Mississippi Power (MSPWP) 10-Q26 Oct 222022 Q3 Quarterly reportFinancial data

Company Profile

Cover Page

Cover Page	9 Months Ended
Cover Page	Sep. 30, 2022 shares
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2022
Document Transition Report	false
Entity File Number	1-3526
Entity Registrant Name	The Southern Company
Entity Tax Identification Number	58-0690070
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	30 Ivan Allen Jr. Boulevard, N.W.
Entity Address, City or Town	Atlanta
Entity Address, State or Province	GA
Entity Address, Postal Zip Code	30308
City Area Code	404
Local Phone Number	506-5000
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 (in shares)	1,088,672,828
Entity Central Index Key	0000092122
Amendment Flag	false
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Common Stock, par value $5 per share
Document Information [Line Items]
Title of 12(b) Security	Common Stock, par value $5 per share
Trading Symbol	SO
Security Exchange Name	NYSE
Series 2017B 5.25% Junior Subordinated Notes due 2077
Document Information [Line Items]
Title of 12(b) Security	Series 2017B 5.25% Junior Subordinated Notes due 2077
Trading Symbol	SOJC
Security Exchange Name	NYSE
2019 Series A Corporate Units
Document Information [Line Items]
Title of 12(b) Security	2019 Series A Corporate Units
Trading Symbol	SOLN
Security Exchange Name	NYSE
Series 2020A 4.95% Junior Subordinated Notes due 2080
Document Information [Line Items]
Title of 12(b) Security	Series 2020A 4.95% Junior Subordinated Notes due 2080
Trading Symbol	SOJD
Security Exchange Name	NYSE
Series 2020C 4.20% Junior Subordinated Notes due 2060
Document Information [Line Items]
Title of 12(b) Security	Series 2020C 4.20% Junior Subordinated Notes due 2060
Trading Symbol	SOJE
Security Exchange Name	NYSE
Series 2021B 1.875% Fixed-to-Fixed Reset Rate Junior Subordinated Notes due 2081
Document Information [Line Items]
Title of 12(b) Security	Series 2021B 1.875% Fixed-to-Fixed Reset Rate Junior Subordinated Notes due 2081
Trading Symbol	SO 81
Security Exchange Name	NYSE
ALABAMA POWER CO
Document Information [Line Items]
Entity File Number	1-3164
Entity Registrant Name	Alabama Power Company
Entity Tax Identification Number	63-0004250
Entity Incorporation, State or Country Code	AL
Entity Address, Address Line One	600 North 18th Street
Entity Address, City or Town	Birmingham
Entity Address, State or Province	AL
Entity Address, Postal Zip Code	35203
City Area Code	205
Local Phone Number	257-1000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)	30,537,500
Entity Central Index Key	0000003153
ALABAMA POWER CO \| 5.00% Series Class A Preferred Stock
Document Information [Line Items]
Title of 12(b) Security	5.00% Series Class A Preferred Stock
Trading Symbol	ALP PR Q
Security Exchange Name	NYSE
GEORGIA POWER CO
Document Information [Line Items]
Entity File Number	1-6468
Entity Registrant Name	Georgia Power Company
Entity Tax Identification Number	58-0257110
Entity Incorporation, State or Country Code	GA
Entity Address, Address Line One	241 Ralph McGill Boulevard, N.E.
Entity Address, City or Town	Atlanta
Entity Address, State or Province	GA
Entity Address, Postal Zip Code	30308
City Area Code	404
Local Phone Number	506-6526
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)	9,261,500
Entity Central Index Key	0000041091
GEORGIA POWER CO \| Series 2017A 5.00% Junior Subordinated Notes due 2077
Document Information [Line Items]
Title of 12(b) Security	Series 2017A 5.00% Junior Subordinated Notes due 2077
Trading Symbol	GPJA
Security Exchange Name	NYSE
MISSISSIPPI POWER CO
Document Information [Line Items]
Entity File Number	001-11229
Entity Registrant Name	Mississippi Power Company
Entity Tax Identification Number	64-0205820
Entity Incorporation, State or Country Code	MS
Entity Address, Address Line One	2992 West Beach Boulevard
Entity Address, City or Town	Gulfport
Entity Address, State or Province	MS
Entity Address, Postal Zip Code	39501
City Area Code	228
Local Phone Number	864-1211
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)	1,121,000
Entity Central Index Key	0000066904
SOUTHERN POWER CO
Document Information [Line Items]
Entity File Number	001-37803
Entity Registrant Name	Southern Power Company
Entity Tax Identification Number	58-2598670
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	30 Ivan Allen Jr. Boulevard, N.W.
Entity Address, City or Town	Atlanta
Entity Address, State or Province	GA
Entity Address, Postal Zip Code	30308
City Area Code	404
Local Phone Number	506-5000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)	1,000
Entity Central Index Key	0001160661
SOUTHERN POWER CO \| Series 2016B 1.850% Senior Notes due 2026
Document Information [Line Items]
Title of 12(b) Security	Series 2016B 1.850% Senior Notes due 2026
Trading Symbol	SO/26A
Security Exchange Name	NYSE
SOUTHERN Co GAS
Document Information [Line Items]
Entity File Number	1-14174
Entity Registrant Name	Southern Company Gas
Entity Tax Identification Number	58-2210952
Entity Incorporation, State or Country Code	GA
Entity Address, Address Line One	Ten Peachtree Place, N.E.
Entity Address, City or Town	Atlanta
Entity Address, State or Province	GA
Entity Address, Postal Zip Code	30309
City Area Code	404
Local Phone Number	584-4000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)	100
Entity Central Index Key	0001004155

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income (Unaudited) - Southern - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Operating Revenues:
Total operating revenues	$ 8,378	$ 6,238	$ 22,232	$ 17,346
Operating Expenses:
Other operations and maintenance	1,547	1,446	4,621	4,257
Depreciation and amortization	922	896	2,728	2,658
Taxes other than income taxes	352	312	1,073	969
Estimated loss on Plant Vogtle Units 3 and 4	(70)	264	(18)	772
Gain on dispositions, net	(20)	(125)	(53)	(179)
Total operating expenses	6,185	4,515	17,000	13,317
Operating Income	2,193	1,723	5,232	4,029
Other Income and (Expense):
Allowance for equity funds used during construction	59	49	163	140
Earnings from equity method investments	28	30	109	35
Interest expense, net of amounts capitalized	(511)	(451)	(1,461)	(1,352)
Other income (expense), net	132	131	414	290
Total other income and (expense)	(292)	(241)	(775)	(887)
Earnings Before Income Taxes	1,901	1,482	4,457	3,142
Income taxes (benefit)	414	372	891	550
Consolidated Net Income	1,487	1,110	3,566	2,592
Dividends on preferred stock of subsidiaries	3	4	10	11
Net income (loss) attributable to noncontrolling interests	12	5	(55)	(27)
Net Income	$ 1,472	$ 1,101	$ 3,611	$ 2,608
Earnings per share -
Basic (in dollars per share)	$ 1.36	$ 1.04	$ 3.38	$ 2.46
Diluted (in dollars per share)	$ 1.35	$ 1.03	$ 3.36	$ 2.44
Average number of shares of common stock outstanding — (in millions)
Basic (in shares)	1,082	1,061	1,070	1,060
Diluted (in shares)	1,088	1,068	1,076	1,067
Retail electric revenues
Operating Revenues:
Total operating revenues	$ 5,961	$ 4,551	$ 14,363	$ 11,492
Wholesale Electric
Operating Revenues:
Total operating revenues	1,197	731	2,798	1,822
Other electric revenues
Operating Revenues:
Total operating revenues	185	179	554	525
Natural Gas
Operating Revenues:
Total operating revenues	857	623	3,998	2,994
Natural gas
Operating Expenses:
Less Gross Gas Costs	294	129	1,840	943
Alternative revenue programs
Operating Revenues:
Total operating revenues	(1)	(1)	0	3
Other revenues
Operating Revenues:
Total operating revenues	178	154	519	513
Operating Expenses:
Less Gross Gas Costs	92	71	275	255
Fuel
Operating Expenses:
Less Gross Gas Costs	2,423	1,234	5,249	2,930
Purchased power
Operating Expenses:
Less Gross Gas Costs	$ 645	$ 288	$ 1,285	$ 712

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Income (Unaudited) - Southern (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Total operating revenues	$ 8,378	$ 6,238	$ 22,232	$ 17,346
Natural Gas
Total operating revenues	857	623	3,998	2,994
Alternative revenue programs
Total operating revenues	$ (1)	$ (1)	$ 0	$ 3

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - Southern - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Statement of Comprehensive Income [Abstract]
Net income	$ 1,487	$ 1,110	$ 3,566	$ 2,592
Qualifying hedges:
Changes in fair value, net of tax	0	1	(27)	(15)
Reclassification adjustment for amounts included in net income, net of tax	26	31	100	81
Pension and other postretirement benefit plans:
Reclassification adjustment for amounts included in net income, net of tax	2	4	8	10
Total other comprehensive income	28	36	81	76
Comprehensive Income	1,515	1,146	3,647	2,668
Dividends on preferred stock of subsidiaries	3	4	10	11
Comprehensive income (loss) attributable to noncontrolling interests	12	5	(55)	(27)
Comprehensive Income	$ 1,500	$ 1,137	$ 3,692	$ 2,684

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - Southern (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Statement of Comprehensive Income [Abstract]
Changes in fair value, tax	$ 2	$ 1	$ (5)	$ (4)
Qualifying hedges, reclassification adjustment, tax	8	10	32	27
Reclassification adjustment for amounts included in net income, tax	$ 1	$ 1	$ 3	$ 4

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Cash Flows (Unaudited) - Southern - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Operating Activities:
Net income (loss)	$ 3,566	$ 2,592
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	3,084	2,944
Deferred income taxes	608	89
Utilization of federal investment tax credits	266	256
Allowance for equity funds used during construction	(163)	(140)
Mark-to-market adjustments	(33)	147
Pension, postretirement, and other employee benefits	(322)	(218)
Settlement of asset retirement obligations	(314)	(341)
Stock based compensation expense	116	134
Estimated loss on Plant Vogtle Units 3 and 4	(18)	772
Storm damage accruals	160	166
Gain on dispositions, net	(41)	(171)
Natural gas cost under recovery – long-term	207	(79)
Retail fuel cost under recovery – long-term	(1,701)	(209)
Other, net	(45)	156
Changes in certain current assets and liabilities —
Receivables	(327)	2
Materials and supplies	(138)	(91)
Natural gas for sale, net of temporary LIFO liquidation	(136)	20
Natural gas cost under recovery	(124)	(432)
Other current assets	(343)	(180)
Accounts payable	805	(45)
Accrued taxes	167	288
Accrued compensation	(123)	(93)
Accrued interest	(101)	(110)
Retail fuel cost over recovery	(1)	(150)
Other current liabilities	(32)	(226)
Net cash provided from operating activities	5,017	5,081
Investing Activities:
Business acquisitions, net of cash acquired	0	(345)
Property additions	(5,502)	(5,222)
Nuclear decommissioning trust fund purchases	(858)	(1,301)
Nuclear decommissioning trust fund sales	854	1,297
Proceeds from dispositions	120	160
Cost of removal, net of salvage	(518)	(282)
Payments pursuant to LTSAs	(121)	(145)
Other investing activities	73	(12)
Net cash used for investing activities	(5,952)	(5,850)
Financing Activities:
Decrease in notes payable, net	(349)	(203)
Proceeds —
Long-term debt	3,800	6,793
Short-term borrowings	1,200	325
Common stock	1,803	62
Redemptions and repurchases —
Long-term debt	(1,932)	(3,060)
Short-term borrowings	(900)	(25)
Capital contributions from noncontrolling interests	73	415
Distributions to noncontrolling interests	(175)	(204)
Payment of common stock dividends	(2,166)	(2,077)
Other financing activities	(235)	(224)
Net cash provided from financing activities	1,119	1,802
Net Change in Cash, Cash Equivalents, and Restricted Cash	184	1,033
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	1,829	1,068
Cash, Cash Equivalents, and Restricted Cash at End of Period	2,013	2,101
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	1,425	1,417
Income taxes, net	160	92
Noncash transactions —
Accrued property additions at year-end	872	915
Contributions from noncontrolling interests	0	89
Contributions of wind turbine equipment	0	82
Right-of-use assets obtained under leases	141	92
Reassessment of right-of-use assets under operating leases	$ 40	$ 0

Condensed Consolidated Statem_6

Condensed Consolidated Statements of Cash Flows (Unaudited) - Southern (Parenthetical) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Statement of Cash Flows [Abstract]
Net cash paid for capitalized interest	$ 74	$ 68

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - Southern - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Current Assets:
Cash and cash equivalents	$ 2,009	$ 1,798
Receivables —
Customer accounts	2,223	1,806
Unbilled revenues	593	711
Other accounts and notes	533	523
Accumulated provision for uncollectible accounts	(80)	(78)
Materials and supplies	1,657	1,543
Fossil fuel for generation	526	450
Natural gas for sale	498	362
Prepaid expenses	373	330
Assets from risk management activities, net of collateral	289	151
Regulatory assets – asset retirement obligations	284	219
Natural gas cost under recovery	390	266
Other regulatory assets	746	653
Other current assets	322	231
Total current assets	10,363	8,965
Property, Plant, and Equipment:
In service	116,236	115,592
Less: Accumulated depreciation	34,922	34,079
Plant in service, net of depreciation	81,314	81,513
Other utility plant, net	602	0
Nuclear fuel, at amortized cost	840	824
Construction work in progress	10,773	8,771
Total property, plant, and equipment	93,529	91,108
Other Property and Investments:
Goodwill	5,280	5,280
Nuclear decommissioning trusts, at fair value	2,031	2,542
Equity investments in unconsolidated subsidiaries	1,292	1,282
Other intangible assets, net of amortization	415	445
Miscellaneous property and investments	590	653
Total other property and investments	9,608	10,202
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	1,560	1,701
Deferred charges related to income taxes	854	824
Prepaid pension costs	2,019	1,657
Unamortized loss on reacquired debt	243	258
Deferred under recovered fuel clause revenues	1,697	410
Regulatory assets – asset retirement obligations, deferred	6,519	5,466
Other regulatory assets, deferred	6,121	5,577
Other deferred charges and assets	1,492	1,366
Total deferred charges and other assets	20,505	17,259
Total Assets	134,005	127,534
Current Liabilities:
Securities due within one year	3,241	2,157
Notes payable	1,398	1,440
Accounts payable	3,079	2,169
Customer deposits	516	479
Accrued taxes —
Accrued income taxes	129	50
Other accrued taxes	882	641
Accrued interest	431	533
Accrued compensation	961	1,070
Asset retirement obligations	689	697
Operating lease obligations	191	250
Other regulatory liabilities	440	563
Other current liabilities	844	872
Total current liabilities	12,801	10,921
Long-term Debt	50,427	50,120
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	9,916	8,862
Deferred credits related to income taxes	5,271	5,401
Accumulated deferred ITCs	2,154	2,216
Employee benefit obligations	1,466	1,550
Operating lease obligations, deferred	1,393	1,503
Asset retirement obligations, deferred	11,007	10,990
Other cost of removal obligations	1,950	2,103
Other regulatory liabilities, deferred	536	485
Other deferred credits and liabilities	1,366	816
Total deferred credits and other liabilities	35,059	33,926
Total Liabilities	98,287	94,967
Redeemable preferred stock	242	291
Total Stockholders' Equity	35,476	32,276
Total Liabilities and Stockholders' Equity	$ 134,005	$ 127,534

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) - Southern (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Other intangible assets, amortization	$ 331	$ 307

Condensed Consolidated Statem_7

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - Southern - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Treasury	Paid-In Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests
Beginning balance (in shares) at Dec. 31, 2020		1,058
Beginning balance (in shares) at Dec. 31, 2020			(1)
Beginning balance at Dec. 31, 2020	$ 32,234	$ 5,268	$ (46)	$ 11,834	$ 11,311	$ (395)	$ 4,262
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated net income (loss)	1,103				1,135		(32)
Other comprehensive income (loss)	28					28
Stock issued (in shares)		2
Stock issued	14	$ 5		9
Stock-based compensation	9			9
Cash dividends on common stock	(678)				(678)
Capital contributions from noncontrolling interests	403						403
Distributions to noncontrolling interests	(46)						(46)
Other	1			2			(1)
Ending balance (in shares) at Mar. 31, 2021		1,060
Ending balance (in shares) at Mar. 31, 2021			(1)
Ending balance at Mar. 31, 2021	33,068	$ 5,273	$ (46)	11,854	11,768	(367)	4,586
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated net income (loss)	372				372		0
Other comprehensive income (loss)	12					12
Stock issued	10	$ 1		9
Stock-based compensation	22			22
Cash dividends on common stock	(699)				(699)
Capital contributions from noncontrolling interests	29						29
Distributions to noncontrolling interests	(68)						(68)
Other	0		$ (2)	1	1
Ending balance (in shares) at Jun. 30, 2021		1,060
Ending balance (in shares) at Jun. 30, 2021			(1)
Ending balance at Jun. 30, 2021	32,746	$ 5,274	$ (48)	11,886	11,442	(355)	4,547
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated net income (loss)	1,106				1,101		5
Other comprehensive income (loss)	36					36
Stock issued (in shares)		1
Stock issued	38	$ 4		34
Stock-based compensation	22			22
Cash dividends on common stock	(700)				(700)
Capital contributions from noncontrolling interests	72						72
Distributions to noncontrolling interests	(94)						(94)
Other	(7)		$ 2	(10)	1
Ending balance (in shares) at Sep. 30, 2021		1,061
Ending balance (in shares) at Sep. 30, 2021			(1)
Ending balance at Sep. 30, 2021	33,219	$ 5,278	$ (46)	11,932	11,844	(319)	4,530
Beginning balance (in shares) at Dec. 31, 2021		1,061
Beginning balance (in shares) at Dec. 31, 2021			(1)
Beginning balance at Dec. 31, 2021	32,276	$ 5,279	$ (47)	11,950	10,929	(237)	4,402
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated net income (loss)	987				1,032		(45)
Other comprehensive income (loss)	42					42
Stock issued (in shares)		3
Stock issued	38	$ 7		31
Stock-based compensation	6			6
Cash dividends on common stock	(702)				(702)
Capital contributions from noncontrolling interests	73						73
Distributions to noncontrolling interests	(98)						(98)
Other	7		$ (2)	7	2
Ending balance (in shares) at Mar. 31, 2022		1,064
Ending balance (in shares) at Mar. 31, 2022			(1)
Ending balance at Mar. 31, 2022	32,629	$ 5,286	$ (49)	11,994	11,261	(195)	4,332
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated net income (loss)	1,085				1,107		(22)
Other comprehensive income (loss)	11					11
Stock issued	23	$ 2		21
Stock-based compensation	14			14
Cash dividends on common stock	(723)				(723)
Distributions to noncontrolling interests	(28)						(28)
Other	2		$ (2)	4
Ending balance (in shares) at Jun. 30, 2022		1,064
Ending balance (in shares) at Jun. 30, 2022			(1)
Ending balance at Jun. 30, 2022	33,013	$ 5,288	$ (51)	12,033	11,645	(184)	4,282
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated net income (loss)	1,484				1,472		12
Other comprehensive income (loss)	28					28
Stock issued (in shares)		26
Stock issued	1,742	$ 129		1,613
Stock-based compensation	15			15
Cash dividends on common stock	(741)				(741)
Distributions to noncontrolling interests	(57)						(57)
Other	(8)		$ (1)	(4)	(2)	(1)
Ending balance (in shares) at Sep. 30, 2022		1,090
Ending balance (in shares) at Sep. 30, 2022			(1)
Ending balance at Sep. 30, 2022	$ 35,476	$ 5,417	$ (52)	$ 13,657	$ 12,374	$ (157)	$ 4,237

Condensed Consolidated Statem_8

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - Southern (Parenthetical) - $ / shares	3 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021
Statement of Stockholders' Equity [Abstract]
Cash dividends (in dollars per share)	$ 0.68	$ 0.68	$ 0.66	$ 0.66	$ 0.66	$ 0.64

Condensed Statements of Income

Condensed Statements of Income (Unaudited) - APC - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Operating Revenues:
Total operating revenues	$ 8,378	$ 6,238	$ 22,232	$ 17,346
Operating Expenses:
Other operations and maintenance	1,547	1,446	4,621	4,257
Depreciation and amortization	922	896	2,728	2,658
Taxes other than income taxes	352	312	1,073	969
Total operating expenses	6,185	4,515	17,000	13,317
Operating Income	2,193	1,723	5,232	4,029
Other Income and (Expense):
Allowance for equity funds used during construction	59	49	163	140
Interest expense, net of amounts capitalized	(511)	(451)	(1,461)	(1,352)
Total other income (expense), net	132	131	414	290
Total other income and (expense)	(292)	(241)	(775)	(887)
Earnings Before Income Taxes	1,901	1,482	4,457	3,142
Income taxes (benefit)	414	372	891	550
Net income	1,487	1,110	3,566	2,592
Dividends on preferred stock of subsidiaries	3	4	10	11
Net Income	1,472	1,101	3,611	2,608
Retail electric revenues
Operating Revenues:
Total operating revenues	5,961	4,551	14,363	11,492
Wholesale Electric
Operating Revenues:
Total operating revenues	1,197	731	2,798	1,822
Other electric revenues
Operating Revenues:
Total operating revenues	185	179	554	525
Natural Gas
Operating Revenues:
Total operating revenues	857	623	3,998	2,994
Other revenues
Operating Revenues:
Total operating revenues	178	154	519	513
Operating Expenses:
Total cost of sales	92	71	275	255
Fuel
Operating Expenses:
Total cost of sales	2,423	1,234	5,249	2,930
Purchased power
Operating Expenses:
Total cost of sales	645	288	1,285	712
Alabama Power
Operating Revenues:
Total operating revenues	2,444	1,904	6,023	5,019
Operating Expenses:
Other operations and maintenance	418	401	1,270	1,175
Depreciation and amortization	220	214	652	640
Taxes other than income taxes	106	99	309	303
Total operating expenses	1,708	1,208	4,237	3,332
Operating Income	736	696	1,786	1,687
Other Income and (Expense):
Allowance for equity funds used during construction	18	14	51	38
Interest expense, net of amounts capitalized	(98)	(84)	(278)	(252)
Total other income (expense), net	38	29	101	93
Total other income and (expense)	(42)	(41)	(126)	(121)
Earnings Before Income Taxes	694	655	1,660	1,566
Income taxes (benefit)	166	152	394	366
Net income	528	503	1,266	1,200
Dividends on preferred stock of subsidiaries	3	4	10	11
Net Income	525	499	1,256	1,189
Alabama Power \| Retail electric revenues
Operating Revenues:
Total operating revenues	2,008	1,651	5,015	4,357
Alabama Power \| Wholesale revenues, non-affiliates
Operating Revenues:
Total operating revenues	250	107	522	285
Alabama Power \| Wholesale revenues, affiliates
Operating Revenues:
Total operating revenues	70	53	170	109
Alabama Power \| Other revenues
Operating Revenues:
Total operating revenues	116	93	316	268
Alabama Power \| Fuel
Operating Expenses:
Total cost of sales	666	373	1,399	927
Alabama Power \| Purchased power
Operating Expenses:
Total cost of sales	185	76	347	173
Alabama Power \| Purchased power, affiliates
Operating Expenses:
Total cost of sales	$ 113	$ 45	$ 260	$ 114

Condensed Statements of Compreh

Condensed Statements of Comprehensive Income (Unaudited) - APC - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Net income	$ 1,487	$ 1,110	$ 3,566	$ 2,592
Qualifying hedges:
Changes in fair value, net of tax	0	1	(27)	(15)
Reclassification adjustment for amounts included in net income, net of tax	26	31	100	81
Total other comprehensive income	28	36	81	76
Comprehensive Income	1,515	1,146	3,647	2,668
Alabama Power
Net income	528	503	1,266	1,200
Qualifying hedges:
Changes in fair value, net of tax	1	4	(1)	3
Reclassification adjustment for amounts included in net income, net of tax	1	1	3	3
Total other comprehensive income	2	5	2	6
Comprehensive Income	$ 530	$ 508	$ 1,268	$ 1,206

Condensed Statements of Compr_2

Condensed Statements of Comprehensive Income (Unaudited) - APC (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Changes in fair value, tax	$ 2	$ 1	$ (5)	$ (4)
Qualifying hedges, reclassification adjustment, tax	8	10	32	27
Alabama Power
Changes in fair value, tax	0	1	0	1
Qualifying hedges, reclassification adjustment, tax	$ 0	$ 0	$ 1	$ 1

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows (Unaudited) - APC - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Operating Activities:
Net income (loss)	$ 3,566	$ 2,592
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	3,084	2,944
Deferred income taxes	608	89
Pension, postretirement, and other employee benefits	(322)	(218)
Settlement of asset retirement obligations	(314)	(341)
Other, net	(45)	156
Changes in certain current assets and liabilities —
Receivables	(327)	2
Retail fuel cost over recovery	(1)	(150)
Other current assets	(343)	(180)
Accounts payable	805	(45)
Accrued taxes	167	288
Other current liabilities	(32)	(226)
Net cash provided from operating activities	5,017	5,081
Investing Activities:
Property additions	(5,502)	(5,222)
Nuclear decommissioning trust fund purchases	(858)	(1,301)
Nuclear decommissioning trust fund sales	854	1,297
Cost of removal, net of salvage	(518)	(282)
Other investing activities	73	(12)
Net cash used for investing activities	(5,952)	(5,850)
Redemptions and repurchases —
Payment of common stock dividends	(2,166)	(2,077)
Other financing activities	(235)	(224)
Net cash provided from financing activities	1,119	1,802
Net Change in Cash, Cash Equivalents, and Restricted Cash	184	1,033
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	1,829	1,068
Cash, Cash Equivalents, and Restricted Cash at End of Period	2,013	2,101
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	1,425	1,417
Income taxes, net	160	92
Noncash transactions —
Accrued property additions at year-end	872	915
Right-of-use assets obtained under leases	141	92
Alabama Power
Operating Activities:
Net income (loss)	1,266	1,200
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	817	748
Deferred income taxes	210	104
Pension, postretirement, and other employee benefits	(85)	(74)
Settlement of asset retirement obligations	(139)	(152)
Retail fuel cost under recovery – long-term	(413)	0
Other, net	(98)	(51)
Changes in certain current assets and liabilities —
Receivables	(296)	(128)
Fossil fuel stock	(40)	91
Prepayments	(34)	(24)
Retail fuel cost over recovery	(93)	(79)
Other current assets	(41)	(32)
Accounts payable	(22)	(230)
Accrued taxes	110	178
Other current liabilities	(70)	(132)
Net cash provided from operating activities	1,072	1,419
Investing Activities:
Property additions	(1,483)	(1,235)
Nuclear decommissioning trust fund purchases	(273)	(536)
Nuclear decommissioning trust fund sales	273	536
Cost of removal, net of salvage	(163)	(93)
Other investing activities	5	(7)
Net cash used for investing activities	(1,641)	(1,335)
Proceeds —
Proceeds — Senior notes	1,700	600
Redemptions and repurchases —
Senior notes	(550)	(200)
Other long-term debt	0	(206)
Capital contributions from parent company	660	630
Payment of common stock dividends	(762)	(738)
Other financing activities	(81)	(30)
Net cash provided from financing activities	967	56
Net Change in Cash, Cash Equivalents, and Restricted Cash	398	140
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	1,060	530
Cash, Cash Equivalents, and Restricted Cash at End of Period	1,458	670
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	278	246
Income taxes, net	178	183
Noncash transactions —
Accrued property additions at year-end	186	178
Right-of-use assets obtained under leases	$ 9	$ 2

Condensed Statements of Cash _2

Condensed Statements of Cash Flows (Unaudited) - APC (Parenthetical) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Net cash paid for capitalized interest	$ 74	$ 68
Alabama Power
Net cash paid for capitalized interest	$ 14	$ 11

Condensed Balance Sheets (Unaud

Condensed Balance Sheets (Unaudited) - APC - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Current Assets:
Cash and cash equivalents	$ 2,009	$ 1,798
Receivables —
Customer accounts	2,223	1,806
Unbilled revenues	593	711
Other accounts and notes	533	523
Accumulated provision for uncollectible accounts	(80)	(78)
Fossil fuel for generation	526	450
Materials and supplies	1,657	1,543
Prepaid expenses	373	330
Other regulatory assets	746	653
Other current assets	322	231
Total current assets	10,363	8,965
Property, Plant, and Equipment:
In service	116,236	115,592
Less: Accumulated depreciation	34,922	34,079
Plant in service, net of depreciation	81,314	81,513
Other utility plant, net	602	0
Nuclear fuel, at amortized cost	840	824
Construction work in progress	10,773	8,771
Total property, plant, and equipment	93,529	91,108
Other Property and Investments:
Nuclear decommissioning trusts, at fair value	2,031	2,542
Equity investments in unconsolidated subsidiaries	1,292	1,282
Miscellaneous property and investments	590	653
Total other property and investments	9,608	10,202
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	1,560	1,701
Deferred charges related to income taxes	854	824
Regulatory assets – asset retirement obligations, deferred	6,519	5,466
Other regulatory assets, deferred	6,121	5,577
Other deferred charges and assets	1,492	1,366
Total deferred charges and other assets	20,505	17,259
Total Assets	134,005	127,534
Current Liabilities:
Securities due within one year	3,241	2,157
Accounts payable —
Customer deposits	516	479
Accrued interest	431	533
Accrued compensation	961	1,070
Asset retirement obligations	689	697
Other regulatory liabilities	440	563
Other current liabilities	844	872
Total current liabilities	12,801	10,921
Long-term Debt	50,427	50,120
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	9,916	8,862
Deferred credits related to income taxes	5,271	5,401
Accumulated deferred ITCs	2,154	2,216
Employee benefit obligations	1,466	1,550
Operating lease obligations, deferred	1,393	1,503
Asset retirement obligations, deferred	11,007	10,990
Other cost of removal obligations	1,950	2,103
Other regulatory liabilities, deferred	536	485
Other deferred credits and liabilities	1,366	816
Total deferred credits and other liabilities	35,059	33,926
Total Liabilities	98,287	94,967
Redeemable preferred stock	242	291
Total Stockholders' Equity	35,476	32,276
Total Liabilities and Stockholders' Equity	134,005	127,534
Alabama Power
Current Assets:
Cash and cash equivalents	1,458	1,060
Receivables —
Customer accounts	573	410
Unbilled revenues	146	138
Affiliated	84	37
Other accounts and notes	131	55
Accumulated provision for uncollectible accounts	(13)	(14)
Fossil fuel for generation	199	159
Materials and supplies	568	548
Prepaid expenses	67	41
Other regulatory assets	298	208
Other current assets	129	67
Total current assets	3,640	2,709
Property, Plant, and Equipment:
In service	33,042	33,135
Less: Accumulated depreciation	10,393	10,313
Plant in service, net of depreciation	22,649	22,822
Other utility plant, net	602	0
Nuclear fuel, at amortized cost	242	247
Construction work in progress	1,524	1,147
Total property, plant, and equipment	25,017	24,216
Other Property and Investments:
Nuclear decommissioning trusts, at fair value	1,067	1,325
Equity investments in unconsolidated subsidiaries	58	57
Miscellaneous property and investments	128	126
Total other property and investments	1,253	1,508
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	70	108
Deferred charges related to income taxes	248	240
Prepaid pension and other postretirement benefit costs	605	513
Regulatory assets – asset retirement obligations, deferred	1,952	1,547
Other regulatory assets, deferred	2,048	1,807
Other deferred charges and assets	413	334
Total deferred charges and other assets	5,336	4,549
Total Assets	35,246	32,982
Current Liabilities:
Securities due within one year	202	751
Accounts payable —
Affiliated	401	309
Other	376	459
Customer deposits	106	106
Accrued taxes	209	98
Accrued interest	86	100
Accrued compensation	200	219
Asset retirement obligations	327	320
Other regulatory liabilities	89	215
Other current liabilities	97	125
Total current liabilities	2,093	2,702
Long-term Debt	10,628	8,936
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	3,829	3,573
Deferred credits related to income taxes	1,930	1,968
Accumulated deferred ITCs	82	88
Employee benefit obligations	171	171
Operating lease obligations, deferred	65	66
Asset retirement obligations, deferred	3,987	4,014
Other cost of removal obligations	57	192
Other regulatory liabilities, deferred	226	210
Other deferred credits and liabilities	62	58
Total deferred credits and other liabilities	10,409	10,340
Total Liabilities	23,130	21,978
Redeemable preferred stock	242	291
Total Stockholders' Equity	11,874	10,713
Total Liabilities and Stockholders' Equity	$ 35,246	$ 32,982

