requirement Increase (Decrease)

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

Regulatory Matters Completed Rate Cases [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Percentage

25.00%

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

Approved Revenue Requirement Increase (Decrease)

$ 74

Approved Return on Equity, Percentage

9.65%

Baltimore Gas and Electric Company [Member] | Maryland 2020 Gas Distribution Base Rate Case [Member] | 2021

Regulatory Matters Completed Rate Cases [Line Items]

Approved Revenue Requirement Increase (Decrease)

$ 53

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

Regulatory Matters Completed Rate Cases [Line Items]

Approved Revenue Requirement Increase (Decrease)

Baltimore Gas and Electric Company [Member] | Maryland 2020 Gas Distribution Base Rate Case [Member] | 2023

Regulatory Matters Completed Rate Cases [Line Items]

Approved Revenue Requirement Increase (Decrease)

$ 10

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

Regulatory Matters Completed Rate Cases [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Percentage

50.00%

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

Approved Revenue Requirement Increase (Decrease)

$ 52

Approved Return on Equity, Percentage

9.55%

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

Regulatory Matters Completed Rate Cases [Line Items]

Approved Revenue Requirement Increase (Decrease)

$ 21

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

Regulatory Matters Completed Rate Cases [Line Items]

Approved Revenue Requirement Increase (Decrease)

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

Regulatory Matters Completed Rate Cases [Line Items]

Approved Revenue Requirement Increase (Decrease)

$ 15

Potomac Electric Power Company [Member] | Maryland 2020 Electric Distribution Base Rate Case [Member] | Offsets | 2022

Regulatory Matters Completed Rate Cases [Line Items]

Public Utilities, Approved Rate Increase (Decrease), Percentage

25.00%

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

Regulatory Matters Completed Rate Cases [Line Items]

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

$ 136

Approved Revenue Requirement Increase (Decrease)

$ 109

Approved Return on Equity, Percentage

9.275%

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

Regulatory Matters Completed Rate Cases [Line Items]

Approved Revenue Requirement Increase (Decrease)

$ 42

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

Regulatory Matters Completed Rate Cases [Line Items]

Approved Revenue Requirement Increase (Decrease)

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

Regulatory Matters Completed Rate Cases [Line Items]

Approved Revenue Requirement Increase (Decrease)

(22)

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

Regulatory Matters Completed Rate Cases [Line Items]

Approved Revenue Requirement Increase (Decrease)

$ (40)

Delmarva Power and Light Company [Member] | Maryland 2021 Electric Distribution Base Rate Case

Regulatory Matters Completed Rate Cases [Line Items]

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

$ 27

Approved Revenue Requirement Increase (Decrease)

$ 13

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

Approved Revenue Requirement Increase (Decrease)

$ 41

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]

Approved Revenue Requirement Increase (Decrease)

$ 11

Regulatory Matters - Schedule_2

Regulatory Matters - Schedule of Pending Rate Cases (Details) - USD ($) $ in Millions	Apr. 15, 2022	Mar. 31, 2022	Feb. 28, 2022
Commonwealth Edison Co [Member] \| Illinois 2022 Electric Distribution Base Rate Case
Regulatory Matters Pending Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)	$ 199
Commonwealth Edison Co [Member] \| Illinois 2022 Electric Distribution Base Rate Case \| 2023
Regulatory Matters Pending Rate Cases [Line Items]
Requested Return on Equity, Percentage	7.85%
Public Utilities, Requested Rate Increase (Decrease), Initial Revenue Requirement, Amount	$ 144
Requested Return on Distribution Rate Base, Percentage	5.94%
Basis points for ComEd's Revenue Requirement	580
Commonwealth Edison Co [Member] \| Illinois 2022 Electric Distribution Base Rate Case \| 2021
Regulatory Matters Pending Rate Cases [Line Items]
Requested Return on Equity, Percentage	7.78%
Public Utilities Requested Rate Increase (Decrease), Prior Year Annual Reconciliation	$ 55
Requested Return on Distribution Rate Base, Percentage	5.91%
Basis points for ComEd's Revenue Requirement	580
Commonwealth Edison Co [Member] \| Illinois 2022 Electric Distribution Base Rate Case \| Performance Metrics Penalty \| 2021
Regulatory Matters Pending Rate Cases [Line Items]
Basis points for ComEd's Revenue Requirement	7
PECO Energy Co [Member] \| Pennsylvania 2022 Natural Gas Distribution Base Rate Case
Regulatory Matters Pending Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)		$ 82
Requested Return on Equity, Percentage		10.95%
Delmarva Power and Light Company [Member] \| Delaware 2022 Natural Gas Distribution Base Rate Case
Regulatory Matters Pending Rate Cases [Line Items]
Requested Revenue Requirement Increase (Decrease)			$ 15
Requested Return on Equity, Percentage			10.30%

Regulatory Matters - Annual Ele

Regulatory Matters - Annual Electric Transmission Fillings (Details) - USD ($) $ in Millions	Apr. 29, 2022	Apr. 27, 2022
Commonwealth Edison Co [Member] \| 2022 Transmission Formula Rate Annual Update [Domain]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount	$ 24
Annual Reconciliation Increase	(24)
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount	$ 0
Public Utilities, Approved Equity Capital Structure, Percentage	8.11%
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	55.00%
Basis points for Transmission Formula Rate	50
Baltimore Gas and Electric Company [Member] \| 2022 Transmission Formula Rate Annual Update [Domain]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amount		$ 25
Annual Reconciliation Increase		(4)
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount		$ 16
Public Utilities, Approved Equity Capital Structure, Percentage		7.30%
Public Utilities, Approved Return on Equity, Percentage		10.50%
Basis points for Transmission Formula Rate		50
Baltimore Gas and Electric Company [Member] \| 2022 Transmission Formula Rate Revenue Reduction
Public Utilities, General Disclosures [Line Items]
Public Utilities, Requested Rate Increase (Decrease), Amended, Amount		$ 5

Regulatory Matters - Capitalize

Regulatory Matters - Capitalized Ratemaking Amount Not Recognized (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Amount of Allowance for Earnings on Equity Capitalized for Rate Making Purposes	$ 49	$ 43
Commonwealth Edison Co [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Amount of Allowance for Earnings on Equity Capitalized for Rate Making Purposes	2	1
PECO Energy Co [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Amount of Allowance for Earnings on Equity Capitalized for Rate Making Purposes	0	0
Baltimore Gas and Electric Company [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Amount of Allowance for Earnings on Equity Capitalized for Rate Making Purposes	34	37
Pepco Holdings LLC [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Amount of Allowance for Earnings on Equity Capitalized for Rate Making Purposes	13	5
Potomac Electric Power Company [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Amount of Allowance for Earnings on Equity Capitalized for Rate Making Purposes	11	3
Delmarva Power and Light Company [Member]
Public Utility, Property, Plant and Equipment [Line Items]
Public Utilities, Amount of Allowance for Earnings on Equity Capitalized for Rate Making Purposes	2	2
Atlantic City Electric Company [Member]
Public Utility, Property, Plant and Equipment [Line Items]
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 - Performance Obligations (Details) $ in Millions	Mar. 31, 2022USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 107
Pepco Holdings LLC [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	107
Potomac Electric Power Company [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	85
Delmarva Power and 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]: 2022-04-01
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	9 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-04-01 \| 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	9 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-04-01 \| Potomac Electric Power Company [Member]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 4
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	9 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-04-01 \| Delmarva Power and 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	9 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-04-01 \| 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	9 months
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 \| 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 and 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 \| 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 and 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 \| 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 and 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 \| 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 and 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)	3 Months Ended
Segment Information - Narrative (Details)	Mar. 31, 2022Reportable_segment
Segment Reporting Information [Line Items]
Number of reportable segments	6
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	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Segment Reporting Information [Line Items]
Revenues	$ 5,327	$ 4,632
Revenue from Related Parties	6	7
Depreciation and Amortization	817	757
Operating Expenses	4,427	3,808
Interest expense, net	338	318
Income (Loss) before income taxes	699	564
Income taxes	218	39
Net income (loss)	598	(264)
Capital expenditures	1,922	2,140
Assets	92,698		$ 133,013
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	481	525
Other Segments
Segment Reporting Information [Line Items]
Assets			86,677
Continuing Operations
Segment Reporting Information [Line Items]
Capital expenditures	1,695	1,746
Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenues	1,404	1,244
Revenue from Related Parties	3	3
Income (Loss) before income taxes	137	136
Income taxes	7	8
Net income (loss)	130	128
Capital expenditures	409	456
Assets	25,636		24,744
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenues	(588)	(501)
Revenue from Related Parties	(587)	(497)
Depreciation and Amortization	0	0
Operating Expenses	(531)	(339)
Interest expense, net	0	0
Income (Loss) before income taxes	(43)	(149)
Income taxes	(10)	(12)
Capital expenditures	0	0
Assets	(4,156)		(8,319)
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	(33)	(137)
Intersegment Eliminations [Member] \| Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenues	(97)	(96)
Revenue from Related Parties	(97)	(96)
Depreciation and Amortization	0	0
Operating Expenses	(97)	(96)
Interest expense, net	0	0
Income (Loss) before income taxes	0	0
Income taxes	0	0
Net income (loss)	0	0
Capital expenditures	0	0
Assets	(44)		(60)
Commonwealth Edison Co [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	1,734	1,535
Depreciation and Amortization	321	292
Operating Expenses	1,406	1,210
Interest expense, net	100	96
Income (Loss) before income taxes	240	236
Income taxes	52	39
Capital expenditures	617	613
Assets	37,013		36,470
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	188	197
Commonwealth Edison Co [Member] \| Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue from Related Parties	6	6
PECO Energy Co [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	1,047	889
Depreciation and Amortization	92	86
Operating Expenses	793	679
Interest expense, net	41	38
Income (Loss) before income taxes	220	177
Income taxes	14	10
Capital expenditures	344	295
Assets	14,113		13,824
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	206	167
PECO Energy Co [Member] \| Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue from Related Parties	1	2
Baltimore Gas and Electric Company [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	1,154	974
Depreciation and Amortization	171	152
Operating Expenses	919	752
Interest expense, net	35	34
Income (Loss) before income taxes	207	196
Income taxes	9	(13)
Capital expenditures	303	336
Assets	12,509		12,324
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	198	209
Baltimore Gas and Electric Company [Member] \| Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue from Related Parties	7	6
Pepco Holdings LLC [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	1,404	1,244
Depreciation and Amortization	218	210
Operating Expenses	1,215	1,058
Interest expense, net	69	67
Income (Loss) before income taxes	137	136
Income taxes	7	8
Net income (loss)	130	128
Capital expenditures	409	456
Assets	25,636		24,744
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	130	128
Pepco Holdings LLC [Member] \| Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue from Related Parties	3	3
Potomac Electric Power Company [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	614	553
Depreciation and Amortization	108	102
Operating Expenses	547	466
Interest expense, net	36	34
Income (Loss) before income taxes	44	65
Income taxes	(2)	6
Net income (loss)	46	59
Capital expenditures	218	220
Assets	10,458		9,903
Potomac Electric Power Company [Member] \| Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue from Related Parties	1	1
Delmarva Power and Light Company [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	431	382
Depreciation and Amortization	57	53
Operating Expenses	357	309
Interest expense, net	16	15
Income (Loss) before income taxes	60	61
Income taxes	4	5
Net income (loss)	56	56
Capital expenditures	103	112
Assets	5,573		5,412
Delmarva Power and Light Company [Member] \| Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue from Related Parties	1	2
Atlantic City Electric Company [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenues	349	310
Depreciation and Amortization	47	47
Operating Expenses	311	282
Interest expense, net	14	15
Income (Loss) before income taxes	27	14
Income taxes	1	0
Net income (loss)	26	14
Capital expenditures	87	123
Assets	4,929		4,556
Atlantic City Electric Company [Member] \| Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue from Related Parties	1	1
Corporate and Other [Member] \| Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Revenues	576	491
Depreciation and Amortization	15	17
Operating Expenses	625	448
Interest expense, net	93	83
Income (Loss) before income taxes	(62)	(32)
Income taxes	146	7
Capital expenditures	22	46
Assets	7,583		7,634
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	(208)	(39)
Corporate and Other [Member] \| Corporate, Non-Segment [Member] \| Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenues	107	95
Depreciation and Amortization	6	8
Operating Expenses	97	97
Interest expense, net	3	3
Income (Loss) before income taxes	6	(4)
Income taxes	4	(3)
Net income (loss)	2	(1)
Capital expenditures	1	1
Assets	4,720		$ 4,933
Corporate and Other [Member] \| Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue from Related Parties	576	487
Corporate and Other [Member] \| Intersegment Eliminations [Member] \| Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Related Parties	97	95
Rate-regulated electric revenues [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	4,522	3,991
Rate-regulated electric revenues [Member] \| Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,323	1,124
Rate-regulated electric revenues [Member] \| Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	(7)	(7)
Rate-regulated electric revenues [Member] \| Intersegment Eliminations [Member] \| Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	7	(4)
Rate-regulated electric revenues [Member] \| Commonwealth Edison Co [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,734	1,535
Rate-regulated electric revenues [Member] \| PECO Energy Co [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	741	661
Rate-regulated electric revenues [Member] \| Baltimore Gas and Electric Company [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	736	632
Rate-regulated electric revenues [Member] \| Pepco Holdings LLC [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,318	1,170
Rate-regulated electric revenues [Member] \| Potomac Electric Power Company [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	614	553
Rate-regulated electric revenues [Member] \| Delmarva Power and Light Company [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	348	311
Rate-regulated electric revenues [Member] \| Atlantic City Electric Company [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	349	310
Rate-regulated electric revenues [Member] \| Corporate and Other [Member] \| Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Rate-regulated electric revenues [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
Rate-regulated natural gas revenues [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	805	641
Rate-regulated natural gas revenues [Member] \| Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	83	71
Rate-regulated natural gas revenues [Member] \| Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	(2)	0
Rate-regulated natural gas revenues [Member] \| Intersegment Eliminations [Member] \| Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Rate-regulated natural gas revenues [Member] \| Commonwealth Edison Co [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Rate-regulated natural gas revenues [Member] \| PECO Energy Co [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	306	228
Rate-regulated natural gas revenues [Member] \| Baltimore Gas and Electric Company [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	418	342
Rate-regulated natural gas revenues [Member] \| Pepco Holdings LLC [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	83	71
Rate-regulated natural gas revenues [Member] \| Potomac Electric Power Company [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Rate-regulated natural gas revenues [Member] \| Delmarva Power and Light Company [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	83	71
Rate-regulated natural gas revenues [Member] \| Atlantic City Electric Company [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Rate-regulated natural gas revenues [Member] \| Corporate and Other [Member] \| Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Rate-regulated natural gas revenues [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
Shared service and other revenues [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Shared service and other revenues [Member] \| Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	(579)	(494)
Shared service and other revenues [Member] \| Intersegment Eliminations [Member] \| Pepco Holdings LLC [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	(104)	(92)
Shared service and other revenues [Member] \| Commonwealth Edison Co [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Shared service and other revenues [Member] \| PECO Energy Co [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Shared service and other revenues [Member] \| Baltimore Gas and Electric Company [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Shared service and other revenues [Member] \| Pepco Holdings LLC [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	3	3
Shared service and other revenues [Member] \| Potomac Electric Power Company [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Shared service and other revenues [Member] \| Delmarva Power and Light Company [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Shared service and other revenues [Member] \| Atlantic City Electric Company [Member] \| Operating Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Shared service and other revenues [Member] \| Corporate and Other [Member] \| Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	576	491
Shared service and other revenues [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	$ 107	$ 95