Condensed Statements of Common

Condensed Statements of Common Stockholders' Equity (Unaudited) - APC - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Paid-In Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Income (Loss)	Alabama Power	Alabama Power Common Stock	Alabama Power Paid-In Capital	Alabama Power Retained Earnings (Accumulated Deficit)	Alabama Power Accumulated Other Comprehensive Income (Loss)
Beginning balance (in shares) at Dec. 31, 2020							31
Beginning balance at Dec. 31, 2020	$ 32,234	$ 5,268	$ 11,834	$ 11,311	$ (395)	$ 9,810	$ 1,222	$ 5,413	$ 3,194	$ (19)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income after dividends on preferred stock						359			359
Capital contributions from parent company						602		602
Other comprehensive income (loss)	28				28	1				1
Cash dividends on common stock	(678)			(678)		(246)			(246)
Other	1		2
Ending balance (in shares) at Mar. 31, 2021							31
Ending balance at Mar. 31, 2021	33,068	5,273	11,854	11,768	(367)	10,526	$ 1,222	6,015	3,307	(18)
Beginning balance (in shares) at Dec. 31, 2020							31
Beginning balance at Dec. 31, 2020	32,234	5,268	11,834	11,311	(395)	9,810	$ 1,222	5,413	3,194	(19)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income after dividends on preferred stock	2,608					1,189
Ending balance (in shares) at Sep. 30, 2021							31
Ending balance at Sep. 30, 2021	33,219	5,278	11,932	11,844	(319)	10,903	$ 1,222	6,050	3,644	(13)
Beginning balance (in shares) at Mar. 31, 2021							31
Beginning balance at Mar. 31, 2021	33,068	5,273	11,854	11,768	(367)	10,526	$ 1,222	6,015	3,307	(18)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income after dividends on preferred stock						331			331
Capital contributions from parent company						26		26
Other comprehensive income (loss)	12				12	1				1
Cash dividends on common stock	(699)			(699)		(246)			(246)
Other	0		1	1		(1)			(1)
Ending balance (in shares) at Jun. 30, 2021							31
Ending balance at Jun. 30, 2021	32,746	5,274	11,886	11,442	(355)	10,637	$ 1,222	6,041	3,391	(17)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income after dividends on preferred stock	1,101					499			499
Capital contributions from parent company						9		9
Other comprehensive income (loss)	36				36	5				5
Cash dividends on common stock	(700)			(700)		(246)			(246)
Other	(7)		(10)	1		(1)				(1)
Ending balance (in shares) at Sep. 30, 2021							31
Ending balance at Sep. 30, 2021	33,219	5,278	11,932	11,844	(319)	10,903	$ 1,222	6,050	3,644	(13)
Beginning balance (in shares) at Dec. 31, 2021							31
Beginning balance at Dec. 31, 2021	32,276	5,279	11,950	10,929	(237)	10,713	$ 1,222	6,056	3,448	(13)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income after dividends on preferred stock						347			347
Capital contributions from parent company						626		626
Other comprehensive income (loss)	42				42
Cash dividends on common stock	(702)			(702)		(254)			(254)
Other	7		7	2
Ending balance (in shares) at Mar. 31, 2022							31
Ending balance at Mar. 31, 2022	32,629	5,286	11,994	11,261	(195)	11,432	$ 1,222	6,682	3,541	(13)
Beginning balance (in shares) at Dec. 31, 2021							31
Beginning balance at Dec. 31, 2021	32,276	5,279	11,950	10,929	(237)	10,713	$ 1,222	6,056	3,448	(13)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income after dividends on preferred stock	3,611					1,256
Ending balance (in shares) at Sep. 30, 2022							31
Ending balance at Sep. 30, 2022	35,476	5,417	13,657	12,374	(157)	11,874	$ 1,222	6,721	3,941	(10)
Beginning balance (in shares) at Mar. 31, 2022							31
Beginning balance at Mar. 31, 2022	32,629	5,286	11,994	11,261	(195)	11,432	$ 1,222	6,682	3,541	(13)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income after dividends on preferred stock						383			383
Capital contributions from parent company						32		32
Other comprehensive income (loss)	11				11	1				1
Cash dividends on common stock	(723)			(723)		(254)			(254)
Other	2		4
Ending balance (in shares) at Jun. 30, 2022							31
Ending balance at Jun. 30, 2022	33,013	5,288	12,033	11,645	(184)	11,594	$ 1,222	6,714	3,670	(12)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income after dividends on preferred stock	1,472					525			525
Capital contributions from parent company						7		7
Other comprehensive income (loss)	28				28	2				2
Cash dividends on common stock	(741)			(741)		(254)			(254)
Other	(8)		(4)	(2)	(1)
Ending balance (in shares) at Sep. 30, 2022							31
Ending balance at Sep. 30, 2022	$ 35,476	$ 5,417	$ 13,657	$ 12,374	$ (157)	$ 11,874	$ 1,222	$ 6,721	$ 3,941	$ (10)

Condensed Statements of Incom_2

Condensed Statements of Income (Unaudited) - GPC - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Operating Revenues:
Total operating revenues	$ 8,378	$ 6,238	$ 22,232	$ 17,346
Operating Expenses:
Other operations and maintenance	1,547	1,446	4,621	4,257
Depreciation and amortization	922	896	2,728	2,658
Taxes other than income taxes	352	312	1,073	969
Estimated loss on Plant Vogtle Units 3 and 4	(70)	264	(18)	772
Total operating expenses	6,185	4,515	17,000	13,317
Operating Income	2,193	1,723	5,232	4,029
Other Income and (Expense):
Allowance for equity funds used during construction	59	49	163	140
Interest expense, net of amounts capitalized	(511)	(451)	(1,461)	(1,352)
Other income (expense), net	132	131	414	290
Total other income and (expense)	(292)	(241)	(775)	(887)
Earnings Before Income Taxes	1,901	1,482	4,457	3,142
Income taxes (benefit)	414	372	891	550
Consolidated Net Income	1,487	1,110	3,566	2,592
Retail electric revenues
Operating Revenues:
Total operating revenues	5,961	4,551	14,363	11,492
Wholesale Electric
Operating Revenues:
Total operating revenues	1,197	731	2,798	1,822
Other electric revenues
Operating Revenues:
Total operating revenues	185	179	554	525
Natural Gas
Operating Revenues:
Total operating revenues	857	623	3,998	2,994
Other revenues
Operating Revenues:
Total operating revenues	178	154	519	513
Operating Expenses:
Less Gross Gas Costs	92	71	275	255
Fuel
Operating Expenses:
Less Gross Gas Costs	2,423	1,234	5,249	2,930
Purchased power
Operating Expenses:
Less Gross Gas Costs	645	288	1,285	712
GEORGIA POWER CO
Operating Revenues:
Total operating revenues	3,889	2,856	9,218	7,050
Operating Expenses:
Other operations and maintenance	595	544	1,686	1,558
Depreciation and amortization	359	345	1,066	1,025
Taxes other than income taxes	155	130	420	365
Estimated loss on Plant Vogtle Units 3 and 4	(70)	264	(18)	772
Total operating expenses	2,755	2,176	6,841	5,842
Operating Income	1,134	680	2,377	1,208
Other Income and (Expense):
Allowance for equity funds used during construction	37	33	102	94
Interest expense, net of amounts capitalized	(123)	(106)	(347)	(315)
Other income (expense), net	36	42	140	124
Total other income and (expense)	(50)	(31)	(105)	(97)
Earnings Before Income Taxes	1,084	649	2,272	1,111
Income taxes (benefit)	226	113	421	81
Consolidated Net Income	858	536	1,851	1,030
GEORGIA POWER CO \| Retail electric revenues
Operating Revenues:
Total operating revenues	3,703	2,652	8,629	6,465
GEORGIA POWER CO \| Wholesale Electric
Operating Revenues:
Total operating revenues	56	63	186	143
GEORGIA POWER CO \| Other revenues
Operating Revenues:
Total operating revenues	130	141	403	442
GEORGIA POWER CO \| Fuel
Operating Expenses:
Less Gross Gas Costs	841	432	1,887	1,088
GEORGIA POWER CO \| Purchased power
Operating Expenses:
Less Gross Gas Costs	304	173	700	461
GEORGIA POWER CO \| Purchased power, affiliates
Operating Expenses:
Less Gross Gas Costs	$ 571	$ 288	$ 1,100	$ 573

Condensed Statements of Compr_3

Condensed Statements of Comprehensive Income (Unaudited) - GPC - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Net income	$ 1,487	$ 1,110	$ 3,566	$ 2,592
Qualifying hedges:
Changes in fair value, net of tax	0	1	(27)	(15)
Reclassification adjustment for amounts included in net income, net of tax	26	31	100	81
Total other comprehensive income	28	36	81	76
Comprehensive Income	1,515	1,146	3,647	2,668
GEORGIA POWER CO
Net income	858	536	1,851	1,030
Qualifying hedges:
Changes in fair value, net of tax	0	0	23	0
Reclassification adjustment for amounts included in net income, net of tax	1	2	4	5
Total other comprehensive income	1	2	27	5
Comprehensive Income	$ 859	$ 538	$ 1,878	$ 1,035

Condensed Statements of Compr_4

Condensed Statements of Comprehensive Income (Unaudited) - GPC (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Changes in fair value, tax	$ 2	$ 1	$ (5)	$ (4)
Qualifying hedges, reclassification adjustment, tax	8	10	32	27
GEORGIA POWER CO
Changes in fair value, tax	0	0	8	0
Qualifying hedges, reclassification adjustment, tax	$ 0	$ 1	$ 1	$ 2

Condensed Statements of Cash _3

Condensed Statements of Cash Flows (Unaudited) - GPC - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Operating Activities:
Net income (loss)	$ 3,566	$ 2,592
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	3,084	2,944
Deferred income taxes	608	89
Utilization of federal investment tax credits	266	256
Allowance for equity funds used during construction	(163)	(140)
Pension, postretirement, and other employee benefits	(322)	(218)
Settlement of asset retirement obligations	(314)	(341)
Storm damage accruals	160	166
Retail fuel cost under recovery – long-term	(1,701)	(209)
Estimated loss on Plant Vogtle Units 3 and 4	(18)	772
Other, net	(45)	156
Changes in certain current assets and liabilities —
Receivables	(327)	2
Materials and supplies	(138)	(91)
Other current assets	(343)	(180)
Accounts payable	805	(45)
Accrued taxes	167	288
Retail fuel cost over recovery	(1)	(150)
Other current liabilities	(32)	(226)
Net cash provided from operating activities	5,017	5,081
Investing Activities:
Property additions	(5,502)	(5,222)
Nuclear decommissioning trust fund purchases	(858)	(1,301)
Nuclear decommissioning trust fund sales	854	1,297
Cost of removal, net of salvage	(518)	(282)
Proceeds from dispositions	120	160
Other investing activities	73	(12)
Net cash used for investing activities	(5,952)	(5,850)
Financing Activities:
Decrease in notes payable, net	(349)	(203)
Proceeds —
Short-term borrowings	1,200	325
Redemptions and repurchases —
Short-term borrowings	(900)	(25)
Payment of common stock dividends	(2,166)	(2,077)
Other financing activities	(235)	(224)
Net cash provided from financing activities	1,119	1,802
Net Change in Cash, Cash Equivalents, and Restricted Cash	184	1,033
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	1,829	1,068
Cash, Cash Equivalents, and Restricted Cash at End of Period	2,013	2,101
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	1,425	1,417
Income taxes, net	160	92
Noncash transactions —
Accrued property additions at year-end	872	915
GEORGIA POWER CO
Operating Activities:
Net income (loss)	1,851	1,030
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	1,211	1,164
Deferred income taxes	266	(299)
Utilization of federal investment tax credits	49	19
Allowance for equity funds used during construction	(102)	(94)
Pension, postretirement, and other employee benefits	(178)	(112)
Settlement of asset retirement obligations	(149)	(154)
Storm damage accruals	160	160
Retail fuel cost under recovery – long-term	(1,287)	(203)
Estimated loss on Plant Vogtle Units 3 and 4	(18)	772
Other, net	(71)	70
Changes in certain current assets and liabilities —
Receivables	(321)	(85)
Fossil fuel stock	(23)	77
Materials and supplies	(67)	(60)
Contract assets	(51)	(32)
Other current assets	(72)	(20)
Accounts payable	211	164
Accrued taxes	151	154
Retail fuel cost over recovery	0	(113)
Other current liabilities	(78)	(88)
Net cash provided from operating activities	1,482	2,350
Investing Activities:
Property additions	(2,658)	(2,411)
Nuclear decommissioning trust fund purchases	(585)	(766)
Nuclear decommissioning trust fund sales	581	761
Cost of removal, net of salvage	(250)	(99)
Change in construction payables, net of joint owner portion	148	(68)
Contributions in aid of construction	102	71
Proceeds from dispositions	56	4
Other investing activities	(47)	(64)
Net cash used for investing activities	(2,653)	(2,572)
Financing Activities:
Decrease in notes payable, net		(60)
Increase in notes payable, net	415
Proceeds —
Proceeds — Senior notes	1,500	750
Pollution control revenue bonds	0	122
FFB loan	0	371
Short-term borrowings	650	0
Redemptions and repurchases —
Senior notes	(400)	(325)
Pollution control revenue bonds	(53)	(69)
FFB loan	(66)	(75)
Short-term borrowings	(250)	0
Other long-term debt	(125)	0
Capital contributions from parent company	813	1,054
Payment of common stock dividends	(1,268)	(1,237)
Other financing activities	(45)	(26)
Net cash provided from financing activities	1,171	505
Net Change in Cash, Cash Equivalents, and Restricted Cash	0	283
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	33	9
Cash, Cash Equivalents, and Restricted Cash at End of Period	33	292
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	332	325
Income taxes, net	151	237
Noncash transactions —
Accrued property additions at year-end	609	477
Right-of-use assets obtained under operating leases	7	(3)
Right-of-use assets obtained under leases	$ 112	$ 0

Condensed Statements of Cash _4

Condensed Statements of Cash Flows (Unaudited) - GPC (Parenthetical) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Net cash paid for capitalized interest	$ 74	$ 68
GEORGIA POWER CO
Net cash paid for capitalized interest	$ 52	$ 47

Condensed Balance Sheets (Una_2

Condensed Balance Sheets (Unaudited) - GPC - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Current Assets:
Cash and cash equivalents	$ 2,009	$ 1,798
Receivables —
Customer accounts	2,223	1,806
Unbilled revenues	593	711
Other accounts and notes	533	523
Fossil fuel for generation	526	450
Materials and supplies	1,657	1,543
Regulatory assets – asset retirement obligations	284	219
Assets from risk management activities	289	151
Other regulatory assets	746	653
Other current assets	322	231
Total current assets	10,363	8,965
Property, Plant, and Equipment:
In service	116,236	115,592
Less: Accumulated depreciation	34,922	34,079
Plant in service, net of depreciation	81,314	81,513
Nuclear fuel, at amortized cost	840	824
Construction work in progress	10,773	8,771
Total property, plant, and equipment	93,529	91,108
Other Property and Investments:
Nuclear decommissioning trusts, at fair value	2,031	2,542
Equity investments in unconsolidated subsidiaries	1,292	1,282
Miscellaneous property and investments	590	653
Total other property and investments	9,608	10,202
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	1,560	1,701
Deferred charges related to income taxes	854	824
Prepaid pension costs	2,019	1,657
Deferred under recovered fuel clause revenues	1,697	410
Regulatory assets – asset retirement obligations, deferred	6,519	5,466
Other regulatory assets, deferred	6,121	5,577
Other deferred charges and assets	1,492	1,366
Total deferred charges and other assets	20,505	17,259
Total Assets	134,005	127,534
Current Liabilities:
Securities due within one year	3,241	2,157
Notes payable	1,398	1,440
Accounts payable —
Customer deposits	516	479
Accrued interest	431	533
Accrued compensation	961	1,070
Operating lease obligations	191	250
Asset retirement obligations	689	697
Other regulatory liabilities	440	563
Other current liabilities	844	872
Total current liabilities	12,801	10,921
Long-term Debt	50,427	50,120
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	9,916	8,862
Deferred credits related to income taxes	5,271	5,401
Accumulated deferred ITCs	2,154	2,216
Employee benefit obligations	1,466	1,550
Operating lease obligations, deferred	1,393	1,503
Asset retirement obligations, deferred	11,007	10,990
Other deferred credits and liabilities	1,366	816
Total deferred credits and other liabilities	35,059	33,926
Total Liabilities	98,287	94,967
Total Stockholders' Equity	35,476	32,276
Total Liabilities and Stockholders' Equity	134,005	127,534
GEORGIA POWER CO
Current Assets:
Cash and cash equivalents	33	33
Receivables —
Customer accounts	866	547
Unbilled revenues	267	231
Joint owner accounts	64	116
Affiliated	66	25
Other accounts and notes	30	44
Fossil fuel for generation	272	248
Materials and supplies	713	670
Regulatory assets – asset retirement obligations	244	178
Assets from risk management activities	88	48
Other regulatory assets	299	289
Other current assets	212	130
Total current assets	3,154	2,559
Property, Plant, and Equipment:
In service	41,159	41,332
Less: Accumulated depreciation	12,942	12,854
Plant in service, net of depreciation	28,217	28,478
Nuclear fuel, at amortized cost	598	577
Construction work in progress	8,053	6,688
Total property, plant, and equipment	36,868	35,743
Other Property and Investments:
Nuclear decommissioning trusts, at fair value	964	1,217
Equity investments in unconsolidated subsidiaries	51	50
Miscellaneous property and investments	87	69
Total other property and investments	1,102	1,336
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	1,034	1,157
Deferred charges related to income taxes	573	550
Prepaid pension costs	697	563
Deferred under recovered fuel clause revenues	1,697	410
Regulatory assets – asset retirement obligations, deferred	4,323	3,688
Other regulatory assets, deferred	2,579	1,964
Other deferred charges and assets	519	491
Total deferred charges and other assets	11,422	8,823
Total Assets	52,546	48,461
Current Liabilities:
Securities due within one year	900	675
Notes payable	814	0
Accounts payable —
Affiliated	880	757
Other	1,025	702
Customer deposits	254	259
Accrued taxes	486	335
Accrued interest	127	136
Accrued compensation	213	232
Operating lease obligations	148	156
Asset retirement obligations	309	317
Other regulatory liabilities	197	280
Other current liabilities	243	254
Total current liabilities	5,596	4,103
Long-term Debt	13,831	13,109
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	3,588	3,019
Deferred credits related to income taxes	2,264	2,321
Accumulated deferred ITCs	321	328
Employee benefit obligations	370	402
Operating lease obligations, deferred	854	999
Asset retirement obligations, deferred	6,547	6,507
Other deferred credits and liabilities	518	439
Total deferred credits and other liabilities	14,462	14,015
Total Liabilities	33,889	31,227
Total Stockholders' Equity	18,657	17,234
Total Liabilities and Stockholders' Equity	$ 52,546	$ 48,461

Condensed Statements of Commo_2

Condensed Statements of Common Stockholders' Equity (Unaudited) - GPC - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Paid-In Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Income (Loss)	GEORGIA POWER CO	GEORGIA POWER CO Common Stock	GEORGIA POWER CO Paid-In Capital	GEORGIA POWER CO Retained Earnings (Accumulated Deficit)	GEORGIA POWER CO Accumulated Other Comprehensive Income (Loss)
Beginning balance (in shares) at Dec. 31, 2020							9
Beginning balance at Dec. 31, 2020	$ 32,234	$ 5,268	$ 11,834	$ 11,311	$ (395)	$ 16,501	$ 398	$ 12,361	$ 3,789	$ (47)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						351			351
Capital contributions from parent company						332		332
Other comprehensive income (loss)	28				28	2				2
Cash dividends on common stock	(678)			(678)		(412)			(412)
Ending balance (in shares) at Mar. 31, 2021							9
Ending balance at Mar. 31, 2021	33,068	5,273	11,854	11,768	(367)	16,774	$ 398	12,693	3,728	(45)
Beginning balance (in shares) at Dec. 31, 2020							9
Beginning balance at Dec. 31, 2020	32,234	5,268	11,834	11,311	(395)	16,501	$ 398	12,361	3,789	(47)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,592					1,030
Ending balance (in shares) at Sep. 30, 2021							9
Ending balance at Sep. 30, 2021	33,219	5,278	11,932	11,844	(319)	17,361	$ 398	13,423	3,582	(42)
Beginning balance (in shares) at Mar. 31, 2021							9
Beginning balance at Mar. 31, 2021	33,068	5,273	11,854	11,768	(367)	16,774	$ 398	12,693	3,728	(45)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						143			143
Capital contributions from parent company						40		40
Other comprehensive income (loss)	12				12	1				1
Cash dividends on common stock	(699)			(699)		(412)			(412)
Ending balance (in shares) at Jun. 30, 2021							9
Ending balance at Jun. 30, 2021	32,746	5,274	11,886	11,442	(355)	16,546	$ 398	12,733	3,459	(44)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,110					536			536
Capital contributions from parent company						690		690
Other comprehensive income (loss)	36				36	2				2
Cash dividends on common stock	(700)			(700)		(413)			(413)
Ending balance (in shares) at Sep. 30, 2021							9
Ending balance at Sep. 30, 2021	33,219	5,278	11,932	11,844	(319)	17,361	$ 398	13,423	3,582	(42)
Beginning balance (in shares) at Dec. 31, 2021							9
Beginning balance at Dec. 31, 2021	32,276	5,279	11,950	10,929	(237)	17,234	$ 398	14,153	2,724	(41)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						385			385
Capital contributions from parent company						443		443
Other comprehensive income (loss)	42				42	10				10
Cash dividends on common stock	(702)			(702)		(423)			(423)
Ending balance (in shares) at Mar. 31, 2022							9
Ending balance at Mar. 31, 2022	32,629	5,286	11,994	11,261	(195)	17,649	$ 398	14,596	2,686	(31)
Beginning balance (in shares) at Dec. 31, 2021							9
Beginning balance at Dec. 31, 2021	32,276	5,279	11,950	10,929	(237)	17,234	$ 398	14,153	2,724	(41)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	3,566					1,851
Ending balance (in shares) at Sep. 30, 2022							9
Ending balance at Sep. 30, 2022	35,476	5,417	13,657	12,374	(157)	18,657	$ 398	14,966	3,307	(14)
Beginning balance (in shares) at Mar. 31, 2022							9
Beginning balance at Mar. 31, 2022	32,629	5,286	11,994	11,261	(195)	17,649	$ 398	14,596	2,686	(31)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						608			608
Capital contributions from parent company						46		46
Other comprehensive income (loss)	11				11	16				16
Cash dividends on common stock	(723)			(723)		(422)			(422)
Ending balance (in shares) at Jun. 30, 2022							9
Ending balance at Jun. 30, 2022	33,013	5,288	12,033	11,645	(184)	17,897	$ 398	14,642	2,872	(15)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,487					858			858
Capital contributions from parent company						324		324
Other comprehensive income (loss)	28				28	1				1
Cash dividends on common stock	(741)			(741)		(423)			(423)
Ending balance (in shares) at Sep. 30, 2022							9
Ending balance at Sep. 30, 2022	$ 35,476	$ 5,417	$ 13,657	$ 12,374	$ (157)	$ 18,657	$ 398	$ 14,966	$ 3,307	$ (14)

Condensed Statements of Commo_3

Condensed Statements of Common Stockholders' Equity (Unaudited) - GPC (Parenthetical) - $ / shares	3 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Jun. 30, 2021	Mar. 31, 2021
Statement of Stockholders' Equity [Abstract]
Cash dividends (in dollars per share)	$ 0.68	$ 0.68	$ 0.66	$ 0.66	$ 0.66	$ 0.64

Condensed Statements of Incom_3

Condensed Statements of Income (Unaudited) - MPC - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Operating Revenues:
Total operating revenues	$ 8,378	$ 6,238	$ 22,232	$ 17,346
Operating Expenses:
Other operations and maintenance	1,547	1,446	4,621	4,257
Depreciation and amortization	922	896	2,728	2,658
Taxes other than income taxes	352	312	1,073	969
Total operating expenses	6,185	4,515	17,000	13,317
Operating Income	2,193	1,723	5,232	4,029
Other Income and (Expense):
Interest expense, net of amounts capitalized	(511)	(451)	(1,461)	(1,352)
Other income (expense), net	132	131	414	290
Total other income and (expense)	(292)	(241)	(775)	(887)
Earnings Before Income Taxes	1,901	1,482	4,457	3,142
Income taxes (benefit)	414	372	891	550
Consolidated Net Income	1,487	1,110	3,566	2,592
Retail electric revenues
Operating Revenues:
Total operating revenues	5,961	4,551	14,363	11,492
Wholesale Electric
Operating Revenues:
Total operating revenues	1,197	731	2,798	1,822
Other electric revenues
Operating Revenues:
Total operating revenues	185	179	554	525
Natural Gas
Operating Revenues:
Total operating revenues	857	623	3,998	2,994
Other revenues
Operating Revenues:
Total operating revenues	178	154	519	513
Operating Expenses:
Total cost of sales	92	71	275	255
Mississippi Power
Operating Revenues:
Total operating revenues	510	378	1,279	988
Operating Expenses:
Other operations and maintenance	86	85	252	230
Depreciation and amortization	45	46	135	138
Taxes other than income taxes	32	33	93	96
Total operating expenses	425	309	1,081	815
Operating Income	85	69	198	173
Other Income and (Expense):
Interest expense, net of amounts capitalized	(15)	(16)	(42)	(45)
Other income (expense), net	9	7	32	27
Total other income and (expense)	(6)	(9)	(10)	(18)
Earnings Before Income Taxes	79	60	188	155
Income taxes (benefit)	17	10	38	22
Consolidated Net Income	62	50	150	133
Mississippi Power \| Retail electric revenues
Operating Revenues:
Total operating revenues	250	248	718	670
Mississippi Power \| Wholesale revenues, non-affiliates
Operating Revenues:
Total operating revenues	60	60	191	178
Mississippi Power \| Wholesale revenues, affiliates
Operating Revenues:
Total operating revenues	187	62	336	120
Mississippi Power \| Other revenues
Operating Revenues:
Total operating revenues	13	8	34	20
Mississippi Power \| Fuel and purchased power
Operating Expenses:
Total cost of sales	$ 262	$ 145	$ 601	$ 351

Condensed Statements of Compr_5

Condensed Statements of Comprehensive Income - MPC - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Net income	$ 1,487	$ 1,110	$ 3,566	$ 2,592
Qualifying hedges:
Reclassification adjustment for amounts included in net income, net of tax	26	31	100	81
Total other comprehensive income	28	36	81	76
Comprehensive Income	1,515	1,146	3,647	2,668
Mississippi Power
Net income	62	50	150	133
Qualifying hedges:
Reclassification adjustment for amounts included in net income, net of tax	0	0	0	1
Total other comprehensive income	0	0	0	1
Comprehensive Income	$ 62	$ 50	$ 150	$ 134

Condensed Statements of Compr_6

Condensed Statements of Comprehensive Income - MPC (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Qualifying hedges, reclassification adjustment, tax	$ 8	$ 10	$ 32	$ 27
Mississippi Power
Qualifying hedges, reclassification adjustment, tax	$ 0	$ 0	$ 0	$ 0

Condensed Statements of Cash _5

Condensed Statements of Cash Flows (Unaudited) - MPC - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Operating Activities:
Net income (loss)	$ 3,566	$ 2,592
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	3,084	2,944
Settlement of asset retirement obligations	(314)	(341)
Other, net	(45)	156
Changes in certain current assets and liabilities —
Receivables	(327)	2
Other current assets	(343)	(180)
Accounts payable	805	(45)
Accrued taxes	167	288
Retail fuel cost over recovery	(1)	(150)
Other current liabilities	(32)	(226)
Net cash provided from operating activities	5,017	5,081
Investing Activities:
Property additions	(5,502)	(5,222)
Payments pursuant to LTSAs	(121)	(145)
Other investing activities	73	(12)
Net cash used for investing activities	(5,952)	(5,850)
Financing Activities:
Decrease in notes payable, net	(349)	(203)
Redemptions and repurchases —
Payment of common stock dividends	(2,166)	(2,077)
Other financing activities	(235)	(224)
Net cash provided from financing activities	1,119	1,802
Net Change in Cash, Cash Equivalents, and Restricted Cash	184	1,033
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	1,829	1,068
Cash, Cash Equivalents, and Restricted Cash at End of Period	2,013	2,101
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	1,425	1,417
Income taxes, net	160	92
Noncash transactions —
Accrued property additions at year-end	872	915
Mississippi Power
Operating Activities:
Net income (loss)	150	133
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	164	161
Settlement of asset retirement obligations	(15)	(18)
Other, net	20	(20)
Changes in certain current assets and liabilities —
Receivables	(58)	(19)
Other current assets	(17)	(9)
Accounts payable	41	(12)
Accrued taxes	(3)	(20)
Retail fuel cost over recovery	0	(19)
Other current liabilities	(3)	(18)
Net cash provided from operating activities	279	159
Investing Activities:
Property additions	(165)	(135)
Construction payables	(9)	(11)
Payments pursuant to LTSAs	(23)	(21)
Other investing activities	(22)	(15)
Net cash used for investing activities	(219)	(182)
Financing Activities:
Increase in notes payable, net	0
Decrease in notes payable, net		(25)
Proceeds — Senior notes	0	525
Redemptions and repurchases —
Other revenue bonds	0	(270)
Other long-term debt	0	(75)
Capital contributions from parent company	55	103
Payment of common stock dividends	(128)	(118)
Other financing activities	1	(10)
Net cash provided from financing activities	(72)	130
Net Change in Cash, Cash Equivalents, and Restricted Cash	(12)	107
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	61	39
Cash, Cash Equivalents, and Restricted Cash at End of Period	49	146
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	49	53
Income taxes, net	18	11
Noncash transactions —
Accrued property additions at year-end	$ 16	$ 23

Condensed Statements of Cash _6

Condensed Statements of Cash Flows (Unaudited) - MPC (Parenthetical) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Net cash paid for capitalized interest	$ 74	$ 68

Condensed Balance Sheets (Una_3

Condensed Balance Sheets (Unaudited) - MPC - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Current Assets:
Cash and cash equivalents	$ 2,009	$ 1,798
Receivables —
Customer accounts	2,223	1,806
Unbilled revenues	593	711
Other accounts and notes	533	523
Fossil fuel for generation	526	450
Materials and supplies	1,657	1,543
Assets from risk management activities	289	151
Other regulatory assets	746	653
Other current assets	322	231
Total current assets	10,363	8,965
Property, Plant, and Equipment:
In service	116,236	115,592
Less: Accumulated depreciation	34,922	34,079
Plant in service, net of depreciation	81,314	81,513
Construction work in progress	10,773	8,771
Total property, plant, and equipment	93,529	91,108
Other Property and Investments:
Total other property and investments	9,608	10,202
Deferred Charges and Other Assets:
Deferred charges related to income taxes	854	824
Regulatory assets – asset retirement obligations, deferred	6,519	5,466
Other regulatory assets, deferred	6,121	5,577
Other deferred charges and assets	1,492	1,366
Total deferred charges and other assets	20,505	17,259
Total Assets	134,005	127,534
Current Liabilities:
Securities due within one year	3,241	2,157
Accounts payable —
Accrued compensation	961	1,070
Asset retirement obligations	689	697
Other regulatory liabilities	440	563
Other current liabilities	844	872
Total current liabilities	12,801	10,921
Long-term Debt	50,427	50,120
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	9,916	8,862
Deferred credits related to income taxes	5,271	5,401
Employee benefit obligations	1,466	1,550
Asset retirement obligations, deferred	11,007	10,990
Other cost of removal obligations	1,950	2,103
Other regulatory liabilities, deferred	536	485
Other deferred credits and liabilities	1,366	816
Total deferred credits and other liabilities	35,059	33,926
Total Liabilities	98,287	94,967
Total Liabilities and Stockholders' Equity	134,005	127,534
Mississippi Power
Current Assets:
Cash and cash equivalents	49	61
Receivables —
Customer accounts	71	37
Unbilled revenues	43	34
Affiliated	39	29
Other accounts and notes	34	28
Fossil fuel for generation	37	28
Materials and supplies	80	70
Assets from risk management activities	69	28
Other regulatory assets	60	54
Other current assets	16	13
Total current assets	498	382
Property, Plant, and Equipment:
In service	5,209	5,106
Less: Accumulated depreciation	1,669	1,591
Plant in service, net of depreciation	3,540	3,515
Construction work in progress	168	127
Total property, plant, and equipment	3,708	3,642
Other Property and Investments:
Total other property and investments	171	179
Deferred Charges and Other Assets:
Deferred charges related to income taxes	30	31
Prepaid pension costs	97	79
Regulatory assets – asset retirement obligations, deferred	238	232
Other regulatory assets, deferred	271	317
Accumulated deferred income taxes	108	118
Other deferred charges and assets	130	100
Total deferred charges and other assets	874	877
Total Assets	5,251	5,080
Current Liabilities:
Securities due within one year	1	1
Accounts payable —
Affiliated	96	81
Other	68	47
Accrued taxes	116	120
Accrued compensation	33	36
Asset retirement obligations	20	30
Other regulatory liabilities	102	59
Other current liabilities	80	65
Total current liabilities	516	439
Long-term Debt	1,509	1,510
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	465	464
Deferred credits related to income taxes	258	269
Employee benefit obligations	86	88
Asset retirement obligations, deferred	162	160
Other cost of removal obligations	197	195
Other regulatory liabilities, deferred	87	64
Other deferred credits and liabilities	25	24
Total deferred credits and other liabilities	1,280	1,264
Total Liabilities	3,305	3,213
Total common stockholders' equity	1,946	1,867
Total Liabilities and Stockholders' Equity	$ 5,251	$ 5,080

Condensed Statements of Commo_4

Condensed Statements of Common Stockholders' Equity (Unaudited) - MPC - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Paid-In Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Income (Loss)	Mississippi Power	Mississippi Power Common Stock	Mississippi Power Paid-In Capital	Mississippi Power Retained Earnings (Accumulated Deficit)	Mississippi Power Accumulated Other Comprehensive Income (Loss)
Beginning balance (in shares) at Dec. 31, 2020							1
Beginning balance at Dec. 31, 2020	$ 32,234	$ 5,268	$ 11,834	$ 11,311	$ (395)	$ 1,742	$ 38	$ 4,460	$ (2,754)	$ (2)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						45			45
Capital contributions from parent company						100		100
Cash dividends on common stock	(678)			(678)		(39)			(39)
Other	1		2
Ending balance (in shares) at Mar. 31, 2021							1
Ending balance at Mar. 31, 2021	33,068	5,273	11,854	11,768	(367)	1,848	$ 38	4,560	(2,748)	(2)
Beginning balance (in shares) at Dec. 31, 2020							1
Beginning balance at Dec. 31, 2020	32,234	5,268	11,834	11,311	(395)	1,742	$ 38	4,460	(2,754)	(2)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,608
Ending balance (in shares) at Sep. 30, 2021							1
Ending balance at Sep. 30, 2021	33,219	5,278	11,932	11,844	(319)	1,863	$ 38	4,565	(2,739)	(1)
Beginning balance (in shares) at Mar. 31, 2021							1
Beginning balance at Mar. 31, 2021	33,068	5,273	11,854	11,768	(367)	1,848	$ 38	4,560	(2,748)	(2)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						38			38
Capital contributions from parent company						2		2
Cash dividends on common stock	(699)			(699)		(39)			(39)
Other	0		1	1					(1)	1
Ending balance (in shares) at Jun. 30, 2021							1
Ending balance at Jun. 30, 2021	32,746	5,274	11,886	11,442	(355)	1,849	$ 38	4,562	(2,750)	(1)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,101					50			50
Capital contributions from parent company						3		3
Cash dividends on common stock	(700)			(700)		(39)			(39)
Other	(7)		(10)	1
Ending balance (in shares) at Sep. 30, 2021							1
Ending balance at Sep. 30, 2021	33,219	5,278	11,932	11,844	(319)	1,863	$ 38	4,565	(2,739)	(1)
Beginning balance (in shares) at Dec. 31, 2021							1
Beginning balance at Dec. 31, 2021	32,276	5,279	11,950	10,929	(237)	1,867	$ 38	4,582	(2,753)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						42			42
Capital contributions from parent company						51		51
Cash dividends on common stock	(702)			(702)		(43)			(43)
Other	7		7	2
Ending balance (in shares) at Mar. 31, 2022							1
Ending balance at Mar. 31, 2022	32,629	5,286	11,994	11,261	(195)	1,917	$ 38	4,633	(2,754)	0
Beginning balance (in shares) at Dec. 31, 2021							1
Beginning balance at Dec. 31, 2021	32,276	5,279	11,950	10,929	(237)	1,867	$ 38	4,582	(2,753)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	3,611
Ending balance (in shares) at Sep. 30, 2022							1
Ending balance at Sep. 30, 2022	35,476	5,417	13,657	12,374	(157)	1,946	$ 38	4,639	(2,731)	0
Beginning balance (in shares) at Mar. 31, 2022							1
Beginning balance at Mar. 31, 2022	32,629	5,286	11,994	11,261	(195)	1,917	$ 38	4,633	(2,754)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						45			45
Capital contributions from parent company						1		1
Cash dividends on common stock	(723)			(723)		(42)			(42)
Other	2		4
Ending balance (in shares) at Jun. 30, 2022							1
Ending balance at Jun. 30, 2022	33,013	5,288	12,033	11,645	(184)	1,921	$ 38	4,634	(2,751)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,472					62			62
Capital contributions from parent company						5		5
Cash dividends on common stock	(741)			(741)		(42)			(42)
Other	(8)		(4)	(2)	(1)
Ending balance (in shares) at Sep. 30, 2022							1
Ending balance at Sep. 30, 2022	$ 35,476	$ 5,417	$ 13,657	$ 12,374	$ (157)	$ 1,946	$ 38	$ 4,639	$ (2,731)	$ 0

Condensed Consolidated Statem_9

Condensed Consolidated Statements of Income (Unaudited) - SPC - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Operating Revenues:
Total operating revenues	$ 8,378	$ 6,238	$ 22,232	$ 17,346
Operating Expenses:
Other operations and maintenance	1,547	1,446	4,621	4,257
Depreciation and amortization	922	896	2,728	2,658
Taxes other than income taxes	352	312	1,073	969
Gain on dispositions, net	(20)	(125)	(53)	(179)
Total operating expenses	6,185	4,515	17,000	13,317
Operating Income	2,193	1,723	5,232	4,029
Other Income and (Expense):
Interest expense, net of amounts capitalized	(511)	(451)	(1,461)	(1,352)
Other income (expense), net	132	131	414	290
Total other income and (expense)	(292)	(241)	(775)	(887)
Earnings Before Income Taxes	1,901	1,482	4,457	3,142
Income taxes (benefit)	414	372	891	550
Consolidated Net Income	1,487	1,110	3,566	2,592
Net income (loss) attributable to noncontrolling interests	12	5	(55)	(27)
Net Income	1,472	1,101	3,611	2,608
Retail electric revenues
Operating Revenues:
Total operating revenues	5,961	4,551	14,363	11,492
Wholesale Electric
Operating Revenues:
Total operating revenues	1,197	731	2,798	1,822
Other electric revenues
Operating Revenues:
Total operating revenues	185	179	554	525
Natural Gas
Operating Revenues:
Total operating revenues	857	623	3,998	2,994
Other revenues
Operating Revenues:
Total operating revenues	178	154	519	513
Operating Expenses:
Total cost of sales	92	71	275	255
Fuel
Operating Expenses:
Total cost of sales	2,423	1,234	5,249	2,930
Purchased power
Operating Expenses:
Total cost of sales	645	288	1,285	712
SOUTHERN POWER CO
Operating Revenues:
Total operating revenues	1,180	679	2,618	1,610
Operating Expenses:
Other operations and maintenance	113	94	331	308
Depreciation and amortization	133	132	384	383
Taxes other than income taxes	13	12	38	35
Loss on sales-type leases	0	15	1	15
Gain on dispositions, net	0	0	(2)	(39)
Total operating expenses	1,008	553	2,259	1,328
Operating Income	172	126	359	282
Other Income and (Expense):
Interest expense, net of amounts capitalized	(32)	(36)	(105)	(111)
Other income (expense), net	3	2	5	10
Total other income and (expense)	(29)	(34)	(100)	(101)
Earnings Before Income Taxes	143	92	259	181
Income taxes (benefit)	36	9	49	(3)
Consolidated Net Income	107	83	210	184
Net income (loss) attributable to noncontrolling interests	12	5	(55)	(27)
Net Income	95	78	265	211
SOUTHERN POWER CO \| Wholesale revenues, non-affiliates
Operating Revenues:
Total operating revenues	835	503	1,918	1,231
SOUTHERN POWER CO \| Wholesale revenues, affiliates
Operating Revenues:
Total operating revenues	336	167	673	361
SOUTHERN POWER CO \| Other revenues
Operating Revenues:
Total operating revenues	9	9	27	18
SOUTHERN POWER CO \| Fuel
Operating Expenses:
Total cost of sales	605	259	1,274	540
SOUTHERN POWER CO \| Purchased power
Operating Expenses:
Total cost of sales	$ 144	$ 41	$ 233	$ 86

Condensed Consolidated State_10

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - SPC - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Net income	$ 1,487	$ 1,110	$ 3,566	$ 2,592
Qualifying hedges:
Changes in fair value, net of tax	0	1	(27)	(15)
Reclassification adjustment for amounts included in net income, net of tax	26	31	100	81
Pension and other postretirement benefit plans:
Reclassification adjustment for amounts included in net income, net of tax	2	4	8	10
Total other comprehensive income	28	36	81	76
Comprehensive Income	1,515	1,146	3,647	2,668
Comprehensive income (loss) attributable to noncontrolling interests	12	5	(55)	(27)
Comprehensive Income	1,500	1,137	3,692	2,684
SOUTHERN POWER CO
Net income	107	83	210	184
Qualifying hedges:
Changes in fair value, net of tax	(35)	(21)	(106)	(48)
Reclassification adjustment for amounts included in net income, net of tax	28	27	106	66
Pension and other postretirement benefit plans:
Reclassification adjustment for amounts included in net income, net of tax	0	1	1	2
Total other comprehensive income	(7)	7	1	20
Comprehensive Income	100	90	211	204
Comprehensive income (loss) attributable to noncontrolling interests	12	5	(55)	(27)
Comprehensive Income	$ 88	$ 85	$ 266	$ 231

Condensed Consolidated State_11

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - SPC (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Changes in fair value, tax	$ 2	$ 1	$ (5)	$ (4)
Qualifying hedges, reclassification adjustment, tax	8	10	32	27
Reclassification adjustment for amounts included in net income, tax	1	1	3	4
SOUTHERN POWER CO
Changes in fair value, tax	(11)	(7)	(35)	(16)
Qualifying hedges, reclassification adjustment, tax	9	9	35	22
Reclassification adjustment for amounts included in net income, tax	$ 0	$ 0	$ 0	$ 1

Condensed Consolidated State_12

Condensed Consolidated Statements of Cash Flows (Unaudited) - SPC - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Operating Activities:
Net income (loss)	$ 3,566	$ 2,592
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	3,084	2,944
Deferred income taxes	608	89
Utilization of federal investment tax credits	266	256
Gain on dispositions, net	(41)	(171)
Other, net	(45)	156
Changes in certain current assets and liabilities —
Receivables	(327)	2
Other current assets	(343)	(180)
Accounts payable	805	(45)
Accrued taxes	167	288
Other current liabilities	(32)	(226)
Net cash provided from operating activities	5,017	5,081
Investing Activities:
Business acquisitions, net of cash acquired	0	(345)
Property additions	(5,502)	(5,222)
Payments pursuant to LTSAs	(121)	(145)
Other investing activities	73	(12)
Net cash used for investing activities	(5,952)	(5,850)
Financing Activities:
Decrease in notes payable, net	(349)	(203)
Capital contributions from noncontrolling interests	73	415
Distributions to noncontrolling interests	(175)	(204)
Payment of common stock dividends	(2,166)	(2,077)
Other financing activities	(235)	(224)
Net cash provided from financing activities	1,119	1,802
Net Change in Cash, Cash Equivalents, and Restricted Cash	184	1,033
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	1,829	1,068
Cash, Cash Equivalents, and Restricted Cash at End of Period	2,013	2,101
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	1,425	1,417
Income taxes, net	160	92
Noncash transactions —
Contributions from noncontrolling interests	0	89
Contributions of wind turbine equipment	0	82
Accrued property additions at year-end	872	915
Reassessment of right-of-use assets under operating leases	40	0
SOUTHERN POWER CO
Operating Activities:
Net income (loss)	210	184
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	404	402
Deferred income taxes	21	(16)
Utilization of federal investment tax credits	218	237
Amortization of investment tax credits	(44)	(44)
Gain on dispositions, net	(2)	(39)
Other, net	1	14
Changes in certain current assets and liabilities —
Receivables	(124)	(117)
Prepaid income taxes	22	63
Other current assets	(15)	(5)
Accounts payable	95	55
Accrued taxes	55	15
Other current liabilities	(14)	1
Net cash provided from operating activities	827	750
Investing Activities:
Business acquisitions, net of cash acquired	0	(345)
Property additions	(64)	(355)
Proceeds from dispositions	48	22
Change in construction payables	(60)	(22)
Payments pursuant to LTSAs	(52)	(61)
Other investing activities	0	8
Net cash used for investing activities	(128)	(753)
Financing Activities:
Decrease in notes payable, net	(5)	(148)
Proceeds — Senior notes	0	400
Redemptions — Senior notes	(677)	0
Capital contributions from parent company	330	4
Return of capital to parent company	0	(271)
Capital contributions from noncontrolling interests	73	415
Distributions to noncontrolling interests	(175)	(204)
Payment of common stock dividends	(148)	(153)
Other financing activities	(1)	(10)
Net cash provided from financing activities	(603)	33
Net Change in Cash, Cash Equivalents, and Restricted Cash	96	30
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	135	183
Cash, Cash Equivalents, and Restricted Cash at End of Period	231	213
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	120	118
Income taxes, net	(202)	(235)
Noncash transactions —
Contributions from noncontrolling interests	0	89
Contributions of wind turbine equipment	0	82
Accrued property additions at year-end	30	53
Right-of-use assets obtained under operating leases	0	66
Reassessment of right-of-use assets under operating leases	$ 40	$ 0

Condensed Consolidated State_13

Condensed Consolidated Statements of Cash Flows (Unaudited) - SPC (Parenthetical) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Net cash paid for capitalized interest	$ 74	$ 68
SOUTHERN POWER CO
Net cash paid for capitalized interest	$ 0	$ 5

Condensed Consolidated Balanc_3

Condensed Consolidated Balance Sheets (Unaudited) - SPC - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Current Assets:
Cash and cash equivalents	$ 2,009	$ 1,798
Receivables —
Customer accounts	2,223	1,806
Other accounts and notes	533	523
Materials and supplies	1,657	1,543
Other current assets	322	231
Total current assets	10,363	8,965
Property, Plant, and Equipment:
In service	116,236	115,592
Less: Accumulated depreciation	34,922	34,079
Plant in service, net of depreciation	81,314	81,513
Construction work in progress	10,773	8,771
Total property, plant, and equipment	93,529	91,108
Other Property and Investments:
Equity investments in unconsolidated subsidiaries	1,292	1,282
Total other property and investments	9,608	10,202
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	1,560	1,701
Other deferred charges and assets	1,492	1,366
Total deferred charges and other assets	20,505	17,259
Total Assets	134,005	127,534
Current Liabilities:
Securities due within one year	3,241	2,157
Notes payable	1,398	1,440
Accounts payable —
Accrued interest	431	533
Other current liabilities	844	872
Total current liabilities	12,801	10,921
Long-term Debt	50,427	50,120
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	9,916	8,862
Accumulated deferred ITCs	2,154	2,216
Operating lease obligations, deferred	1,393	1,503
Other deferred credits and liabilities	1,366	816
Total deferred credits and other liabilities	35,059	33,926
Total Liabilities	98,287	94,967
Total Stockholders' Equity (See accompanying statements)	35,476	32,276
Total Liabilities and Stockholders' Equity	134,005	127,534
SOUTHERN POWER CO
Current Assets:
Cash and cash equivalents	229	107
Receivables —
Customer accounts	232	139
Affiliated	95	51
Other accounts and notes	24	29
Materials and supplies	112	106
Prepaid income taxes	5	27
Other current assets	51	46
Total current assets	748	505
Property, Plant, and Equipment:
In service	14,641	14,585
Less: Accumulated depreciation	3,589	3,241
Plant in service, net of depreciation	11,052	11,344
Construction work in progress	48	45
Total property, plant, and equipment	11,100	11,389
Other Property and Investments:
Intangible assets, net of amortization	268	282
Equity investments in unconsolidated subsidiaries	49	86
Net investment in sales-type leases	155	161
Total other property and investments	472	529
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	491	479
Prepaid LTSAs	210	210
Other deferred charges and assets	262	278
Total deferred charges and other assets	963	967
Total Assets	13,283	13,390
Current Liabilities:
Securities due within one year	290	679
Notes payable	208	211
Accounts payable —
Affiliated	179	92
Other	70	85
Accrued taxes	208	14
Accrued interest	22	32
Other current liabilities	96	140
Total current liabilities	1,073	1,253
Long-term Debt	2,642	3,009
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	315	215
Accumulated deferred ITCs	1,571	1,614
Operating lease obligations, deferred	515	497
Other deferred credits and liabilities	287	204
Total deferred credits and other liabilities	2,688	2,530
Total Liabilities	6,403	6,792
Total Stockholders' Equity (See accompanying statements)	6,880	6,598
Total Liabilities and Stockholders' Equity	$ 13,283	$ 13,390

Condensed Consolidated Balanc_4

Condensed Consolidated Balance Sheets (Unaudited) - SPC (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Other intangible assets, amortization	$ 331	$ 307
SOUTHERN POWER CO
Other intangible assets, amortization	$ 124	$ 109

Condensed Consolidated State_14

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - SPC - USD ($) $ in Millions	Total	Paid-In Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests	SOUTHERN POWER CO	SOUTHERN POWER CO Total Common Stockholders' Equity	SOUTHERN POWER CO Paid-In Capital	SOUTHERN POWER CO Retained Earnings (Accumulated Deficit)	SOUTHERN POWER CO Accumulated Other Comprehensive Income (Loss)	SOUTHERN POWER CO Noncontrolling Interests
Beginning balance at Dec. 31, 2020	$ 32,234	$ 11,834	$ 11,311	$ (395)	$ 4,262	$ 6,631	$ 2,369	$ 914	$ 1,522	$ (67)	$ 4,262
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						65	97		97		(32)
Return of capital to parent company						(271)	(271)	(271)
Other comprehensive income (loss)	28			28		16	16			16
Cash dividends on common stock	(678)		(678)			(51)	(51)		(51)
Capital contributions from noncontrolling interests	403				403	403					403
Distributions to noncontrolling interests	(46)				(46)	(46)					(46)
Other	1	2			(1)	(3)	(2)	(2)	1	(1)	(1)
Ending balance at Mar. 31, 2021	33,068	11,854	11,768	(367)	4,586	6,744	2,158	641	1,569	(52)	4,586
Beginning balance at Dec. 31, 2020	32,234	11,834	11,311	(395)	4,262	6,631	2,369	914	1,522	(67)	4,262
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,592					184
Ending balance at Sep. 30, 2021	33,219	11,932	11,844	(319)	4,530	6,707	2,177	643	1,581	(47)	4,530
Beginning balance at Mar. 31, 2021	33,068	11,854	11,768	(367)	4,586	6,744	2,158	641	1,569	(52)	4,586
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						36	36		36		0
Other comprehensive income (loss)	12			12		(3)	(3)			(3)
Cash dividends on common stock	(699)		(699)			(51)	(51)		(51)
Capital contributions from noncontrolling interests	29				29	29					29
Distributions to noncontrolling interests	(68)				(68)	(68)					(68)
Other	0	1	1			3	3	2		1
Ending balance at Jun. 30, 2021	32,746	11,886	11,442	(355)	4,547	6,690	2,143	643	1,554	(54)	4,547
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,110					83	78		78		5
Other comprehensive income (loss)	36			36		7	7			7
Cash dividends on common stock	(700)		(700)			(51)	(51)		(51)
Capital contributions from noncontrolling interests	72				72	73					73
Distributions to noncontrolling interests	(94)				(94)	(95)					(95)
Other	(7)	(10)	1
Ending balance at Sep. 30, 2021	33,219	11,932	11,844	(319)	4,530	6,707	2,177	643	1,581	(47)	4,530
Beginning balance at Dec. 31, 2021	32,276	11,950	10,929	(237)	4,402	6,598	2,196	638	1,585	(27)	4,402
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						27	72		72		(45)
Other comprehensive income (loss)	42			42		5	5			5
Cash dividends on common stock	(702)		(702)			(49)	(49)		(49)
Capital contributions from noncontrolling interests	73				73	73					73
Distributions to noncontrolling interests	(98)				(98)	(98)					(98)
Other	7	7	2
Ending balance at Mar. 31, 2022	32,629	11,994	11,261	(195)	4,332	6,556	2,224	638	1,608	(22)	4,332
Beginning balance at Dec. 31, 2021	32,276	11,950	10,929	(237)	4,402	6,598	2,196	638	1,585	(27)	4,402
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	3,566					210
Ending balance at Sep. 30, 2022	35,476	13,657	12,374	(157)	4,237	6,880	2,643	969	1,701	(27)	4,237
Beginning balance at Mar. 31, 2022	32,629	11,994	11,261	(195)	4,332	6,556	2,224	638	1,608	(22)	4,332
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						76	98		98		(22)
Capital contributions from parent company						322	322	322
Other comprehensive income (loss)	11			11		3	3			3
Cash dividends on common stock	(723)		(723)			(50)	(50)		(50)
Distributions to noncontrolling interests	(28)				(28)	(28)					(28)
Other	2	4
Ending balance at Jun. 30, 2022	33,013	12,033	11,645	(184)	4,282	6,879	2,597	960	1,656	(19)	4,282
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,487					107	95		95		12
Capital contributions from parent company						9	9	9
Other comprehensive income (loss)	28			28		(7)	(7)			(7)
Cash dividends on common stock	(741)		(741)			(49)	(49)		(49)
Distributions to noncontrolling interests	(57)				(57)	(57)					(57)
Other	(8)	(4)	(2)	(1)		(2)	(2)		(1)	(1)
Ending balance at Sep. 30, 2022	$ 35,476	$ 13,657	$ 12,374	$ (157)	$ 4,237	$ 6,880	$ 2,643	$ 969	$ 1,701	$ (27)	$ 4,237

Condensed Consolidated State_15

Condensed Consolidated Statements of Income (Unaudited) - GAS - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Operating Revenues:
Total operating revenues	$ 8,378	$ 6,238	$ 22,232	$ 17,346
Operating Expenses:
Other operations and maintenance	1,547	1,446	4,621	4,257
Depreciation and amortization	922	896	2,728	2,658
Taxes other than income taxes	352	312	1,073	969
Gain on dispositions, net	(20)	(125)	(53)	(179)
Total operating expenses	6,185	4,515	17,000	13,317
Operating Income	2,193	1,723	5,232	4,029
Other Income and (Expense):
Earnings from equity method investments	28	30	109	35
Interest expense, net of amounts capitalized	(511)	(451)	(1,461)	(1,352)
Other income (expense), net	132	131	414	290
Total other income and (expense)	(292)	(241)	(775)	(887)
Earnings Before Income Taxes	1,901	1,482	4,457	3,142
Income taxes (benefit)	414	372	891	550
Consolidated Net Income	1,487	1,110	3,566	2,592
Retail electric revenues
Operating Revenues:
Total operating revenues	5,961	4,551	14,363	11,492
Wholesale Electric
Operating Revenues:
Total operating revenues	1,197	731	2,798	1,822
Other electric revenues
Operating Revenues:
Total operating revenues	185	179	554	525
Natural Gas
Operating Revenues:
Total operating revenues	857	623	3,998	2,994
Natural gas
Operating Expenses:
Total cost of sales	294	129	1,840	943
Alternative revenue programs
Operating Revenues:
Total operating revenues	(1)	(1)	0	3
Other revenues
Operating Revenues:
Total operating revenues	178	154	519	513
Operating Expenses:
Total cost of sales	92	71	275	255
SOUTHERN Co GAS
Operating Revenues:
Total operating revenues	$ 857	$ 623	$ 3,998	$ 2,994
Operating Expenses:
Cost, Product and Service [Extensible Enumeration]	Natural gas	Natural gas	Natural gas	Natural gas
Other operations and maintenance	$ 252	$ 238	$ 829	$ 776
Depreciation and amortization	140	133	414	396
Taxes other than income taxes	45	36	208	166
Gain on dispositions, net	0	(121)	(5)	(127)
Total operating expenses	731	415	3,286	2,154
Operating Income	126	208	712	840
Other Income and (Expense):
Earnings from equity method investments	34	25	105	14
Interest expense, net of amounts capitalized	(65)	(57)	(187)	(175)
Other income (expense), net	15	13	47	(66)
Total other income and (expense)	(16)	(19)	(35)	(227)
Earnings Before Income Taxes	110	189	677	613
Income taxes (benefit)	27	133	161	224
Consolidated Net Income	83	56	516	389
SOUTHERN Co GAS \| Natural gas
Operating Revenues:
Total operating revenues	858	624	3,998	2,991
Operating Expenses:
Total cost of sales	294	129	1,840	943
SOUTHERN Co GAS \| Alternative revenue programs
Operating Revenues:
Total operating revenues	$ (1)	$ (1)	$ 0	$ 3

Condensed Consolidated State_16

Condensed Consolidated Statements of Income (Unaudited) - GAS (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
SOUTHERN Co GAS
Revenue taxes collected	$ 15	$ 12	$ 118	$ 89

Condensed Consolidated State_17

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - GAS - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Net income	$ 1,487	$ 1,110	$ 3,566	$ 2,592
Qualifying hedges:
Changes in fair value, net of tax	0	1	(27)	(15)
Reclassification adjustment for amounts included in net income, net of tax	26	31	100	81
Total other comprehensive income	28	36	81	76
Comprehensive Income	1,515	1,146	3,647	2,668
SOUTHERN Co GAS
Net income	83	56	516	389
Qualifying hedges:
Changes in fair value, net of tax	19	23	39	32
Reclassification adjustment for amounts included in net income, net of tax	(5)	(2)	(17)	1
Total other comprehensive income	14	21	22	33
Comprehensive Income	$ 97	$ 77	$ 538	$ 422

Condensed Consolidated State_18

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - GAS (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Changes in fair value, tax	$ 2	$ 1	$ (5)	$ (4)
Qualifying hedges, reclassification adjustment, tax	8	10	32	27
SOUTHERN Co GAS
Changes in fair value, tax	8	8	16	11
Qualifying hedges, reclassification adjustment, tax	$ (2)	$ 0	$ (7)	$ 1

Condensed Consolidated State_19

Condensed Consolidated Statements of Cash Flows (Unaudited) - GAS - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Operating Activities:
Net income (loss)	$ 3,566	$ 2,592
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	3,084	2,944
Deferred income taxes	608	89
Mark-to-market adjustments	(33)	147
Gain on dispositions, net	(41)	(171)
Natural gas cost under recovery – long-term	207	(79)
Other, net	(45)	156
Changes in certain current assets and liabilities —
Receivables	(327)	2
Natural gas for sale, net of temporary LIFO liquidation	(136)	20
Natural gas cost under recovery	(124)	(432)
Other current assets	(343)	(180)
Accounts payable	805	(45)
Other current liabilities	(32)	(226)
Net cash provided from operating activities	5,017	5,081
Investing Activities:
Property additions	(5,502)	(5,222)
Cost of removal, net of salvage	(518)	(282)
Proceeds from dispositions	120	160
Other investing activities	73	(12)
Net cash used for investing activities	(5,952)	(5,850)
Financing Activities:
Decrease in notes payable, net	(349)	(203)
Proceeds —
Short-term borrowings	1,200	325
Redemptions and repurchases —
Short-term borrowings	(900)	(25)
Payment of common stock dividends	(2,166)	(2,077)
Other financing activities	(235)	(224)
Net cash provided from financing activities	1,119	1,802
Net Change in Cash, Cash Equivalents, and Restricted Cash	184	1,033
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	1,829	1,068
Cash, Cash Equivalents, and Restricted Cash at End of Period	2,013	2,101
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	1,425	1,417
Income taxes, net	160	92
Noncash transactions —
Accrued property additions at year-end	872	915
SOUTHERN Co GAS
Operating Activities:
Net income (loss)	516	389
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	414	396
Deferred income taxes	109	289
Mark-to-market adjustments	(34)	147
Impairment of PennEast Pipeline investment	0	84
Gain on dispositions, net	(5)	(127)
Natural gas cost under recovery – long-term	207	(79)
Other, net	27	32
Changes in certain current assets and liabilities —
Receivables	301	311
Natural gas for sale, net of temporary LIFO liquidation	(136)	20
Prepaid income taxes	(77)	(148)
Natural gas cost under recovery	(124)	(432)
Other current assets	7	(98)
Accounts payable	342	30
Other current liabilities	(15)	(57)
Net cash provided from operating activities	1,532	757
Investing Activities:
Property additions	(1,063)	(1,045)
Cost of removal, net of salvage	(84)	(74)
Construction payables	(103)	4
Proceeds from dispositions	0	126
Other investing activities	11	23
Net cash used for investing activities	(1,239)	(966)
Financing Activities:
Decrease in notes payable, net	(749)
Increase in notes payable, net		38
Proceeds —
Short-term borrowings	50	300
First mortgage bonds	100	100
Proceeds — Senior notes	500	450
Redemptions and repurchases —
Short-term borrowings	(150)	0
Senior notes	0	(300)
Medium-term notes	(46)	(30)
Capital contributions from parent company	357	63
Payment of common stock dividends	(389)	(397)
Other financing activities	14	(2)
Net cash provided from financing activities	(313)	222
Net Change in Cash, Cash Equivalents, and Restricted Cash	(20)	13
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	48	19
Cash, Cash Equivalents, and Restricted Cash at End of Period	28	32
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	186	173
Income taxes, net	193	85
Noncash transactions —
Accrued property additions at year-end	$ 10	$ 146

Condensed Consolidated State_20

Condensed Consolidated Statements of Cash Flows (Unaudited) - GAS (Parenthetical) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Net cash paid for capitalized interest	$ 74	$ 68
SOUTHERN Co GAS
Net cash paid for capitalized interest	$ 7	$ 6

Condensed Consolidated Balanc_5

Condensed Consolidated Balance Sheets (Unaudited) - GAS - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Current Assets:
Cash and cash equivalents	$ 2,009	$ 1,798
Receivables —
Customer accounts	2,223	1,806
Unbilled revenues	593	711
Other accounts and notes	533	523
Accumulated provision for uncollectible accounts	(80)	(78)
Natural gas for sale	498	362
Prepaid expenses	373	330
Natural gas cost under recovery	390	266
Other regulatory assets	746	653
Other current assets	322	231
Total current assets	10,363	8,965
Property, Plant, and Equipment:
In service	116,236	115,592
Less: Accumulated depreciation	34,922	34,079
Plant in service, net of depreciation	81,314	81,513
Construction work in progress	10,773	8,771
Total property, plant, and equipment	93,529	91,108
Other Property and Investments:
Goodwill	5,280	5,280
Equity investments in unconsolidated subsidiaries	1,292	1,282
Other intangible assets, net of amortization	415	445
Miscellaneous property and investments	590	653
Total other property and investments	9,608	10,202
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	1,560	1,701
Prepaid pension costs	2,019	1,657
Other regulatory assets, deferred	6,121	5,577
Other deferred charges and assets	1,492	1,366
Total deferred charges and other assets	20,505	17,259
Total Assets	134,005	127,534
Current Liabilities:
Securities due within one year	3,241	2,157
Notes payable	1,398	1,440
Accounts payable —
Customer deposits	516	479
Accrued interest	431	533
Accrued compensation	961	1,070
Other regulatory liabilities	440	563
Other current liabilities	844	872
Total current liabilities	12,801	10,921
Long-term Debt	50,427	50,120
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	9,916	8,862
Deferred credits related to income taxes	5,271	5,401
Employee benefit obligations	1,466	1,550
Operating lease obligations, deferred	1,393	1,503
Other cost of removal obligations	1,950	2,103
Other deferred credits and liabilities	1,366	816
Total deferred credits and other liabilities	35,059	33,926
Total Liabilities	98,287	94,967
Total Stockholders' Equity	35,476	32,276
Total Liabilities and Stockholders' Equity	134,005	127,534
SOUTHERN Co GAS
Current Assets:
Cash and cash equivalents	26	45
Receivables —
Customer accounts	296	462
Unbilled revenues	122	278
Other accounts and notes	58	49
Accumulated provision for uncollectible accounts	(41)	(39)
Natural gas for sale	498	362
Prepaid expenses	192	114
Natural gas cost under recovery	390	266
Other regulatory assets	121	136
Other current assets	118	82
Total current assets	1,780	1,755
Property, Plant, and Equipment:
In service	19,656	18,880
Less: Accumulated depreciation	5,270	5,067
Plant in service, net of depreciation	14,386	13,813
Construction work in progress	871	684
Total property, plant, and equipment	15,257	14,497
Other Property and Investments:
Goodwill	5,015	5,015
Equity investments in unconsolidated subsidiaries	1,125	1,173
Other intangible assets, net of amortization	28	37
Miscellaneous property and investments	27	19
Total other property and investments	6,195	6,244
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	61	70
Prepaid pension costs	200	175
Other regulatory assets, deferred	468	689
Other deferred charges and assets	136	130
Total deferred charges and other assets	865	1,064
Total Assets	24,097	23,560
Current Liabilities:
Securities due within one year	0	47
Notes payable	360	1,209
Accounts payable —
Affiliated	64	58
Other	592	361
Customer deposits	137	95
Accrued taxes	71	124
Accrued interest	67	59
Accrued compensation	92	110
Other regulatory liabilities	15	8
Other current liabilities	168	155
Total current liabilities	1,566	2,226
Long-term Debt	7,361	6,855
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	1,662	1,555
Deferred credits related to income taxes	793	816
Employee benefit obligations	158	176
Operating lease obligations, deferred	53	59
Other cost of removal obligations	1,696	1,683
Accrued environmental remediation	217	197
Other deferred credits and liabilities	153	77
Total deferred credits and other liabilities	4,732	4,563
Total Liabilities	13,659	13,644
Total Stockholders' Equity	10,438	9,916
Total Liabilities and Stockholders' Equity	$ 24,097	$ 23,560