Segment Information - Electric

Segment Information - Electric and Gas Revenue by Customer Class (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Revenue, Major Customer [Line Items]
Revenues	$ 5,327	$ 4,632
Revenue from Related Parties	6	7
Commonwealth Edison Co [Member]
Revenue, Major Customer [Line Items]
Revenues	1,734	1,535
Revenue from Related Parties	6	6
Commonwealth Edison Co [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenues	1,686	1,473
Commonwealth Edison Co [Member] \| Other Regulated Revenue [Member]
Revenue, Major Customer [Line Items]
Revenues	48	62
PECO Energy Co [Member]
Revenue, Major Customer [Line Items]
Revenues	1,047	889
Revenue from Related Parties	1	2
PECO Energy Co [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenues	1,037	879
PECO Energy Co [Member] \| Other Regulated Revenue [Member]
Revenue, Major Customer [Line Items]
Revenues	10	10
Baltimore Gas and Electric Company [Member]
Revenue, Major Customer [Line Items]
Revenues	1,154	974
Revenue from Related Parties	7	6
Baltimore Gas and Electric Company [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenues	1,160	956
Baltimore Gas and Electric Company [Member] \| Other Regulated Revenue [Member]
Revenue, Major Customer [Line Items]
Revenues	(6)	18
Pepco Holdings LLC [Member]
Revenue, Major Customer [Line Items]
Revenues	1,404	1,244
Revenue from Related Parties	3	3
Pepco Holdings LLC [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenues	1,408	1,198
Pepco Holdings LLC [Member] \| Other Regulated Revenue [Member]
Revenue, Major Customer [Line Items]
Revenues	(4)	46
Potomac Electric Power Company [Member]
Revenue, Major Customer [Line Items]
Revenues	614	553
Revenue from Related Parties	1	1
Potomac Electric Power Company [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenues	620	527
Potomac Electric Power Company [Member] \| Other Regulated Revenue [Member]
Revenue, Major Customer [Line Items]
Revenues	(6)	26
Delmarva Power and Light Company [Member]
Revenue, Major Customer [Line Items]
Revenues	431	382
Revenue from Related Parties	1	2
Delmarva Power and Light Company [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenues	432	373
Delmarva Power and Light Company [Member] \| Other Regulated Revenue [Member]
Revenue, Major Customer [Line Items]
Revenues	(1)	9
Atlantic City Electric Company [Member]
Revenue, Major Customer [Line Items]
Revenues	349	310
Revenue from Related Parties	1	1
Atlantic City Electric Company [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenues	346	299
Atlantic City Electric Company [Member] \| Other Regulated Revenue [Member]
Revenue, Major Customer [Line Items]
Revenues	3	11
Rate-regulated electric revenues [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	4,522	3,991
Rate-regulated electric revenues [Member] \| Commonwealth Edison Co [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,688	1,475
Rate-regulated electric revenues [Member] \| Commonwealth Edison Co [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,686	1,473
Revenue from Related Parties	6	6
Rate-regulated electric revenues [Member] \| Commonwealth Edison Co [Member] \| Regulated Operation [Member] \| Operating Segment [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	8	8
Rate-regulated electric revenues [Member] \| Commonwealth Edison Co [Member] \| Regulated Operation [Member] \| Residential [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	857	741
Rate-regulated electric revenues [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	423	367
Rate-regulated electric revenues [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	153	134
Rate-regulated electric revenues [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	14	11
Rate-regulated electric revenues [Member] \| Commonwealth Edison Co [Member] \| Regulated Operation [Member] \| Other [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	239	220
Rate-regulated electric revenues [Member] \| PECO Energy Co [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	734	649
Rate-regulated electric revenues [Member] \| PECO Energy Co [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	732	651
Revenue from Related Parties	1	1
Rate-regulated electric revenues [Member] \| PECO Energy Co [Member] \| Regulated Operation [Member] \| Operating Segment [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	3	0
Rate-regulated electric revenues [Member] \| PECO Energy Co [Member] \| Regulated Operation [Member] \| Residential [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	487	433
Rate-regulated electric revenues [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	111	100
Rate-regulated electric revenues [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	64	57
Rate-regulated electric revenues [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	8	9
Rate-regulated electric revenues [Member] \| PECO Energy Co [Member] \| Regulated Operation [Member] \| Other [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	62	52
Rate-regulated electric revenues [Member] \| Baltimore Gas and Electric Company [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	735	620
Rate-regulated electric revenues [Member] \| Baltimore Gas and Electric Company [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	733	620
Revenue from Related Parties	2	2
Rate-regulated electric revenues [Member] \| Baltimore Gas and Electric Company [Member] \| Regulated Operation [Member] \| Operating Segment [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	4	0
Rate-regulated electric revenues [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	417	362
Rate-regulated electric revenues [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	81	69
Rate-regulated electric revenues [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	131	105
Rate-regulated electric revenues [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	7	7
Rate-regulated electric revenues [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	97	77
Rate-regulated electric revenues [Member] \| Pepco Holdings LLC [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,323	1,124
Rate-regulated electric revenues [Member] \| Pepco Holdings LLC [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1,325	1,127
Revenue from Related Parties	3	3
Rate-regulated electric revenues [Member] \| Pepco Holdings LLC [Member] \| Regulated Operation [Member] \| Operating Segment [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1	0
Rate-regulated electric revenues [Member] \| Pepco Holdings LLC [Member] \| Regulated Operation [Member] \| Residential [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	652	605
Rate-regulated electric revenues [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	141	118
Rate-regulated electric revenues [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	323	248
Rate-regulated electric revenues [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	16	13
Rate-regulated electric revenues [Member] \| Pepco Holdings LLC [Member] \| Regulated Operation [Member] \| Other [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	193	143
Rate-regulated electric revenues [Member] \| Potomac Electric Power Company [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	620	526
Rate-regulated electric revenues [Member] \| Potomac Electric Power Company [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	620	527
Revenue from Related Parties	1	1
Rate-regulated electric revenues [Member] \| Potomac Electric Power Company [Member] \| Regulated Operation [Member] \| Operating Segment [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1	0
Rate-regulated electric revenues [Member] \| Potomac Electric Power Company [Member] \| Regulated Operation [Member] \| Residential [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	275	253
Rate-regulated electric revenues [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	38	33
Rate-regulated electric revenues [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	253	184
Rate-regulated electric revenues [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	8	6
Rate-regulated electric revenues [Member] \| Potomac Electric Power Company [Member] \| Regulated Operation [Member] \| Other [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	46	51
Rate-regulated electric revenues [Member] \| Delmarva Power and Light Company [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	348	300
Rate-regulated electric revenues [Member] \| Delmarva Power and Light Company [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	349	302
Revenue from Related Parties	2	2
Rate-regulated electric revenues [Member] \| Delmarva Power and Light Company [Member] \| Regulated Operation [Member] \| Operating Segment [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Rate-regulated electric revenues [Member] \| Delmarva Power and Light Company [Member] \| Regulated Operation [Member] \| Residential [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	207	190
Rate-regulated electric revenues [Member] \| Delmarva Power and Light Company [Member] \| Regulated Operation [Member] \| Small Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	56	46
Rate-regulated electric revenues [Member] \| Delmarva Power and Light Company [Member] \| Regulated Operation [Member] \| Large Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	26	21
Rate-regulated electric revenues [Member] \| Delmarva Power and Light Company [Member] \| Regulated Operation [Member] \| Public Authorities & Electric Railroads [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	4	4
Rate-regulated electric revenues [Member] \| Delmarva Power and Light Company [Member] \| Regulated Operation [Member] \| Other [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	56	41
Rate-regulated electric revenues [Member] \| Atlantic City Electric Company [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	345	298
Rate-regulated electric revenues [Member] \| Atlantic City Electric Company [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	346	299
Revenue from Related Parties	1	1
Rate-regulated electric revenues [Member] \| Atlantic City Electric Company [Member] \| Regulated Operation [Member] \| Operating Segment [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Rate-regulated electric revenues [Member] \| Atlantic City Electric Company [Member] \| Regulated Operation [Member] \| Residential [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	170	162
Rate-regulated electric revenues [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	47	39
Rate-regulated electric revenues [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	44	43
Rate-regulated electric revenues [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	4	3
Rate-regulated electric revenues [Member] \| Atlantic City Electric Company [Member] \| Regulated Operation [Member] \| Other [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	81	52
Rate-regulated natural gas revenues [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	805	641
Rate-regulated natural gas revenues [Member] \| Commonwealth Edison Co [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Rate-regulated natural gas revenues [Member] \| Commonwealth Edison Co [Member] \| Regulated Operation [Member] \| Operating Segment [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0
Rate-regulated natural gas revenues [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
Rate-regulated natural gas revenues [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
Rate-regulated natural gas revenues [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
Rate-regulated natural gas revenues [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
Rate-regulated natural gas revenues [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
Rate-regulated natural gas revenues [Member] \| PECO Energy Co [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	306	228
Rate-regulated natural gas revenues [Member] \| PECO Energy Co [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	305	228
Revenue from Related Parties	0	0
Rate-regulated natural gas revenues [Member] \| PECO Energy Co [Member] \| Regulated Operation [Member] \| Operating Segment [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	1
Rate-regulated natural gas revenues [Member] \| PECO Energy Co [Member] \| Regulated Operation [Member] \| Residential [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	218	160
Rate-regulated natural gas revenues [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	76	59
Rate-regulated natural gas revenues [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
Rate-regulated natural gas revenues [Member] \| PECO Energy Co [Member] \| Regulated Operation [Member] \| Transportation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	8	7
Rate-regulated natural gas revenues [Member] \| PECO Energy Co [Member] \| Regulated Operation [Member] \| Other [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	3	2
Rate-regulated natural gas revenues [Member] \| Baltimore Gas and Electric Company [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	424	330
Rate-regulated natural gas revenues [Member] \| Baltimore Gas and Electric Company [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	427	336
Revenue from Related Parties	6	4
Rate-regulated natural gas revenues [Member] \| Baltimore Gas and Electric Company [Member] \| Regulated Operation [Member] \| Operating Segment [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	2
Rate-regulated natural gas revenues [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	282	216
Rate-regulated natural gas revenues [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	45	35
Rate-regulated natural gas revenues [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	65	54
Rate-regulated natural gas revenues [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
Rate-regulated natural gas revenues [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	35	31
Rate-regulated natural gas revenues [Member] \| Pepco Holdings LLC [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	83	71
Rate-regulated natural gas revenues [Member] \| Pepco Holdings LLC [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	83	71
Rate-regulated natural gas revenues [Member] \| Pepco Holdings LLC [Member] \| Regulated Operation [Member] \| Operating Segment [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0
Rate-regulated natural gas revenues [Member] \| Pepco Holdings LLC [Member] \| Regulated Operation [Member] \| Residential [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	51	46
Rate-regulated natural gas revenues [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	21	18
Rate-regulated natural gas revenues [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	3	2
Rate-regulated natural gas revenues [Member] \| Pepco Holdings LLC [Member] \| Regulated Operation [Member] \| Transportation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	4	4
Rate-regulated natural gas revenues [Member] \| Pepco Holdings LLC [Member] \| Regulated Operation [Member] \| Other [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	4	1
Rate-regulated natural gas revenues [Member] \| Potomac Electric Power Company [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Rate-regulated natural gas revenues [Member] \| Potomac Electric Power Company [Member] \| Regulated Operation [Member] \| Operating Segment [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0
Rate-regulated natural gas revenues [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
Rate-regulated natural gas revenues [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
Rate-regulated natural gas revenues [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
Rate-regulated natural gas revenues [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
Rate-regulated natural gas revenues [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
Rate-regulated natural gas revenues [Member] \| Delmarva Power and Light Company [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	83	71
Rate-regulated natural gas revenues [Member] \| Delmarva Power and Light Company [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	83	71
Rate-regulated natural gas revenues [Member] \| Delmarva Power and Light Company [Member] \| Regulated Operation [Member] \| Operating Segment [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0
Rate-regulated natural gas revenues [Member] \| Delmarva Power and Light Company [Member] \| Regulated Operation [Member] \| Residential [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	51	46
Rate-regulated natural gas revenues [Member] \| Delmarva Power and Light Company [Member] \| Regulated Operation [Member] \| Small Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	21	18
Rate-regulated natural gas revenues [Member] \| Delmarva Power and Light Company [Member] \| Regulated Operation [Member] \| Large Commercial & Industrial [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	3	2
Rate-regulated natural gas revenues [Member] \| Delmarva Power and Light Company [Member] \| Regulated Operation [Member] \| Transportation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	4	4
Rate-regulated natural gas revenues [Member] \| Delmarva Power and Light Company [Member] \| Regulated Operation [Member] \| Other [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	4	1
Rate-regulated natural gas revenues [Member] \| Atlantic City Electric Company [Member] \| Regulated Operation [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0	0
Rate-regulated natural gas revenues [Member] \| Atlantic City Electric Company [Member] \| Regulated Operation [Member] \| Operating Segment [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	0
Rate-regulated natural gas revenues [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
Rate-regulated natural gas revenues [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
Rate-regulated natural gas revenues [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
Rate-regulated natural gas revenues [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
Rate-regulated natural gas revenues [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
Alternative revenue programs [Member] \| Commonwealth Edison Co [Member] \| Regulated Operation [Member] \| Operating Segment [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	40	54
Alternative revenue programs [Member] \| PECO Energy Co [Member] \| Regulated Operation [Member] \| Operating Segment [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	6	10
Alternative revenue programs [Member] \| Baltimore Gas and Electric Company [Member] \| Regulated Operation [Member] \| Operating Segment [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	(12)	18
Alternative revenue programs [Member] \| Pepco Holdings LLC [Member] \| Regulated Operation [Member] \| Operating Segment [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	(5)	46
Alternative revenue programs [Member] \| Potomac Electric Power Company [Member] \| Regulated Operation [Member] \| Operating Segment [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	(7)	26
Alternative revenue programs [Member] \| Delmarva Power and Light Company [Member] \| Regulated Operation [Member] \| Operating Segment [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	(1)	9
Alternative revenue programs [Member] \| Atlantic City Electric Company [Member] \| Regulated Operation [Member] \| Operating Segment [Member]
Revenue, Major Customer [Line Items]
Revenue from Contract with Customer, Including Assessed Tax	$ 3	$ 11

Accounts Receivable - Allowance

Accounts Receivable - Allowance for Credit Losses Rollforward (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current period provision for expected credit losses	$ (78)	$ (85)
Commonwealth Edison Co [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current period provision for expected credit losses	(17)	(13)
PECO Energy Co [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current period provision for expected credit losses	(27)	(24)
Baltimore Gas and Electric Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current period provision for expected credit losses	(18)	(4)
Pepco Holdings LLC [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current period provision for expected credit losses	(18)	(10)
Potomac Electric Power Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current period provision for expected credit losses	(9)	(5)
Delmarva Power and Light Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current period provision for expected credit losses	(6)	(4)
Atlantic City Electric Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Current period provision for expected credit losses	(3)	(1)
Customer accounts receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	320	334
Current period provision for expected credit losses	110	70
Writeoffs, net of recoveries	41	27
Ending balance	389	377
Customer accounts receivable \| Commonwealth Edison Co [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	73	97
Current period provision for expected credit losses	26	21
Writeoffs, net of recoveries	7	15
Ending balance	92	103
Customer accounts receivable \| PECO Energy Co [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	105	116
Current period provision for expected credit losses	31	20
Writeoffs, net of recoveries	11	6
Ending balance	125	130
Customer accounts receivable \| Baltimore Gas and Electric Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	38	35
Current period provision for expected credit losses	26	9
Writeoffs, net of recoveries	5	1
Ending balance	59	43
Customer accounts receivable \| Pepco Holdings LLC [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	104	86
Current period provision for expected credit losses	27	20
Writeoffs, net of recoveries	18	5
Ending balance	113	101
Customer accounts receivable \| Potomac Electric Power Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	37	32
Current period provision for expected credit losses	11	11
Writeoffs, net of recoveries	8	2
Ending balance	40	41
Customer accounts receivable \| Delmarva Power and Light Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	18	22
Current period provision for expected credit losses	7	6
Writeoffs, net of recoveries	1	3
Ending balance	24	25
Customer accounts receivable \| Atlantic City Electric Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	49	32
Current period provision for expected credit losses	9	3
Writeoffs, net of recoveries	9	0
Ending balance	49	35
Other receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	72	71
Current period provision for expected credit losses	14	10
Writeoffs, net of recoveries	5	2
Ending balance	81	79
Other receivables \| Commonwealth Edison Co [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	17	21
Current period provision for expected credit losses	4	1
Writeoffs, net of recoveries	1	0
Ending balance	20	22
Other receivables \| PECO Energy Co [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	7	8
Current period provision for expected credit losses	3	4
Writeoffs, net of recoveries	1	1
Ending balance	9	11
Other receivables \| Baltimore Gas and Electric Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	9	9
Current period provision for expected credit losses	3	1
Writeoffs, net of recoveries	1	1
Ending balance	11	9
Other receivables \| Pepco Holdings LLC [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	39	33
Current period provision for expected credit losses	4	4
Writeoffs, net of recoveries	2	0
Ending balance	41	37
Other receivables \| Potomac Electric Power Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	16	13
Current period provision for expected credit losses	2	2
Writeoffs, net of recoveries	0	0
Ending balance	18	15
Other receivables \| Delmarva Power and Light Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	8	9
Current period provision for expected credit losses	1	1
Writeoffs, net of recoveries	0	0
Ending balance	9	10
Other receivables \| Atlantic City Electric Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance	15	11
Current period provision for expected credit losses	1	1
Writeoffs, net of recoveries	2	0
Ending balance	$ 14	$ 12

Accounts Receivable - Unbilled

Accounts Receivable - Unbilled Customer Revenue (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled customer revenue	$ 629	$ 747
Commonwealth Edison Co [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled customer revenue	189	240
PECO Energy Co [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled customer revenue	127	161
Baltimore Gas and Electric Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled customer revenue	139	171
Pepco Holdings LLC [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled customer revenue	174	175
Potomac Electric Power Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled customer revenue	89	82
Delmarva Power and Light Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled customer revenue	50	53
Atlantic City Electric Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled customer revenue	$ 35	$ 40

Accounts Receivable - Purchases

Accounts Receivable - Purchases and Sales of Accounts Receivable (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Purchase	$ 1,044	$ 1,023
Commonwealth Edison Co [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Purchase	248	266
PECO Energy Co [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Purchase	292	290
Baltimore Gas and Electric Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Purchase	222	199
Pepco Holdings LLC [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Purchase	282	268
Potomac Electric Power Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Purchase	174	166
Delmarva Power and Light Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Purchase	57	56
Atlantic City Electric Company [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts Receivable, Purchase	51	46
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	$ 4	$ 12

Early Plant Retirements - Narra

Early Plant Retirements - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Property, Plant and Equipment [Line Items]
Cost, Depreciation and Amortization	$ 817	$ 757

Early Plant Retirements - Impli

Early Plant Retirements - Implications of Potential Early Plant Retirement on Balance Sheet (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Implications of Potential Early Plant Retirement [Line Items]
Materials and supplies inventory, net	$ 473	$ 476
Property, plant and equipment, net	$ 65,465	$ 64,558

Nuclear Decommissioning - Narra

Nuclear Decommissioning - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Nuclear Decommissioning Additional Narrative Information [Line Items]
Increase in PPE related to ARO update	$ (335)	$ 2

Nuclear Decommissioning - Rollf

Nuclear Decommissioning - Rollforward of Nuclear Decommissioning ARO (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Accretion expense	$ 44	$ 127

Asset Impairments - Narrative (

Asset Impairments - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Property, Plant and Equipment [Line Items]
Impairment of Long-Lived Assets Held-for-use	$ 0	$ 1
Net income (loss) attributable to noncontrolling interests	1	25
Deferred income taxes and amortization of investment tax credits	$ 110	$ (142)

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) $ in Millions	3 Months Ended
Income Taxes - Narrative (Details) $ in Millions	Mar. 31, 2022USD ($)
Income Tax Additional Narrative Information [Line Items]
Income tax expense related to separation	$ 148
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount	67
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	40
Income Tax Credits and Adjustments	15
Income Taxes Receivable, Current	55
Notes Payable, Current	11
Notes Payable, Noncurrent	484
State and Local Jurisdiction [Member] \| Atlantic City Electric Company [Member]
Income Tax Additional Narrative Information [Line Items]
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Amount of Unrecorded Benefit	14
Federal and State
Income Tax Additional Narrative Information [Line Items]
Income Tax Credits and Adjustments	17
Total transaction costs taxes relating to the Separation	$ 24

Income Taxes - Reconciliation t

Income Taxes - Reconciliation to Effective Tax Rate (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Effective Income Tax Rate Reconciliation, Percent [Abstract]
U.S. Federal statutory rate	21.00%	21.00%
Increase (decrease) due to:
State income taxes, net of Federal income tax benefit	21.10%	2.80%
Plant basis differences	(3.60%)	(3.40%)
Excess deferred tax amortization	(11.50%)	(12.00%)
Amortization of investment tax credit, including deferred taxes on basis difference	(0.10%)	(0.10%)
Effective Income Tax Rate Reconciliation, Tax Credit, Other, Percent	1.70%	(0.30%)
Other	2.60%	(1.10%)
Effective income tax rate	31.20%	6.90%
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Amount	$ 67
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	40
Income Tax Credits and Adjustments	15
Total transaction costs relating to the Separation	$ 19
Commonwealth Edison Co [Member]
Effective Income Tax Rate Reconciliation, Percent [Abstract]
U.S. Federal statutory rate	21.00%	21.00%
Increase (decrease) due to:
State income taxes, net of Federal income tax benefit	8.00%	6.80%
Plant basis differences	(0.60%)	(0.60%)
Excess deferred tax amortization	(6.30%)	(6.90%)
Amortization of investment tax credit, including deferred taxes on basis difference	(0.10%)	(0.10%)
Effective Income Tax Rate Reconciliation, Tax Credit, Other, Percent	(0.30%)	(0.20%)
Other	0.00%	(3.50%)
Effective income tax rate	21.70%	16.50%
PECO Energy Co [Member]
Effective Income Tax Rate Reconciliation, Percent [Abstract]
U.S. Federal statutory rate	21.00%	21.00%
Increase (decrease) due to:
State income taxes, net of Federal income tax benefit	(0.10%)	(1.60%)
Plant basis differences	(11.30%)	(10.50%)
Excess deferred tax amortization	(3.20%)	(3.20%)
Amortization of investment tax credit, including deferred taxes on basis difference	0.00%	0.00%
Effective Income Tax Rate Reconciliation, Tax Credit, Other, Percent	0.00%	0.00%
Other	0.00%	(0.10%)
Effective income tax rate	6.40%	5.60%
Baltimore Gas and Electric Company [Member]
Effective Income Tax Rate Reconciliation, Percent [Abstract]
U.S. Federal statutory rate	21.00%	21.00%
Increase (decrease) due to:
State income taxes, net of Federal income tax benefit	2.40%	(10.10%)
Plant basis differences	(0.90%)	(1.40%)
Excess deferred tax amortization	(17.60%)	(15.50%)
Amortization of investment tax credit, including deferred taxes on basis difference	(0.10%)	(0.10%)
Effective Income Tax Rate Reconciliation, Tax Credit, Other, Percent	(0.40%)	(0.40%)
Other	(0.10%)	(0.10%)
Effective income tax rate	4.30%	(6.60%)
Pepco Holdings LLC [Member]
Effective Income Tax Rate Reconciliation, Percent [Abstract]
U.S. Federal statutory rate	21.00%	21.00%
Increase (decrease) due to:
State income taxes, net of Federal income tax benefit	3.70%	6.10%
Plant basis differences	(1.60%)	(1.50%)
Excess deferred tax amortization	(17.70%)	(19.30%)
Amortization of investment tax credit, including deferred taxes on basis difference	(0.10%)	(0.10%)
Effective Income Tax Rate Reconciliation, Tax Credit, Other, Percent	(0.40%)	(0.20%)
Other	0.20%	(0.10%)
Effective income tax rate	5.10%	5.90%
Potomac Electric Power Company [Member]
Effective Income Tax Rate Reconciliation, Percent [Abstract]
U.S. Federal statutory rate	21.00%	21.00%
Increase (decrease) due to:
State income taxes, net of Federal income tax benefit	(4.50%)	5.50%
Plant basis differences	(2.60%)	(2.10%)
Excess deferred tax amortization	(17.40%)	(15.10%)
Amortization of investment tax credit, including deferred taxes on basis difference	0.00%	0.00%
Effective Income Tax Rate Reconciliation, Tax Credit, Other, Percent	(0.40%)	(0.20%)
Other	(0.60%)	0.10%
Effective income tax rate	(4.50%)	9.20%
Delmarva Power and Light Company [Member]
Effective Income Tax Rate Reconciliation, Percent [Abstract]
U.S. Federal statutory rate	21.00%	21.00%
Increase (decrease) due to:
State income taxes, net of Federal income tax benefit	6.20%	6.40%
Plant basis differences	(0.70%)	(0.70%)
Excess deferred tax amortization	(19.40%)	(18.50%)
Amortization of investment tax credit, including deferred taxes on basis difference	(0.20%)	(0.20%)
Effective Income Tax Rate Reconciliation, Tax Credit, Other, Percent	(0.30%)	(0.10%)
Other	0.10%	0.30%
Effective income tax rate	6.70%	8.20%
Atlantic City Electric Company [Member]
Effective Income Tax Rate Reconciliation, Percent [Abstract]
U.S. Federal statutory rate	21.00%	21.00%
Increase (decrease) due to:
State income taxes, net of Federal income tax benefit	6.80%	6.90%
Plant basis differences	(1.30%)	(0.90%)
Excess deferred tax amortization	(22.20%)	(28.70%)
Amortization of investment tax credit, including deferred taxes on basis difference	(0.20%)	(0.20%)
Effective Income Tax Rate Reconciliation, Tax Credit, Other, Percent	(0.30%)	(0.30%)
Other	(0.10%)	2.20%
Effective income tax rate	3.70%	0.00%

Income Taxes - Unrecognized Tax

Income Taxes - Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits	$ 146	$ 143
Income Taxes Receivable, Noncurrent	50
Pepco Holdings LLC [Member]
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits	56	56
Atlantic City Electric Company [Member]
Income Tax Contingency [Line Items]
Unrecognized Tax Benefits	$ 16	$ 16

Retirement Benefits - Narrative

Retirement Benefits - Narrative (Details) - USD ($) $ in Millions	2 Months Ended	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2022	Feb. 01, 2022
Defined Benefit Plan Disclosure [Line Items]
Increase (Decrease) in Obligation, Pension Benefits	$ (921)	$ (24)
Increase (Decrease) in Obligation, Other Postretirement Benefits	(893)	5
Accumulated Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), after Tax	5	5	$ (1,994)
Defined Benefit Plan Amounts Recognized In Regulatory Assets Before Tax	14	(30)
Defined Benefit Plan Amounts Recognized In Regulatory Liabilities Before Tax	$ 5	$ (3)
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on assets		7000000.00%
Discount rate		3240000.00%
Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected return on assets		6440000.00%
Discount rate		3200000.00%

Retirement Benefits - Calculati

Retirement Benefits - Calculation of Net Periodic Benefit Cost (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Amortization of:
Non-service net periodic benefit cost	$ 17	$ 20
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	61	74
Interest cost	110	102
Expected return on assets	(209)	(213)
Amortization of:
Prior service cost (credit)	1	1
Actuarial loss	76	100
Curtailment benefits	0	0
Non-service net periodic benefit cost	39	64
Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	10	14
Interest cost	19	17
Expected return on assets	(25)	(26)
Amortization of:
Prior service cost (credit)	(5)	(6)
Actuarial loss	4	7
Curtailment benefits	0	(1)
Non-service net periodic benefit cost	$ 3	$ 5