Condensed Consolidated Balanc_6

Condensed Consolidated Balance Sheets (Unaudited) - GAS (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Other intangible assets, amortization	$ 331	$ 307
SOUTHERN Co GAS
Other intangible assets, amortization	$ 154	$ 145

Condensed Consolidated State_21

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - GAS - USD ($) $ in Millions	Total	Paid-In Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Income (Loss)	SOUTHERN Co GAS	SOUTHERN Co GAS Paid-In Capital	SOUTHERN Co GAS Retained Earnings (Accumulated Deficit)	SOUTHERN Co GAS Accumulated Other Comprehensive Income (Loss)
Beginning balance at Dec. 31, 2020	$ 32,234	$ 11,834	$ 11,311	$ (395)	$ 9,767	$ 9,930	$ (141)	$ (22)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income					398		398
Capital contributions from parent company					57	57
Other comprehensive income (loss)	28			28	4			4
Cash dividends on common stock	(678)		(678)		(132)		(132)
Other	1	2
Ending balance at Mar. 31, 2021	33,068	11,854	11,768	(367)	10,094	9,987	125	(18)
Beginning balance at Dec. 31, 2020	32,234	11,834	11,311	(395)	9,767	9,930	(141)	(22)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,592				389
Ending balance at Sep. 30, 2021	33,219	11,932	11,844	(319)	9,876	10,014	(149)	11
Beginning balance at Mar. 31, 2021	33,068	11,854	11,768	(367)	10,094	9,987	125	(18)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income					(65)		(65)
Capital contributions from parent company					25	25
Other comprehensive income (loss)	12			12	8			8
Cash dividends on common stock	(699)		(699)		(133)		(133)
Other	0	1	1
Ending balance at Jun. 30, 2021	32,746	11,886	11,442	(355)	9,929	10,012	(73)	(10)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,110				56		56
Capital contributions from parent company					2	2
Other comprehensive income (loss)	36			36	21			21
Cash dividends on common stock	(700)		(700)		(132)		(132)
Other	(7)	(10)	1
Ending balance at Sep. 30, 2021	33,219	11,932	11,844	(319)	9,876	10,014	(149)	11
Beginning balance at Dec. 31, 2021	32,276	11,950	10,929	(237)	9,916	10,024	(132)	24
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income					319		319
Capital contributions from parent company					50	50
Other comprehensive income (loss)	42			42	20			20
Cash dividends on common stock	(702)		(702)		(130)		(130)
Other	7	7	2
Ending balance at Mar. 31, 2022	32,629	11,994	11,261	(195)	10,175	10,074	57	44
Beginning balance at Dec. 31, 2021	32,276	11,950	10,929	(237)	9,916	10,024	(132)	24
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	3,566				516
Ending balance at Sep. 30, 2022	35,476	13,657	12,374	(157)	10,438	10,397	(5)	46
Beginning balance at Mar. 31, 2022	32,629	11,994	11,261	(195)	10,175	10,074	57	44
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income					115		115
Capital contributions from parent company					312	312
Other comprehensive income (loss)	11			11	(12)			(12)
Cash dividends on common stock	(723)		(723)		(130)		(130)
Other	2	4
Ending balance at Jun. 30, 2022	33,013	12,033	11,645	(184)	10,460	10,386	42	32
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,487				83		83
Capital contributions from parent company					11	11
Other comprehensive income (loss)	28			28	14			14
Cash dividends on common stock	(741)		(741)		(130)		(130)
Other	(8)	(4)	(2)	(1)
Ending balance at Sep. 30, 2022	$ 35,476	$ 13,657	$ 12,374	$ (157)	$ 10,438	$ 10,397	$ (5)	$ 46

Introduction

Introduction	9 Months Ended
Introduction	Sep. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Introduction	INTRODUCTION The condensed quarterly financial statements of each Registrant included herein have been prepared by such Registrant, without audit, pursuant to the rules and regulations of the SEC. The Condensed Balance Sheets at December 31, 2021 have been derived from the audited financial statements of each Registrant. In the opinion of each Registrant's management, the information regarding such Registrant furnished herein reflects all adjustments, which, except as otherwise disclosed, are of a normal recurring nature, necessary to present fairly the results of operations for the periods ended September 30, 2022 and 2021. Certain information and footnote disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations, although each Registrant believes that the disclosures regarding such Registrant are adequate to make the information presented not misleading. Disclosures which would substantially duplicate the disclosures in the Form 10-K and details which have not changed significantly in amount or composition since the filing of the Form 10-K are generally omitted from this Quarterly Report on Form 10-Q unless specifically required by GAAP. Therefore, these Condensed Financial Statements should be read in conjunction with the financial statements and the notes thereto included in the Form 10-K. Due to the seasonal variations in the demand for energy and other factors, operating results for the periods presented are not necessarily indicative of the operating results to be expected for the full year. Certain prior year data presented in the financial statements have been reclassified to conform to the current year presentation. These reclassifications had no impact on the overall results of operations, financial position, or cash flows of any Registrant. Goodwill and Other Intangible Assets Goodwill at September 30, 2022 and December 31, 2021 was as follows: Goodwill (in millions) Southern Company $ 5,280 Southern Company Gas: Gas distribution operations $ 4,034 Gas marketing services 981 Southern Company Gas total $ 5,015 Goodwill is not amortized, but is subject to an annual impairment test during the fourth quarter of each year, or more frequently if impairment indicators arise. Other intangible assets were as follows: At September 30, 2022 At December 31, 2021 Gross Carrying Amount Accumulated Amortization Other Gross Carrying Amount Accumulated Amortization Other (in millions) (in millions) Southern Company Other intangible assets subject to amortization: Customer relationships $ 212 $ (159) $ 53 $ 212 $ (150) $ 62 Trade names 64 (44) 20 64 (38) 26 PPA fair value adjustments 390 (124) 266 390 (109) 281 Other 5 (4) 1 11 (10) 1 Total other intangible assets subject to amortization $ 671 $ (331) $ 340 $ 677 $ (307) $ 370 Other intangible assets not subject to amortization: Federal Communications Commission licenses 75 — 75 75 — 75 Total other intangible assets $ 746 $ (331) $ 415 $ 752 $ (307) $ 445 Southern Power Other intangible assets subject to amortization: PPA fair value adjustments $ 390 $ (124) $ 266 $ 390 $ (109) $ 281 Southern Company Gas Other intangible assets subject to amortization: Gas marketing services Customer relationships $ 156 $ (137) $ 19 $ 156 $ (130) $ 26 Trade names 26 (17) 9 26 (15) 11 Total other intangible assets subject to amortization $ 182 $ (154) $ 28 $ 182 $ (145) $ 37 Amortization associated with other intangible assets was as follows: Three Months Ended Nine Months Ended September 30, 2022 (in millions) Southern Company (a) $ 11 $ 30 Southern Power (b) 5 15 Southern Company Gas 4 9 (a) Includes $5 million and $15 million for the three and nine months ended September 30, 2022, respectively, recorded as a reduction to operating revenues. (b) Recorded as a reduction to operating revenues. Cash, Cash Equivalents, and Restricted Cash The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the condensed balance sheets that total to the amount shown in the condensed statements of cash flows for the applicable Registrants: Southern Southern Southern September 30, 2022 December 31, 2021 September 30, 2022 December 31, 2021 September 30, 2022 December 31, 2021 (in millions) Cash and cash equivalents $ 2,009 $ 1,798 $ 229 $ 107 $ 26 $ 45 Restricted cash (a) : Other current assets 2 2 — — 2 2 Other deferred charges and assets 3 29 3 29 — — Total cash, cash equivalents, and restricted cash (b) $ 2,013 $ 1,829 $ 231 $ 135 $ 28 $ 48 (a) For Southern Power, reflects $3 million and $10 million at September 30, 2022 and December 31, 2021, respectively, held to fund estimated construction completion costs at the Deuel Harvest wind facility and $19 million at December 31, 2021 related to tax equity contributions restricted until the Garland battery energy storage facility achieved final contracted capacity. For Southern Company Gas, reflects collateral for workers' compensation, life insurance, and long-term disability insurance. (b) Total may not add due to rounding. Natural Gas for Sale With the exception of Nicor Gas, Southern Company Gas records natural gas inventories on a WACOG basis. For any declines in market prices below the WACOG considered to be other than temporary, an adjustment is recorded to reduce the value of natural gas inventories to market value. Nicor Gas' natural gas inventory is carried at cost on a LIFO basis. Inventory decrements occurring during the year that are restored prior to year end are charged to cost of natural gas at the estimated annual replacement cost. Inventory decrements that are not restored prior to year end are charged to cost of natural gas at the actual LIFO cost of the inventory layers liquidated. Southern Company Gas recorded no material adjustments to natural gas inventories for either period presented. Nicor Gas had no inventory decrement at September 30, 2022. Depreciation and Amortization See Note 5 to the financial statements under "Depreciation and Amortization" in Item 8 of the Form 10-K for additional information. Alabama Power On September 23, 2022, the FERC authorized Alabama Power to use updated depreciation rates from its 2021 depreciation study effective January 1, 2023. The study was also provided to the Alabama PSC, and the new depreciation rates will be reflected in Alabama Power's future rate filings. See Note 2 to the financial statements under "Alabama Power" in Item 8 of the Form 10-K for additional information. Southern Power Effective January 1, 2022, Southern Power revised the depreciable lives of its wind generating facilities from up to 30 years to up to 35 years. This revision resulted in an immaterial decrease in depreciation for the three and nine months ended September 30, 2022.

Regulatory Matters

Regulatory Matters	9 Months Ended
Regulatory Matters	Sep. 30, 2022
Regulated Operations [Abstract]
Regulatory Matters	REGULATORY MATTERS See Note 2 to the financial statements in Item 8 of the Form 10-K for additional information relating to regulatory matters. The recovery balances for certain retail regulatory clauses of the traditional electric operating companies and Southern Company Gas at September 30, 2022 and December 31, 2021 were as follows: Regulatory Clause Balance Sheet Line Item September 30, December 31, 2021 (in millions) Alabama Power Rate CNP Compliance Other regulatory liabilities, deferred $ 4 $ — Other regulatory assets, deferred — 16 Rate CNP PPA Other regulatory assets, deferred 125 84 Retail Energy Cost Recovery () Other regulatory assets, current 93 — Other regulatory assets, deferred 413 126 Georgia Power Fuel Cost Recovery Deferred under recovered fuel clause revenues $ 1,697 $ 410 Mississippi Power Fuel Cost Recovery Other customer accounts receivable $ 13 $ 4 Ad Valorem Tax Other regulatory assets, current 12 12 Other regulatory assets, deferred 22 37 Southern Company Gas Natural Gas Cost Recovery Natural gas cost under recovery $ 390 $ 266 Other regulatory assets, deferred — 207 () In accordance with an Alabama PSC order issued on February 1, 2022, Alabama Power applied $126 million of its 2021 Rate RSE refund to reduce the Rate ECR under recovered balance. Alabama Power Certificates of Convenience and Necessity On July 12, 2022, the Alabama PSC approved a certificate of convenience and necessity (CCN) authorizing Alabama Power to complete the acquisition of the Calhoun Generating Station, which was approved by the FERC on March 25, 202 2. The transaction clo sed on September 30, 2022 and, on October 3, 2022, Alabama Power filed Rate CNP New Plant with the Alabama PSC to recover the related costs. The filing reflected an increase in annual revenues of $34 million, or 0.6%, effective with the billing month of November 2022. Alabama Power expects to recover all approved costs associated with the acquisition through existing rate mechanisms as outlined in Note 2 to the financial statements in Item 8 of the Form 10-K. See Note (K) under "Alabama Power" for additional information. With the completion of the Calhoun Generating Station acquisition, Alabama Power expects to retire Plant Barry Unit 5 as early as 2023. In September 2022, Alabama Power reclassified approximately $600 million for Plant Barry Unit 5 from plant in service, net of depreciation to other utility plant, net and will continue to depreciate the asset according to the original depreciation rates. At retirement, Alabama Power will reclassify the remaining net investment costs of the unit to a regulatory asset to be recovered over the unit's remaining useful life, as established prior to the decision to retire, through Rate CNP Compliance. See Note 2 to the financial statements under "Alabama Power – Environmental Accounting Order" in Item 8 of the Form 10-K for additional information. In its 2020 order authorizing the CCN for Alabama Power's construction of Plant Barry Unit 8, the Alabama PSC authorized recovery of estimated actual in-service costs of $652 million. At September 30, 2022, project expenditures associated with Plant Barry Unit 8 included in CWIP totaled approximately $484 million and the unit is expected to be placed in service in November 2023. The ultimate outcome of this matter cannot be determined at this time. Rate ECR On July 12, 2022, the Alabama PSC approved an adjustment to Rate ECR from 1.960 cents per KWH to 2.557 cents per KWH, or approximately $310 million annually, effective with August 2022 billings. The approved increase in the Rate ECR factor has no significant effect on Alabama Power's net income, but does increase operating cash flows related to fuel cost recovery. The rate will adjust to 5.910 cents per KWH in January 2025 absent a further order from the Alabama PSC. Rate NDR On July 12, 2022, the Alabama PSC approved modifications to Rate NDR, which include an adjustment to the charges to establish and maintain the reserve and an adjustment to the recovery period for any existing deferred storm-related operations and maintenance costs and future reserve deficits from 24 months to 48 months. As modified, the maximum total Rate NDR charge to recover a deficit is limited to $5.00 per month per non-residential customer account and $2.50 per month per residential customer account. Beginning with August 2022 billings, the reserve establishment charge was suspended and the reserve maintenance charge was activated as a result of the NDR balance exceeding $75 million. Alabama Power expects to collect $6 million in the second half of 2022 and approximately $12 million annually beginning in 2023 under Rate NDR unless the NDR balance falls below $50 million. At September 30, 2022, Alabama Power's NDR balance was $103 million. Alabama Power continues to have the authority to accrue additional amounts to the NDR as circumstances warrant. Reliability Reserve Accounting Order On July 12, 2022, the Alabama PSC approved an accounting order authorizing Alabama Power to create a reliability reserve separate from the NDR and transition the previous Rate NDR authority related to reliability expenditures to the reliability reserve. Alabama Power may make accruals to the reliability reserve if the NDR balance exceeds $35 million. Renewable Generation Certificate Through the issuance of a Renewable Generation Certificate (RGC), Alabama Power is authorized by the Alabama PSC to procure up to 500 MWs of renewable capacity and energy by September 16, 2027 and to market the related energy and environmental attributes to customers and other third parties. In April 2022, one of the existing solar projects which was expected to be served through a PPA commencing in first quarter 2024 was terminated, resulting in the restoration of 80 MWs of capacity under the RGC. On October 4, 2022, the Alabama PSC approved two new solar PPAs totaling 160 MWs. Alabama Power has procured solar capacity totaling approximately 330 MWs under the RGC. The ultimate outcome of this matter cannot be determined at this time. Georgia Power Rate Plans 2022 Base Rate Case On June 24, 2022, Georgia Power filed a base rate case (Georgia Power 2022 Base Rate Case) with the Georgia PSC. The filing, as modified on August 22, 2022, proposes a three-year alternate rate plan with requested rate increases totaling $889 million, $107 million, and $45 million effective January 1, 2023, January 1, 2024, and January 1, 2025, respectively. These increases are based on a proposed retail ROE of 11.00% using the currently approved equity ratio of 56% and reflect levelized revenue requirements during the three-year period, with the exception of incremental compliance costs related to CCR AROs, Demand-Side Management (DSM) programs, and related adjustments to the Municipal Franchise Fee tariff. Georgia Power has requested recovery of the proposed increases through its existing base rate tariffs as follows: Tariff 2023 2024 2025 (in millions) Traditional base $ 762 $ — $ — ECCR Traditional 5 — — CCR ARO (a) 64 78 47 DSM (a) 37 27 (2) Municipal Franchise Fee 21 2 1 Total (b) $ 889 $ 107 $ 45 (a) As determined by the Georgia PSC through annual compliance filings. (b) Totals may not add due to rounding. Georgia Power's filing primarily reflects requests to (i) recover the costs of recent and future capital investments in the electric grid including the transmission and distribution systems and the continuation of its grid investment plan, all designed to support customer long-term reliability and resiliency needs, (ii) recover the cost of coal-fired generation units proposed for retirement, or made unavailable, as requested in the 2022 IRP, as Georgia Power continues the transition of the generation fleet to more economical and cleaner resources, (iii) make the necessary investments and recover costs to comply with federal and state environmental regulations, including costs associated with the CCR AROs related to ash pond and landfill closures and post-closure care, and (iv) reduce operating costs despite significant inflationary pressures. In addition, the filing includes the following provisions: • Continuation of an allowed retail ROE range of 9.50% to 12.00%. • Continuation of the process whereby 80% of any earnings above the top of the allowed ROE range are shared with Georgia Power's customers and the remaining 20% are retained by Georgia Power. • Continuation of the option to file an Interim Cost Recovery tariff in the event earnings are projected to fall below the bottom of the allowed ROE range during the three-year term of the plan. Georgia Power expects the Georgia PSC to render a final decision in this matter on December 20, 2022. The ultimate outcome of this matter cannot be determined at this time. 2019 ARP In 2020, the Georgia PSC denied a motion for reconsideration filed by Sierra Club regarding the Georgia PSC's decision in the 2019 ARP allowing Georgia Power to recover compliance costs for CCR AROs. The Superior Court of Fulton County subsequently affirmed the Georgia PSC's decision and, in October 2021, the Georgia Court of Appeals affirmed the Superior Court of Fulton County's order. In December 2021, Sierra Club filed a petition for writ of certiorari to the Georgia Supreme Court, which was denied on July 14, 2022. This matter is now concluded. See Note 6 to the financial statements in Item 8 of the Form 10-K for additional information regarding Georgia Power's AROs. Integrated Resource Plans In response to supply chain challenges in the solar industry, the Georgia PSC approved Georgia Power's request to amend 970 MWs of utility-scale solar PPAs that were authorized by the Georgia PSC in Georgia Power's 2019 IRP. The amendments extended the required commercial operation dates for the PPAs from 2023 to 2024. On July 21, 2022, the Georgia PSC approved the 2022 IRP, as modified by a stipulated agreement among Georgia Power, the staff of the Georgia PSC, and certain intervenors and as further modified by the Georgia PSC. In the 2022 IRP decision, the Georgia PSC approved the following requests: • Decertification and retirement of Plant Wansley Units 1 and 2 (926 MWs based on 53.5% ownership), which occurred on August 31, 2022, and reclassification to regulatory asset accounts of the remaining net book values and any remaining unusable materials and supplies inventories upon retirement. The regulatory asset accounts for the remaining net book values of the units ($299 million and $277 million for Unit 1 and Unit 2, respectively, at September 30, 2022) are being amortized at a rate equal to the unit depreciation rates authorized in the 2019 ARP through December 31, 2022. In the Georgia Power 2022 Base Rate Case, Georgia Power requested recovery of the remaining regulatory asset balances for the net book values of the units through 2030 and requested that the timing of recovery of the regulatory asset account for the unusable materials and supplies inventories be determined in a future base rate case. • Decertification and retirement of Plant Scherer Unit 3 (614 MWs based on 75% ownership) by December 31, 2028 and reclassification to regulatory asset accounts of the remaining net book value (approximately $608 million at September 30, 2022) and any remaining unusable materials and supplies inventory to regulatory asset accounts upon retirement. The timing of recovery for these regulatory assets is expected to be determined in a future base rate case. • Decertification and retirement of Plant Gaston Units 1 through 4 (500 MWs based on 50% ownership through SEGCO) by December 31, 2028. See Note 7 to the financial statements under "SEGCO" in Item 8 of the Form 10-K for additional information. • Georgia Power's environmental compliance strategy, including approval of Georgia Power's plans to address CCR at its ash ponds and landfills. Recovery of the related costs is expected to be determined in future base rate cases. The Georgia PSC's approval included a change in the method of closure for one ash pond. Georgia Power is currently evaluating the related impact on its cost estimates and AROs; however, it is not expected to be material. • Installation of environmental controls at Plants Bowen and Scherer for compliance with rules related to effluent limitations guidelines. • Initiation of a license renewal application with the NRC for Plant Hatch. • Investments related to the continued hydro operations of Plants Sinclair and Burton. • Provisional authorization for development of a 265-MW battery energy storage facility with expected commercial operation in 2026. • Issuance of requests for proposals (RFP) for 2,300 MWs of renewable resources, an additional 500 MWs of energy storage, and up to 140 MWs of biomass generation. • Related transmission projects necessary to support the generation facilities plan. • Certification of six PPAs (including five affiliate PPAs with Southern Power that are subject to approval by the FERC) with capacities of 1,567 MWs beginning in 2024, 380 MWs beginning in 2025, and 228 MWs beginning in 2028, procured through RFPs authorized in the 2019 IRP. See Note (F) under "Georgia Power Lease Modification" for additional information. The Georgia PSC deferred a decision on the requested decertification and retirement of Plant Bowen Units 1 and 2 (1,400 MWs) to the 2025 IRP and rejected Georgia Power's request to certify approximately 88 MWs of wholesale capacity to be placed in retail rate base between January 1, 2024 and January 1, 2025. Georgia Power may offer such capacity in the wholesale market or to the retail jurisdiction in a future regulatory proceeding. On August 26, 2022, Restore Chattooga Gorge Coalition (RCG) filed a petition in the Superior Court of Fulton County, Georgia against Georgia Power and the Georgia PSC. The petition challenges Georgia Power's plan to expend $115 million to modernize Plant Tugalo, as approved in the 2019 IRP, and seeks judicial review of the Georgia PSC's order in the 2022 IRP proceeding with respect to the denial of RCG's challenge to the modernization plan. The ultimate outcome of these matters cannot be determined at this time. Nuclear Construction In 2009, the Georgia PSC certified construction of Plant Vogtle Units 3 and 4, in which Georgia Power holds a 45.7% ownership interest. In 2012, the NRC issued the related combined construction and operating licenses, which allowed full construction of the two AP1000 nuclear units (with electric generating capacity of approximately 1,100 MWs each) and related facilities to begin. Until March 2017, construction on Plant Vogtle Units 3 and 4 continued under the Vogtle 3 and 4 Agreement, which was a substantially fixed price agreement. In connection with the EPC Contractor's bankruptcy filing in March 2017, Georgia Power, acting for itself and as agent for the other Vogtle Owners, entered into several transitional arrangements to allow construction to continue. In July 2017, Georgia Power, acting for itself and as agent for the other Vogtle Owners, entered into the Vogtle Services Agreement, whereby Westinghouse provides facility design and engineering services, procurement and technical support, and staff augmentation on a time and materials cost basis. The Vogtle Services Agreement provides that it will continue until the start-up and testing of Plant Vogtle Units 3 and 4 are complete and electricity is generated and sold from both units. The Vogtle Services Agreement is terminable by the Vogtle Owners upon 30 days' written notice. In October 2017, Georgia Power, acting for itself and as agent for the other Vogtle Owners, executed the Bechtel Agreement, under which Bechtel is reimbursed for actual costs plus a base fee and an at-risk fee, subject to adjustment based on Bechtel's performance against cost and schedule targets. Each Vogtle Owner is severally (not jointly) liable for its proportionate share, based on its ownership interest, of all amounts owed to Bechtel under the Bechtel Agreement. The Vogtle Owners may terminate the Bechtel Agreement at any time for their convenience, provided that the Vogtle Owners will be required to pay amounts related to work performed prior to the termination (including the applicable portion of the base fee), certain termination-related costs, and, at certain stages of the work, the applicable portion of the at-risk fee. Bechtel may terminate the Bechtel Agreement under certain circumstances, including certain Vogtle Owner suspensions of work, certain breaches of the Bechtel Agreement by the Vogtle Owners, Vogtle Owner insolvency, and certain other events. See Note 8 to the financial statements under "Long-term Debt – DOE Loan Guarantee Borrowings" in Item 8 of the Form 10-K for information on the Amended and Restated Loan Guarantee Agreement, including applicable covenants, events of default, and mandatory prepayment events. Cost and Schedule Georgia Power's approximate proportionate share of the remaining estimated capital cost to complete Plant Vogtle Units 3 and 4, including contingency, through the end of the first quarter 2023 and the fourth quarter 2023, respectively, is as follows: (in millions) Base project capital cost forecast (a)(b) $ 10,334 Construction contingency estimate 49 Total project capital cost forecast (a)(b) 10,383 Net investment at September 30, 2022 (b) (9,280) Remaining estimate to complete $ 1,103 (a) Includes approximately $590 million of costs that are not shared with the other Vogtle Owners and approximately $353 million of incremental costs under the cost-sharing and tender provisions of the joint ownership agreements described below. Excludes financing costs expected to be capitalized through AFUDC of approximately $385 million, of which $275 million had been accrued through September 30, 2022. (b) Net of $1.7 billion received from Toshiba under the Guarantee Settlement Agreement and approximately $188 million in related customer refunds. Georgia Power estimates that its financing costs for construction of Plant Vogtle Units 3 and 4 will total approximately $3.4 billion, of which $3.1 billion had been incurred through September 30, 2022. As part of its ongoing processes, Southern Nuclear continues to evaluate cost and schedule forecasts on a regular basis to incorporate current information available, particularly in the areas of engineering support, commodity installation, system turnovers and related test results, and workforce statistics. Southern Nuclear establishes aggressive target values for monthly construction production and system turnover activities, which are reflected in the site work plans. Since March 2020, the number of active COVID-19 cases at the site has fluctuated consistent with the surrounding area and impacted productivity levels and pace of activity completion, with the site experiencing peaks in the number of active cases in January 2021, August 2021, and January 2022. Georgia Power estimates the productivity impacts of the COVID-19 pandemic have consumed approximately three On July 29, 2022, Southern Nuclear announced that all Unit 3 ITAACs had been submitted to the NRC. On August 3, 2022, the NRC published its 103(g) finding that the acceptance criteria in the combined license for Unit 3 had been met, which allowed nuclear fuel to be loaded and allows start-up testing to begin. Fuel load for Unit 3 was completed on October 17, 2022, and the unit is projected to be placed in service by the end of the first quarter 2023. Unit 4 is projected to be placed in service by the end of the fourth quarter 2023. During the first nine months of 2022, established construction contingency totaling $170 million was assigned to the base capital cost forecast for costs primarily associated with construction productivity, the pace of system turnovers, additional craft and support resources, and procurement for Units 3 and 4. Georgia Power also increased its total project capital cost forecast by adding $36 million and $32 million to replenish construction contingency in the second quarter 2022 and the third quarter 2022, respectively. After considering the significant level of uncertainty that exists regarding the future recoverability of these costs since the ultimate outcome of these matters is subject to the outcome of future assessments by management, as well as Georgia PSC decisions in future regulatory proceedings, Georgia Power recorded pre-tax charges to income in the second quarter 2022 and the third quarter 2022 of $36 million ($27 million after tax) and $32 million ($24 million after tax), respectively, for the increases in the total project capital cost forecast. Georgia Power may request the Georgia PSC to evaluate those expenditures for rate recovery during the prudence review following the Unit 4 fuel load pursuant to the twenty-fourth VCM stipulation described below. The projected schedule for Unit 3 primarily depends on the pace of system and area transitions to operations, including the completion of closure documentation necessary to support start-up testing, and the progression of start-up, final component, and pre-operational testing, which may be impacted by equipment or other operational failures. The projected schedule for Unit 4 primarily depends on Unit 3 progress through start-up and testing; overall construction productivity and production levels improving, particularly in electrical installation, including terminations; and appropriate levels of craft laborers, particularly electricians, being added and maintained. As Unit 4 progresses through construction and continues to transition into testing, ongoing and potential future challenges include the pace and quality of electrical, mechanical, and instrumentation and controls commodities installation; availability of craft and supervisory resources, including the temporary diversion of such resources to support Unit 3; the pace of work package closures and system turnovers; and the timeframe and duration of hot functional and other testing. Ongoing or future challenges for both units also include management of contractors and vendors; subcontractor performance; supervision of craft labor and related productivity; ability to attract and retain craft labor; and/or related cost escalation. New challenges also may arise, particularly as Units 3 and 4 move into initial testing and start-up, which may result in required engineering changes or remediation related to plant systems, structures, or components (some of which are based on new technology that only within the last few years began initial operation in the global nuclear industry at this scale). These challenges may result in further schedule delays and/or cost increases. There have been technical and procedural challenges to the construction and licensing of Plant Vogtle Units 3 and 4 at the federal and state level and additional challenges may arise. Processes are in place that are designed to ensure compliance with the requirements specified in the Westinghouse Design Control Document and the combined construction and operating licenses, including inspections by Southern Nuclear and the NRC that occur throughout construction. On March 25, 2022, the NRC completed a follow-up inspection related to the November 2021 final significance report on its special inspection to review the root cause of additional construction remediation work identified in 2021 and Southern Nuclear's corresponding corrective action plans. The NRC closed the two white findings identified in November 2021 and returned Vogtle Unit 3 to the NRC's baseline inspection program. With the receipt of the NRC's 103(g) finding, Unit 3 is now under the NRC's operating reactor oversight process and must meet applicable technical and operational requirements contained within Unit 3's operating license. Various design and other licensing-based compliance matters, including the timely submittal by Southern Nuclear of the ITAAC documentation and the related reviews and approvals by the NRC necessary to support NRC authorization to load fuel for Unit 4, may arise, which may result in additional license amendment requests or require other resolution. If any license amendment requests or other licensing-based compliance issues, including inspections and ITAACs for Unit 4, are not resolved in a timely manner, there may be delays in the project schedule that could result in increased costs. The ultimate outcome of these matters cannot be determined at this time. However, any extension of the in-service date beyond the first quarter 2023 for Unit 3 or the fourth quarter 2023 for Unit 4, including the current level of cost sharing described below, is estimated to result in additional base capital costs for Georgia Power of up to $15 million per month for Unit 3 and $35 million per month for Unit 4, as well as the related AFUDC and any additional related construction, support resources, or testing costs. While Georgia Power is not precluded from seeking retail recovery of any future capital cost forecast increase other than the amounts related to the cost-sharing and tender provisions of the joint ownership agreements described below, management will ultimately determine whether or not to seek recovery. Any further changes to the capital cost forecast that are not expected to be recoverable through regulated rates will be required to be charged to income and such charges could be material. Joint Owner Contracts In November 2017, the Vogtle Owners entered into an amendment to their joint ownership agreements for Plant Vogtle Units 3 and 4 to provide for, among other conditions, additional Vogtle Owner approval requirements. Effective in August 2018, the Vogtle Owners further amended the joint ownership agreements to clarify and provide procedures for certain provisions of the joint ownership agreements related to adverse events that require the vote of the holders of at least 90% of the ownership interests in Plant Vogtle Units 3 and 4 to continue construction (as amended, and together with the November 2017 amendment, the Vogtle Joint Ownership Agreements). The Vogtle Joint Ownership Agreements also confirm that the Vogtle Owners' sole recourse against Georgia Power or Southern Nuclear for any action or inaction in connection with their performance as agent for the Vogtle Owners is limited to removal of Georgia Power and/or Southern Nuclear as agent, except in cases of willful misconduct. Amendments to the Vogtle Joint Ownership Agreements In connection with a September 2018 vote by the Vogtle Owners to continue construction, Georgia Power entered into (i) a binding term sheet (Vogtle Owner Term Sheet) with the other Vogtle Owners and MEAG Power's wholly-owned subsidiaries MEAG Power SPVJ, LLC (MEAG SPVJ), MEAG Power SPVM, LLC (MEAG SPVM), and MEAG Power SPVP, LLC (MEAG SPVP) to take certain actions which partially mitigate potential financial exposure for the other Vogtle Owners, including additional amendments to the Vogtle Joint Ownership Agreements and the purchase of PTCs from the other Vogtle Owners at pre-established prices, and (ii) a term sheet (MEAG Term Sheet) with MEAG Power and MEAG SPVJ to provide up to $300 million of funding with respect to MEAG SPVJ's ownership interest in Plant Vogtle Units 3 and 4 under certain circumstances. In January 2019, Georgia Power, MEAG Power, and MEAG SPVJ entered into an agreement to implement the provisions of the MEAG Term Sheet. In February 2019, Georgia Power, the other Vogtle Owners, and MEAG Power's wholly-owned subsidiaries MEAG SPVJ, MEAG SPVM, and MEAG SPVP entered into certain amendments to the Vogtle Joint Ownership Agreements to implement the provisions of the Vogtle Owner Term Sheet (Global Amendments). Pursuant to the Global Amendments: (i) each Vogtle Owner must pay its proportionate share of qualifying construction costs for Plant Vogtle Units 3 and 4 based on its ownership percentage up to the estimated cost at completion (EAC) for Plant Vogtle Units 3 and 4 which formed the basis of Georgia Power's forecast of $8.4 billion in the nineteenth VCM plus $800 million; (ii) Georgia Power will be responsible for 55.7% of actual qualifying construction costs between $800 million and $1.6 billion over the EAC in the nineteenth VCM (resulting in $80 million of potential additional costs to Georgia Power), with the remaining Vogtle Owners responsible for 44.3% of such costs pro rata in accordance with their respective ownership interests; and (iii) Georgia Power will be responsible for 65.7% of qualifying construction costs between $1.6 billion and $2.1 billion over the EAC in the nineteenth VCM (resulting in a further $100 million of potential additional costs to Georgia Power), with the remaining Vogtle Owners responsible for 34.3% of such costs pro rata in accordance with their respective ownership interests. The Global Amendments provide that if the EAC is revised and exceeds the EAC in the nineteenth VCM by more than $2.1 billion, each of the other Vogtle Owners will have a one-time option at the time the project budget cost forecast is so revised to tender a portion of its ownership interest to Georgia Power in exchange for Georgia Power's agreement to pay 100% of such Vogtle Owner's remaining share of total construction costs in excess of the EAC in the nineteenth VCM plus $2.1 billion. For purposes of the foregoing provisions, qualifying construction costs will not include costs (i) resulting from force majeure events, including epidemics and quarantines, governmental actions or inactions (or significant delays associated with issuance of such actions) that affect the licensing, completion, start-up, operations, or financing of Plant Vogtle Units 3 and 4, administrative proceedings or litigation regarding ITAAC or other regulatory challenges to commencement of operation of Plant Vogtle Units 3 and 4, and changes in laws or regulations governing Plant Vogtle Units 3 and 4, (ii) legal fees and legal expenses incurred due to litigation with contractors or subcontractors that are not subsidiaries or affiliates of Southern Company, and (iii) additional costs caused by requests from the Vogtle Owners other than Georgia Power, except for the exercise of a right to vote granted under the Vogtle Joint Ownership Agreements, that increase costs by $100,000 or more. In addition, pursuant to the Global Amendments, the holders of at least 90% of the ownership interests in Plant Vogtle Units 3 and 4 must vote to continue construction if certain adverse events (Project Adverse Events) occur, including, among other events: (i) the bankruptcy of Toshiba; (ii) the termination or rejection in bankruptcy of certain agreements, including the Vogtle Services Agreement, the Bechtel Agreement, or the agency agreement with Southern Nuclear; (iii) Georgia Power's public announcement of its intention not to submit for rate recovery any portion of its investment in Plant Vogtle Units 3 and 4 or the Georgia PSC determines that any of Georgia Power's costs relating to the construction of Plant Vogtle Units 3 and 4 will not be recovered in retail rates, excluding any additional amounts paid by Georgia Power on behalf of the other Vogtle Owners pursuant to the Global Amendments described above and the first 6% of costs during any six-month VCM reporting period that are disallowed by the Georgia PSC for recovery, or for which Georgia Power elects not to seek cost recovery, through retail rates; and (iv) an incremental extension of one year or more from the seventeenth VCM report estimated in-service dates of November 2021 and November 2022 for Units 3 and 4, respectively. The schedule extension announced in February 2022 triggered the requirement for a vote to continue construction. Effective February 25, 2022, all of the Vogtle Owners had voted to continue construction. Georgia Power and the other Vogtle Owners do not agree on either the starting dollar amount for the determination of cost increases subject to the cost-sharing and tender provisions of the Global Amendments or the extent to which COVID-19-related costs impact those provisions. Based on the definition in the Global Amendments, Georgia Power believes the starting dollar amount is $18.38 billion and the current project capital cost forecast exceeds the cost-sharing provision threshold, but not the tender provision threshold. The other Vogtle Owners have notified Georgia Power that they believe the current capital cost expenditures have already exceeded the cost-sharing thresholds and the current project capital cost forecast triggers the tender provisions under the Global Amendments. In October 2021, Georgia Power and the other Vogtle