Retirement Benefits - Allocated

Retirement Benefits - Allocated Portion of Pension and Postretirement Benefit Plan Costs (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Pension and Other Postretirement Benefits Costs	$ 44	$ 95
Pension and other post retirement benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and Other Postretirement Benefits Costs	42	69
Commonwealth Edison Co [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and Other Postretirement Benefits Costs	16	32
Commonwealth Edison Co [Member] \| Pension and other post retirement benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and Other Postretirement Benefits Costs	16	32
PECO Energy Co [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and Other Postretirement Benefits Costs	(2)	2
PECO Energy Co [Member] \| Pension and other post retirement benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and Other Postretirement Benefits Costs	(2)	2
Baltimore Gas and Electric Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and Other Postretirement Benefits Costs	12	14
Baltimore Gas and Electric Company [Member] \| Pension and other post retirement benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and Other Postretirement Benefits Costs	11	15
Pepco Holdings LLC [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and Other Postretirement Benefits Costs	13	12
Pepco Holdings LLC [Member] \| Pension and other post retirement benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and Other Postretirement Benefits Costs	13	12
Potomac Electric Power Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and Other Postretirement Benefits Costs	2	2
Potomac Electric Power Company [Member] \| Pension and other post retirement benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and Other Postretirement Benefits Costs	2	2
Delmarva Power and Light Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and Other Postretirement Benefits Costs	1	1
Delmarva Power and Light Company [Member] \| Pension and other post retirement benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and Other Postretirement Benefits Costs	1	1
Atlantic City Electric Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and Other Postretirement Benefits Costs	3	3
Atlantic City Electric Company [Member] \| Pension and other post retirement benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Pension and Other Postretirement Benefits Costs	$ 3	$ 3

Retirement Benefits - Defined C

Retirement Benefits - Defined Contribution Savings Plans (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Defined Benefit Plan Disclosure [Line Items]
Savings Plans Matching Contributions	$ 20	$ 20
Commonwealth Edison Co [Member]
Defined Benefit Plan Disclosure [Line Items]
Savings Plans Matching Contributions	8	8
PECO Energy Co [Member]
Defined Benefit Plan Disclosure [Line Items]
Savings Plans Matching Contributions	3	3
Baltimore Gas and Electric Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Savings Plans Matching Contributions	2	2
Pepco Holdings LLC [Member]
Defined Benefit Plan Disclosure [Line Items]
Savings Plans Matching Contributions	3	3
Potomac Electric Power Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Savings Plans Matching Contributions	1	1
Delmarva Power and Light Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Savings Plans Matching Contributions	1	1
Atlantic City Electric Company [Member]
Defined Benefit Plan Disclosure [Line Items]
Savings Plans Matching Contributions	$ 0	$ 0

Derivative Financial Instrume_2

Derivative Financial Instruments - Narrative (Details) MWh in Millions, $ in Millions	1 Months Ended
	Jun. 30, 2012MWh	Mar. 31, 2022USD ($)	Dec. 31, 2021USD ($)
Derivative [Line Items]
Other		$ 964	$ 766
Commonwealth Edison Co [Member]
Derivative [Line Items]
Long-term Purchase Commitment, Minimum Energy Volume Required \| MWh	1.3
Other		161	133
PECO Energy Co [Member]
Derivative [Line Items]
Other		41	35
Incremental Collateral For Loss Of Investment Grade Credit Rating		39
Baltimore Gas and Electric Company [Member]
Derivative [Line Items]
Other		61	48
Incremental Collateral For Loss Of Investment Grade Credit Rating		62
Delmarva Power and Light Company [Member]
Derivative [Line Items]
Other		88	59
Incremental Collateral For Loss Of Investment Grade Credit Rating		16
Atlantic City Electric Company [Member]
Derivative [Line Items]
Other		18	12
Pepco Holdings LLC [Member]
Derivative [Line Items]
Other		215	171
Commodity Contract [Member] \| External Counterparties \| Collateral [Member]
Derivative [Line Items]
Other		192
Commodity Contract [Member] \| Commonwealth Edison Co [Member] \| External Counterparties \| Collateral [Member]
Derivative [Line Items]
Other		72	41
Commodity Contract [Member] \| Delmarva Power and Light Company [Member] \| External Counterparties \| Collateral [Member]
Derivative [Line Items]
Other		73	$ 43
Commodity Contract [Member] \| Pepco Holdings LLC [Member] \| External Counterparties \| Collateral [Member]
Derivative [Line Items]
Other		$ 86

Debt and Credit Agreements - Na

Debt and Credit Agreements - Narrative (Details) - Corporate [Member] $ in Millions	3 Months Ended
	Mar. 31, 2022USD ($)
Debt Instrument [Line Items]
Notes Receivable, Related Parties	$ 319
Proceeds from Sale and Collection of Notes Receivable	258
ShortTermDebt03232017
Short-term Debt [Line Items]
Short-term Bank Loans and Notes Payable	$ 500
ShortTermDebt03232017 \| London Interbank Offered Rate (LIBOR) [Member]
Short-term Debt [Line Items]
Debt Instrument, Interest Rate Terms	SOFR plus 0.65
ShortTermDebt03312021.1
Short-term Debt [Line Items]
Short-term Bank Loans and Notes Payable	$ 150
ShortTermDebt03312021.1 \| London Interbank Offered Rate (LIBOR) [Member]
Short-term Debt [Line Items]
Debt Instrument, Interest Rate Terms	LIBOR plus 0.65
ShortTermDebtSOFRplus0.75Jan2023
Short-term Debt [Line Items]
Short-term Bank Loans and Notes Payable	$ 1,150
ShortTermDebtSOFRplus0.75Jan2023 \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Short-term Debt [Line Items]
Debt Instrument, Interest Rate Terms	0.75
ShortTermDebtSOFRplus075PLUS22.5BPincreaseJan2023 \| Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate
Short-term Debt [Line Items]
Debt Instrument, Interest Rate Terms	22.5

Debt and Credit Agreements - Co

Debt and Credit Agreements - Commercial Paper Borrowings (Details) - Commercial Paper [Member] - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Short-term Debt [Line Items]
Commercial Paper	$ 250	$ 599
Short-term Debt, Weighted Average Interest Rate, at Point in Time	0.87%	0.35%
Corporate [Member]
Short-term Debt [Line Items]
Commercial Paper	$ 0	$ 0
Commonwealth Edison Co [Member]
Short-term Debt [Line Items]
Commercial Paper	0	0
PECO Energy Co [Member]
Short-term Debt [Line Items]
Commercial Paper	0	0
Baltimore Gas and Electric Company [Member]
Short-term Debt [Line Items]
Commercial Paper	$ 250	$ 130
Short-term Debt, Weighted Average Interest Rate, at Point in Time	0.87%	0.37%
Pepco Holdings LLC [Member]
Short-term Debt [Line Items]
Commercial Paper	$ 0	$ 469
Short-term Debt, Weighted Average Interest Rate, at Point in Time	0.00%	0.35%
Potomac Electric Power Company [Member]
Short-term Debt [Line Items]
Commercial Paper	$ 0	$ 175
Short-term Debt, Weighted Average Interest Rate, at Point in Time	0.00%	0.33%
Delmarva Power and Light Company [Member]
Short-term Debt [Line Items]
Commercial Paper	$ 0	$ 149
Short-term Debt, Weighted Average Interest Rate, at Point in Time	0.00%	0.36%
Atlantic City Electric Company [Member]
Short-term Debt [Line Items]
Commercial Paper	$ 0	$ 145
Short-term Debt, Weighted Average Interest Rate, at Point in Time	0.00%	0.35%

Summary of Revolving Credit Agr

Summary of Revolving Credit Agreements (Details) - Revolving Credit Facility [Member] $ in Millions	Mar. 31, 2022USD ($)
Commonwealth Edison Co [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 1,000
Commonwealth Edison Co [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	1.00%
PECO Energy Co [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 600
PECO Energy Co [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] \| 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] \| 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 and Light Company [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 300
Delmarva Power and Light Company [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	1.00%
Atlantic City Electric Company [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	$ 300
Atlantic City Electric Company [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	$ 900
Corporate, Non-Segment [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 - Is

Debt and Credit Agreements - Issuance of Long-Term Debt (Details) $ in Millions	Mar. 31, 2022USD ($)
Corporate [Member] \| SMBCTermLoanJuly2023 \| Notes Payable to Banks [Member]
Debt Instrument [Line Items]
Interest Rate	0.65%
Debt Instrument, Face Amount	$ 300
Corporate [Member] \| USBTermLoanJuly2023 \| Notes Payable to Banks [Member]
Debt Instrument [Line Items]
Interest Rate	0.65%
Debt Instrument, Face Amount	$ 300
Corporate [Member] \| PNCTermLoanJuly2023 \| Notes Payable to Banks [Member]
Debt Instrument [Line Items]
Interest Rate	0.65%
Debt Instrument, Face Amount	$ 250
Corporate [Member] \| Notes275Mar2027 \| Notes Payable to Banks [Member]
Debt Instrument [Line Items]
Interest Rate	2.75%
Debt Instrument, Face Amount	$ 650
Corporate [Member] \| Notes335Mar2032 \| Notes Payable to Banks [Member]
Debt Instrument [Line Items]
Interest Rate	3.35%
Debt Instrument, Face Amount	$ 650
Corporate [Member] \| Notes410Mar2052 \| Notes Payable to Banks [Member]
Debt Instrument [Line Items]
Interest Rate	4.10%
Debt Instrument, Face Amount	$ 700
Commonwealth Edison Co [Member] \| FMB315Mar2032 \| First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Interest Rate	3.15%
Debt Instrument, Face Amount	$ 300
Commonwealth Edison Co [Member] \| FMB385Mar2052 \| First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Interest Rate	3.85%
Debt Instrument, Face Amount	$ 450
Potomac Electric Power Company [Member] \| FMB397Mar2052 \| First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Interest Rate	3.97%
Debt Instrument, Face Amount	$ 400
Potomac Electric Power Company [Member] \| FMB336Sept2032 \| First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Interest Rate	3.35%
Debt Instrument, Face Amount	$ 225
Delmarva Power and Light Company [Member] \| Bonds105July2020 [Member] \| First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Interest Rate	3.06%
Debt Instrument, Face Amount	$ 125
Atlantic City Electric Company [Member] \| FMB230Mar2031 \| First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Interest Rate	2.27%
Debt Instrument, Face Amount	$ 25
Atlantic City Electric Company [Member] \| FMB324June2050 [Member] \| First Mortgage Bonds [Member]
Debt Instrument [Line Items]
Interest Rate	3.06%
Debt Instrument, Face Amount	$ 150

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	Mar. 31, 2022	Dec. 31, 2021
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt to financing trust	$ 390	$ 390
Reported Value Measurement [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	37,162	32,902
Long-term debt to financing trust	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)	37,819	37,114
Long-term debt to financing trust	435	470
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 trust	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)	35,174	34,897
Long-term debt to financing trust	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)	2,645	2,217
Long-term debt to financing trust	435	470
Commonwealth Edison Co [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt to financing trust	205	205
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)	10,515	9,773
Long-term debt to financing trust	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)	10,894	11,305
Long-term debt to financing trust	228	248
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 trust	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)	10,894	11,305
Long-term debt to financing trust	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 trust	228	248
PECO Energy Co [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt to financing trust	184	184
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)	4,198	4,197
Long-term debt to financing trust	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)	4,294	4,790
Long-term debt to financing trust	207	222
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 trust	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)	4,244	4,740
Long-term debt to financing trust	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 trust	207	222
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	3,961
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)	3,969	4,406
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)	3,969	4,406
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
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)	8,233	7,547
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)	8,048	8,137
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)	5,453	5,970
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)	2,595	2,167
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)	3,841	3,445
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)	4,173	4,176
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)	2,901	3,201
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)	1,272	975
Delmarva Power and Light Company [Member] \| Reported Value Measurement [Member]
Financial Instruments, Financial Liabilities, Balance Sheet Groupings [Abstract]
Long-term debt (including amounts due within one year)	1,935	1,810
Delmarva Power and 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)	1,892	1,978
Delmarva Power and 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 and 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)	1,300	1,426
Delmarva Power and 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)	592	552
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)	1,757	1,582
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)	1,739	1,732
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)	1,007	1,091
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)	$ 732	$ 641

Fair Value of Financial Asset_4

Fair Value of Financial Assets and Liabilities - Fair Value Measurements of Assets and Liabilities, Recurring and Nonrecurring (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Mark-to-market derivative liabilities (current liabilities)	$ 0	$ 18
Derivative Liability, Noncurrent	144	201
Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash equivalents	2,418	524
Assets, Fair Value Disclosure	2,647	752
Deferred Compensation Liability, Current and Noncurrent	(84)	(131)
Total Liabilities	(228)	(350)
Fair Value, Net Asset (Liability)	2,419	402
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	(144)	(219)
Fair Value, Recurring [Member] \| Cash and Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash equivalents	470	464
Fair Value, Recurring [Member] \| Restricted cash member [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash equivalents	110	49
Fair Value, Recurring [Member] \| Other Assets [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash equivalents	92	44
Fair Value, Recurring [Member] \| Rabbi Trust Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	229	228
Fair Value, Recurring [Member] \| Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	65	60
Fair Value, Recurring [Member] \| Mutual Funds [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	55	60
Fair Value, Recurring [Member] \| Fixed Income Investments [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	9	10
Fair Value, Recurring [Member] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	100	98
Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash equivalents	2,418	524
Assets, Fair Value Disclosure	2,538	644
Deferred Compensation Liability, Current and Noncurrent	0	0
Total Liabilities	0	0
Fair Value, Net Asset (Liability)	2,538	644
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	120
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	65	60
Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Mutual Funds [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	55	60
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 equivalents	0	0
Assets, Fair Value Disclosure	72	71
Deferred Compensation Liability, Current and Noncurrent	(84)	(131)
Total Liabilities	(84)	(131)
Fair Value, Net Asset (Liability)	(12)	(60)
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	72	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 Funds [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	9	10
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	63	61
Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash equivalents	0	0
Assets, Fair Value Disclosure	37	37
Deferred Compensation Liability, Current and Noncurrent	0	0
Total Liabilities	(144)	(219)
Fair Value, Net Asset (Liability)	(107)	(182)
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	(144)	(219)
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	37
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 Funds [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	37
Commonwealth Edison Co [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Mark-to-market derivative liabilities (current liabilities)	0	18
Derivative Liability, Noncurrent	144	201
Commonwealth Edison Co [Member] \| Other Assets [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash equivalents		43
Commonwealth Edison Co [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash equivalents	537	237
Assets, Fair Value Disclosure	537	237
Total mark-to-market derivative liabilities	(144)	(219)
Deferred Compensation Liability, Current and Noncurrent	(9)	(10)
Total Liabilities	(153)	(229)
Fair Value, Net Asset (Liability)	384	8
Mark-to-market derivative liabilities (current liabilities)		18
Derivative Liability, Noncurrent		201
Commonwealth Edison Co [Member] \| Fair Value, Recurring [Member] \| Cash and Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash equivalents	71	105
Commonwealth Edison Co [Member] \| Fair Value, Recurring [Member] \| Restricted cash member [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash equivalents	73	42
Commonwealth Edison Co [Member] \| Fair Value, Recurring [Member] \| Other Assets [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash equivalents	92	92
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] \| Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0
Commonwealth Edison Co [Member] \| Fair Value, Recurring [Member] \| Mutual Funds [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 equivalents	537	237
Assets, Fair Value Disclosure	537	237
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)	537	237
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] \| Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0
Commonwealth Edison Co [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Mutual Funds [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 equivalents	0	0
Assets, Fair Value Disclosure	0	0
Total mark-to-market derivative liabilities	0	0
Deferred Compensation Liability, Current and Noncurrent	(9)	(10)
Total Liabilities	(9)	(10)
Fair Value, Net Asset (Liability)	(9)	(10)
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] \| Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0
Commonwealth Edison Co [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Mutual Funds [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] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash equivalents	0	0
Assets, Fair Value Disclosure	0	0
Total mark-to-market derivative liabilities	(144)	(219)
Deferred Compensation Liability, Current and Noncurrent	0	0
Total Liabilities	(144)	(219)
Fair Value, Net Asset (Liability)	(144)	(219)
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] \| Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0
Commonwealth Edison Co [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Mutual Funds [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] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash equivalents	9	9
Assets, Fair Value Disclosure	36	36
Total mark-to-market derivative liabilities	0	0
Deferred Compensation Liability, Current and Noncurrent	(8)	(9)
Total Liabilities	(8)	(9)
Fair Value, Net Asset (Liability)	28	27
PECO Energy Co [Member] \| Fair Value, Recurring [Member] \| Cash and Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash equivalents	25	35
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	27
PECO Energy Co [Member] \| Fair Value, Recurring [Member] \| Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	1
PECO Energy Co [Member] \| Fair Value, Recurring [Member] \| Mutual Funds [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	9	11
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	17	16
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 equivalents	9	9
Assets, Fair Value Disclosure	19	20
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)	19	20
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	10	11
PECO Energy Co [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	1
PECO Energy Co [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Mutual Funds [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	9	11
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 equivalents	0	0
Assets, Fair Value Disclosure	17	16
Total mark-to-market derivative liabilities	0	0
Deferred Compensation Liability, Current and Noncurrent	(8)	(9)
Total Liabilities	(8)	(9)
Fair Value, Net Asset (Liability)	9	7
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	17	16
PECO Energy Co [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
PECO Energy Co [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Mutual Funds [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	17	16
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 equivalents	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] \| Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0
PECO Energy Co [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Mutual Funds [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] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash equivalents	0	0
Assets, Fair Value Disclosure	7	14
Total mark-to-market derivative liabilities	0	0
Deferred Compensation Liability, Current and Noncurrent	(5)	(7)
Total Liabilities	(5)	(7)
Fair Value, Net Asset (Liability)	2	7
Baltimore Gas and Electric Company [Member] \| Fair Value, Recurring [Member] \| Cash and Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash equivalents	41	51
Baltimore Gas and Electric Company [Member] \| Fair Value, Recurring [Member] \| Restricted cash member [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash equivalents	34	4
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	7	14
Baltimore Gas and 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
Baltimore Gas and Electric Company [Member] \| Fair Value, Recurring [Member] \| Mutual Funds [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	7	14
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 equivalents	0	0
Assets, Fair Value Disclosure	7	14
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)	7	14
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	7	14
Baltimore Gas and 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
Baltimore Gas and Electric Company [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Mutual Funds [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	7	14
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 equivalents	0	0
Assets, Fair Value Disclosure	0	0
Total mark-to-market derivative liabilities	0	0
Deferred Compensation Liability, Current and Noncurrent	(5)	(7)
Total Liabilities	(5)	(7)
Fair Value, Net Asset (Liability)	(5)	(7)
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] \| Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0
Baltimore Gas and Electric Company [Member] \| Fair Value, Inputs, Level 2 [Member] \| Fair Value, Recurring [Member] \| Mutual Funds [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 equivalents	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] \| Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	0
Baltimore Gas and Electric Company [Member] \| Fair Value, Inputs, Level 3 [Member] \| Fair Value, Recurring [Member] \| Mutual Funds [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] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash equivalents	599	110
Assets, Fair Value Disclosure	741	255
Deferred Compensation Liability, Current and Noncurrent	(17)	(18)
Total Liabilities	(17)	(18)
Fair Value, Net Asset (Liability)	724	237
Pepco Holdings LLC [Member] \| Fair Value, Recurring [Member] \| Cash and Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash equivalents	300	100
Pepco Holdings LLC [Member] \| Fair Value, Recurring [Member] \| Restricted cash member [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash equivalents	3
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	142	145
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	61	59
Pepco Holdings LLC [Member] \| Fair Value, Recurring [Member] \| Mutual Funds [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	12	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	9	10
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	60	62
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 equivalents	599	110
Assets, Fair Value Disclosure	672	183
Deferred Compensation Liability, Current and Noncurrent	0	0
Total Liabilities	0	0
Fair Value, Net Asset (Liability)	672	183
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	73
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	61	59
Pepco Holdings LLC [Member] \| Fair Value, Inputs, Level 1 [Member] \| Fair Value, Recurring [Member] \| Mutual Funds [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	12	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 equivalents	0	0
Assets, Fair Value Disclosure	33	37
Deferred Compensation Liability, Current and Noncurrent	(17)	(18)
Total Liabilities	(17)	(18)
Fair Value, Net Asset (Liability)	16	19
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	33	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 Funds [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	9	10
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	24	27
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 equivalents	0	0
Assets, Fair Value Disclosure	36	35
Deferred Compensation Liability, Current and Noncurrent	0	0
Total Liabilities	0	0
Fair Value, Net Asset (Liability)	36	35
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	36	35
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 Funds [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	36	35
Potomac Electric Power Company [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash equivalents	294	31
Assets, Fair Value Disclosure	413	151
Deferred Compensation Liability, Current and Noncurrent	(2)	(2)
Total Liabilities	(2)	(2)
Fair Value, Net Asset (Liability)	411	149
Potomac Electric Power Company [Member] \| Fair Value, Recurring [Member] \| Cash and Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash equivalents	239	34
Potomac Electric Power Company [Member] \| Fair Value, Recurring [Member] \| Restricted cash member [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash equivalents	3
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	119	120
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	59	58
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	60	62
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 equivalents	294	31
Assets, Fair Value Disclosure	353	89
Deferred Compensation Liability, Current and Noncurrent	0	0
Total Liabilities	0	0
Fair Value, Net Asset (Liability)	353	89
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	59	58
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	59	58
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 equivalents	0	0
Assets, Fair Value Disclosure	24	27
Deferred Compensation Liability, Current and Noncurrent	(2)	(2)
Total Liabilities	(2)	(2)
Fair Value, Net Asset (Liability)	22	25
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	24	27
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] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	24	27
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 equivalents	0	0
Assets, Fair Value Disclosure	36	35
Deferred Compensation Liability, Current and Noncurrent	0	0
Total Liabilities	0	0
Fair Value, Net Asset (Liability)	36	35
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	36	35
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] \| 6311 Life Insurance [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Investments, Fair Value Disclosure	36	35
Delmarva Power and Light Company [Member] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash equivalents	152	43
Assets, Fair Value Disclosure	152	43
Deferred Compensation Liability, Current and Noncurrent	0	0
Total Liabilities	0	0
Fair Value, Net Asset (Liability)	152	43
Delmarva Power and Light Company [Member] \| Fair Value, Recurring [Member] \| Cash and Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash equivalents	41	28
Delmarva Power and 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 and 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 and 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 and 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 equivalents	152	43
Assets, Fair Value Disclosure	152	43
Deferred Compensation Liability, Current and Noncurrent	0	0
Total Liabilities	0	0
Fair Value, Net Asset (Liability)	152	43
Delmarva Power and 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 and 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 and 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 and 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 equivalents	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 and 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 and 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 and 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 and 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 equivalents	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 and 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 and 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 and 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] \| Fair Value, Recurring [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash equivalents	153	0
Assets, Fair Value Disclosure	153	0
Deferred Compensation Liability, Current and Noncurrent	0	0
Total Liabilities	0	0
Fair Value, Net Asset (Liability)	153	0
Atlantic City Electric Company [Member] \| Fair Value, Recurring [Member] \| Cash and Cash Equivalents [Member]
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Cash equivalents	15	29
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] \| 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 equivalents	153	0
Assets, Fair Value Disclosure	153	0
Deferred Compensation Liability, Current and Noncurrent	0	0
Total Liabilities	0	0
Fair Value, Net Asset (Liability)	153	0
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] \| 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 equivalents	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] \| 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 equivalents	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] \| 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 Assets Liabilities Measured On Recurring Basis Unobservable Input Reconciliation (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Fair Value, Inputs, Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning Balance	$ (182)	$ (267)
Total realized / unrealized gains (losses)
Included in net income	1	1
Included in regulatory assets	75	6
Purchases, sales, issuances and settlements
Transfers out of Level 3	(1)
Ending Balance	(107)	(260)
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)	1	1
Commonwealth Edison Co [Member] \| Derivative [Member] \| Interest Rate Swap [Member]
Footnotes To Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Abstract]
Realized Investment Gains (Losses)	6	8
Commonwealth Edison Co [Member] \| Fair Value, Inputs, Level 3 [Member] \| Derivative [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning Balance	(219)	(301)
Total realized / unrealized gains (losses)
Included in net income	0	0
Included in regulatory assets	75	6
Purchases, sales, issuances and settlements
Transfers out of Level 3	0
Ending Balance	(144)	(295)
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)	0	0
Footnotes To Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Abstract]
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Inputs Reconciliation, Period Increase (Decrease)	(69)	(2)
Pepco Holdings LLC [Member] \| Fair Value, Inputs, Level 3 [Member] \| 6311 Life Insurance [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning Balance	35	34
Total realized / unrealized gains (losses)
Included in net income	1	1
Included in regulatory assets	0	0
Purchases, sales, issuances and settlements
Transfers out of Level 3	0
Ending Balance	36	35
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)	1	1
Potomac Electric Power Company [Member] \| Fair Value, Inputs, Level 3 [Member] \| 6311 Life Insurance [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning Balance	35	34
Total realized / unrealized gains (losses)
Included in net income	1	1
Included in regulatory assets	0	0
Purchases, sales, issuances and settlements
Transfers out of Level 3	0
Ending Balance	36	35
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)	$ 1	$ 1

Fair Value of Financial Asset_6

Fair Value of Financial Assets and Liabilities - Fair Value Assets And Liabilities Measured On Recurring Basis Gain Loss Included In Earnings (Details) - Fair Value, Inputs, Level 3 [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Fair Value Assets And Liabilities Measured On Recurring Basis Gain Loss Included In Earnings [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Earnings	$ (1)	$ (1)
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss)	$ 1	$ 1

Fair Value of Financial Asset_7

Fair Value of Financial Assets and Liabilities - Fair Value Inputs Assets Quantitative Information (Details) - Fair Value, Inputs, Level 3 [Member] - Derivative [Member] $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2022USD ($)	Dec. 31, 2021USD ($)
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	$ (144)	$ (219)
Discounted Cash Flow [Member] \| Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Abstract]
Derivative Asset (Liability) Net, Measurement Input	0.04	0.03
Forward heat rate	890.00%	900.00%
Fair Value Inputs Renewable Factor	92.00%	92.00%
Discounted Cash Flow [Member] \| Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Abstract]
Derivative Asset (Liability) Net, Measurement Input	0.05	0.07
Forward heat rate	910.00%	1000.00%
Fair Value Inputs Renewable Factor	120.00%	120.00%
Discounted Cash Flow [Member] \| Arithmetic Average [Member]
Fair Value Measurement Inputs and Valuation Techniques [Abstract]
Derivative Asset (Liability) Net, Measurement Input	0.0435	0.0477
Forward heat rate	900.00%	913.00%
Fair Value Inputs Renewable Factor	98.00%	97.00%
Commonwealth Edison Co [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	$ (144)	$ (219)
Commonwealth Edison Co [Member] \| Discounted Cash Flow [Member] \| Minimum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Abstract]
Derivative Asset (Liability) Net, Measurement Input	0.04	0.03
Forward heat rate	890.00%	900.00%
Fair Value Inputs Renewable Factor	92.00%	92.00%
Commonwealth Edison Co [Member] \| Discounted Cash Flow [Member] \| Maximum [Member]
Fair Value Measurement Inputs and Valuation Techniques [Abstract]
Derivative Asset (Liability) Net, Measurement Input	0.05	0.07
Forward heat rate	910.00%	1000.00%
Fair Value Inputs Renewable Factor	120.00%	120.00%
Commonwealth Edison Co [Member] \| Discounted Cash Flow [Member] \| Arithmetic Average [Member]
Fair Value Measurement Inputs and Valuation Techniques [Abstract]
Derivative Asset (Liability) Net, Measurement Input	0.0435	0.0477
Forward heat rate	900.00%	913.00%
Fair Value Inputs Renewable Factor	98.00%	97.00%

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) $ in Millions	Mar. 23, 2016MW	Nov. 30, 2020USD ($)	Dec. 31, 2022MW	Dec. 31, 2018MW	Dec. 31, 2017MW	Mar. 31, 2022USD ($)MGPSite	Dec. 31, 2021USD ($)
Commitments And Contingencies Additional Narrative Information [Line Items]
Other Commitment						$ 623
Accrual for Environmental Loss Contingencies, Gross						354	$ 352
Commonwealth Edison Co [Member]
Commitments And Contingencies Additional Narrative Information [Line Items]
Other Commitment						$ 224
Mgp Site Contingency Monitoring Count \| MGPSite						21
Accrual for Environmental Loss Contingencies, Gross						$ 279	279
Deferred Prosecution Agreement Payments		$ 200
Customer Refund Liability, Noncurrent						38
PECO Energy Co [Member]
Commitments And Contingencies Additional Narrative Information [Line Items]
Other Commitment						$ 182
Mgp Site Contingency Monitoring Count \| MGPSite						6
Accrual for Environmental Loss Contingencies, Gross						$ 21	22
Baltimore Gas and Electric Company [Member]
Commitments And Contingencies Additional Narrative Information [Line Items]
Other Commitment						$ 6
Mgp Site Contingency Monitoring Count \| MGPSite						4
Accrual for Environmental Loss Contingencies, Gross						$ 7	6
Pepco Holdings LLC [Member]
Commitments And Contingencies Additional Narrative Information [Line Items]
Other Commitment						124
Accrual for Environmental Loss Contingencies, Gross						42	42
Potomac Electric Power Company [Member]
Commitments And Contingencies Additional Narrative Information [Line Items]
Other Commitment						94
Accrual for Environmental Loss Contingencies, Gross						40	40
Delmarva Power and Light Company [Member]
Commitments And Contingencies Additional Narrative Information [Line Items]
Other Commitment						$ 19
Mgp Site Contingency Count \| MGPSite						1
Accrual for Environmental Loss Contingencies, Gross						$ 1	$ 1
Pepco Holdings Inc [Member]
Commitments And Contingencies Additional Narrative Information [Line Items]
Other Commitment						513
Pepco Holdings Inc [Member] \| Pepco Holdings LLC [Member]
Commitments And Contingencies Additional Narrative Information [Line Items]
Other Commitment						320
Pepco Holdings Inc [Member] \| Potomac Electric Power Company [Member]
Commitments And Contingencies Additional Narrative Information [Line Items]
Other Commitment						120
Pepco Holdings Inc [Member] \| Delmarva Power and Light Company [Member]
Commitments And Contingencies Additional Narrative Information [Line Items]
Other Commitment						$ 89
Wind Assets [Member] \| Pepco Holdings Inc [Member]
Commitments And Contingencies Additional Narrative Information [Line Items]
Other Non-Financial Commitment \| MW	100
Wind Assets [Member] \| Pepco Holdings Inc [Member] \| Delmarva Power and Light Company [Member]
Commitments And Contingencies Additional Narrative Information [Line Items]
Purchase Commitment \| MW	120			40	40
Wind Assets [Member] \| Pepco Holdings Inc [Member] \| Delmarva Power and Light Company [Member] \| Forecast [Member]
Commitments And Contingencies Additional Narrative Information [Line Items]
Purchase Commitment \| MW			40