Contingencies

Contingencies	9 Months Ended
Contingencies	Sep. 30, 2022
Commitments and Contingencies Disclosure [Abstract]
Contingencies	CONTINGENCIESSee Note 3 to the financial statements in Item 8 of the Form 10-K for information relating to various lawsuits and other contingencies. General Litigation Matters The Registrants are involved in various matters being litigated and regulatory matters. The ultimate outcome of such pending or potential litigation or regulatory matters against each Registrant and any subsidiaries cannot be determined at this time; however, for current proceedings not specifically reported herein, management does not anticipate that the ultimate liabilities, if any, arising from such current proceedings would have a material effect on such Registrant's financial statements. The Registrants believe the pending legal challenges discussed below have no merit; however, the ultimate outcome of these matters cannot be determined at this time. Southern Company In February 2017, Jean Vineyard and Judy Mesirov each filed a shareholder derivative lawsuit in the U.S. District Court for the Northern District of Georgia. Each of these lawsuits named as defendants Southern Company, certain of its directors, certain of its current and former officers, and certain former Mississippi Power officers. In 2017, these two shareholder derivative lawsuits were consolidated in the U.S. District Court for the Northern District of Georgia. The complaints alleged that the defendants caused Southern Company to make false or misleading statements regarding the Kemper County energy facility cost and schedule. Further, the complaints alleged that the defendants were unjustly enriched and caused the waste of corporate assets and also alleged that the individual defendants violated their fiduciary duties. In May 2017, Helen E. Piper Survivor's Trust filed a shareholder derivative lawsuit in the Superior Court of Gwinnett County, Georgia that named as defendants Southern Company, certain of its directors, certain of its current and former officers, and certain former Mississippi Power officers. The complaint alleged that the individual defendants, among other things, breached their fiduciary duties in connection with schedule delays and cost overruns associated with the construction of the Kemper County energy facility. The complaint further alleged that the individual defendants authorized or failed to correct false and misleading statements regarding the Kemper County energy facility schedule and cost and failed to implement necessary internal controls to prevent harm to Southern Company. In August 2019, the court granted a motion filed by the plaintiff in July 2019 to substitute a new named plaintiff, Martin J. Kobuck, in place of Helen E. Piper Survivor's Trust. The plaintiffs in each of these cases sought to recover, on behalf of Southern Company, unspecified actual damages and, on each plaintiff's own behalf, attorneys' fees and costs in bringing the lawsuit. The plaintiffs also sought certain changes to Southern Company's corporate governance and internal processes. On January 21, 2022, the plaintiffs in the federal court action filed a motion for preliminary approval of settlement, together with an executed stipulation of settlement, which applied to both actions. On June 9, 2022, the U.S. District Court for the Northern District of Georgia granted final approval of the settlement and, on June 16, 2022, the Superior Court of Gwinnett County, Georgia entered an order awarding attorneys' fees and expenses related to the Martin J. Kobuck lawsuit. The settlement consisted of an aggregate payment by Southern Company's insurers of approximately $4.5 million for attorneys' fees and expenses, as well as adoption of various corporate governance reforms by Southern Company. These matters are now concluded. Alabama Power On September 26, 2022, Mobile Baykeeper, through its counsel Southern Environmental Law Center, filed a citizen suit in the U.S. District Court for the Southern District of Alabama alleging that Alabama Power's plan to close the Plant Barry ash pond utilizing a closure-in-place methodology violates the Resource Conservation and Recovery Act (RCRA) and regulations governing CCR. Among other relief requested, Mobile Baykeeper seeks a declaratory judgment that the RCRA and regulations governing CCR are being violated, preliminary and injunctive relief to Georgia Power In 2011, plaintiffs filed a putative class action against Georgia Power in the Superior Court of Fulton County, Georgia alleging that Georgia Power's collection in rates of amounts for municipal franchise fees (which fees are paid to municipalities) exceeded the amounts allowed in orders of the Georgia PSC and alleging certain state law claims. This case has been ruled upon and appealed numerous times over the last several years. In 2019, the Georgia PSC issued an order that found Georgia Power has appropriately implemented the municipal franchise fee schedule. In March 2021, the Superior Court of Fulton County granted class certification and Georgia Power's motion for summary judgment and the plaintiffs filed a notice of appeal. In April 2021, Georgia Power filed a notice of cross appeal on the issue of class certification. In December 2021, the Georgia Court of Appeals affirmed the Superior Court's ruling that granted summary judgment to Georgia Power and dismissed Georgia Power's cross appeal on the issue of class certification as moot. Also in December 2021, the plaintiffs filed a petition for writ of certiorari to the Georgia Supreme Court. The amount of any possible losses cannot be estimated at this time because, among other factors, it is unknown whether any losses would be subject to recovery from any municipalities. In July 2020, a group of individual plaintiffs filed a complaint in the Superior Court of Fulton County, Georgia against Georgia Power alleging that releases from Plant Scherer have impacted groundwater, surface water, and air, resulting in alleged personal injuries and property damage. The plaintiffs seek an unspecified amount of monetary damages including punitive damages, a medical monitoring fund, and injunctive relief. Georgia Power has filed multiple motions to dismiss the complaint. In October 2021, three additional complaints were filed in the Superior Court of Monroe County, Georgia against Georgia Power alleging that releases from Plant Scherer have impacted groundwater and air, resulting in alleged personal injuries and property damage. The plaintiffs seek an unspecified amount of monetary damages including punitive damages. In November 2021, Georgia Power filed a notice to remove the three cases pending in the Superior Court of Monroe County, Georgia to the U.S. District Court for the Middle District of Georgia. On February 7, 2022, four additional complaints were filed in the Superior Court of Monroe County, Georgia against Georgia Power seeking damages for alleged personal injuries or property damage. On March 9, 2022, Georgia Power filed a notice to remove the four cases pending in the Superior Court of Monroe County, Georgia to the U.S. District Court for the Middle District of Georgia. The amount of any possible losses from these matters cannot be estimated at this time. Mississippi Power In 2018, Ray C. Turnage and 10 other individual plaintiffs filed a putative class action complaint against Mississippi Power and the three then-serving members of the Mississippi PSC in the U.S. District Court for the Southern District of Mississippi, which was amended in March 2019 to include four additional plaintiffs. Mississippi Power received Mississippi PSC approval in 2013 to charge a mirror CWIP rate premised upon including in its rate base pre-construction and construction costs for the Kemper IGCC prior to placing the Kemper IGCC into service. The Mississippi Supreme Court reversed that approval and ordered Mississippi Power to refund the amounts paid by customers under the previously-approved mirror CWIP rate. The plaintiffs allege that the initial approval process, and the amount approved, were improper and make claims for gross negligence, reckless conduct, and intentional wrongdoing. They also allege that Mississippi Power underpaid customers by up to $23.5 million in the refund process by applying an incorrect interest rate. The plaintiffs seek to recover, on behalf of themselves and their putative class, actual damages, punitive damages, pre-judgment interest, post-judgment interest, attorney's fees, and costs. The district court dismissed the amended complaint; however, in March 2020, the plaintiffs filed a motion seeking to name the new members of the Mississippi PSC, the Mississippi Development Authority, and Southern Company as additional defendants and add a cause of action against all defendants based on a dormant commerce clause theory under the U.S. Constitution. In July 2020, the plaintiffs filed a motion for leave to file a third amended complaint, which included the same federal claims as the proposed second amended complaint, as well as several Environmental Remediation The Southern Company system must comply with environmental laws and regulations governing the handling and disposal of waste and releases of hazardous substances. Under these various laws and regulations, the Southern Company system could incur substantial costs to clean up affected sites. The traditional electric operating companies and the natural gas distribution utilities in Illinois and Georgia have each received authority from their respective state PSCs or other applicable state regulatory agencies to recover approved environmental remediation costs through regulatory mechanisms. These regulatory mechanisms are adjusted annually or as necessary within limits approved by the state PSCs or other applicable state regulatory agencies. Georgia Power's environmental remediation liability was $16 million and $17 million at September 30, 2022 and December 31, 2021, respectively. Georgia Power has been designated or identified as a potentially responsible party at sites governed by the Georgia Hazardous Site Response Act and/or by the federal Comprehensive Environmental Response, Compensation, and Liability Act, and assessment and potential cleanup of such sites is expected. Southern Company Gas' environmental remediation liability was $270 million and $249 million at September 30, 2022 and December 31, 2021, respectively, based on the estimated cost of environmental investigation and remediation associated with known former manufactured gas plant operating sites. The ultimate outcome of these matters cannot be determined at this time; however, as a result of the regulatory treatment for environmental remediation expenses described above, the final disposition of these matters is not expected to have a material impact on the financial statements of the applicable Registrants. Other Matters Mississippi Power In conjunction with Southern Company's 2019 sale of Gulf Power, NextEra Energy, Inc. held back $75 million of the purchase price pending Mississippi Power and Gulf Power negotiating a mutually acceptable revised operating agreement for Plant Daniel. On July 12, 2022, the co-owners executed a revised operating agreement and Southern Company subsequently received the remaining $75 million of the purchase price. The revised operating agreement contains dispatch procedures for the two jointly-owned coal units at Plant Daniel such that Mississippi Power will designate one of the two units as primary and the other as secondary in lieu of each company separately owning 100% of a single generating unit. Mississippi Power has the option to purchase its co-owner's ownership interest for $1 on January 15, 2024, provided that Mississippi Power exercises the option no later than 120 days prior to that date. The revised operating agreement is not expected to have a material impact on Mississippi Power's financial statements. See Note 15 to the financial statements under "Southern Company" in Item 8 of the Form 10-K for additional information regarding the sale of Gulf Power. On August 31, 2022, the Mississippi Department of Revenue (Mississippi DOR) completed an audit of sales and use taxes paid by Mississippi Power from 2016 to 2019 and entered a final assessment, indicating a total amount due of $28 million, including associated penalties and interest. Mississippi Power does not agree with the audit findings and expects to exercise its rights to an administrative appeal with the Mississippi DOR by October 30, 2022. Excluding amounts associated with the gasifier and other abandoned Kemper IGCC assets, Mississippi Power's sales and use taxes are generally authorized for rate recovery; however, the ultimate outcome of this matter cannot be determined at this time.

Revenue from Contracts with Cus

Revenue from Contracts with Customers and Lease Income	9 Months Ended
Revenue from Contracts with Customers and Lease Income	Sep. 30, 2022
Revenue from Contract with Customer [Abstract]
Revenue from Contracts with Customers and Lease Income	REVENUE FROM CONTRACTS WITH CUSTOMERS AND LEASE INCOME Revenue from Contracts with Customers The Registrants generate revenues from a variety of sources, some of which are not accounted for as revenue from contracts with customers, such as leases, derivatives, and certain cost recovery mechanisms. See Note 1 to the financial statements under "Revenues" in Item 8 of the Form 10-K for additional information on the revenue policies of the Registrants. See "Lease Income" herein and Note (J) for additional information on revenue accounted for under lease and derivative accounting guidance, respectively. The following table disaggregates revenue from contracts with customers for the three and nine months ended September 30, 2022 and 2021: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Three Months Ended September 30, 2022 Operating revenues Retail electric revenues Residential $ 2,104 $ 799 $ 1,212 $ 93 $ — $ — Commercial 1,637 499 1,051 87 — — Industrial 1,183 452 642 89 — — Other 27 3 22 2 — — Total retail electric revenues 4,951 1,753 2,927 271 — — Natural gas distribution revenues Residential 331 — — — — 331 Commercial 93 — — — — 93 Transportation 259 — — — — 259 Industrial 12 — — — — 12 Other 49 — — — — 49 Total natural gas distribution revenues 744 — — — — 744 Wholesale electric revenues PPA energy revenues 812 187 40 4 591 — PPA capacity revenues 175 56 12 1 107 — Non-PPA revenues 58 67 4 242 303 — Total wholesale electric revenues 1,045 310 56 247 1,001 — Other natural gas revenues Gas marketing services 84 — — — — 84 Other natural gas revenues 15 — — — — 15 Total natural gas revenues 99 — — — — 99 Other revenues 277 65 110 13 9 — Total revenue from contracts with customers 7,116 2,128 3,093 531 1,010 843 Other revenue sources (a) 1,262 316 796 (21) 170 14 Total operating revenues $ 8,378 $ 2,444 $ 3,889 $ 510 $ 1,180 $ 857 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Nine Months Ended September 30, 2022 Operating revenues Retail electric revenues Residential $ 5,282 $ 2,049 $ 2,995 $ 238 $ — $ — Commercial 4,202 1,285 2,688 229 — — Industrial 2,914 1,143 1,529 242 — — Other 79 10 62 7 — — Total retail electric revenues 12,477 4,487 7,274 716 — — Natural gas distribution revenues Residential 1,821 — — — — 1,821 Commercial 493 — — — — 493 Transportation 872 — — — — 872 Industrial 60 — — — — 60 Other 244 — — — — 244 Total natural gas distribution revenues 3,490 — — — — 3,490 Wholesale electric revenues PPA energy revenues 1,739 354 112 11 1,285 — PPA capacity revenues 443 135 35 4 273 — Non-PPA revenues 182 166 19 511 572 — Total wholesale electric revenues 2,364 655 166 526 2,130 — Other natural gas revenues Gas marketing services 417 — — — — 417 Other natural gas revenues 41 — — — — 41 Total natural gas revenues 458 — — — — 458 Other revenues 810 173 327 34 27 — Total revenue from contracts with customers 19,599 5,315 7,767 1,276 2,157 3,948 Other revenue sources (a) 2,633 708 1,451 3 461 50 Total operating revenues $ 22,232 $ 6,023 $ 9,218 $ 1,279 $ 2,618 $ 3,998 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Three Months Ended September 30, 2021 Operating revenues Retail electric revenues Residential $ 1,974 $ 750 $ 1,138 $ 86 $ — $ — Commercial 1,432 471 882 79 — — Industrial 902 394 428 80 — — Other 24 4 18 2 — — Total retail electric revenues 4,332 1,619 2,466 247 — — Natural gas distribution revenues Residential 218 — — — — 218 Commercial 55 — — — — 55 Transportation 239 — — — — 239 Industrial 6 — — — — 6 Other 31 — — — — 31 Total natural gas distribution revenues 549 — — — — 549 Wholesale electric revenues PPA energy revenues 359 61 41 2 261 — PPA capacity revenues 125 14 14 1 97 — Non-PPA revenues 63 54 3 120 134 — Total wholesale electric revenues 547 129 58 123 492 — Other natural gas revenues Gas marketing services 45 — — — — 45 Other natural gas revenues 11 — — — — 11 Total natural gas revenues 56 — — — — 56 Other revenues 248 53 112 8 9 — Total revenue from contracts with customers 5,732 1,801 2,636 378 501 605 Other revenue sources (a) 506 103 220 — 178 18 Total operating revenues $ 6,238 $ 1,904 $ 2,856 $ 378 $ 679 $ 623 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Nine Months Ended September 30, 2021 Operating revenues Retail electric revenues Residential $ 4,910 $ 1,931 $ 2,765 $ 214 $ — $ — Commercial 3,727 1,229 2,293 205 — — Industrial 2,299 1,048 1,034 217 — — Other 70 13 51 6 — — Total retail electric revenues 11,006 4,221 6,143 642 — — Natural gas distribution revenues Residential 1,143 — — — — 1,143 Commercial 298 — — — — 298 Transportation 775 — — — — 775 Industrial 29 — — — — 29 Other 187 — — — — 187 Total natural gas distribution revenues 2,432 — — — — 2,432 Wholesale electric revenues PPA energy revenues 782 143 71 9 575 — PPA capacity revenues 375 86 41 4 247 — Non-PPA revenues 181 108 14 283 273 — Total wholesale electric revenues 1,338 337 126 296 1,095 — Other natural gas revenues Wholesale gas services 2,168 — — — — 2,168 Gas marketing services 303 — — — — 303 Other natural gas revenues 27 — — — — 27 Total natural gas revenues 2,498 — — — — 2,498 Other revenues 792 150 362 22 18 — Total revenue from contracts with customers 18,066 4,708 6,631 960 1,113 4,930 Other revenue sources (a) 2,979 311 419 28 497 1,763 Other adjustments (b) (3,699) — — — — (3,699) Total operating revenues $ 17,346 $ 5,019 $ 7,050 $ 988 $ 1,610 $ 2,994 (a) Other revenue sources relate to revenues from customers accounted for as derivatives and leases, alternative revenue programs at Southern Company Gas, and cost recovery mechanisms and revenues that meet other scope exceptions for revenues from contracts with customers at the traditional electric operating companies. (b) Other adjustments relate to the cost of Southern Company Gas' energy and risk management activities. Wholesale gas services revenues are presented net of the related costs of those activities on the statement of income. See Note 15 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K and Note (L) under "Southern Company Gas" for information on the sale of Sequent and components of wholesale gas services' operating revenues, respectively. Contract Balances The following table reflects the closing balances of receivables, contract assets, and contract liabilities related to revenues from contracts with customers at September 30, 2022 and December 31, 2021: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Accounts Receivable At September 30, 2022 $ 2,760 $ 800 $ 1,035 $ 98 $ 264 $ 433 At December 31, 2021 2,504 589 736 73 149 753 Contract Assets At September 30, 2022 $ 178 $ 5 $ 114 $ — $ — $ — At December 31, 2021 117 2 63 — 1 — Contract Liabilities At September 30, 2022 $ 56 $ 5 $ 6 $ 7 $ 2 $ — At December 31, 2021 57 4 14 — 1 — At September 30, 2022 and December 31, 2021, Georgia Power had contract assets primarily related to retail customer fixed bill programs, where the payment is contingent upon Georgia Power's continued performance and the customer's continued participation in the program over a one-year contract term, and unregulated service agreements, where payment is contingent on project completion. Contract liabilities for Georgia Power relate to cash collections recognized in advance of revenue for unregulated service agreements. Southern Company's unregulated distributed generation business had $59 million and $50 million of contract assets and $37 million and $39 million of contract liabilities at September 30, 2022 and December 31, 2021, respectively, for outstanding performance obligations. Revenues recognized in the three and nine months ended September 30, 2022, which were included in contract liabilities at December 31, 2021, were $13 million and $32 million, respectively, for Southern Company and immaterial for the other Registrants. Remaining Performance Obligations The Subsidiary Registrants have long-term contracts with customers in which revenues are recognized as performance obligations are satisfied over the contract term. For the traditional electric operating companies and Southern Power, these contracts primarily relate to PPAs whereby electricity and generation capacity are provided to a customer. The revenue recognized for the delivery of electricity is variable; however, certain PPAs include a fixed payment for fixed generation capacity over the term of the contract. For Southern Company Gas, these contracts involve energy infrastructure enhancement and upgrade projects for certain governmental customers. Southern Company's unregulated distributed generation business also has partially satisfied performance obligations related to certain fixed price contracts. Revenues from contracts with customers related to these performance obligations remaining at September 30, 2022 are expected to be recognized as follows: 2022 (remaining) 2023 2024 2025 2026 Thereafter (in millions) Southern Company $ 243 $ 619 $ 434 $ 322 $ 307 $ 2,340 Alabama Power 8 24 7 5 — — Georgia Power 20 70 34 22 11 21 Southern Power 80 341 344 294 299 2,334 Southern Company Gas 12 29 29 — — — Revenue expected to be recognized for performance obligations remaining at September 30, 2022 w as immaterial for Mississippi Power. Lease Income Lease income for the three and nine months ended September 30, 2022 and 2021 is as follows: Southern Alabama Power Georgia Power Mississippi Southern Power Southern Company Gas (in millions) For the Three Months Ended September 30, 2022 Lease income - interest income on sales-type leases $ 7 $ — $ — $ 4 $ 3 $ — Lease income - operating leases 50 19 8 1 21 9 Variable lease income 139 — — — 145 — Total lease income $ 196 $ 19 $ 8 $ 5 $ 169 $ 9 For the Nine Months Ended September 30, 2022 Lease income - interest income on sales-type leases $ 19 $ — $ — $ 11 $ 8 $ — Lease income - operating leases 149 58 24 1 64 27 Variable lease income 355 1 — — 372 — Total lease income $ 523 $ 59 $ 24 $ 12 $ 444 $ 27 For the Three Months Ended September 30, 2021 Lease income - interest income on sales-type leases $ 4 $ — $ — $ 4 $ — $ — Lease income - operating leases 56 21 11 — 21 9 Variable lease income 143 — — — 151 — Total lease income $ 203 $ 21 $ 11 $ 4 $ 172 $ 9 For the Nine Months Ended September 30, 2021 Lease income - interest income on sales-type leases $ 11 $ — $ — $ 10 $ — $ — Lease income - operating leases 168 62 31 1 64 26 Variable lease income 355 — — — 379 — Total lease income $ 534 $ 62 $ 31 $ 11 $ 443 $ 26 Lease payments received under tolling arrangements and PPAs consist of either scheduled payments or variable payments based on the amount of energy produced by the underlying electric generating units. Lease income for Alabama Power and Southern Power is included in wholesale revenues.

Consolidated Entities and Equit

Consolidated Entities and Equity Method Investments	9 Months Ended
Consolidated Entities and Equity Method Investments	Sep. 30, 2022
Regulated Operations [Abstract]
Consolidated Entities and Equity Method Investments	CONSOLIDATED ENTITIES AND EQUITY METHOD INVESTMENTSSee Note 7 to the financial statements in Item 8 of the Form 10-K for additional information. Southern Power Variable Interest Entities Southern Power has certain subsidiaries that are determined to be VIEs. Southern Power is considered the primary beneficiary of these VIEs because it controls the most significant activities of the VIEs, including operating and maintaining the respective assets, and has the obligation to absorb expected losses of these VIEs to the extent of its equity interests. SP Solar and SP Wind At September 30, 2022 and December 31, 2021, SP Solar had total assets of $6.0 billion and $6.1 billion, respectively, total liabilities of $0.4 billion, and noncontrolling interests of $1.1 billion. Cash distributions from SP Solar are allocated 67% to Southern Power and 33% to Global Atlantic in accordance with their partnership interest percentage. Under the terms of the limited partnership agreement, distributions without limited partner consent are limited to available cash and SP Solar is obligated to distribute all such available cash to its partners each quarter. Available cash includes all cash generated in the quarter subject to the maintenance of appropriate operating reserves. At September 30, 2022 and December 31, 2021, SP Wind had total assets of $2.3 billion, total liabilities of $191 million and $130 million, respectively, and noncontrolling interests of $40 million and $41 million, respectively. Under the terms of the limited liability agreement, distributions without Class A member consent are limited to available cash and SP Wind is obligated to distribute all such available cash to its members each quarter. Available cash includes all cash generated in the quarter subject to the maintenance of appropriate operating reserves. Cash distributions from SP Wind are generally allocated 60% to Southern Power and 40% to the three financial investors in accordance with the limited liability agreement. Southern Power consolidates both SP Solar and SP Wind, as the primary beneficiary, since it controls the most significant activities of each entity, including operating and maintaining their assets. Certain transfers and sales of the assets in the VIEs are subject to partner consent and the liabilities are non-recourse to the general credit of Southern Power. Liabilities consist of customary working capital items and do not include any long-term debt. Other Variable Interest Entities Southern Power has other consolidated VIEs that relate to certain subsidiaries that have either sold noncontrolling interests to tax equity investors or acquired less than a 100% interest from facility developers. These entities are considered VIEs because the arrangements are structured similar to a limited partnership and the noncontrolling members do not have substantive kick-out rights. At September 30, 2022 and December 31, 2021, the other VIEs had total assets of $1.9 billion, total liabilities of $0.2 billion and $0.3 billion, respectively, and noncontrolling interests of $0.8 billion and $0.9 billion, respectively. Under the terms of the partnership agreements, distributions of all available cash are required each month or quarter and additional distributions require partner consent. Equity Method Investments At September 30, 2022 and December 31, 2021, Southern Power had equity method investments in wind and battery energy storage projects totaling $49 million and $86 million, respectively. Earnings (loss) from these investments were immaterial for all periods presented. During the nine months ended September 30, 2022, Southern Power sold equity method investments in wind projects and received proceeds totaling $38 million. The gains associated with the sales were immaterial. Southern Company Gas Equity Method Investments The carrying amounts of Southern Company Gas' equity method investments at September 30, 2022 and December 31, 2021 and related earnings (loss) from those investments for the three and nine months ended September 30, 2022 and 2021 were as follows: Investment Balance September 30, 2022 December 31, 2021 (in millions) SNG $ 1,091 $ 1,129 Other () 34 44 Total $ 1,125 $ 1,173 () Balance at September 30, 2022 reflects an $11 million distribution received in 2022 from PennEast Pipeline. Three Months Ended September 30, Nine Months Ended September 30, Earnings (Loss) from Equity Method Investments 2022 2021 2022 2021 (in millions) SNG $ 34 $ 27 $ 104 $ 93 PennEast Pipeline () — (2) — (81) Other — — 1 2 Total $ 34 $ 25 $ 105 $ 14 () Primarily reflects pre-tax impairment charges. See Note 7 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K for additional information.

Financing and Leases

Financing and Leases	9 Months Ended
Financing and Leases	Sep. 30, 2022
Debt Disclosure [Abstract]
Financing and Leases	FINANCING AND LEASES Bank Credit Arrangements See Note 8 to the financial statements under "Bank Credit Arrangements" in Item 8 of the Form 10-K for additional information. At September 30, 2022, committed credit arrangements with banks were as follows: Expires Company 2023 2024 2025 2026 Total Unused Expires within (in millions) Southern Company parent $ — $ — $ — $ 2,000 $ 2,000 $ 1,998 $ — Alabama Power — 550 — 700 1,250 1,250 — Georgia Power — — — 1,750 1,750 1,726 — Mississippi Power — 150 125 — 275 275 — Southern Power (a) — — — 600 600 569 — Southern Company Gas (b) 250 — — 1,500 1,750 1,748 250 SEGCO 30 — — — 30 30 30 Southern Company $ 280 $ 700 $ 125 $ 6,550 $ 7,655 $ 7,596 $ 280 (a) Does not include Southern Power Company's two $75 million continuing letter of credit facilities for standby letters of credit, expiring in 2023 and 2025, respectively, of which $11 million and $5 million, respectively, was unused at September 30, 2022. Southern Power's subsidiaries are not parties to its bank credit arrangements or letter of credit facilities. (b) Southern Company Gas, as the parent entity, guarantees the obligations of Southern Company Gas Capital, which is the borrower of $800 million of the credit arrangement expiring in 2026. Southern Company Gas' committed credit arrangement expiring in 2026 also includes $700 million for which Nicor Gas is the borrower and which is restricted for working capital needs of Nicor Gas. Pursuant to the multi-year credit arrangement expiring in 2026, the allocations between Southern Company Gas Capital and Nicor Gas may be adjusted. Nicor Gas is also the borrower of a new $250 million credit arrangement expiring in 2023. As reflected in the table above, in March 2022, Mississippi Power amended and restated its $125 million revolving credit arrangement, which among other things, extended the maturity date from 2023 to 2025 and allows for borrowing based on term SOFR. Subject to applicable market conditions, Southern Company and its subsidiaries expect to renew or replace their bank credit arrangements as needed, prior to expiration. In connection therewith, Southern Company and its subsidiaries may extend the maturity dates and/or increase or decrease the lending commitments thereunder. These bank credit arrangements, as well as the term loan arrangements of the Registrants, Nicor Gas, and SEGCO, contain covenants that limit debt levels and contain cross-acceleration or, in the case of Southern Power, cross-default provisions to other indebtedness (including guarantee obligations) that are restricted only to the indebtedness of the individual company. Such cross-default provisions to other indebtedness would trigger an event of default if Southern Power defaulted on indebtedness or guarantee obligations over a specified threshold. Such cross-acceleration provisions to other indebtedness would trigger an event of default if the applicable borrower defaulted on indebtedness, the payment of which was then accelerated. At September 30, 2022, the Registrants, Nicor Gas, and SEGCO were in compliance with all such covenants. None of the bank credit arrangements contain material adverse change clauses at the time of borrowings. Equity Units In May 2022, Southern Company remarketed $862.5 million aggregate principal amount of its Series 2019A Remarketable Junior Subordinated Notes due August 1, 2024 (2019A RSNs) and $862.5 million aggregate principal amount of its Series 2019B Remarketable Junior Subordinated Notes due August 1, 2027 (2019B RSNs), pursuant to the terms of its 2019 Series A Equity Units (Equity Units). In connection with the remarketing, the interest rates on the 2019A RSNs and the 2019B RSNs were reset to 4.475% and 5.113%, respectively, payable on a semi-annual basis, and Southern Company ceased to have the ability to redeem these securities prior to maturity or to defer interest payments. Southern Company did not receive any proceeds from the remarketing, which were used to purchase a portfolio of treasury securities maturing on July 28, 2022. On August 1, 2022, the proceeds from this portfolio were used to settle the purchase contracts entered into as part of the Equity Units and Southern Company issued approximately 25.2 million shares of common stock and received proceeds of $1.725 billion. At September 30, 2022 and December 31, 2021, the 2019A RSNs and the 2019B RSNs are included in long-term debt on Southern Company's consolidated balance sheets. Earnings per Share For Southern Company, the only differences in computing basic and diluted earnings per share are attributable to awards outstanding under stock-based compensation plans and the Equity Units until they were settled in August 2022. Earnings per share dilution resulting from stock-based compensation plans and the Equity Units issuance is determined using the treasury stock method. See Note 8 to the financial statements under "Equity Units" in Item 8 of the Form 10-K and "Equity Units" herein for information on the Equity Units and Note 12 to the financial statements in Item 8 of the Form 10-K for information on stock-based compensation plans. Shares used to compute diluted earnings per share were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 (in millions) As reported shares 1,082 1,061 1,070 1,060 Effect of stock-based compensation 6 7 6 7 Diluted shares 1,088 1,068 1,076 1,067 For all periods presented, an immaterial number of stock-based compensation awards was not included in the diluted earnings per share calculation because the awards were anti-dilutive. Southern Company Leveraged Lease See Note 9 to the financial statements in Item 8 of the Form 10-K for information on a leveraged lease agreement related to energy generation. On June 30, 2022, the Southern Holdings subsidiary operating the generating plant for the lessee provided notice to the lessee to terminate the related operating and maintenance agreement effective June 30, 2023. The parties to the lease agreement are currently negotiating a potential restructuring, which could result in rescission of the termination notice. The ultimate outcome of this matter cannot be determined at this time but is not expected to have a material impact on Southern Company's financial statements. Georgia Power Lease Modification See Note 9 to the financial statements in Item 8 of the Form 10-K for information on Georgia Power's leases. In July 2022, Georgia Power recognized a lease modification related to an existing non-affiliate PPA which converted from an operating lease to a finance lease upon its approval in the 2022 IRP. As a result, Georgia Power removed from its balance sheet operating lease right-of-use assets, net of amortization of $17 million and lease obligations of $18 million maturing through 2024 and recorded finance lease right-of-use assets of $112 million and lease obligations of $113 million maturing through 2039.

Income Taxes

Income Taxes	9 Months Ended
Income Taxes	Sep. 30, 2022
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES See Note 10 to the financial statements in Item 8 of the Form 10-K for additional tax information. Current and Deferred Income Taxes Tax Credit and Net Operating Loss Carryforwards Southern Company had federal ITC and PTC carryforwards (primarily related to Southern Power) totaling $1.0 billion at September 30, 2022 compared to $1.2 billion at December 31, 2021. The federal PTC and ITC carryforwards begin expiring in 2032, but are expected to be fully utilized by 2025. The utilization of each Registrant's estimated tax credit and state net operating loss carryforwards and related valuation allowances could be impacted by numerous factors, including the acquisition of additional renewable projects, the purchase of rights to additional PTCs of Plant Vogtle Units 3 and 4 pursuant to certain joint ownership agreements, an increase in Georgia Power's ownership interest percentage in Plant Vogtle Units 3 and 4, changes in taxable income projections, and potential income tax rate changes. See Note (B) and Note 2 to the financial statements in Item 8 of the Form 10-K under "Georgia Power – Nuclear Construction" for additional information on Plant Vogtle Units 3 and 4. Effective Tax Rate Southern Company's effective tax rate is typically lower than the statutory rate due to employee stock plans' dividend deduction, non-taxable AFUDC equity at the traditional electric operating companies, flowback of excess deferred income taxes at the regulated utilities, and federal income tax benefits from ITCs and PTCs primarily at Southern Power. Details of significant changes in the effective tax rate for the applicable Registrants are provided herein. Southern Company Southern Company's effective tax rate was 20.0% for the nine months ended September 30, 2022 compared to 17.5% for the corresponding period in 2021. The effective tax rate increase was primarily due to higher pre-tax earnings and an adjustment related to a prior year state tax credit carryforward at Georgia Power in 2022, partially offset by additional tax expense in 2021 as a result of the sale of Sequent. See Note 15 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K for additional information. Georgia Power Georgia Power's effective tax rate was 18.5% for the nine months ended September 30, 2022 compared to 7.3% for the corresponding period in 2021. The effective tax rate increase was primarily due to higher pre-tax earnings and an adjustment related to a prior year state tax credit carryforward in 2022. Mississippi Power Mississippi Power's effective tax rate was 20.1% for the nine months ended September 30, 2022 compared to 14.3% for the corresponding period in 2021. The effective tax rate increase was primarily due to a decrease in the flowback of excess deferred income taxes in 2022. Southern Power Southern Power's effective tax rate was 18.8% for the nine months ended September 30, 2022 compared to a tax benefit rate of (1.6)% for the corresponding period in 2021. The effective tax rate increase was primarily due to higher pre-tax earnings in 2022 and a change in state apportionment methodology resulting from tax legislation enacted by the State of Alabama in the first quarter 2021, partially offset by higher wind PTCs in 2022. Southern Company Gas Southern Company Gas' effective tax rate was 23.7% for the nine months ended September 30, 2022 compared to 36.6% for the corresponding period in 2021. The effective tax rate decrease was primarily due to additional tax expense in 2021 as a result of the sale of Sequent. See Note 15 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K for additional information. Unrecognized Tax Benefits Southern Company's and Southern Company Gas' unrecognized tax positions balances at September 30, 2022 were $79 million and $32 million, respectively, compared to $47 million for Southern Company at December 31, 2021. The increases from prior periods are related to the amendment of certain 2018 state tax filing positions related to Southern Company Gas dispositions. If accepted by the states, these positions would decrease Southern Company's and Southern Company Gas' annual effective tax rates. The ultimate outcome of these unrecognized tax benefits is dependent on acceptance by each state and is not expected to be resolved in the next 12 months.

Retirement Benefits

Retirement Benefits	9 Months Ended
Retirement Benefits	Sep. 30, 2022
Retirement Benefits [Abstract]
Retirement Benefits	RETIREMENT BENEFITS The Southern Company system has a qualified defined benefit, trusteed, pension plan covering substantially all employees, with the exception of employees at PowerSecure. The qualified pension plan is funded in accordance with requirements of the Employee Retirement Income Security Act of 1974, as amended (ERISA). No mandatory contributions to the qualified pension plan are anticipated for the year ending December 31, 2022. The Southern Company system also provides certain non-qualified defined benefits for a select group of management and highly compensated employees, which are funded on a cash basis. In addition, the Southern Company system provides certain medical care and life insurance benefits for retired employees through other postretirement benefit plans. The traditional electric operating companies fund other postretirement trusts to the extent required by their respective regulatory commissions. Southern Company Gas has a separate unfunded supplemental retirement health care plan that provides medical care and life insurance benefits to employees of discontinued businesses. During 2022, the qualified pension plan achieved the predetermined funding threshold whereby the asset allocation was adjusted to invest a larger portion of the portfolio in fixed rate debt securities. See Note 11 to the financial statements in Item 8 of the Form 10-K for additional information. On each Registrant's condensed statements of income, the service cost component of net periodic benefit costs is included in other operations and maintenance expenses and all other components of net periodic benefit costs are included in other income (expense), net. Components of the net periodic benefit costs for the three and nine months ended September 30, 2022 and 2021 are presented in the following tables. Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) Three Months Ended September 30, 2022 Pension Plans Service cost $ 103 $ 25 $ 26 $ 5 $ 2 $ 9 Interest cost 102 24 31 5 2 7 Expected return on plan assets (316) (77) (99) (15) (4) (22) Amortization: Prior service costs — — — — — (1) Regulatory asset — — — — — 3 Net loss 60 16 18 2 1 2 Net periodic pension cost (income) $ (51) $ (12) $ (24) $ (3) $ 1 $ (2) Postretirement Benefits Service cost $ 6 $ 2 $ 2 $ 1 $ 1 $ — Interest cost 10 3 4 — — 1 Expected return on plan assets (20) (9) (8) — — (2) Amortization: Prior service costs (1) — — — — — Regulatory asset — — — — — 2 Net (gain)/loss 1 — — — — (1) Net periodic postretirement benefit cost (income) $ (4) $ (4) $ (2) $ 1 $ 1 $ — Nine Months Ended September 30, 2022 Pension Plans Service cost $ 309 $ 74 $ 78 $ 13 $ 7 $ 26 Interest cost 306 72 92 14 5 21 Expected return on plan assets (949) (229) (298) (44) (12) (68) Amortization: Prior service costs — — 1 — — (2) Regulatory asset — — — — — 11 Net loss 180 47 55 9 2 5 Net periodic pension cost (income) $ (154) $ (36) $ (72) $ (8) $ 2 $ (7) Postretirement Benefits Service cost $ 17 $ 5 $ 5 $ 1 $ 1 $ 1 Interest cost 31 8 11 1 — 4 Expected return on plan assets (60) (25) (21) (1) — (6) Amortization: Prior service costs (1) — — — — — Regulatory asset — — — — — 5 Net (gain)/loss 1 — 1 — — (2) Net periodic postretirement benefit cost (income) $ (12) $ (12) $ (4) $ 1 $ 1 $ 2 Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) Three Months Ended September 30, 2021 Pension Plans Service cost $ 109 $ 26 $ 28 $ 4 $ 2 $ 10 Interest cost 87 20 26 4 2 6 Expected return on plan assets (298) (72) (94) (14) (4) (21) Amortization: Prior service costs — — — — — (1) Regulatory asset — — — — — 3 Net loss 78 21 25 4 1 3 Net periodic pension cost (income) $ (24) $ (5) $ (15) $ (2) $ 1 $ — Postretirement Benefits Service cost $ 6 $ 2 $ 2 $ 1 $ 1 $ — Interest cost 9 2 3 — — 1 Expected return on plan assets (19) (8) (7) (1) — (2) Amortization: Regulatory asset — — — — — 2 Net (gain)/loss 1 — 1 — — (1) Net periodic postretirement benefit cost (income) $ (3) $ (4) $ (1) $ — $ 1 $ — Nine Months Ended September 30, 2021 Pension Plans Service cost $ 326 $ 77 $ 84 $ 13 $ 7 $ 28 Interest cost 260 61 78 12 4 18 Expected return on plan assets (893) (215) (282) (41) (11) (64) Amortization: Prior service costs — — 1 — — (2) Regulatory asset — — — — — 11 Net loss 235 62 75 11 3 9 Net periodic pension cost (income) $ (72) $ (15) $ (44) $ (5) $ 3 $ — Postretirement Benefits Service cost $ 18 $ 5 $ 5 $ 1 $ 1 $ 1 Interest cost 26 6 9 1 — 3 Expected return on plan assets (57) (22) (20) (2) — (6) Amortization: Prior service costs (1) — — — — — Regulatory asset — — — — — 5 Net (gain)/loss 3 — 2 — — (2) Net periodic postretirement benefit cost (income) $ (11) $ (11) $ (4) $ — $ 1 $ 1

Fair Value Measurements

Fair Value Measurements	9 Months Ended
Fair Value Measurements	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS At September 30, 2022, assets and liabilities measured at fair value on a recurring basis during the period, together with their associated level of the fair value hierarchy, were as follows: Fair Value Measurements Using: At September 30, 2022 Quoted Prices Significant Significant Net Asset Value as a Practical Expedient (NAV) Total (in millions) Southern Company Assets: Energy-related derivatives (a) $ 49 $ 454 $ — $ — $ 503 Investments in trusts: (b)(c) Domestic equity 610 161 — — 771 Foreign equity 111 129 — — 240 U.S. Treasury and government agency securities — 265 — — 265 Municipal bonds — 52 — — 52 Pooled funds – fixed income — 7 — — 7 Corporate bonds — 438 — — 438 Mortgage and asset backed securities — 87 — — 87 Private equity — — — 156 156 Cash and cash equivalents 4 — — — 4 Other 17 13 — — 30 Cash equivalents 1,402 18 — — 1,420 Other investments 9 26 — — 35 Total $ 2,202 $ 1,650 $ — $ 156 $ 4,008 Liabilities: Energy-related derivatives (a) $ 20 $ 141 $ — $ — $ 161 Interest rate derivatives — 311 — — 311 Foreign currency derivatives — 323 — — 323 Contingent consideration — — 14 — 14 Other — 13 — — 13 Total $ 20 $ 788 $ 14 $ — $ 822 Fair Value Measurements Using: At September 30, 2022 Quoted Prices Significant Significant Net Asset Value as a Practical Expedient (NAV) Total (in millions) Alabama Power Assets: Energy-related derivatives $ — $ 147 $ — $ — $ 147 Nuclear decommissioning trusts: (b) Domestic equity 370 152 — — 522 Foreign equity 111 — — — 111 U.S. Treasury and government agency securities — 15 — — 15 Municipal bonds — 2 — — 2 Corporate bonds — 230 — — 230 Mortgage and asset backed securities — 20 — — 20 Private equity — — — 156 156 Other 10 — — — 10 Cash equivalents 1,225 18 — — 1,243 Other investments — 26 — — 26 Total $ 1,716 $ 610 $ — $ 156 $ 2,482 Liabilities: Energy-related derivatives $ — $ 35 $ — $ — $ 35 Georgia Power Assets: Energy-related derivatives $ — $ 145 $ — $ — $ 145 Nuclear decommissioning trusts: (b)(c) Domestic equity 240 1 — — 241 Foreign equity — 128 — — 128 U.S. Treasury and government agency securities — 250 — — 250 Municipal bonds — 50 — — 50 Corporate bonds — 208 — — 208 Mortgage and asset backed securities — 67 — — 67 Other 7 13 — — 20 Total $ 247 $ 862 $ — $ — $ 1,109 Liabilities: Energy-related derivatives $ — $ 51 $ — $ — $ 51 Fair Value Measurements Using: At September 30, 2022 Quoted Prices Significant Significant Net Asset Value as a Practical Expedient (NAV) Total (in millions) Mississippi Power Assets: Energy-related derivatives $ — $ 133 $ — $ — $ 133 Cash equivalents 30 — — — 30 Total $ 30 $ 133 $ — $ — $ 163 Liabilities: Energy-related derivatives $ — $ 24 $ — $ — $ 24 Southern Power Assets: Energy-related derivatives $ — $ 7 $ — $ — $ 7 Liabilities: Energy-related derivatives $ — $ 13 $ — $ — $ 13 Foreign currency derivatives — 80 — — 80 Contingent consideration — — 14 — 14 Other — 13 — — 13 Total $ — $ 106 $ 14 $ — $ 120 Southern Company Gas Assets: Energy-related derivatives (a) $ 49 $ 22 $ — $ — $ 71 Non-qualified deferred compensation trusts: Domestic equity — 8 — — 8 Foreign equity — 1 — — 1 Pooled funds – fixed income — 7 — — 7 Cash equivalents 4 — — — 4 Total $ 53 $ 38 $ — $ — $ 91 Liabilities: Energy-related derivatives (a) $ 20 $ 17 $ — $ — $ 37 Interest rate derivatives — 87 — — 87 Total $ 20 $ 104 $ — $ — $ 124 (a) Excludes cash collateral of $15 million. (b) Excludes receivables related to investment income, pending investment sales, payables related to pending investment purchases, and currencies. See Note 6 to the financial statements in Item 8 of the Form 10-K for additional information. (c) Includes investment securities pledged to creditors and collateral received and excludes payables related to the securities lending program. At September 30, 2022, approximately $46 million of the fair market value of Georgia Power's nuclear decommissioning trust funds' securities were on loan to creditors under the funds' managers' securities lending program. See Note 6 to the financial statements in Item 8 of the Form 10-K for additional information. Southern Company, Alabama Power, and Georgia Power continue to elect the option to fair value investment securities held in the nuclear decommissioning trust funds. The fair value of the funds, including reinvested interest and dividends and excluding the funds' expenses, increased (decreased) by the amounts shown in the table below for the three and nine months ended September 30, 2022 and 2021. The changes were recorded as a change to the regulatory assets and liabilities related to AROs for Georgia Power and Alabama Power, respectively. Fair value increases (decreases) Three Months Ended September 30, 2022 Three Months Ended September 30, 2021 Nine Months Ended September 30, 2022 Nine Months Ended September 30, 2021 (in millions) Southern Company $ (106) $ 9 $ (486) $ 173 Alabama Power (53) 15 (245) 133 Georgia Power (53) (6) (241) 40 Valuation Methodologies The energy-related derivatives primarily consist of exchange-traded and over-the-counter financial products for natural gas and physical power products, including, from time to time, basis swaps. These are standard products used within the energy industry and are valued using the market approach. The inputs used are mainly from observable market sources, such as forward natural gas prices, power prices, implied volatility, and overnight index swap interest rates. Interest rate derivatives are also standard over-the-counter products that are valued using observable market data and assumptions commonly used by market participants. The fair value of interest rate derivatives reflects the net present value of expected payments and receipts under the swap agreement based on the market's expectation of future interest rates. Additional inputs to the net present value calculation may include the contract terms, counterparty credit risk, and occasionally, implied volatility of interest rate options. The fair value of cross-currency swaps reflects the net present value of expected payments and receipts under the swap agreement based on the market's expectation of future foreign currency exchange rates. Additional inputs to the net present value calculation may include the contract terms, counterparty credit risk, and discount rates. The interest rate derivatives and cross-currency swaps are categorized as Level 2 under Fair Value Measurements as these inputs are based on observable data and valuations of similar instruments. See Note (J) for additional information on how these derivatives are used. For fair value measurements of the investments within the nuclear decommissioning trusts and the non-qualified deferred compensation trusts, external pricing vendors are designated for each asset class with each security specifically assigned a primary pricing source. For investments held within commingled funds, fair value is determined at the end of each business day through the net asset value, which is established by obtaining the underlying securities' individual prices from the primary pricing source. A market price secured from the primary source vendor is then evaluated by management in its valuation of the assets within the trusts. As a general approach, fixed income market pricing vendors gather market data (including indices and market research reports) and integrate relative credit information, observed market movements, and sector news into proprietary pricing models, pricing systems, and mathematical tools. Dealer quotes and other market information, including live trading levels and pricing analysts' judgments, are also obtained when available. The NRC requires licensees of commissioned nuclear power reactors to establish a plan for providing reasonable assurance of funds for future decommissioning. See Note 6 to the financial statements under "Nuclear Decommissioning" in Item 8 of the Form 10-K for additional information. Southern Power has contingent payment obligations related to certain acquisitions whereby it is primarily obligated to make generation-based payments to the seller, which commenced at the commercial operation of the respective facility and continue through 2026. The obligations are categorized as Level 3 under Fair Value Measurements as the fair value is determined using significant unobservable inputs for the forecasted facility generation in MW-hours, as well as other inputs such as a fixed dollar amount per MW-hour, and a discount rate. The fair value of contingent consideration reflects the net present value of expected payments and any periodic change arising from forecasted generation is expected to be immaterial. Southern Power also has payment obligations through 2040 whereby it must reimburse the transmission owners for interconnection facilities and network upgrades constructed to support connection of a Southern Power generating facility to the transmission system. The obligations are categorized as Level 2 under Fair Value Measurements as the fair value is determined using observable inputs for the contracted amounts and reimbursement period, as well as a discount rate. The fair value of the obligations reflects the net present value of expected payments. "Other investments" include investments traded in the open market that have maturities greater than 90 days, which are categorized as Level 2 under Fair Value Measurements and are comprised of corporate bonds, bank certificates of deposit, treasury bonds, and/or agency bonds. At September 30, 2022, the fair value measurements of private equity investments held in Alabama Power's nuclear decommissioning trusts that are calculated at net asset value per share (or its equivalent) as a practical expedient totaled $156 million and unfunded commitments related to the private equity investments totaled $84 million. Private equity investments include high-quality private equity funds across several market sectors and funds that invest in real estate assets. Private equity funds do not have redemption rights. Distributions from these funds will be received as the underlying investments in the funds are liquidated. At September 30, 2022, other financial instruments for which the carrying amount did not equal fair value were as follows: Southern Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas () (in billions) Long-term debt, including securities due within one year: Carrying amount $ 53.4 $ 10.8 $ 14.5 $ 1.5 $ 2.9 $ 7.4 Fair value 46.4 9.3 12.6 1.2 2.7 6.3 () The long-term debt of Southern Company Gas is recorded at amortized cost, including the fair value adjustments at the effective date of the 2016 merger with Southern Company. Southern Company Gas amortizes the fair value adjustments over the remaining lives of the respective bonds, the latest being through 2043. The fair values are determined using Level 2 measurements and are based on quoted market prices for the same or similar issues or on the current rates available to the Registrants.

Derivatives

Derivatives	9 Months Ended
Derivatives	Sep. 30, 2022
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives	DERIVATIVES The Registrants are exposed to market risks, including commodity price risk, interest rate risk, weather risk, and occasionally foreign currency exchange rate risk. To manage the volatility attributable to these exposures, each company nets its exposures, where possible, to take advantage of natural offsets and enters into various derivative transactions for the remaining exposures pursuant to each company's policies in areas such as counterparty exposure and risk management practices. Prior to the sale of Sequent on July 1, 2021, Southern Company Gas' wholesale gas operations used various contracts in its commercial activities that generally met the definition of derivatives. For the traditional electric operating companies, Southern Power, and Southern Company Gas' other businesses, each company's policy is that derivatives are to be used primarily for hedging purposes and mandates strict adherence to all applicable risk management policies. Derivative positions are monitored using techniques including, but not limited to, market valuation, value at risk, stress testing, and sensitivity analysis. Derivative instruments are recognized at fair value in the balance sheets as either assets or liabilities and are presented on a net basis. See Note (I) for additional fair value information. In the statements of cash flows, any cash impacts of settled energy-related and interest rate derivatives are recorded as operating activities. Any cash impacts of settled foreign currency derivatives are classified as operating or financing activities to correspond with the classification of the hedged interest or principal, respectively. See Note 1 to the financial statements under "Financial Instruments" in Item 8 of the Form 10-K for additional information. See Note 15 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K for additional information regarding the sale of Sequent. Energy-Related Derivatives The Subsidiary Registrants enter into energy-related derivatives to hedge exposures to electricity, natural gas, and other fuel price changes. However, due to cost-based rate regulations and other various cost recovery mechanisms, the traditional electric operating companies and the natural gas distribution utilities have limited exposure to market volatility in energy-related commodity prices. Each of the traditional electric operating companies and certain of the natural gas distribution utilities of Southern Company Gas manage fuel-hedging programs, implemented per the guidelines of their respective state PSCs or other applicable state regulatory agencies, through the use of financial derivative contracts, which are expected to continue to mitigate price volatility. The traditional electric operating companies (with respect to wholesale generating capacity) and Southern Power have limited exposure to market volatility in energy-related commodity prices because their long-term sales contracts shift substantially all fuel cost responsibility to the purchaser. However, the traditional electric operating companies and Southern Power may be exposed to market volatility in energy-related commodity prices to the extent any uncontracted capacity is used to sell electricity. Southern Company Gas retains exposure to price changes that can, in a volatile energy market, be material and can adversely affect its results of operations. Southern Company Gas also enters into weather derivative contracts as economic hedges in the event of warmer-than-normal weather. Exchange-traded options are carried at fair value, with changes reflected in operating revenues. Non-exchange-traded options are accounted for using the intrinsic value method. Changes in the intrinsic value for non-exchange-traded contracts are reflected in operating revenues. Energy-related derivative contracts are accounted for under one of three methods: • Regulatory Hedges – Energy-related derivative contracts designated as regulatory hedges relate primarily to the traditional electric operating companies' and the natural gas distribution utilities' fuel-hedging programs, where gains and losses are initially recorded as regulatory liabilities and assets, respectively, and then are included in fuel expense as the underlying fuel is used in operations and ultimately recovered through an approved cost recovery mechanism. • Cash Flow Hedges – Gains and losses on energy-related derivatives designated as cash flow hedges (which are mainly used to hedge anticipated purchases and sales) are initially deferred in accumulated OCI before being recognized in the statements of income in the same period and in the same income statement line item as the earnings effect of the hedged transactions. • Not Designated – Gains and losses on energy-related derivative contracts that are not designated or fail to qualify as hedges are recognized in the statements of income as incurred. Some energy-related derivative contracts require physical delivery as opposed to financial settlement, and this type of derivative is both common and prevalent within the electric and natural gas industries. When an energy-related derivative contract is settled physically, any cumulative unrealized gain or loss is reversed and the contract price is recognized in the respective line item representing the actual price of the underlying goods being delivered. At September 30, 2022, the net volume of energy-related derivative contracts for natural gas positions, together with the longest hedge date over which the respective entity is hedging its exposure to the variability in future cash flows for forecasted transactions and the longest non-hedge date for derivatives not designated as hedges, were as follows: Net Longest Longest (in millions) Southern Company () 399 2030 2025 Alabama Power 105 2026 — Georgia Power 116 2025 — Mississippi Power 82 2027 — Southern Power 11 2030 2023 Southern Company Gas () 85 2025 2025 () Southern Company Gas' derivative instruments include both long and short natural gas positions. A long position is a contract to purchase natural gas and a short position is a contract to sell natural gas. Southern Company Gas' volume represents the net of long natural gas positions of 95.7 million mmBtu and short natural gas positions of 10.6 million mmBtu at September 30, 2022, which is also included in Southern Company's total volume. In addition to the volumes discussed above, the traditional electric operating companies and Southern Power enter into physical natural gas supply contracts that provide the option to sell back excess natural gas due to operational constraints. The maximum expected volume of natural gas subject to such a feature is 15 million mmBtu for Southern Company, which includes 4 million mmBtu for Alabama Power, 5 million mmBtu for Georgia Power, 2 million mmBtu for Mississippi Power, and 4 million mmBtu for Southern Power. For cash flow hedges of energy-related derivatives, the estimated pre-tax gains (losses) expected to be reclassified from accumulated OCI to earnings for the 12-month period ending September 30, 2023 are $17 million for Southern Company, $26 million for Southern Company Gas, and immaterial for the other Registrants. Interest Rate Derivatives Southern Company and certain subsidiaries may enter into interest rate derivatives to hedge exposure to changes in interest rates. Derivatives related to existing variable rate securities or forecasted transactions are accounted for as cash flow hedges where the derivatives' fair value gains or losses are recorded in OCI and are reclassified into earnings at the same time and presented on the same income statement line item as the earnings effect of the hedged transactions. Derivatives related to existing fixed rate securities are accounted for as fair value hedges, where the derivatives' fair value gains or losses and hedged items' fair value gains or losses are both recorded directly to earnings on the same income statement line item. Fair value gains or losses on derivatives that are not designated or fail to qualify as hedges are recognized in the statements of income as incurred. At September 30, 2022, the following interest rate derivatives were outstanding: Notional Interest Weighted Hedge Fair Value Gain (Loss) at September 30, 2022 (in millions) (in millions) Cash Flow Hedges of Existing Debt Southern Company parent $ 175 — 4.25% September 2025 $ — Southern Company parent 175 — 3.83% August 2032 — Fair Value Hedges of Existing Debt Southern Company parent 400 1.75% 1-month LIBOR + 0.68% March 2028 (57) Southern Company parent 1,000 3.70% 1-month LIBOR + 2.36% April (167) Southern Company Gas 500 1.75% 1-month LIBOR + 0.38% January 2031 (87) Southern Company $ 2,250 $ (311) For cash flow hedges of interest rate derivatives, the estimated pre-tax gains (losses) expected to be reclassified from accumulated OCI to interest expense for the 12-month period ending September 30, 2023 are $(17) million for Southern Company and immaterial for the other Registrants. Deferred gains and losses related to interest rate derivatives are expected to be amortized into earnings through 2052 for Southern Company, Alabama Power, and Georgia Power, 2028 for Mississippi Power, and 2046 for Southern Company Gas. Foreign Currency Derivatives Southern Company and certain subsidiaries, including Southern Power, may enter into foreign currency derivatives to hedge exposure to changes in foreign currency exchange rates, such as that arising from the issuance of debt denominated in a currency other than U.S. dollars. Derivatives related to forecasted transactions are accounted for as cash flow hedges where the derivatives' fair value gains or losses are recorded in OCI and are reclassified into earnings at the same time and on the same income statement line as the earnings effect of the hedged transactions, including foreign currency gains or losses arising from changes in the U.S. currency exchange rates. Derivatives related to existing fixed rate securities are accounted for as fair value hedges, where the derivatives' fair value gains or losses and hedged items' fair value gains or losses are both recorded directly to earnings on the same income statement line item, including foreign currency gains or losses arising from changes in the U.S. currency exchange rates. Southern Company has elected to exclude the cross-currency basis spread from the assessment of effectiveness in the fair value hedges of its foreign currency risk and record any difference between the change in the fair value of the excluded components and the amounts recognized in earnings as a component of OCI. At September 30, 2022, the following foreign currency derivatives were outstanding: Pay Notional Pay Receive Notional Receive Hedge Fair Value Gain (Loss) at September 30, 2022 (in millions) (in millions) (in millions) Cash Flow Hedges of Existing Debt Southern Power $ 564 3.78% € 500 1.85% June 2026 $ (80) Fair Value Hedges of Existing Debt Southern Company parent 1,476 3.39% 1,250 1.88% September 2027 (243) Southern Company $ 2,040 € 1,750 $ (323) For cash flow hedges of foreign currency derivatives, the estimated pre-tax losses expected to be reclassified from accumulated OCI to earnings for the 12-month period ending September 30, 2023 are $12 million for Southern Power. Derivative Financial Statement Presentation and Amounts The Registrants enter into derivative contracts that may contain certain provisions that permit intra-contract netting of derivative receivables and payables for routine billing and offsets related to events of default and settlements. Southern Company and certain subsidiaries also utilize master netting agreements to mitigate exposure to counterparty credit risk. These agreements may contain provisions that permit netting across product lines and against cash collateral. The fair value amounts of derivative assets and liabilities on the balance sheets are presented net to the extent that there are netting arrangements or similar agreements with the counterparties. The fair value of energy-related derivatives, interest rate derivatives, and foreign currency derivatives was reflected in the balance sheets as follows: At September 30, 2022 At December 31, 2021 Derivative Category and Balance Sheet Location Assets Liabilities Assets Liabilities (in millions) (in millions) Southern Company Energy-related derivatives designated as hedging instruments for regulatory purposes Assets from risk management activities/Other current liabilities $ 299 $ 70 $ 129 $ 30 Other deferred charges and assets/Other deferred credits and liabilities 150 59 72 6 Total derivatives designated as hedging instruments for regulatory purposes 449 129 201 36 Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Assets from risk management activities/Other current liabilities 27 13 7 5 Other deferred charges and assets/Other deferred credits and liabilities 7 1 1 — Interest rate derivatives: Assets from risk management activities/Other current liabilities — 44 19 — Other deferred charges and assets/Other deferred credits and liabilities — 266 — 29 Foreign currency derivatives: Assets from risk management activities/Other current liabilities — 37 — 39 Other deferred charges and assets/Other deferred credits and liabilities — 285 — 40 Total derivatives designated as hedging instruments in cash flow and fair value hedges 34 646 27 113 Energy-related derivatives not designated as hedging instruments Assets from risk management activities/Other current liabilities 19 18 9 4 Other deferred charges and assets/Other deferred credits and liabilities 2 1 1 — Total derivatives not designated as hedging instruments 21 19 10 4 Gross amounts recognized 504 794 238 153 Gross amounts offset (a) (113) (128) (25) (28) Net amounts recognized in the Balance Sheets (b) $ 391 $ 666 $ 213 $ 125 At September 30, 2022 At December 31, 2021 Derivative Category and Balance Sheet Location Assets Liabilities Assets Liabilities (in millions) (in millions) Alabama Power Energy-related derivatives designated as hedging instruments for regulatory purposes Other current assets/Other current liabilities $ 90 $ 12 $ 30 $ 9 Other deferred charges and assets/Other deferred credits and liabilities 57 23 25 2 Total derivatives designated as hedging instruments for regulatory purposes 147 35 55 11 Gross amounts offset (31) (31) (5) (5) Net amounts recognized in the Balance Sheets $ 116 $ 4 $ 50 $ 6 Georgia Power Energy-related derivatives designated as hedging instruments for regulatory purposes Assets from risk management activities/Other current liabilities $ 107 $ 28 $ 54 $ 6 Other deferred charges and assets/Other deferred credits and liabilities 38 23 21 2 Total derivatives designated as hedging instruments for regulatory purposes 145 51 75 8 Energy-related derivatives not designated as hedging instruments Other current assets/Other current liabilities 1 — — — Gross amounts recognized 146 51 75 8 Gross amounts offset (41) (41) (8) (8) Net amounts recognized in the Balance Sheets $ 105 $ 10 $ 67 $ — Mississippi Power Energy-related derivatives designated as hedging instruments for regulatory purposes Assets from risk management activities/Other current liabilities $ 78 $ 12 $ 30 $ 3 Other deferred charges and assets/Other deferred credits and liabilities 55 12 26 2 Total derivatives designated as hedging instruments for regulatory purposes 133 24 56 5 Gross amounts offset (20) (20) (4) (4) Net amounts recognized in the Balance Sheets $ 113 $ 4 $ 52 $ 1 At September 30, 2022 At December 31, 2021 Derivative Category and Balance Sheet Location Assets Liabilities Assets Liabilities (in millions) (in millions) Southern Power Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Other current assets/Other current liabilities $ — $ 10 $ 2 $ — Other deferred charges and assets/Other deferred credits and liabilities 5 1 1 — Foreign currency derivatives: Other current assets/Other current liabilities — 12 — 16 Other deferred charges and assets/Other deferred credits and liabilities — 68 — — Total derivatives designated as hedging instruments in cash flow and fair value hedges 5 91 3 16 Energy-related derivatives not designated as hedging instruments Other current assets/Other current liabilities 2 2 1 — Gross amounts recognized 7 93 4 16 Gross amounts offset (3) (3) — — Net amounts recognized in the Balance Sheets $ 4 $ 90 $ 4 $ 16 Southern Company Gas Energy-related derivatives designated as hedging instruments for regulatory purposes Other current assets/Other current liabilities $ 24 $ 17 $ 15 $ 12 Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Other current assets/Other current liabilities 26 3 5 5 Other deferred charges and assets/Other deferred credits and liabilities 3 — — — Interest rate derivatives: Other current assets/Other current liabilities — 13 6 — Other deferred charges and assets/Other deferred credits and liabilities — 74 — 6 Total derivatives designated as hedging instruments in cash flow and fair value hedges 29 90 11 11 Energy-related derivatives not designated as hedging instruments Other current assets/Other current liabilities 16 16 8 4 Other deferred charges and assets/Other deferred credits and liabilities 2 1 1 — Total derivatives not designated as hedging instruments 18 17 9 4 Gross amounts recognized 71 124 35 27 Gross amounts offset (a) (18) (33) (8) (11) Net amounts recognized in the Balance Sheets (b) $ 53 $ 91 $ 27 $ 16 (a) Gross amounts offset includes cash collateral held on deposit in broker margin accounts of $15 million and $3 million at September 30, 2022 and December 31, 2021, respectively. (b) Net amounts of derivative instruments outstanding exclude immaterial premium and intrinsic value associated with weather derivatives for all periods presented. Energy-related derivatives not designated as hedging instruments were immaterial for Alabama Power and Mississippi Power at September 30, 2022. There were no such instruments for the traditional electric operating companies at December 31, 2021. At September 30, 2022 and December 31, 2021, the pre-tax effects of unrealized derivative gains (losses) arising from energy-related derivative instruments designated as regulatory hedging instruments and deferred were as follows: Regulatory Hedge Unrealized Gain (Loss) Recognized in the Balance Sheet Derivative Category and Balance Sheet Southern Alabama Georgia Mississippi Southern Company Gas (in millions) At September 30, 2022: Energy-related derivatives: Other regulatory assets, current $ (17) $ (2) $ (8) $ (3) $ (4) Other regulatory assets, deferred (6) (2) (3) (1) — Other regulatory liabilities, current 246 80 87 69 10 Other regulatory liabilities, deferred 98 36 18 44 — Total energy-related derivative gains (losses) $ 321 $ 112 $ 94 $ 109 $ 6 At December 31, 2021: Energy-related derivatives: Other regulatory assets, current $ (17) $ (6) $ — $ — $ (11) Other regulatory liabilities, current 107 28 48 27 4 Other regulatory liabilities, deferred 65 22 19 24 — Total energy-related derivative gains (losses) $ 155 $ 44 $ 67 $ 51 $ (7) For the three and nine months ended September 30, 2022 and 2021, the pre-tax effects of cash flow and fair value hedge accounting on accumulated OCI were as follows: Gain (Loss) Recognized in OCI on Derivative For the Three Months Ended September 30, For the Nine Months Ended September 30, 2022 2021 2022 2021 (in millions) (in millions) Southern Company Cash flow hedges: Energy-related derivatives $ 11 $ 38 $ 51 $ 59 Interest rate derivatives 6 5 36 7 Foreign currency derivatives (35) (36) (137) (79) Fair value hedges () : Foreign currency derivatives 20 (4) 18 (4) Total $ 2 $ 3 $ (32) $ (17) Georgia Power Interest rate derivatives $ — $ — $ 31 $ — Southern Power Cash flow hedges: Energy-related derivatives $ (11) $ 8 $ (4) $ 16 Foreign currency derivatives (35) (36) (137) (79) Total $ (46) $ (28) $ (141) $ (63) Southern Company Gas Cash flow hedges: Energy-related derivatives $ 22 $ 30 $ 55 $ 43 Interest rate derivatives 5 — — — Total $ 27 $ 30 $ 55 $ 43 () Represents amounts excluded from the assessment of effectiveness for which the difference between changes in fair value and periodic amortization is recorded in OCI. For the three and nine months ended September 30, 2022 and 2021, the pre-tax effects of interest rate derivatives designated as cash flow hedging instruments on accumulated OCI were immaterial for the other Registrants. For the three and nine months ended September 30, 2022 and 2021, the pre-tax effects of cash flow and fair value hedge accounting on income were as follows: Location and Amount of Gain (Loss) Recognized in Income on Cash Flow and Fair Value Hedging Relationships For the Three Months Ended September 30, For the Nine Months Ended September 30, 2022 2021 2022 2021 (in millions) (in millions) Southern Company Total cost of natural gas $ 294 $ 129 $ 1,840 $ 943 Gain (loss) on energy-related cash flow hedges (a) 9 2 28 — Total depreciation and amortization 922 896 2,728 2,658 Gain (loss) on energy-related cash flow hedges (a) (1) 3 5 6 Total interest expense, net of amounts capitalized (511) (451) (1,461) (1,352) Gain (loss) on interest rate cash flow hedges (a) (7) (7) (19) (20) Gain (loss) on foreign currency cash flow hedges (a) (3) (6) (16) (18) Gain (loss) on interest rate fair value hedges (b) (102) (4) (300) (16) Total other income (expense), net 132 131 414 290 Gain (loss) on foreign currency cash flow hedges (a)(c) (32) (34) (129) (76) Gain (loss) on foreign currency fair value hedges (59) (32) (180) (32) Amount excluded from effectiveness testing recognized in earnings (21) 4 (17) 4 Southern Power Total depreciation and amortization $ 133 $ 132 $ 384 $ 383 Gain (loss) on energy-related cash flow hedges (a) (1) 3 5 6 Total interest expense, net of amounts capitalized (32) (36) (105) (111) Gain (loss) on foreign currency cash flow hedges (a) (3) (6) (16) (18) Total other income (expense), net 3 2 5 10 Gain (loss) on foreign currency cash flow hedges (a)(c) (32) (34) (129) (76) Southern Company Gas Total cost of natural gas $ 294 $ 129 $ 1,840 $ 943 Gain (loss) on energy-related cash flow hedges (a) 9 2 28 — Total interest expense, net of amounts capitalized (65) (57) (187) (175) Gain (loss) on interest rate cash flow hedges (a) (2) (1) (3) (2) Gain (loss) on interest rate fair value hedges (b) (30) — (87) 2 (a) Reclassified from accumulated OCI into earnings. (b) For fair value hedges, changes in the fair value of the derivative contracts are generally equal to changes in the fair value of the underlying debt and have no material impact on income. (c) The reclassification from accumulated OCI into other income (expense), net completely offsets currency gains and losses arising from changes in the U.S. currency exchange rates used to record the euro-denominated notes. For the three and nine months ended September 30, 2022 and 2021, the pre-tax effects of cash flow hedge accounting on income for interest rate derivatives were immaterial for Alabama Power, Georgia Power, and Mississippi Power. At September 30, 2022 and December 31, 2021, the following amounts were recorded on the balance sheets related to cumulative basis adjustments for fair value hedges: Carrying Amount of the Hedged Item Cumulative Amount of Fair Value Hedging Adjustment included in Carrying Amount of the Hedged Item Balance Sheet Location of Hedged Items At September 30, 2022 At December 31, 2021 At September 30, 2022 At December 31, 2021 (in millions) (in millions) Southern Company Long-term debt $ (2,788) $ (3,280) $ 306 $ 9 Southern Company Gas Long-term debt $ (411) $ (493) $ 86 $ 2 For the three and nine months ended September 30, 2022 and 2021, the pre-tax effects of energy-related derivatives not designated as hedging instruments on the statements of income of Southern Company and Southern Company Gas were as follows: Gain (Loss) Three Months Ended September 30, Nine Months Ended September 30, Derivatives in Non-Designated Hedging Relationships Statements of Income Location 2022 2021 2022 2021 (in millions) (in millions) Energy-related derivatives: Natural gas revenues () $ 3 $ (2) $ (10) $ (122) Cost of natural gas (2) 20 (7) 36 Total derivatives in non-designated hedging relationships $ 1 $ 18 $ (17) $ (86) (*) Excludes immaterial gains (losses) recorded in natural gas revenues associated with weather derivatives for all periods presented. For the three and nine months ended September 30, 2022 and 2021, the pre-tax effects of energy-related derivatives not designated as hedging instruments were immaterial for the other Registrants. Contingent Features The Registrants do not have any credit arrangements that would require material changes in payment schedules or terminations as a result of a credit rating downgrade. There are certain derivatives that could require collateral, but not accelerated payment, in the event of various credit rating changes of certain Southern Company subsidiaries. Generally, collateral may be provided by a Southern Company guaranty, letter of credit, or cash. At September 30, 2022, the Registrants had no collateral posted with derivative counterparties to satisfy these arrangements. For Southern Company and Southern Power, the fair value of interest rate derivative liabilities with contingent features and the maximum potential collateral requirements arising from the credit-risk-related contingent features, at a rating below BBB- and/or Baa3, were $156 million and $38 million, respectively at September 30, 2022. For the traditional electric operating companies and Southern Power, energy-related derivative liabilities with contingent features and the maximum potential collateral requirements arising from the credit-risk-related contingent features, at a rating below BBB- and/or Baa3, were immaterial at September 30, 2022. The maximum potential collateral requirements arising from the credit-risk-related contingent features for the traditional electric operating companies and Southern Power include certain agreements that could require collateral in the event that one or more Southern Company power pool participants has a credit rating change to below investment grade. Following the sale of Gulf Power to NextEra Energy, Inc., Gulf Power continued participating in the Southern Company power pool through July 13, 2022. Alabama Power and Southern Power maintain accounts with certain regional transmission organizations to facilitate financial derivative transactions and they may be required to post collateral based on the value of the positions in these accounts and the associated margin requirements. At September 30, 2022, cash collateral posted in these accounts was immaterial. Southern Company Gas maintains accounts with brokers or the clearing houses of certain exchanges to facilitate financial derivative transactions. Based on the value of the positions in these accounts and the associated margin requirements, Southern Company Gas may be required to deposit cash into these accounts. At September 30, 2022, cash collateral held on deposit in broker margin accounts was $15 million. The Registrants are exposed to losses related to financial instruments in the event of counterparties' nonperformance. The Registrants only enter into agreements and material transactions with counterparties that have investment grade credit ratings by Moody's and S&P or with counterparties who have posted collateral to cover potential credit exposure. The Registrants have also established risk management policies and controls to determine and monitor the creditworthiness of counterparties in order to mitigate their exposure to counterparty credit risk. Southern Company Gas uses established credit policies to determine and monitor the creditworthiness of counterparties, including requirements to post collateral or other credit security, as well as the quality of pledged collateral. Collateral or credit security is most often in the form of cash or letters of credit from an investment-grade financial institution, but may also include cash or U.S. government securities held by a trustee. Prior to entering a physical transaction, Southern Company Gas assigns its counterparties an internal credit rating and credit limit based on the counterparties' Moody's, S&P, and Fitch ratings, commercially available credit reports, and audited financial statements. Southern Company Gas may require counterparties to pledge additional collateral when deemed necessary. Southern Company Gas utilizes netting agreements whenever possible to mitigate exposure to counterparty credit risk. Netting agreements enable Southern Company Gas to net certain assets and liabilities by counterparty across product lines and against cash collateral, provided the netting and cash collateral agreements include such provisions. While the amounts due from, or owed to, counterparties are settled net, they are recorded on a gross basis on the balance sheet as energy marketing receivables and energy marketing payables. The Registrants do not anticipate a material adverse effect on their respective financial statements as a result of counterparty nonperformance.