Commitments and Contingencies_3

Commitments and Contingencies - Merger Commitment (Details) $ in Millions	Mar. 31, 2022USD ($)
Other Commitments [Line Items]
Other Commitment	$ 623
Pepco Holdings LLC [Member]
Other Commitments [Line Items]
Other Commitment	124
Potomac Electric Power Company [Member]
Other Commitments [Line Items]
Other Commitment	94
Delmarva Power and Light Company [Member]
Other Commitments [Line Items]
Other Commitment	19
Atlantic City Electric Company [Member]
Other Commitments [Line Items]
Other Commitment	11
Pepco Holdings Inc [Member]
Other Commitments [Line Items]
Other Commitment	513
Pepco Holdings Inc [Member] \| Remaining commitment
Other Commitments [Line Items]
Other Commitment	65
Pepco Holdings Inc [Member] \| Pepco Holdings LLC [Member]
Other Commitments [Line Items]
Other Commitment	320
Pepco Holdings Inc [Member] \| Pepco Holdings LLC [Member] \| Remaining commitment
Other Commitments [Line Items]
Other Commitment	55
Pepco Holdings Inc [Member] \| Potomac Electric Power Company [Member]
Other Commitments [Line Items]
Other Commitment	120
Pepco Holdings Inc [Member] \| Potomac Electric Power Company [Member] \| Remaining commitment
Other Commitments [Line Items]
Other Commitment	46
Pepco Holdings Inc [Member] \| Delmarva Power and Light Company [Member]
Other Commitments [Line Items]
Other Commitment	89
Pepco Holdings Inc [Member] \| Delmarva Power and Light Company [Member] \| Remaining commitment
Other Commitments [Line Items]
Other Commitment	6
Pepco Holdings Inc [Member] \| Atlantic City Electric Company [Member]
Other Commitments [Line Items]
Other Commitment	111
Pepco Holdings Inc [Member] \| Atlantic City Electric Company [Member] \| Remaining commitment
Other Commitments [Line Items]
Other Commitment	$ 3

Commitments and Contingencies_4

Commitments and Contingencies - Schedule of Commercial Commitments (Details) $ in Millions	Mar. 31, 2022USD ($)
Other Commitments [Line Items]
Other Commitment	$ 623
Other Commitment, to be Paid, Remainder of Fiscal Year	201
Other Commitment, to be Paid, Year One	16
Other Commitment, to be Paid, Year Two	8
Other Commitment, to be Paid, Year Three	5
Other Commitment, to be Paid, Year Four	5
Other Commitment, to be Paid, Year Five and Beyond	388
Guarantor Obligations, Maximum Exposure, Undiscounted	73
Letters of Credit
Other Commitments [Line Items]
Other Commitment	14
Other Commitment, to be Paid, Remainder of Fiscal Year	12
Other Commitment, to be Paid, Year One	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 and Beyond	0
Surety Bonds
Other Commitments [Line Items]
Other Commitment	201
Other Commitment, to be Paid, Remainder of Fiscal Year	188
Other Commitment, to be Paid, Year One	11
Other Commitment, to be Paid, Year Two	2
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five and Beyond	0
Financing trust guarantees
Other Commitments [Line Items]
Other Commitment	378
Other Commitment, to be Paid, Remainder of Fiscal Year	0
Other Commitment, to be Paid, Year One	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 and Beyond	378
Guaranteed lease residual values
Other Commitments [Line Items]
Other Commitment	30
Other Commitment, to be Paid, Remainder of Fiscal Year	1
Other Commitment, to be Paid, Year One	3
Other Commitment, to be Paid, Year Two	6
Other Commitment, to be Paid, Year Three	5
Other Commitment, to be Paid, Year Four	5
Other Commitment, to be Paid, Year Five and Beyond	10
Commonwealth Edison Co [Member]
Other Commitments [Line Items]
Other Commitment	224
Other Commitment, to be Paid, Remainder of Fiscal Year	19
Other Commitment, to be Paid, Year One	3
Other Commitment, to be Paid, Year Two	2
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five and Beyond	200
Commonwealth Edison Co [Member] \| Letters of Credit
Other Commitments [Line Items]
Other Commitment	7
Other Commitment, to be Paid, Remainder of Fiscal Year	7
Other Commitment, to be Paid, Year One	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 and Beyond	0
Commonwealth Edison Co [Member] \| Surety Bonds
Other Commitments [Line Items]
Other Commitment	17
Other Commitment, to be Paid, Remainder of Fiscal Year	12
Other Commitment, to be Paid, Year One	3
Other Commitment, to be Paid, Year Two	2
Other Commitment, to be Paid, Year Three	0
Other Commitment, to be Paid, Year Four	0
Other Commitment, to be Paid, Year Five and Beyond	0
Commonwealth Edison Co [Member] \| Financing trust guarantees
Other Commitments [Line Items]
Other Commitment	200
Other Commitment, to be Paid, Remainder of Fiscal Year	0
Other Commitment, to be Paid, Year One	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 and Beyond	200
PECO Energy Co [Member]
Other Commitments [Line Items]
Other Commitment	182
Other Commitment, to be Paid, Remainder of Fiscal Year	3
Other Commitment, to be Paid, Year One	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 and Beyond	178
PECO Energy Co [Member] \| Surety Bonds
Other Commitments [Line Items]
Other Commitment	3
Other Commitment, to be Paid, Remainder of Fiscal Year	2
Other Commitment, to be Paid, Year One	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 and Beyond	0
PECO Energy Co [Member] \| Financing trust guarantees
Other Commitments [Line Items]
Other Commitment	178
Other Commitment, to be Paid, Remainder of Fiscal Year	0
Other Commitment, to be Paid, Year One	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 and Beyond	178
PECO Energy Co [Member] \| Standby Letters of Credit
Other Commitments [Line Items]
Other Commitment	1
Other Commitment, to be Paid, Remainder of Fiscal Year	1
Other Commitment, to be Paid, Year One	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, after Year Five	0
Baltimore Gas and Electric Company [Member]
Other Commitments [Line Items]
Other Commitment	6
Other Commitment, to be Paid, Remainder of Fiscal Year	5
Other Commitment, to be Paid, Year One	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 and Beyond	0
Baltimore Gas and Electric Company [Member] \| Letters of Credit
Other Commitments [Line Items]
Other Commitment	2
Other Commitment, to be Paid, Remainder of Fiscal Year	2
Other Commitment, to be Paid, Year One	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 and Beyond	0
Baltimore Gas and Electric Company [Member] \| Surety Bonds
Other Commitments [Line Items]
Other Commitment	4
Other Commitment, to be Paid, Remainder of Fiscal Year	3
Other Commitment, to be Paid, Year One	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 and Beyond	0
Pepco Holdings LLC [Member]
Other Commitments [Line Items]
Other Commitment	124
Other Commitment, to be Paid, Remainder of Fiscal Year	92
Other Commitment, to be Paid, Year One	6
Other Commitment, to be Paid, Year Two	6
Other Commitment, to be Paid, Year Three	5
Other Commitment, to be Paid, Year Four	5
Other Commitment, to be Paid, Year Five and Beyond	10
Guarantor Obligations, Maximum Exposure, Undiscounted	73
Pepco Holdings LLC [Member] \| Surety Bonds
Other Commitments [Line Items]
Other Commitment	94
Other Commitment, to be Paid, Remainder of Fiscal Year	91
Other Commitment, to be Paid, Year One	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 and Beyond	0
Pepco Holdings LLC [Member] \| Guaranteed lease residual values
Other Commitments [Line Items]
Other Commitment	30
Other Commitment, to be Paid, Remainder of Fiscal Year	1
Other Commitment, to be Paid, Year One	3
Other Commitment, to be Paid, Year Two	6
Other Commitment, to be Paid, Year Three	5
Other Commitment, to be Paid, Year Four	5
Other Commitment, to be Paid, Year Five and Beyond	10
Potomac Electric Power Company [Member]
Other Commitments [Line Items]
Other Commitment	94
Other Commitment, to be Paid, Remainder of Fiscal Year	84
Other Commitment, to be Paid, Year One	1
Other Commitment, to be Paid, Year Two	2
Other Commitment, to be Paid, Year Three	2
Other Commitment, to be Paid, Year Four	2
Other Commitment, to be Paid, Year Five and Beyond	3
Guarantor Obligations, Maximum Exposure, Undiscounted	25
Potomac Electric Power Company [Member] \| Surety Bonds
Other Commitments [Line Items]
Other Commitment	84
Other Commitment, to be Paid, Remainder of Fiscal Year	84
Other Commitment, to be Paid, Year One	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 and Beyond	0
Potomac Electric Power Company [Member] \| Guaranteed lease residual values
Other Commitments [Line Items]
Other Commitment	10
Other Commitment, to be Paid, Remainder of Fiscal Year	0
Other Commitment, to be Paid, Year One	1
Other Commitment, to be Paid, Year Two	2
Other Commitment, to be Paid, Year Three	2
Other Commitment, to be Paid, Year Four	2
Other Commitment, to be Paid, Year Five and Beyond	3
Delmarva Power and Light Company [Member]
Other Commitments [Line Items]
Other Commitment	19
Other Commitment, to be Paid, Remainder of Fiscal Year	4
Other Commitment, to be Paid, Year One	4
Other Commitment, to be Paid, Year Two	3
Other Commitment, to be Paid, Year Three	2
Other Commitment, to be Paid, Year Four	2
Other Commitment, to be Paid, Year Five and Beyond	4
Guarantor Obligations, Maximum Exposure, Undiscounted	30
Delmarva Power and Light Company [Member] \| Surety Bonds
Other Commitments [Line Items]
Other Commitment	6
Other Commitment, to be Paid, Remainder of Fiscal Year	3
Other Commitment, to be Paid, Year One	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 and Beyond	0
Delmarva Power and Light Company [Member] \| Guaranteed lease residual values
Other Commitments [Line Items]
Other Commitment	13
Other Commitment, to be Paid, Remainder of Fiscal Year	1
Other Commitment, to be Paid, Year One	1
Other Commitment, to be Paid, Year Two	3
Other Commitment, to be Paid, Year Three	2
Other Commitment, to be Paid, Year Four	2
Other Commitment, to be Paid, Year Five and Beyond	4
Atlantic City Electric Company [Member]
Other Commitments [Line Items]
Other Commitment	11
Other Commitment, to be Paid, Remainder of Fiscal Year	4
Other Commitment, to be Paid, Year One	1
Other Commitment, to be Paid, Year Two	1
Other Commitment, to be Paid, Year Three	1
Other Commitment, to be Paid, Year Four	1
Other Commitment, to be Paid, Year Five and Beyond	3
Guarantor Obligations, Maximum Exposure, Undiscounted	18
Atlantic City Electric Company [Member] \| Surety Bonds
Other Commitments [Line Items]
Other Commitment	4
Other Commitment, to be Paid, Remainder of Fiscal Year	4
Other Commitment, to be Paid, Year One	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 and Beyond	0
Atlantic City Electric Company [Member] \| Guaranteed lease residual values
Other Commitments [Line Items]
Other Commitment	7
Other Commitment, to be Paid, Remainder of Fiscal Year	0
Other Commitment, to be Paid, Year One	1
Other Commitment, to be Paid, Year Two	1
Other Commitment, to be Paid, Year Three	1
Other Commitment, to be Paid, Year Four	1
Other Commitment, to be Paid, Year Five and Beyond	$ 3
Minimum [Member] \| Guaranteed lease residual values
Other Commitments [Line Items]
Lessor, Operating Lease, Term of Contract	1 year
Maximum [Member] \| Guaranteed lease residual values
Other Commitments [Line Items]
Lessor, Operating Lease, Term of Contract	8 years

Commitments and Contingencies_5

Commitments and Contingencies - Schedule of Accruals for Environmental Matters (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	$ 354	$ 352
Commonwealth Edison Co [Member]
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	279	279
PECO Energy Co [Member]
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	21	22
Baltimore Gas and Electric Company [Member]
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	7	6
Pepco Holdings LLC [Member]
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	42	42
Potomac Electric Power Company [Member]
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	40	40
Delmarva Power and Light Company [Member]
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	1	1
Atlantic City Electric Company [Member]
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	1	1
Accrual For MGP Investigation And Remediation [Member]
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	305	303
Accrual For MGP Investigation And Remediation [Member] \| Commonwealth Edison Co [Member]
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	279	279
Accrual For MGP Investigation And Remediation [Member] \| PECO Energy Co [Member]
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	20	20
Accrual For MGP Investigation And Remediation [Member] \| Baltimore Gas and Electric Company [Member]
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	6	4
Accrual For MGP Investigation And Remediation [Member] \| Pepco Holdings LLC [Member]
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	0	0
Accrual For MGP Investigation And Remediation [Member] \| Potomac Electric Power Company [Member]
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	0	0
Accrual For MGP Investigation And Remediation [Member] \| Delmarva Power and Light Company [Member]
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	0	0
Accrual For MGP Investigation And Remediation [Member] \| Atlantic City Electric Company [Member]
Site Contingency [Line Items]
Total environmental investigation and remediation reserve	$ 0	$ 0

Changes in Accumulated Other _3

Changes in Accumulated Other Comprehensive Income - Schedule of Changes in AOCI (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Movement in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	$ 34,795	$ 34,868
Other comprehensive income (loss), net of income taxes	14	54
Ending balance	23,491	34,313
Gains (Losses) on Cash Flow Hedges
Movement in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(6)	(5)
OCI before reclassifications		0
Amounts reclassified from AOCI	0	0
Other comprehensive income (loss), net of income taxes	0	0
Ending balance	0	(5)
Gains (Losses) on Cash Flow Hedges \| Exelon Generation Co L L C [Member]
Movement in Accumulated Other Comprehensive Income [Roll Forward]
Other comprehensive income (loss), net of income taxes	6
Pension and Non-Pension Postretirement Benefit Plan Items
Movement in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(2,721)	(3,372)
OCI before reclassifications		(2)
Amounts reclassified from AOCI	14	55
Other comprehensive income (loss), net of income taxes	14	53
Ending balance	(713)	(3,319)
Pension and Non-Pension Postretirement Benefit Plan Items \| Exelon Generation Co L L C [Member]
Movement in Accumulated Other Comprehensive Income [Roll Forward]
Other comprehensive income (loss), net of income taxes	1,994
Foreign Currency Items
Movement in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(23)	(23)
OCI before reclassifications		1
Amounts reclassified from AOCI	0	0
Other comprehensive income (loss), net of income taxes	0	1
Ending balance	0	(22)
Foreign Currency Items \| Exelon Generation Co L L C [Member]
Movement in Accumulated Other Comprehensive Income [Roll Forward]
Other comprehensive income (loss), net of income taxes	23
Total
Movement in Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(2,750)	(3,400)
OCI before reclassifications		(1)
Amounts reclassified from AOCI	14	55
Other comprehensive income (loss), net of income taxes	14	54
Ending balance	(713)	$ (3,346)
Total \| Exelon Generation Co L L C [Member]
Movement in Accumulated Other Comprehensive Income [Roll Forward]
Other comprehensive income (loss), net of income taxes	$ 2,023

Changes in Accumulated Other _4

Changes in Accumulated Other Comprehensive Income - Income Taxes Allocated to Other Comprehensive Income (Loss) Components (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Prior service costs
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), Tax	$ 0	$ 1
Actuarial losses
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), Tax	$ (5)	$ (19)

Variable Interest Entities - Na

Variable Interest Entities - Narrative (Details) $ in Millions	Mar. 31, 2022USD ($)
Variable Interest Entity [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 73

Variable Interest Entities - As

Variable Interest Entities - Assets and Liabilities of Consolidated VIES (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Variable Interest Entity [Line Items]
Cash and cash equivalents	$ 2,476	$ 672	$ 1,908	$ 663
Restricted cash and cash equivalents	430	321	374	438
Accounts receivable, net
Customer	1,976	1,869
Inventory, net
Materials and supplies	473	476
Current assets of discontinued operations	0	7,835
Other current assets	463	387
Total current assets	8,145	13,957
Property, plant and equipment, net	65,465	64,558
Other Assets, Noncurrent	1,045	885
Assets	92,698	133,013
Long-term debt due within one year	2,154	2,153
Accounts payable	2,175	2,379
Accrued expenses	1,029	1,137
Unamortized energy contract liabilities	13	89
Current liabilities of discontinued operations	0	7,940
Other	964	766
Total current liabilities	8,635	16,111
Long-term debt	35,008	30,749
Asset retirement obligations, noncurrent	273	271
Unamortized energy contract liabilities	42	146
Other	2,187	1,573
Liabilities	69,207	98,218
Pepco Holdings LLC [Member]
Variable Interest Entity [Line Items]
Cash and cash equivalents	796	136	558	111
Restricted cash and cash equivalents	106	77	37	39
Accounts receivable, net
Customer	505	512
Inventory, net
Materials and supplies	209	209
Other current assets	69	69
Total current assets	2,368	1,692
Property, plant and equipment, net	16,701	16,498
Other Assets, Noncurrent	253	258
Assets	25,636	24,744
Long-term debt due within one year	400	399
Accounts payable	522	578
Accrued expenses	264	281
Unamortized energy contract liabilities	13	89
Other	215	171
Total current liabilities	1,748	2,246
Long-term debt	7,833	7,148
Asset retirement obligations, noncurrent	70	70
Unamortized energy contract liabilities	42	146
Other	661	570
Liabilities	14,319	14,159
Atlantic City Electric Company [Member]
Variable Interest Entity [Line Items]
Cash and cash equivalents	168	29	353	17
Restricted cash and cash equivalents	0	0	$ 4	$ 3
Accounts receivable, net
Customer	128	141
Inventory, net
Other current assets	5	3
Total current assets	540	333
Property, plant and equipment, net	3,763	3,729
Other Assets, Noncurrent	37	37
Assets	4,929	4,556
Long-term debt due within one year	3	3
Accounts payable	139	165
Accrued expenses	43	44
Other	18	12
Total current liabilities	349	445
Long-term debt	1,754	1,579
Other	165	49
Liabilities	$ 3,174	$ 2,981

Variable Interest Entities - Su

Variable Interest Entities - Summary of Significant Unconsolidated VIEs (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Variable Interest Entity [Line Items]
Total assets	$ 92,698	$ 133,013
Total liabilities	$ 69,207	$ 98,218

Supplemental Financial Inform_3

Supplemental Financial Information - Operations (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Other, Net [Abstract]
AFUDC - Equity	$ 36	$ 28
Non-service net periodic benefit cost	17	20
Commonwealth Edison Co [Member]
Other, Net [Abstract]
AFUDC - Equity	8	4
Non-service net periodic benefit cost	0	0
PECO Energy Co [Member]
Other, Net [Abstract]
AFUDC - Equity	7	6
Non-service net periodic benefit cost	0	0
Baltimore Gas and Electric Company [Member]
Other, Net [Abstract]
AFUDC - Equity	6	7
Non-service net periodic benefit cost	0	0
Pepco Holdings LLC [Member]
Other, Net [Abstract]
AFUDC - Equity	15	11
Non-service net periodic benefit cost	0	0
Potomac Electric Power Company [Member]
Other, Net [Abstract]
AFUDC - Equity	11	9
Non-service net periodic benefit cost	0	0
Delmarva Power and Light Company [Member]
Other, Net [Abstract]
AFUDC - Equity	2	1
Non-service net periodic benefit cost	0	0
Atlantic City Electric Company [Member]
Other, Net [Abstract]
AFUDC - Equity	2	1
Non-service net periodic benefit cost	$ 0	$ 0

Supplemental Financial Inform_4

Supplemental Financial Information - Taxes Other Than Income Taxes (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Supplemental Statement of Operations Information [Line Items]
Utility taxes	$ 221	$ 193
Property	94	86
Payroll	37	33
Commonwealth Edison Co [Member]
Supplemental Statement of Operations Information [Line Items]
Utility taxes	78	59
Property	10	8
Payroll	7	7
PECO Energy Co [Member]
Supplemental Statement of Operations Information [Line Items]
Utility taxes	38	35
Property	4	4
Payroll	4	4
Baltimore Gas and Electric Company [Member]
Supplemental Statement of Operations Information [Line Items]
Utility taxes	27	25
Property	46	42
Payroll	4	5
Pepco Holdings LLC [Member]
Supplemental Statement of Operations Information [Line Items]
Utility taxes	78	74
Property	34	32
Payroll	7	7
Potomac Electric Power Company [Member]
Supplemental Statement of Operations Information [Line Items]
Utility taxes	70	67
Property	23	21
Payroll	2	2
Delmarva Power and Light Company [Member]
Supplemental Statement of Operations Information [Line Items]
Utility taxes	7	6
Property	10	10
Payroll	1	1
Atlantic City Electric Company [Member]
Supplemental Statement of Operations Information [Line Items]
Utility taxes	1	1
Property	1	1
Payroll	$ 1	$ 0

Supplemental Financial Inform_5

Supplemental Financial Information - Cash Flow (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Depreciation, Amortization and Accretion [Abstract]
Property, plant and equipment	$ 726	$ 1,522
Amortization of regulatory assets	179	160
Amortization of intangible assets, net	6	15
Amortization of energy contract assets and liabilities	3	4
Nuclear fuel	66	276
ARO accretion	44	127
Depreciation, Amortization and Accretion, Net	1,024	2,104
Other Non-Cash Operating Activities [Abstract]
Pension and non-pension postretirement benefit costs	44	95
Allowance for credit losses	78	85
Other decommissioning-related activity	36	(322)
Energy-related options	60	17
True-up adjustments to decoupling mechanisms and formula rates	29	129
Long-term incentive plan	25	32
Amortization of operating ROU asset	23	37
AFUDC - Equity	(36)	(28)
Other Non-Cash Activity
Other Non-Cash Operating Activities [Abstract]
True-up adjustments to decoupling mechanisms and formula rates	(29)	(129)
Return on borrowed funds
Other Non-Cash Operating Activities [Abstract]
AFUDC - Equity	(36)	(28)
Commonwealth Edison Co [Member]
Depreciation, Amortization and Accretion [Abstract]
Property, plant and equipment	254	239
Amortization of regulatory assets	67	53
Amortization of intangible assets, net	0	0
Amortization of energy contract assets and liabilities	0	0
Nuclear fuel	0	0
ARO accretion	0	0
Depreciation, Amortization and Accretion, Net	321	292
Other Non-Cash Operating Activities [Abstract]
Pension and non-pension postretirement benefit costs	16	32
Allowance for credit losses	17	13
Other decommissioning-related activity	0	0
Energy-related options	0	0
True-up adjustments to decoupling mechanisms and formula rates	40	54
Long-term incentive plan	0	0
Amortization of operating ROU asset	1	0
AFUDC - Equity	(8)	(4)
Commonwealth Edison Co [Member] \| Other Non-Cash Activity
Other Non-Cash Operating Activities [Abstract]
True-up adjustments to decoupling mechanisms and formula rates	(40)	(54)
Commonwealth Edison Co [Member] \| Return on borrowed funds
Other Non-Cash Operating Activities [Abstract]
AFUDC - Equity	(8)	(4)
PECO Energy Co [Member]
Depreciation, Amortization and Accretion [Abstract]
Property, plant and equipment	88	82
Amortization of regulatory assets	4	4
Amortization of intangible assets, net	0	0
Amortization of energy contract assets and liabilities	0	0
Nuclear fuel	0	0
ARO accretion	0	0
Depreciation, Amortization and Accretion, Net	92	86
Other Non-Cash Operating Activities [Abstract]
Pension and non-pension postretirement benefit costs	(2)	2
Allowance for credit losses	27	24
Other decommissioning-related activity	0	0
Energy-related options	0	0
True-up adjustments to decoupling mechanisms and formula rates	6	10
Long-term incentive plan	0	0
Amortization of operating ROU asset	0	0
AFUDC - Equity	(7)	(6)
PECO Energy Co [Member] \| Other Non-Cash Activity
Other Non-Cash Operating Activities [Abstract]
True-up adjustments to decoupling mechanisms and formula rates	(6)	(10)
PECO Energy Co [Member] \| Return on borrowed funds
Other Non-Cash Operating Activities [Abstract]
AFUDC - Equity	(7)	(6)
Baltimore Gas and Electric Company [Member]
Depreciation, Amortization and Accretion [Abstract]
Property, plant and equipment	117	106
Amortization of regulatory assets	54	46
Amortization of intangible assets, net	0	0
Amortization of energy contract assets and liabilities	0	0
Nuclear fuel	0	0
ARO accretion	0	0
Depreciation, Amortization and Accretion, Net	171	152
Other Non-Cash Operating Activities [Abstract]
Pension and non-pension postretirement benefit costs	12	14
Allowance for credit losses	18	4
Other decommissioning-related activity	0	0
Energy-related options	0	0
True-up adjustments to decoupling mechanisms and formula rates	(12)	18
Long-term incentive plan	0	0
Amortization of operating ROU asset	7	7
AFUDC - Equity	(6)	(7)
Baltimore Gas and Electric Company [Member] \| Other Non-Cash Activity
Other Non-Cash Operating Activities [Abstract]
True-up adjustments to decoupling mechanisms and formula rates	12	(18)
Baltimore Gas and Electric Company [Member] \| Return on borrowed funds
Other Non-Cash Operating Activities [Abstract]
AFUDC - Equity	(6)	(7)
Pepco Holdings LLC [Member]
Depreciation, Amortization and Accretion [Abstract]
Property, plant and equipment	164	154
Amortization of regulatory assets	54	56
Amortization of intangible assets, net	0	0
Amortization of energy contract assets and liabilities	0	0
Nuclear fuel	0	0
ARO accretion	0	0
Depreciation, Amortization and Accretion, Net	218	210
Other Non-Cash Operating Activities [Abstract]
Pension and non-pension postretirement benefit costs	13	12
Allowance for credit losses	18	10
Other decommissioning-related activity	0	0
Energy-related options	0	0
True-up adjustments to decoupling mechanisms and formula rates	(5)	46
Long-term incentive plan	0	0
Amortization of operating ROU asset	7	7
AFUDC - Equity	(15)	(11)
Pepco Holdings LLC [Member] \| Other Non-Cash Activity
Other Non-Cash Operating Activities [Abstract]
True-up adjustments to decoupling mechanisms and formula rates	5	(46)
Pepco Holdings LLC [Member] \| Return on borrowed funds
Other Non-Cash Operating Activities [Abstract]
AFUDC - Equity	(15)	(11)
Potomac Electric Power Company [Member]
Depreciation, Amortization and Accretion [Abstract]
Property, plant and equipment	72	67
Amortization of regulatory assets	36	35
Amortization of intangible assets, net	0	0
Amortization of energy contract assets and liabilities	0	0
Nuclear fuel	0	0
ARO accretion	0	0
Depreciation, Amortization and Accretion, Net	108	102
Other Non-Cash Operating Activities [Abstract]
Pension and non-pension postretirement benefit costs	2	2
Allowance for credit losses	9	5
Other decommissioning-related activity	0	0
Energy-related options	0	0
True-up adjustments to decoupling mechanisms and formula rates	(7)	26
Long-term incentive plan	0	0
Amortization of operating ROU asset	2	1
AFUDC - Equity	(11)	(9)
Potomac Electric Power Company [Member] \| Other Non-Cash Activity
Other Non-Cash Operating Activities [Abstract]
True-up adjustments to decoupling mechanisms and formula rates	7	(26)
Potomac Electric Power Company [Member] \| Return on borrowed funds
Other Non-Cash Operating Activities [Abstract]
AFUDC - Equity	(11)	(9)
Delmarva Power and Light Company [Member]
Depreciation, Amortization and Accretion [Abstract]
Property, plant and equipment	45	42
Amortization of regulatory assets	12	11
Amortization of intangible assets, net	0	0
Amortization of energy contract assets and liabilities	0	0
Nuclear fuel	0	0
ARO accretion	0	0
Depreciation, Amortization and Accretion, Net	57	53
Other Non-Cash Operating Activities [Abstract]
Pension and non-pension postretirement benefit costs	1	1
Allowance for credit losses	6	4
Other decommissioning-related activity	0	0
Energy-related options	0	0
True-up adjustments to decoupling mechanisms and formula rates	(1)	9
Long-term incentive plan	0	0
Amortization of operating ROU asset	2	3
AFUDC - Equity	(2)	(1)
Delmarva Power and Light Company [Member] \| Other Non-Cash Activity
Other Non-Cash Operating Activities [Abstract]
True-up adjustments to decoupling mechanisms and formula rates	1	(9)
Delmarva Power and Light Company [Member] \| Return on borrowed funds
Other Non-Cash Operating Activities [Abstract]
AFUDC - Equity	(2)	(1)
Atlantic City Electric Company [Member]
Depreciation, Amortization and Accretion [Abstract]
Property, plant and equipment	41	37
Amortization of regulatory assets	6	10
Amortization of intangible assets, net	0	0
Amortization of energy contract assets and liabilities	0	0
Nuclear fuel	0	0
ARO accretion	0	0
Depreciation, Amortization and Accretion, Net	47	47
Other Non-Cash Operating Activities [Abstract]
Pension and non-pension postretirement benefit costs	3	3
Allowance for credit losses	3	1
Other decommissioning-related activity	0	0
Energy-related options	0	0
True-up adjustments to decoupling mechanisms and formula rates	3	11
Long-term incentive plan	0	0
Amortization of operating ROU asset	1	1
AFUDC - Equity	(2)	(1)
Atlantic City Electric Company [Member] \| Other Non-Cash Activity
Other Non-Cash Operating Activities [Abstract]
True-up adjustments to decoupling mechanisms and formula rates	(3)	(11)
Atlantic City Electric Company [Member] \| Return on borrowed funds
Other Non-Cash Operating Activities [Abstract]
AFUDC - Equity	$ (2)	$ (1)