Acquisitions and Dispositions

Acquisitions and Dispositions	9 Months Ended
Acquisitions and Dispositions	Sep. 30, 2022
Business Combination and Asset Acquisition [Abstract]
Acquisitions and Dispositions	ACQUISITIONS AND DISPOSITIONSSee Note 15 to the financial statements in Item 8 of the Form 10-K for additional information. Alabama Power On September 30, 2022, Alabama Power completed its acquisition of the Calhoun Generating Station, which was accounted for as an asset acquisition. The total purchase price was $179 million, of which $171 million was related to net assets recorded within property, plant, and equipment on the balance sheet and the remainder primarily related to fossil fuel stock and materials and supplies. See Note (B) and Note 15 to the financial statements in Item 8 of the Form 10-K under "Alabama Power" for additional information. Southern Power Construction Projects During the nine months ended September 30, 2022, Southern Power completed construction of and placed in service the remaining 40 MWs of the Tranquillity battery energy storage facility and the remaining 15 MWs of the Garland battery energy storage facility. Project Facility Resource Approximate Nameplate Capacity ( MW ) Location COD PPA Contract Period Projects Completed During the Nine Months Ended September 30, 2022 Garland Solar Storage (a) Battery energy storage system 88 Kern County, CA September 2021 through February 2022 (b) 20 years Tranquillity Solar Storage (a) Battery energy storage system 72 Fresno County, CA November 2021 through March 2022 (c) 20 years (a) Southern Power consolidates each project's operating results in its financial statements and the tax equity partner and two other partners each own a noncontrolling interest. (b) The facility has a total capacity of 88 MWs, of which 73 MWs were placed in service in 2021 and 15 MWs were placed in service in February 2022. (c) The facility has a total capacity of 72 MWs, of which 32 MWs were placed in service in 2021 and 40 MWs were placed in service in March 2022. Southern Company Gas Sale of Natural Gas Storage Facilities On September 7, 2022, certain affiliates of Southern Company Gas entered into agreements to sell two natural gas storage facilities located in California and Texas for an aggregate purchase price of $186 million, plus working capital and certain other adjustments. Completion of the sales is subject to material closing conditions, including, among others, release of a Southern Company Gas parent guarantee, approval from the California Public Utility Commission without a material burdensome condition, and the expiration or termination of any applicable waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976. The parent guarantee release was executed on October 20, 2022, which resolved a material closing condition. As a result, Southern Company Gas expects to record pre-tax impairment charges totaling approximately $125 million ($95 million after tax) in the fourth quarter 2022. The sale of the Texas facility is expected to be completed later in the fourth quarter 2022, and the sale of the California facility is expected to be completed during 2023; however, the ultimate outcome of these matters cannot be determined at this time. Sale of Pivotal LNG On May 20, 2022, Southern Company Gas received the final $5 million contingent payment from Dominion Modular LNG Holdings, Inc. in connection with its 2020 sale of Pivotal LNG, Inc.

Segment and Related Information

Segment and Related Information	9 Months Ended
Segment and Related Information	Sep. 30, 2022
Segment Reporting [Abstract]
Segment and Related Information	SEGMENT AND RELATED INFORMATION Southern Company The primary businesses of the Southern Company system are electricity sales by the traditional electric operating companies and Southern Power and the distribution of natural gas by Southern Company Gas. The traditional electric operating companies are vertically integrated utilities providing electric service in three Southeastern states. Southern Power develops, constructs, acquires, owns, and manages power generation assets, including renewable energy and battery energy storage projects, and sells electricity at market-based rates in the wholesale market. Southern Company Gas distributes natural gas through its natural gas distribution utilities and is involved in several other complementary businesses including gas pipeline investments and gas marketing services. Prior to the sale of Sequent on July 1, 2021, Southern Company Gas' other businesses also included wholesale gas services. Financial data for business segments and products and services for the three and nine months ended September 30, 2022 and 2021 was as follows: Electric Utilities Traditional Southern Eliminations Total Southern Company Gas All Eliminations Consolidated (in millions) Three Months Ended September 30, 2022 Operating revenues $ 6,938 $ 1,180 $ (691) $ 7,427 $ 857 $ 135 $ (41) $ 8,378 Segment net income (loss) (a)(b) 1,445 95 — 1,540 83 (152) 1 1,472 Nine Months Ended September 30, 2022 Operating revenues $ 16,716 $ 2,618 $ (1,391) $ 17,943 $ 3,998 $ 418 $ (127) $ 22,232 Segment net income (loss) (a)(b) 3,256 265 — 3,521 516 (415) (11) 3,611 At September 30, 2022 Goodwill $ — $ 2 $ — $ 2 $ 5,015 $ 263 $ — $ 5,280 Total assets 95,659 13,283 (748) 108,194 24,097 2,372 (658) 134,005 Three Months Ended September 30, 2021 Operating revenues $ 5,018 $ 679 $ (170) $ 5,527 $ 623 $ 124 $ (36) $ 6,238 Segment net income (loss) (a)(b)(c) 1,085 78 — 1,163 56 (121) 3 1,101 Nine Months Ended September 30, 2021 Operating revenues $ 12,813 $ 1,610 $ (372) $ 14,051 $ 2,994 $ 412 $ (111) $ 17,346 Segment net income (loss) (a)(b)(c)(d)(e) 2,352 211 — 2,563 389 (338) (6) 2,608 At December 31, 2021 Goodwill $ — $ 2 $ — $ 2 $ 5,015 $ 263 $ — $ 5,280 Total assets 89,051 13,390 (667) 101,774 23,560 2,975 (775) 127,534 (a) Attributable to Southern Company. (b) For the traditional electric operating companies, includes pre-tax charges (credits) to income at Georgia Power for the estimated probable loss associated with the construction of Plant Vogtle Units 3 and 4 of $(70) million ($(52) million after tax) and $(18) million ($(13) million after tax) for the three and nine months ended September 30, 2022, respectively, and $264 million ($197 million after tax) and $772 million ($576 million after tax) for the three and nine months ended September 30, 2021, respectively. See Note (B) and Note 2 to the financial statements in Item 8 of the Form 10-K under "Georgia Power – Nuclear Construction" for additional information. (c) For Southern Company Gas, includes a pre-tax gain of $121 million ($93 million after tax) related to its sale of Sequent, as well as the resulting $85 million of additional tax expense as a result of the sale. See Note 15 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K for additional information. (d) For Southern Power, includes gains on wind turbine equipment contributed to various equity method investments totaling approximately $37 million pre-tax ($28 million after tax). See Note 15 to the financial statements under "Southern Power – Development Projects" in Item 8 of the Form 10-K for additional information. (e) For Southern Company Gas, includes pre-tax impairment charges totaling $84 million ($67 million after tax) related to its equity method investment in the PennEast Pipeline project. See Note 7 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K for additional information. Products and Services Electric Utilities' Revenues Retail Wholesale Other Total (in millions) Three Months Ended September 30, 2022 $ 5,961 $ 1,197 $ 269 $ 7,427 Three Months Ended September 30, 2021 4,551 731 245 5,527 Nine Months Ended September 30, 2022 $ 14,363 $ 2,798 $ 782 $ 17,943 Nine Months Ended September 30, 2021 11,492 1,822 737 14,051 Southern Company Gas' Revenues Gas Wholesale Gas Services () Gas Other Total (in millions) Three Months Ended September 30, 2022 $ 748 $ — $ 85 $ 24 $ 857 Three Months Ended September 30, 2021 553 — 52 18 623 Nine Months Ended September 30, 2022 $ 3,513 $ — $ 420 $ 65 $ 3,998 Nine Months Ended September 30, 2021 2,451 188 311 44 2,994 () Prior to the sale of Sequent, the revenues for wholesale gas services were netted with costs associated with its energy and risk management activities. See "Southern Company Gas" herein and Note 15 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K for additional information. Southern Company Gas Southern Company Gas manages its business through three reportable segments – gas distribution operations, gas pipeline investments, and gas marketing services. Prior to the sale of Sequent on July 1, 2021, Southern Company Gas' reportable segments also included wholesale gas services. The non-reportable segments are combined and presented as all other. See Note 15 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K for additional information on the sale of Sequent. Gas distribution operations is the largest component of Southern Company Gas' business and includes natural gas local distribution utilities that construct, manage, and maintain intrastate natural gas pipelines and gas distribution facilities in four states. Gas pipeline investments consists of joint ventures in natural gas pipeline investments including a 50% interest in SNG and a 50% joint ownership interest in the Dalton Pipeline. These natural gas pipelines enable the provision of diverse sources of natural gas supplies to the customers of Southern Company Gas. Gas pipeline investments also includes a 20% ownership interest in the PennEast Pipeline project, which was cancelled in September 2021. See Note 7 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K for additional information. Through July 1, 2021, wholesale gas services provided natural gas asset management and/or related logistics services for each of Southern Company Gas' utilities except Nicor Gas as well as for non-affiliated companies. Additionally, wholesale gas services engaged in natural gas storage and gas pipeline arbitrage and related activities. Gas marketing services provides natural gas marketing to end-use customers primarily in Georgia and Illinois through SouthStar. The all other column includes segments and subsidiaries that fall below the quantitative threshold for separate disclosure, including storage and fuels operations. See Note (K) under "Southern Company Gas" for information regarding agreements by certain affiliates of Southern Company Gas to sell two natural gas storage facilities. Business segment financial data for the three and nine months ended September 30, 2022 and 2021 was as follows: Gas Distribution Operations Gas Pipeline Investments Wholesale Gas Services (a) Gas Marketing Services Total All Other Eliminations Consolidated (in millions) Three Months Ended September 30, 2022 Operating revenues $ 751 $ 8 $ — $ 85 $ 844 $ 16 $ (3) $ 857 Segment net income (loss) 59 24 — (2) 81 2 — 83 Nine Months Ended September 30, 2022 Operating revenues $ 3,533 $ 24 $ — $ 420 $ 3,977 $ 43 $ (22) $ 3,998 Segment net income (loss) 365 76 — 65 506 10 — 516 Total assets at September 30, 2022 21,605 1,425 — 1,595 24,625 9,100 (9,628) 24,097 Three Months Ended September 30, 2021 Operating revenues $ 556 $ 8 $ — $ 52 $ 616 $ 11 $ (4) $ 623 Segment net income (loss) (b)(c) 45 10 94 (2) 147 (91) — 56 Nine Months Ended September 30, 2021 Operating revenues $ 2,466 $ 24 $ 188 $ 311 $ 2,989 $ 29 $ (24) $ 2,994 Segment net income (loss) (b)(c)(d) 308 3 108 60 479 (90) — 389 Total assets at December 31, 2021 20,917 1,467 31 1,556 23,971 12,114 (12,525) 23,560 (a) As a result of the sale of Sequent, wholesale gas services is no longer a reportable segment for the three and nine months ended September 30, 2022. Prior to the sale of Sequent, the revenues for wholesale gas services were netted with costs associated with its energy and risk management activities. A reconciliation of operating revenues and intercompany revenues is shown in the following table. Third Party Gross Revenues Intercompany Revenues Total Gross Revenues Less Gross Gas Costs Operating Revenues (in millions) Nine Months Ended September 30, 2021 $ 3,881 $ 90 $ 3,971 $ 3,783 $ 188 (b) For wholesale gas services, includes a pre-tax gain of $121 million ($93 million after tax) related to the sale of Sequent. See Note 15 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K for additional information. (c) For the "All Other" column, includes $85 million of additional tax expense as a result of the sale. See Note 15 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K for additional information. (d) For gas pipeline investments, includes pre-tax impairment charges totaling $84 million ($67 million after tax) related to the equity method investment in the PennEast Pipeline project. See Note 7 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K for additional information.

Introduction (Policies)

Introduction (Policies)	9 Months Ended
Introduction (Policies)	Sep. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Accounting	The condensed quarterly financial statements of each Registrant included herein have been prepared by such Registrant, without audit, pursuant to the rules and regulations of the SEC. The Condensed Balance Sheets at December 31, 2021 have been derived from the audited financial statements of each Registrant. In the opinion of each Registrant's management, the information regarding such Registrant furnished herein reflects all adjustments, which, except as otherwise disclosed, are of a normal recurring nature, necessary to present fairly the results of operations for the periods ended September 30, 2022 and 2021. Certain information and footnote disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations, although each Registrant believes that the disclosures regarding such Registrant are adequate to make the information presented not misleading. Disclosures which would substantially duplicate the disclosures in the Form 10-K and details which have not changed significantly in amount or composition since the filing of the Form 10-K are generally omitted from this Quarterly Report on Form 10-Q unless specifically required by GAAP. Therefore, these Condensed Financial Statements should be read in conjunction with the financial statements and the notes thereto included in the Form 10-K. Due to the seasonal variations in the demand for energy and other factors, operating results for the periods presented are not necessarily indicative of the operating results to be expected for the full year.
Reclassifications	Certain prior year data presented in the financial statements have been reclassified to conform to the current year presentation. These reclassifications had no impact on the overall results of operations, financial position, or cash flows of any Registrant.
Goodwill	Goodwill is not amortized, but is subject to an annual impairment test during the fourth quarter of each year, or more frequently if impairment indicators arise.
Natural Gas for Sale	Natural Gas for Sale With the exception of Nicor Gas, Southern Company Gas records natural gas inventories on a WACOG basis. For any declines in market prices below the WACOG considered to be other than temporary, an adjustment is recorded to reduce the value of natural gas inventories to market value. Nicor Gas' natural gas inventory is carried at cost on a LIFO basis. Inventory decrements occurring during the year that are restored prior to year end are charged to cost of natural gas at the estimated annual replacement cost. Inventory decrements that are not restored prior to year end are charged to cost of natural gas at the actual LIFO cost of the inventory layers liquidated.
Valuation Methodologies	Valuation Methodologies The energy-related derivatives primarily consist of exchange-traded and over-the-counter financial products for natural gas and physical power products, including, from time to time, basis swaps. These are standard products used within the energy industry and are valued using the market approach. The inputs used are mainly from observable market sources, such as forward natural gas prices, power prices, implied volatility, and overnight index swap interest rates. Interest rate derivatives are also standard over-the-counter products that are valued using observable market data and assumptions commonly used by market participants. The fair value of interest rate derivatives reflects the net present value of expected payments and receipts under the swap agreement based on the market's expectation of future interest rates. Additional inputs to the net present value calculation may include the contract terms, counterparty credit risk, and occasionally, implied volatility of interest rate options. The fair value of cross-currency swaps reflects the net present value of expected payments and receipts under the swap agreement based on the market's expectation of future foreign currency exchange rates. Additional inputs to the net present value calculation may include the contract terms, counterparty credit risk, and discount rates. The interest rate derivatives and cross-currency swaps are categorized as Level 2 under Fair Value Measurements as these inputs are based on observable data and valuations of similar instruments. See Note (J) for additional information on how these derivatives are used. For fair value measurements of the investments within the nuclear decommissioning trusts and the non-qualified deferred compensation trusts, external pricing vendors are designated for each asset class with each security specifically assigned a primary pricing source. For investments held within commingled funds, fair value is determined at the end of each business day through the net asset value, which is established by obtaining the underlying securities' individual prices from the primary pricing source. A market price secured from the primary source vendor is then evaluated by management in its valuation of the assets within the trusts. As a general approach, fixed income market pricing vendors gather market data (including indices and market research reports) and integrate relative credit information, observed market movements, and sector news into proprietary pricing models, pricing systems, and mathematical tools. Dealer quotes and other market information, including live trading levels and pricing analysts' judgments, are also obtained when available. The NRC requires licensees of commissioned nuclear power reactors to establish a plan for providing reasonable assurance of funds for future decommissioning. See Note 6 to the financial statements under "Nuclear Decommissioning" in Item 8 of the Form 10-K for additional information.
Derivatives	The Registrants are exposed to market risks, including commodity price risk, interest rate risk, weather risk, and occasionally foreign currency exchange rate risk. To manage the volatility attributable to these exposures, each company nets its exposures, where possible, to take advantage of natural offsets and enters into various derivative transactions for the remaining exposures pursuant to each company's policies in areas such as counterparty exposure and risk management practices. Prior to the sale of Sequent on July 1, 2021, Southern Company Gas' wholesale gas operations used various contracts in its commercial activities that generally met the definition of derivatives. For the traditional electric operating companies, Southern Power, and Southern Company Gas' other businesses, each company's policy is that derivatives are to be used primarily for hedging purposes and mandates strict adherence to all applicable risk management policies. Derivative positions are monitored using techniques including, but not limited to, market valuation, value at risk, stress testing, and sensitivity analysis. Derivative instruments are recognized at fair value in the balance sheets as either assets or liabilities and are presented on a net basis. See Note (I) for additional fair value information. In the statements of cash flows, any cash impacts of settled energy-related and interest rate derivatives are recorded as operating activities. Any cash impacts of settled foreign currency derivatives are classified as operating or financing activities to correspond with the classification of the hedged interest or principal, respectively. See Note 1 to the financial statements under "Financial Instruments" in Item 8 of the Form 10-K for additional information. See Note 15 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K for additional information regarding the sale of Sequent. Energy-Related Derivatives The Subsidiary Registrants enter into energy-related derivatives to hedge exposures to electricity, natural gas, and other fuel price changes. However, due to cost-based rate regulations and other various cost recovery mechanisms, the traditional electric operating companies and the natural gas distribution utilities have limited exposure to market volatility in energy-related commodity prices. Each of the traditional electric operating companies and certain of the natural gas distribution utilities of Southern Company Gas manage fuel-hedging programs, implemented per the guidelines of their respective state PSCs or other applicable state regulatory agencies, through the use of financial derivative contracts, which are expected to continue to mitigate price volatility. The traditional electric operating companies (with respect to wholesale generating capacity) and Southern Power have limited exposure to market volatility in energy-related commodity prices because their long-term sales contracts shift substantially all fuel cost responsibility to the purchaser. However, the traditional electric operating companies and Southern Power may be exposed to market volatility in energy-related commodity prices to the extent any uncontracted capacity is used to sell electricity. Southern Company Gas retains exposure to price changes that can, in a volatile energy market, be material and can adversely affect its results of operations. Southern Company Gas also enters into weather derivative contracts as economic hedges in the event of warmer-than-normal weather. Exchange-traded options are carried at fair value, with changes reflected in operating revenues. Non-exchange-traded options are accounted for using the intrinsic value method. Changes in the intrinsic value for non-exchange-traded contracts are reflected in operating revenues. Energy-related derivative contracts are accounted for under one of three methods: • Regulatory Hedges – Energy-related derivative contracts designated as regulatory hedges relate primarily to the traditional electric operating companies' and the natural gas distribution utilities' fuel-hedging programs, where gains and losses are initially recorded as regulatory liabilities and assets, respectively, and then are included in fuel expense as the underlying fuel is used in operations and ultimately recovered through an approved cost recovery mechanism. • Cash Flow Hedges – Gains and losses on energy-related derivatives designated as cash flow hedges (which are mainly used to hedge anticipated purchases and sales) are initially deferred in accumulated OCI before being recognized in the statements of income in the same period and in the same income statement line item as the earnings effect of the hedged transactions. • Not Designated – Gains and losses on energy-related derivative contracts that are not designated or fail to qualify as hedges are recognized in the statements of income as incurred. Some energy-related derivative contracts require physical delivery as opposed to financial settlement, and this type of derivative is both common and prevalent within the electric and natural gas industries. When an energy-related derivative contract is settled physically, any cumulative unrealized gain or loss is reversed and the contract price is recognized in the respective line item representing the actual price of the underlying goods being delivered. Interest Rate Derivatives Southern Company and certain subsidiaries may enter into interest rate derivatives to hedge exposure to changes in interest rates. Derivatives related to existing variable rate securities or forecasted transactions are accounted for as cash flow hedges where the derivatives' fair value gains or losses are recorded in OCI and are reclassified into earnings at the same time and presented on the same income statement line item as the earnings effect of the hedged transactions. Derivatives related to existing fixed rate securities are accounted for as fair value hedges, where the derivatives' fair value gains or losses and hedged items' fair value gains or losses are both recorded directly to earnings on the same income statement line item. Fair value gains or losses on derivatives that are not designated or fail to qualify as hedges are recognized in the statements of income as incurred. Foreign Currency Derivatives Southern Company and certain subsidiaries, including Southern Power, may enter into foreign currency derivatives to hedge exposure to changes in foreign currency exchange rates, such as that arising from the issuance of debt denominated in a currency other than U.S. dollars. Derivatives related to forecasted transactions are accounted for as cash flow hedges where the derivatives' fair value gains or losses are recorded in OCI and are reclassified into earnings at the same time and on the same income statement line as the earnings effect of the hedged transactions, including foreign currency gains or losses arising from changes in the U.S. currency exchange rates. Derivatives related to existing fixed rate securities are accounted for as fair value hedges, where the derivatives' fair value gains or losses and hedged items' fair value gains or losses are both recorded directly to earnings on the same income statement line item, including foreign currency gains or losses arising from changes in the U.S. currency exchange rates. Southern Company has elected to exclude the cross-currency basis spread from the assessment of effectiveness in the fair value hedges of its foreign currency risk and record any difference between the change in the fair value of the excluded components and the amounts recognized in earnings as a component of OCI. Derivative Financial Statement Presentation and Amounts The Registrants enter into derivative contracts that may contain certain provisions that permit intra-contract netting of derivative receivables and payables for routine billing and offsets related to events of default and settlements. Southern Company and certain subsidiaries also utilize master netting agreements to mitigate exposure to counterparty credit risk. These agreements may contain provisions that permit netting across product lines and against cash collateral. The fair value amounts of derivative assets and liabilities on the balance sheets are presented net to the extent that there are netting arrangements or similar agreements with the counterparties.