Supplemental Financial Inform_6

Supplemental Financial Information - Balance Sheet (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Dec. 31, 2020
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	$ 2,476	$ 672	$ 1,908	$ 663
Restricted cash	430	321	374	438
Restricted cash included in other long-term assets	92	44	52	53
Cash, restricted cash, and cash equivalents - Held for Sale		582		12
Total cash, restricted cash, and cash equivalents	2,998	1,619	2,334	1,166
Accrued Expenses [Abstract]
Compensation-related accruals	370	596
Taxes accrued	258	253
Interest accrued	346	297
Commonwealth Edison Co [Member]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	343	131	86	83
Restricted cash	246	210	270	279
Restricted cash included in other long-term assets	92	43	43	43
Cash, restricted cash, and cash equivalents - Held for Sale		0		0
Total cash, restricted cash, and cash equivalents	681	384	399	405
Accrued Expenses [Abstract]
Compensation-related accruals	95	155
Taxes accrued	95	94
Interest accrued	66	116
PECO Energy Co [Member]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	26	36	48	19
Restricted cash	8	8	7	7
Restricted cash included in other long-term assets	0	0	0	0
Cash, restricted cash, and cash equivalents - Held for Sale		0		0
Total cash, restricted cash, and cash equivalents	34	44	55	26
Accrued Expenses [Abstract]
Compensation-related accruals	51	77
Taxes accrued	15	14
Interest accrued	36	41
Baltimore Gas and Electric Company [Member]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	41	51	21	144
Restricted cash	34	4	1	1
Restricted cash included in other long-term assets	0	0	0	0
Cash, restricted cash, and cash equivalents - Held for Sale		0		0
Total cash, restricted cash, and cash equivalents	75	55	22	145
Accrued Expenses [Abstract]
Compensation-related accruals	48	78
Taxes accrued	78	53
Interest accrued	39	44
Pepco Holdings LLC [Member]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	796	136	558	111
Restricted cash	106	77	37	39
Restricted cash included in other long-term assets	0	0	9	10
Cash, restricted cash, and cash equivalents - Held for Sale		0		0
Total cash, restricted cash, and cash equivalents	902	213	604	160
Accrued Expenses [Abstract]
Compensation-related accruals	73	113
Taxes accrued	94	96
Interest accrued	77	52
Potomac Electric Power Company [Member]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	502	34	134	30
Restricted cash	34	34	33	35
Restricted cash included in other long-term assets	0	0	0	0
Cash, restricted cash, and cash equivalents - Held for Sale		0		0
Total cash, restricted cash, and cash equivalents	536	68	167	65
Accrued Expenses [Abstract]
Compensation-related accruals	26	35
Taxes accrued	85	88
Interest accrued	37	28
Delmarva Power and Light Company [Member]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	120	28	64	15
Restricted cash	73	43	0	0
Restricted cash included in other long-term assets	0	0	0	0
Cash, restricted cash, and cash equivalents - Held for Sale		0		0
Total cash, restricted cash, and cash equivalents	193	71	64	15
Accrued Expenses [Abstract]
Compensation-related accruals	15	20
Taxes accrued	10	9
Interest accrued	21	8
Atlantic City Electric Company [Member]
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Cash and cash equivalents	168	29	353	17
Restricted cash	0	0	4	3
Restricted cash included in other long-term assets	0	0	9	10
Cash, restricted cash, and cash equivalents - Held for Sale		0		0
Total cash, restricted cash, and cash equivalents	168	29	$ 366	$ 30
Accrued Expenses [Abstract]
Compensation-related accruals	12	17
Taxes accrued	9	11
Interest accrued	$ 17	$ 11

Related Party Transactions - Op

Related Party Transactions - Operating Revenues and Purchased Power and Fuel (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Related Party Transaction [Line Items]
Revenue from Related Parties	$ 6	$ 7
Purchased power and/or fuel from affiliates	(159)	(293)
Exelon Generation Co L L C [Member] \| Commonwealth Edison Co Affiliate [Member]
Related Party Transaction [Line Items]
Revenue from Related Parties	59	85
Exelon Generation Co L L C [Member] \| PECO Energy Co Affiliate [Member]
Related Party Transaction [Line Items]
Revenue from Related Parties	33	42
Exelon Generation Co L L C [Member] \| Baltimore Gas And Electric Company Affiliate [Member]
Related Party Transaction [Line Items]
Revenue from Related Parties	18	72
Exelon Generation Co L L C [Member] \| Pepco Holdings LLC Affiliate [Member]
Related Party Transaction [Line Items]
Revenue from Related Parties	51	100
Exelon Generation Co L L C [Member] \| Potomac Electric Power Co Affiliate [Member]
Related Party Transaction [Line Items]
Revenue from Related Parties	39	75
Exelon Generation Co L L C [Member] \| Delmarva Power and Light Co Affiliate [Member]
Related Party Transaction [Line Items]
Revenue from Related Parties	10	21
Exelon Generation Co L L C [Member] \| Atlantic City Electric Co Affiliate [Member]
Related Party Transaction [Line Items]
Revenue from Related Parties	2	4
Commonwealth Edison Co [Member]
Related Party Transaction [Line Items]
Revenue from Related Parties	6	6
Purchased power and/or fuel from affiliates	$ (59)	$ (85)

Related Party Transactions - BS

Related Party Transactions - BSC and PHISCO Service Companies (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Exelon Business Services Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction Capitalized Costs Support Services	$ 205	$ 114
PHI Service Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction Capitalized Costs Support Services	19	17
Commonwealth Edison Co [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	85	71
Commonwealth Edison Co [Member] \| Exelon Business Services Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	85	71
Related Party Transaction Capitalized Costs Support Services	85	45
PECO Energy Co [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	51	41
PECO Energy Co [Member] \| Exelon Business Services Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	49	39
Related Party Transaction Capitalized Costs Support Services	36	17
Baltimore Gas and Electric Company [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	51	45
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	51	43
Related Party Transaction Capitalized Costs Support Services	38	20
Pepco Holdings LLC [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	51	40
Pepco Holdings LLC [Member] \| Exelon Business Services Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	50	39
Related Party Transaction Capitalized Costs Support Services	46	32
Pepco Holdings LLC [Member] \| PHI Service Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction Capitalized Costs Support Services	19	17
Potomac Electric Power Company [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	58	52
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	29	22
Related Party Transaction Capitalized Costs Support Services	17	13
Potomac Electric Power Company [Member] \| PHI Service Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	29	30
Related Party Transaction Capitalized Costs Support Services	8	7
Delmarva Power and Light Company [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	42	39
Delmarva Power and Light Company [Member] \| Exelon Business Services Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	18	14
Related Party Transaction Capitalized Costs Support Services	14	10
Delmarva Power and Light Company [Member] \| PHI Service Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	24	25
Related Party Transaction Capitalized Costs Support Services	6	5
Atlantic City Electric Company [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	37	34
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	15	12
Related Party Transaction Capitalized Costs Support Services	15	8
Atlantic City Electric Company [Member] \| PHI Service Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Expenses from Transactions with Related Party	21	22
Related Party Transaction Capitalized Costs Support Services	$ 5	$ 5

Related Party Transactions - Cu

Related Party Transactions - Current Receivables From/Payables To Affiliates (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	$ 234	$ 523
Accounts Payable, Related Parties, Current	6	5
Commonwealth Edison Co [Member]
Related Party Transaction [Line Items]
Accounts Payable, Related Parties, Current	66	121
Accounts Receivable, Related Parties, Current	3	16
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
Commonwealth Edison Co [Member] \| Affiliated Entity [Member]
Related Party Transaction [Line Items]
Accounts Payable, Related Parties, Current	66	121
Commonwealth Edison Co [Member] \| PECO Energy Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
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	0
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	0
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	3
PECO Energy Co [Member]
Related Party Transaction [Line Items]
Accounts Payable, Related Parties, Current	38	70
Accounts Receivable, Related Parties, Current	0	1
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
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	0	1
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	0
Baltimore Gas and Electric Company [Member]
Related Party Transaction [Line Items]
Accounts Payable, Related Parties, Current	37	48
Accounts Receivable, Related Parties, Current	0	1
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
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	0	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	0
Pepco Holdings LLC [Member]
Related Party Transaction [Line Items]
Accounts Payable, Related Parties, Current	51	104
Accounts Receivable, Related Parties, Current	0	2
Pepco Holdings LLC [Member] \| Affiliated Entity [Member]
Related Party Transaction [Line Items]
Accounts Payable, Related Parties, Current	18	16
Potomac Electric Power Company [Member]
Related Party Transaction [Line Items]
Accounts Payable, Related Parties, Current	34	59
Accounts Receivable, Related Parties, Current	0	0
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
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	0
Delmarva Power and Light Company [Member]
Related Party Transaction [Line Items]
Accounts Payable, Related Parties, Current	15	33
Accounts Receivable, Related Parties, Current	0	1
Delmarva Power and Light Company [Member] \| Exelon Generation Co LLC Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current		0
Delmarva Power and Light Company [Member] \| Commonwealth Edison Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Delmarva Power and Light Company [Member] \| PECO Energy Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Delmarva Power and Light 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
Delmarva Power and Light Company [Member] \| Pepco Holdings LLC Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Delmarva Power and Light Company [Member] \| Potomac Electric Power Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	1
Delmarva Power and Light Company [Member] \| Atlantic City Electric Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Delmarva Power and Light Company [Member] \| Other Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	0
Atlantic City Electric Company [Member]
Related Party Transaction [Line Items]
Accounts Payable, Related Parties, Current	23	31
Accounts Receivable, Related Parties, Current	0	2
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
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	0	1
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	0	1
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	0
Business Services Company [Member]
Related Party Transaction [Line Items]
Accounts Receivable, Related Parties, Current	173	306
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
Business Services Company [Member] \| Commonwealth Edison Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	64	71
Business Services Company [Member] \| PECO Energy Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	33	36
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	35	41
Business Services Company [Member] \| Pepco Holdings LLC Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	7	5
Business Services Company [Member] \| Potomac Electric Power Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	19	21
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	3	17
Business Services Company [Member] \| Atlantic City Electric Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	12	13
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]
Accounts Receivable, Related Parties, Current	39	32
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
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	1	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	15	12
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	12	11
PHI Service Company [Member] \| Atlantic City Electric Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	11	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]
Accounts Payable, Related Parties, Current	3	14
Accounts Receivable, Related Parties, Current	19	47
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
Other Legal Entities [Member] \| Commonwealth Edison Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	2	9
Other Legal Entities [Member] \| PECO Energy Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	5	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	2	3
Other Legal Entities [Member] \| Pepco Holdings LLC Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	10	9
Other Legal Entities [Member] \| Potomac Electric Power Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current	0	3
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	0	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	$ 0	2
Exelon Generation Co LLC Affiliate [Member]
Related Party Transaction [Line Items]
Accounts Payable, Related Parties, Current		131
Accounts Receivable, Related Parties, Current		117
Exelon Generation Co LLC Affiliate [Member] \| Commonwealth Edison Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current		41
Exelon Generation Co LLC Affiliate [Member] \| PECO Energy Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current		30
Exelon Generation Co LLC Affiliate [Member] \| Baltimore Gas And Electric Company Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current		4
Exelon Generation Co LLC Affiliate [Member] \| Pepco Holdings LLC Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current		0
Exelon Generation Co LLC Affiliate [Member] \| Potomac Electric Power Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current		20
Exelon Generation Co LLC Affiliate [Member] \| Delmarva Power and Light Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current		4
Exelon Generation Co LLC Affiliate [Member] \| Atlantic City Electric Co Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current		7
Exelon Generation Co LLC Affiliate [Member] \| Other Affiliate [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Due from (to) Related Party, Current		$ 11

Related Party Transactions - Lo

Related Party Transactions - Long Term Debt to Financing Trusts (Details) - USD ($) $ in Millions	Mar. 31, 2022	Dec. 31, 2021
Related Party Transaction [Line Items]
Long-term debt to financing trust	$ 390	$ 390
ComEd Financing Three Affiliate [Member]
Related Party Transaction [Line Items]
Long-term debt to financing trust	206	206
PECO Trust Three Affiliate [Member]
Related Party Transaction [Line Items]
Long-term debt to financing trust	81	81
PECO Trust Four Affiliate [Member]
Related Party Transaction [Line Items]
Long-term debt to financing trust	103	103
Commonwealth Edison Co [Member]
Related Party Transaction [Line Items]
Long-term debt to financing trust	205	205
Commonwealth Edison Co [Member] \| ComEd Financing Three Affiliate [Member]
Related Party Transaction [Line Items]
Long-term debt to financing trust	205	205
Commonwealth Edison Co [Member] \| PECO Trust Three Affiliate [Member]
Related Party Transaction [Line Items]
Long-term debt to financing trust	0	0
Commonwealth Edison Co [Member] \| PECO Trust Four Affiliate [Member]
Related Party Transaction [Line Items]
Long-term debt to financing trust	0	0
PECO Energy Co [Member]
Related Party Transaction [Line Items]
Long-term debt to financing trust	184	184
PECO Energy Co [Member] \| ComEd Financing Three Affiliate [Member]
Related Party Transaction [Line Items]
Long-term debt to financing trust	0	0
PECO Energy Co [Member] \| PECO Trust Three Affiliate [Member]
Related Party Transaction [Line Items]
Long-term debt to financing trust	81	81
PECO Energy Co [Member] \| PECO Trust Four Affiliate [Member]
Related Party Transaction [Line Items]
Long-term debt to financing trust	$ 103	$ 103