Introduction (Tables)

Introduction (Tables)	9 Months Ended
Introduction (Tables)	Sep. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Goodwill	Goodwill at September 30, 2022 and December 31, 2021 was as follows: Goodwill (in millions) Southern Company $ 5,280 Southern Company Gas: Gas distribution operations $ 4,034 Gas marketing services 981 Southern Company Gas total $ 5,015
Schedule of Other Intangible Assets, Indefinite-Lived	Other intangible assets were as follows: At September 30, 2022 At December 31, 2021 Gross Carrying Amount Accumulated Amortization Other Gross Carrying Amount Accumulated Amortization Other (in millions) (in millions) Southern Company Other intangible assets subject to amortization: Customer relationships $ 212 $ (159) $ 53 $ 212 $ (150) $ 62 Trade names 64 (44) 20 64 (38) 26 PPA fair value adjustments 390 (124) 266 390 (109) 281 Other 5 (4) 1 11 (10) 1 Total other intangible assets subject to amortization $ 671 $ (331) $ 340 $ 677 $ (307) $ 370 Other intangible assets not subject to amortization: Federal Communications Commission licenses 75 — 75 75 — 75 Total other intangible assets $ 746 $ (331) $ 415 $ 752 $ (307) $ 445 Southern Power Other intangible assets subject to amortization: PPA fair value adjustments $ 390 $ (124) $ 266 $ 390 $ (109) $ 281 Southern Company Gas Other intangible assets subject to amortization: Gas marketing services Customer relationships $ 156 $ (137) $ 19 $ 156 $ (130) $ 26 Trade names 26 (17) 9 26 (15) 11 Total other intangible assets subject to amortization $ 182 $ (154) $ 28 $ 182 $ (145) $ 37
Schedule of Other Intangible Assets, Finite-Lived	Other intangible assets were as follows: At September 30, 2022 At December 31, 2021 Gross Carrying Amount Accumulated Amortization Other Gross Carrying Amount Accumulated Amortization Other (in millions) (in millions) Southern Company Other intangible assets subject to amortization: Customer relationships $ 212 $ (159) $ 53 $ 212 $ (150) $ 62 Trade names 64 (44) 20 64 (38) 26 PPA fair value adjustments 390 (124) 266 390 (109) 281 Other 5 (4) 1 11 (10) 1 Total other intangible assets subject to amortization $ 671 $ (331) $ 340 $ 677 $ (307) $ 370 Other intangible assets not subject to amortization: Federal Communications Commission licenses 75 — 75 75 — 75 Total other intangible assets $ 746 $ (331) $ 415 $ 752 $ (307) $ 445 Southern Power Other intangible assets subject to amortization: PPA fair value adjustments $ 390 $ (124) $ 266 $ 390 $ (109) $ 281 Southern Company Gas Other intangible assets subject to amortization: Gas marketing services Customer relationships $ 156 $ (137) $ 19 $ 156 $ (130) $ 26 Trade names 26 (17) 9 26 (15) 11 Total other intangible assets subject to amortization $ 182 $ (154) $ 28 $ 182 $ (145) $ 37
Schedule of Amortization of Other Intangible Assets	Amortization associated with other intangible assets was as follows: Three Months Ended Nine Months Ended September 30, 2022 (in millions) Southern Company (a) $ 11 $ 30 Southern Power (b) 5 15 Southern Company Gas 4 9 (a) Includes $5 million and $15 million for the three and nine months ended September 30, 2022, respectively, recorded as a reduction to operating revenues. (b) Recorded as a reduction to operating revenues.
Schedule of Restrictions on Cash and Cash Equivalents	The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the condensed balance sheets that total to the amount shown in the condensed statements of cash flows for the applicable Registrants: Southern Southern Southern September 30, 2022 December 31, 2021 September 30, 2022 December 31, 2021 September 30, 2022 December 31, 2021 (in millions) Cash and cash equivalents $ 2,009 $ 1,798 $ 229 $ 107 $ 26 $ 45 Restricted cash (a) : Other current assets 2 2 — — 2 2 Other deferred charges and assets 3 29 3 29 — — Total cash, cash equivalents, and restricted cash (b) $ 2,013 $ 1,829 $ 231 $ 135 $ 28 $ 48 (a) For Southern Power, reflects $3 million and $10 million at September 30, 2022 and December 31, 2021, respectively, held to fund estimated construction completion costs at the Deuel Harvest wind facility and $19 million at December 31, 2021 related to tax equity contributions restricted until the Garland battery energy storage facility achieved final contracted capacity. For Southern Company Gas, reflects collateral for workers' compensation, life insurance, and long-term disability insurance. (b) Total may not add due to rounding.
Schedule of Cash and Cash Equivalents	The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the condensed balance sheets that total to the amount shown in the condensed statements of cash flows for the applicable Registrants: Southern Southern Southern September 30, 2022 December 31, 2021 September 30, 2022 December 31, 2021 September 30, 2022 December 31, 2021 (in millions) Cash and cash equivalents $ 2,009 $ 1,798 $ 229 $ 107 $ 26 $ 45 Restricted cash (a) : Other current assets 2 2 — — 2 2 Other deferred charges and assets 3 29 3 29 — — Total cash, cash equivalents, and restricted cash (b) $ 2,013 $ 1,829 $ 231 $ 135 $ 28 $ 48 (a) For Southern Power, reflects $3 million and $10 million at September 30, 2022 and December 31, 2021, respectively, held to fund estimated construction completion costs at the Deuel Harvest wind facility and $19 million at December 31, 2021 related to tax equity contributions restricted until the Garland battery energy storage facility achieved final contracted capacity. For Southern Company Gas, reflects collateral for workers' compensation, life insurance, and long-term disability insurance. (b) Total may not add due to rounding.

Regulatory Matters (Tables)

Regulatory Matters (Tables)	9 Months Ended
Regulatory Matters (Tables)	Sep. 30, 2022
Regulated Operations [Abstract]
Schedule of Cost Recovery Clauses	The recovery balances for certain retail regulatory clauses of the traditional electric operating companies and Southern Company Gas at September 30, 2022 and December 31, 2021 were as follows: Regulatory Clause Balance Sheet Line Item September 30, December 31, 2021 (in millions) Alabama Power Rate CNP Compliance Other regulatory liabilities, deferred $ 4 $ — Other regulatory assets, deferred — 16 Rate CNP PPA Other regulatory assets, deferred 125 84 Retail Energy Cost Recovery () Other regulatory assets, current 93 — Other regulatory assets, deferred 413 126 Georgia Power Fuel Cost Recovery Deferred under recovered fuel clause revenues $ 1,697 $ 410 Mississippi Power Fuel Cost Recovery Other customer accounts receivable $ 13 $ 4 Ad Valorem Tax Other regulatory assets, current 12 12 Other regulatory assets, deferred 22 37 Southern Company Gas Natural Gas Cost Recovery Natural gas cost under recovery $ 390 $ 266 Other regulatory assets, deferred — 207 () In accordance with an Alabama PSC order issued on February 1, 2022, Alabama Power applied $126 million of its 2021 Rate RSE refund to reduce the Rate ECR under recovered balance.
Nuclear Construction Cost and Schedule	Georgia Power's approximate proportionate share of the remaining estimated capital cost to complete Plant Vogtle Units 3 and 4, including contingency, through the end of the first quarter 2023 and the fourth quarter 2023, respectively, is as follows: (in millions) Base project capital cost forecast (a)(b) $ 10,334 Construction contingency estimate 49 Total project capital cost forecast (a)(b) 10,383 Net investment at September 30, 2022 (b) (9,280) Remaining estimate to complete $ 1,103 (a) Includes approximately $590 million of costs that are not shared with the other Vogtle Owners and approximately $353 million of incremental costs under the cost-sharing and tender provisions of the joint ownership agreements described below. Excludes financing costs expected to be capitalized through AFUDC of approximately $385 million, of which $275 million had been accrued through September 30, 2022. (b) Net of $1.7 billion received from Toshiba under the Guarantee Settlement Agreement and approximately $188 million in related customer refunds.
Schedule of Infrastructure Replacement Programs and Capital Projects	Georgia Power has requested recovery of the proposed increases through its existing base rate tariffs as follows: Tariff 2023 2024 2025 (in millions) Traditional base $ 762 $ — $ — ECCR Traditional 5 — — CCR ARO (a) 64 78 47 DSM (a) 37 27 (2) Municipal Franchise Fee 21 2 1 Total (b) $ 889 $ 107 $ 45 (a) As determined by the Georgia PSC through annual compliance filings. (b) Totals may not add due to rounding. Capital expenditures incurred under specific infrastructure replacement programs and capital projects during the first nine months of 2022 were as follows: Utility Program Nine Months Ended September 30, 2022 (in millions) Nicor Gas Investing in Illinois $ 311 Virginia Natural Gas SAVE 52 Atlanta Gas Light System Reinforcement Rider 51 Chattanooga Gas Pipeline Replacement Program 2 Total $ 416

Revenue from Contracts with C_2

Revenue from Contracts with Customers and Lease Income (Tables)	9 Months Ended
	Sep. 30, 2022
Revenue from Contract with Customer [Abstract]
Schedule of Disaggregation of Revenue	The following table disaggregates revenue from contracts with customers for the three and nine months ended September 30, 2022 and 2021: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Three Months Ended September 30, 2022 Operating revenues Retail electric revenues Residential $ 2,104 $ 799 $ 1,212 $ 93 $ — $ — Commercial 1,637 499 1,051 87 — — Industrial 1,183 452 642 89 — — Other 27 3 22 2 — — Total retail electric revenues 4,951 1,753 2,927 271 — — Natural gas distribution revenues Residential 331 — — — — 331 Commercial 93 — — — — 93 Transportation 259 — — — — 259 Industrial 12 — — — — 12 Other 49 — — — — 49 Total natural gas distribution revenues 744 — — — — 744 Wholesale electric revenues PPA energy revenues 812 187 40 4 591 — PPA capacity revenues 175 56 12 1 107 — Non-PPA revenues 58 67 4 242 303 — Total wholesale electric revenues 1,045 310 56 247 1,001 — Other natural gas revenues Gas marketing services 84 — — — — 84 Other natural gas revenues 15 — — — — 15 Total natural gas revenues 99 — — — — 99 Other revenues 277 65 110 13 9 — Total revenue from contracts with customers 7,116 2,128 3,093 531 1,010 843 Other revenue sources (a) 1,262 316 796 (21) 170 14 Total operating revenues $ 8,378 $ 2,444 $ 3,889 $ 510 $ 1,180 $ 857 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Nine Months Ended September 30, 2022 Operating revenues Retail electric revenues Residential $ 5,282 $ 2,049 $ 2,995 $ 238 $ — $ — Commercial 4,202 1,285 2,688 229 — — Industrial 2,914 1,143 1,529 242 — — Other 79 10 62 7 — — Total retail electric revenues 12,477 4,487 7,274 716 — — Natural gas distribution revenues Residential 1,821 — — — — 1,821 Commercial 493 — — — — 493 Transportation 872 — — — — 872 Industrial 60 — — — — 60 Other 244 — — — — 244 Total natural gas distribution revenues 3,490 — — — — 3,490 Wholesale electric revenues PPA energy revenues 1,739 354 112 11 1,285 — PPA capacity revenues 443 135 35 4 273 — Non-PPA revenues 182 166 19 511 572 — Total wholesale electric revenues 2,364 655 166 526 2,130 — Other natural gas revenues Gas marketing services 417 — — — — 417 Other natural gas revenues 41 — — — — 41 Total natural gas revenues 458 — — — — 458 Other revenues 810 173 327 34 27 — Total revenue from contracts with customers 19,599 5,315 7,767 1,276 2,157 3,948 Other revenue sources (a) 2,633 708 1,451 3 461 50 Total operating revenues $ 22,232 $ 6,023 $ 9,218 $ 1,279 $ 2,618 $ 3,998 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Three Months Ended September 30, 2021 Operating revenues Retail electric revenues Residential $ 1,974 $ 750 $ 1,138 $ 86 $ — $ — Commercial 1,432 471 882 79 — — Industrial 902 394 428 80 — — Other 24 4 18 2 — — Total retail electric revenues 4,332 1,619 2,466 247 — — Natural gas distribution revenues Residential 218 — — — — 218 Commercial 55 — — — — 55 Transportation 239 — — — — 239 Industrial 6 — — — — 6 Other 31 — — — — 31 Total natural gas distribution revenues 549 — — — — 549 Wholesale electric revenues PPA energy revenues 359 61 41 2 261 — PPA capacity revenues 125 14 14 1 97 — Non-PPA revenues 63 54 3 120 134 — Total wholesale electric revenues 547 129 58 123 492 — Other natural gas revenues Gas marketing services 45 — — — — 45 Other natural gas revenues 11 — — — — 11 Total natural gas revenues 56 — — — — 56 Other revenues 248 53 112 8 9 — Total revenue from contracts with customers 5,732 1,801 2,636 378 501 605 Other revenue sources (a) 506 103 220 — 178 18 Total operating revenues $ 6,238 $ 1,904 $ 2,856 $ 378 $ 679 $ 623 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Nine Months Ended September 30, 2021 Operating revenues Retail electric revenues Residential $ 4,910 $ 1,931 $ 2,765 $ 214 $ — $ — Commercial 3,727 1,229 2,293 205 — — Industrial 2,299 1,048 1,034 217 — — Other 70 13 51 6 — — Total retail electric revenues 11,006 4,221 6,143 642 — — Natural gas distribution revenues Residential 1,143 — — — — 1,143 Commercial 298 — — — — 298 Transportation 775 — — — — 775 Industrial 29 — — — — 29 Other 187 — — — — 187 Total natural gas distribution revenues 2,432 — — — — 2,432 Wholesale electric revenues PPA energy revenues 782 143 71 9 575 — PPA capacity revenues 375 86 41 4 247 — Non-PPA revenues 181 108 14 283 273 — Total wholesale electric revenues 1,338 337 126 296 1,095 — Other natural gas revenues Wholesale gas services 2,168 — — — — 2,168 Gas marketing services 303 — — — — 303 Other natural gas revenues 27 — — — — 27 Total natural gas revenues 2,498 — — — — 2,498 Other revenues 792 150 362 22 18 — Total revenue from contracts with customers 18,066 4,708 6,631 960 1,113 4,930 Other revenue sources (a) 2,979 311 419 28 497 1,763 Other adjustments (b) (3,699) — — — — (3,699) Total operating revenues $ 17,346 $ 5,019 $ 7,050 $ 988 $ 1,610 $ 2,994 (a) Other revenue sources relate to revenues from customers accounted for as derivatives and leases, alternative revenue programs at Southern Company Gas, and cost recovery mechanisms and revenues that meet other scope exceptions for revenues from contracts with customers at the traditional electric operating companies. (b) Other adjustments relate to the cost of Southern Company Gas' energy and risk management activities. Wholesale gas services revenues are presented net of the related costs of those activities on the statement of income. See Note 15 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K and Note (L) under "Southern Company Gas" for information on the sale of Sequent and components of wholesale gas services' operating revenues, respectively.
Schedule of Contract Balances	The following table reflects the closing balances of receivables, contract assets, and contract liabilities related to revenues from contracts with customers at September 30, 2022 and December 31, 2021: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Accounts Receivable At September 30, 2022 $ 2,760 $ 800 $ 1,035 $ 98 $ 264 $ 433 At December 31, 2021 2,504 589 736 73 149 753 Contract Assets At September 30, 2022 $ 178 $ 5 $ 114 $ — $ — $ — At December 31, 2021 117 2 63 — 1 — Contract Liabilities At September 30, 2022 $ 56 $ 5 $ 6 $ 7 $ 2 $ — At December 31, 2021 57 4 14 — 1 —
Schedule of Remaining Performance Obligations	Revenues from contracts with customers related to these performance obligations remaining at September 30, 2022 are expected to be recognized as follows: 2022 (remaining) 2023 2024 2025 2026 Thereafter (in millions) Southern Company $ 243 $ 619 $ 434 $ 322 $ 307 $ 2,340 Alabama Power 8 24 7 5 — — Georgia Power 20 70 34 22 11 21 Southern Power 80 341 344 294 299 2,334 Southern Company Gas 12 29 29 — — —
Schedule of Lease Income	Lease income for the three and nine months ended September 30, 2022 and 2021 is as follows: Southern Alabama Power Georgia Power Mississippi Southern Power Southern Company Gas (in millions) For the Three Months Ended September 30, 2022 Lease income - interest income on sales-type leases $ 7 $ — $ — $ 4 $ 3 $ — Lease income - operating leases 50 19 8 1 21 9 Variable lease income 139 — — — 145 — Total lease income $ 196 $ 19 $ 8 $ 5 $ 169 $ 9 For the Nine Months Ended September 30, 2022 Lease income - interest income on sales-type leases $ 19 $ — $ — $ 11 $ 8 $ — Lease income - operating leases 149 58 24 1 64 27 Variable lease income 355 1 — — 372 — Total lease income $ 523 $ 59 $ 24 $ 12 $ 444 $ 27 For the Three Months Ended September 30, 2021 Lease income - interest income on sales-type leases $ 4 $ — $ — $ 4 $ — $ — Lease income - operating leases 56 21 11 — 21 9 Variable lease income 143 — — — 151 — Total lease income $ 203 $ 21 $ 11 $ 4 $ 172 $ 9 For the Nine Months Ended September 30, 2021 Lease income - interest income on sales-type leases $ 11 $ — $ — $ 10 $ — $ — Lease income - operating leases 168 62 31 1 64 26 Variable lease income 355 — — — 379 — Total lease income $ 534 $ 62 $ 31 $ 11 $ 443 $ 26

Consolidated Entities and Equ_2

Consolidated Entities and Equity Method Investments (Tables)	9 Months Ended
	Sep. 30, 2022
Regulated Operations [Abstract]
Schedule of Equity Method Investments	The carrying amounts of Southern Company Gas' equity method investments at September 30, 2022 and December 31, 2021 and related earnings (loss) from those investments for the three and nine months ended September 30, 2022 and 2021 were as follows: Investment Balance September 30, 2022 December 31, 2021 (in millions) SNG $ 1,091 $ 1,129 Other () 34 44 Total $ 1,125 $ 1,173 () Balance at September 30, 2022 reflects an $11 million distribution received in 2022 from PennEast Pipeline.
Schedule of Earnings (Loss) from Equity Method Investments	Three Months Ended September 30, Nine Months Ended September 30, Earnings (Loss) from Equity Method Investments 2022 2021 2022 2021 (in millions) SNG $ 34 $ 27 $ 104 $ 93 PennEast Pipeline () — (2) — (81) Other — — 1 2 Total $ 34 $ 25 $ 105 $ 14 () Primarily reflects pre-tax impairment charges. See Note 7 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K for additional information.

Financing and Leases (Tables)

Financing and Leases (Tables)	9 Months Ended
Financing and Leases (Tables)	Sep. 30, 2022
Debt Disclosure [Abstract]
Schedule of Credit Arrangements	At September 30, 2022, committed credit arrangements with banks were as follows: Expires Company 2023 2024 2025 2026 Total Unused Expires within (in millions) Southern Company parent $ — $ — $ — $ 2,000 $ 2,000 $ 1,998 $ — Alabama Power — 550 — 700 1,250 1,250 — Georgia Power — — — 1,750 1,750 1,726 — Mississippi Power — 150 125 — 275 275 — Southern Power (a) — — — 600 600 569 — Southern Company Gas (b) 250 — — 1,500 1,750 1,748 250 SEGCO 30 — — — 30 30 30 Southern Company $ 280 $ 700 $ 125 $ 6,550 $ 7,655 $ 7,596 $ 280 (a) Does not include Southern Power Company's two $75 million continuing letter of credit facilities for standby letters of credit, expiring in 2023 and 2025, respectively, of which $11 million and $5 million, respectively, was unused at September 30, 2022. Southern Power's subsidiaries are not parties to its bank credit arrangements or letter of credit facilities. (b) Southern Company Gas, as the parent entity, guarantees the obligations of Southern Company Gas Capital, which is the borrower of $800 million of the credit arrangement expiring in 2026. Southern Company Gas' committed credit arrangement expiring in 2026 also includes $700 million for which Nicor Gas is the borrower and which is restricted for working capital needs of Nicor Gas. Pursuant to the multi-year credit arrangement expiring in 2026, the allocations between Southern Company Gas Capital and Nicor Gas may be adjusted. Nicor Gas is also the borrower of a new $250 million credit arrangement expiring in 2023.
Schedule of Shares Used to Compute Diluted Earnings Per Share	Shares used to compute diluted earnings per share were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2022 2021 2022 2021 (in millions) As reported shares 1,082 1,061 1,070 1,060 Effect of stock-based compensation 6 7 6 7 Diluted shares 1,088 1,068 1,076 1,067

Retirement Benefits (Tables)

Retirement Benefits (Tables)	9 Months Ended
Retirement Benefits (Tables)	Sep. 30, 2022
Retirement Benefits [Abstract]
Schedule of Pension Plans and Postretirement Plans	Components of the net periodic benefit costs for the three and nine months ended September 30, 2022 and 2021 are presented in the following tables. Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) Three Months Ended September 30, 2022 Pension Plans Service cost $ 103 $ 25 $ 26 $ 5 $ 2 $ 9 Interest cost 102 24 31 5 2 7 Expected return on plan assets (316) (77) (99) (15) (4) (22) Amortization: Prior service costs — — — — — (1) Regulatory asset — — — — — 3 Net loss 60 16 18 2 1 2 Net periodic pension cost (income) $ (51) $ (12) $ (24) $ (3) $ 1 $ (2) Postretirement Benefits Service cost $ 6 $ 2 $ 2 $ 1 $ 1 $ — Interest cost 10 3 4 — — 1 Expected return on plan assets (20) (9) (8) — — (2) Amortization: Prior service costs (1) — — — — — Regulatory asset — — — — — 2 Net (gain)/loss 1 — — — — (1) Net periodic postretirement benefit cost (income) $ (4) $ (4) $ (2) $ 1 $ 1 $ — Nine Months Ended September 30, 2022 Pension Plans Service cost $ 309 $ 74 $ 78 $ 13 $ 7 $ 26 Interest cost 306 72 92 14 5 21 Expected return on plan assets (949) (229) (298) (44) (12) (68) Amortization: Prior service costs — — 1 — — (2) Regulatory asset — — — — — 11 Net loss 180 47 55 9 2 5 Net periodic pension cost (income) $ (154) $ (36) $ (72) $ (8) $ 2 $ (7) Postretirement Benefits Service cost $ 17 $ 5 $ 5 $ 1 $ 1 $ 1 Interest cost 31 8 11 1 — 4 Expected return on plan assets (60) (25) (21) (1) — (6) Amortization: Prior service costs (1) — — — — — Regulatory asset — — — — — 5 Net (gain)/loss 1 — 1 — — (2) Net periodic postretirement benefit cost (income) $ (12) $ (12) $ (4) $ 1 $ 1 $ 2 Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) Three Months Ended September 30, 2021 Pension Plans Service cost $ 109 $ 26 $ 28 $ 4 $ 2 $ 10 Interest cost 87 20 26 4 2 6 Expected return on plan assets (298) (72) (94) (14) (4) (21) Amortization: Prior service costs — — — — — (1) Regulatory asset — — — — — 3 Net loss 78 21 25 4 1 3 Net periodic pension cost (income) $ (24) $ (5) $ (15) $ (2) $ 1 $ — Postretirement Benefits Service cost $ 6 $ 2 $ 2 $ 1 $ 1 $ — Interest cost 9 2 3 — — 1 Expected return on plan assets (19) (8) (7) (1) — (2) Amortization: Regulatory asset — — — — — 2 Net (gain)/loss 1 — 1 — — (1) Net periodic postretirement benefit cost (income) $ (3) $ (4) $ (1) $ — $ 1 $ — Nine Months Ended September 30, 2021 Pension Plans Service cost $ 326 $ 77 $ 84 $ 13 $ 7 $ 28 Interest cost 260 61 78 12 4 18 Expected return on plan assets (893) (215) (282) (41) (11) (64) Amortization: Prior service costs — — 1 — — (2) Regulatory asset — — — — — 11 Net loss 235 62 75 11 3 9 Net periodic pension cost (income) $ (72) $ (15) $ (44) $ (5) $ 3 $ — Postretirement Benefits Service cost $ 18 $ 5 $ 5 $ 1 $ 1 $ 1 Interest cost 26 6 9 1 — 3 Expected return on plan assets (57) (22) (20) (2) — (6) Amortization: Prior service costs (1) — — — — — Regulatory asset — — — — — 5 Net (gain)/loss 3 — 2 — — (2) Net periodic postretirement benefit cost (income) $ (11) $ (11) $ (4) $ — $ 1 $ 1

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
Fair Value Measurements (Tables)	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Schedule of Assets and Liabilities Measured at Fair Value	At September 30, 2022, assets and liabilities measured at fair value on a recurring basis during the period, together with their associated level of the fair value hierarchy, were as follows: Fair Value Measurements Using: At September 30, 2022 Quoted Prices Significant Significant Net Asset Value as a Practical Expedient (NAV) Total (in millions) Southern Company Assets: Energy-related derivatives (a) $ 49 $ 454 $ — $ — $ 503 Investments in trusts: (b)(c) Domestic equity 610 161 — — 771 Foreign equity 111 129 — — 240 U.S. Treasury and government agency securities — 265 — — 265 Municipal bonds — 52 — — 52 Pooled funds – fixed income — 7 — — 7 Corporate bonds — 438 — — 438 Mortgage and asset backed securities — 87 — — 87 Private equity — — — 156 156 Cash and cash equivalents 4 — — — 4 Other 17 13 — — 30 Cash equivalents 1,402 18 — — 1,420 Other investments 9 26 — — 35 Total $ 2,202 $ 1,650 $ — $ 156 $ 4,008 Liabilities: Energy-related derivatives (a) $ 20 $ 141 $ — $ — $ 161 Interest rate derivatives — 311 — — 311 Foreign currency derivatives — 323 — — 323 Contingent consideration — — 14 — 14 Other — 13 — — 13 Total $ 20 $ 788 $ 14 $ — $ 822 Fair Value Measurements Using: At September 30, 2022 Quoted Prices Significant Significant Net Asset Value as a Practical Expedient (NAV) Total (in millions) Alabama Power Assets: Energy-related derivatives $ — $ 147 $ — $ — $ 147 Nuclear decommissioning trusts: (b) Domestic equity 370 152 — — 522 Foreign equity 111 — — — 111 U.S. Treasury and government agency securities — 15 — — 15 Municipal bonds — 2 — — 2 Corporate bonds — 230 — — 230 Mortgage and asset backed securities — 20 — — 20 Private equity — — — 156 156 Other 10 — — — 10 Cash equivalents 1,225 18 — — 1,243 Other investments — 26 — — 26 Total $ 1,716 $ 610 $ — $ 156 $ 2,482 Liabilities: Energy-related derivatives $ — $ 35 $ — $ — $ 35 Georgia Power Assets: Energy-related derivatives $ — $ 145 $ — $ — $ 145 Nuclear decommissioning trusts: (b)(c) Domestic equity 240 1 — — 241 Foreign equity — 128 — — 128 U.S. Treasury and government agency securities — 250 — — 250 Municipal bonds — 50 — — 50 Corporate bonds — 208 — — 208 Mortgage and asset backed securities — 67 — — 67 Other 7 13 — — 20 Total $ 247 $ 862 $ — $ — $ 1,109 Liabilities: Energy-related derivatives $ — $ 51 $ — $ — $ 51 Fair Value Measurements Using: At September 30, 2022 Quoted Prices Significant Significant Net Asset Value as a Practical Expedient (NAV) Total (in millions) Mississippi Power Assets: Energy-related derivatives $ — $ 133 $ — $ — $ 133 Cash equivalents 30 — — — 30 Total $ 30 $ 133 $ — $ — $ 163 Liabilities: Energy-related derivatives $ — $ 24 $ — $ — $ 24 Southern Power Assets: Energy-related derivatives $ — $ 7 $ — $ — $ 7 Liabilities: Energy-related derivatives $ — $ 13 $ — $ — $ 13 Foreign currency derivatives — 80 — — 80 Contingent consideration — — 14 — 14 Other — 13 — — 13 Total $ — $ 106 $ 14 $ — $ 120 Southern Company Gas Assets: Energy-related derivatives (a) $ 49 $ 22 $ — $ — $ 71 Non-qualified deferred compensation trusts: Domestic equity — 8 — — 8 Foreign equity — 1 — — 1 Pooled funds – fixed income — 7 — — 7 Cash equivalents 4 — — — 4 Total $ 53 $ 38 $ — $ — $ 91 Liabilities: Energy-related derivatives (a) $ 20 $ 17 $ — $ — $ 37 Interest rate derivatives — 87 — — 87 Total $ 20 $ 104 $ — $ — $ 124 (a) Excludes cash collateral of $15 million. (b) Excludes receivables related to investment income, pending investment sales, payables related to pending investment purchases, and currencies. See Note 6 to the financial statements in Item 8 of the Form 10-K for additional information. (c) Includes investment securities pledged to creditors and collateral received and excludes payables related to the securities lending program. At September 30, 2022, approximately $46 million of the fair market value of Georgia Power's nuclear decommissioning trust funds' securities were on loan to creditors under the funds' managers' securities lending program. See Note 6 to the financial statements in Item 8 of the Form 10-K for additional information.
Schedule of Increase (Decrease) In Fair Value Of Funds	The fair value of the funds, including reinvested interest and dividends and excluding the funds' expenses, increased (decreased) by the amounts shown in the table below for the three and nine months ended September 30, 2022 and 2021. The changes were recorded as a change to the regulatory assets and liabilities related to AROs for Georgia Power and Alabama Power, respectively. Fair value increases (decreases) Three Months Ended September 30, 2022 Three Months Ended September 30, 2021 Nine Months Ended September 30, 2022 Nine Months Ended September 30, 2021 (in millions) Southern Company $ (106) $ 9 $ (486) $ 173 Alabama Power (53) 15 (245) 133 Georgia Power (53) (6) (241) 40
Schedule of Financial Instruments for which Carrying Amount Did Not Equal Fair Value	At September 30, 2022, other financial instruments for which the carrying amount did not equal fair value were as follows: Southern Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas () (in billions) Long-term debt, including securities due within one year: Carrying amount $ 53.4 $ 10.8 $ 14.5 $ 1.5 $ 2.9 $ 7.4 Fair value 46.4 9.3 12.6 1.2 2.7 6.3 () The long-term debt of Southern Company Gas is recorded at amortized cost, including the fair value adjustments at the effective date of the 2016 merger with Southern Company. Southern Company Gas amortizes the fair value adjustments over the remaining lives of the respective bonds, the latest being through 2043.

Derivatives (Tables)

Derivatives (Tables)	9 Months Ended
Derivatives (Tables)	Sep. 30, 2022
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Energy-Related Derivatives	At September 30, 2022, the net volume of energy-related derivative contracts for natural gas positions, together with the longest hedge date over which the respective entity is hedging its exposure to the variability in future cash flows for forecasted transactions and the longest non-hedge date for derivatives not designated as hedges, were as follows: Net Longest Longest (in millions) Southern Company () 399 2030 2025 Alabama Power 105 2026 — Georgia Power 116 2025 — Mississippi Power 82 2027 — Southern Power 11 2030 2023 Southern Company Gas () 85 2025 2025 (*) Southern Company Gas' derivative instruments include both long and short natural gas positions. A long position is a contract to purchase natural gas and a short position is a contract to sell natural gas. Southern Company Gas' volume represents the net of long natural gas positions of 95.7 million mmBtu and short natural gas positions of 10.6 million mmBtu at September 30, 2022, which is also included in Southern Company's total volume.
Schedule of Interest Rate Derivatives	At September 30, 2022, the following interest rate derivatives were outstanding: Notional Interest Weighted Hedge Fair Value Gain (Loss) at September 30, 2022 (in millions) (in millions) Cash Flow Hedges of Existing Debt Southern Company parent $ 175 — 4.25% September 2025 $ — Southern Company parent 175 — 3.83% August 2032 — Fair Value Hedges of Existing Debt Southern Company parent 400 1.75% 1-month LIBOR + 0.68% March 2028 (57) Southern Company parent 1,000 3.70% 1-month LIBOR + 2.36% April (167) Southern Company Gas 500 1.75% 1-month LIBOR + 0.38% January 2031 (87) Southern Company $ 2,250 $ (311)
Schedule of Foreign Currency Derivatives	At September 30, 2022, the following foreign currency derivatives were outstanding: Pay Notional Pay Receive Notional Receive Hedge Fair Value Gain (Loss) at September 30, 2022 (in millions) (in millions) (in millions) Cash Flow Hedges of Existing Debt Southern Power $ 564 3.78% € 500 1.85% June 2026 $ (80) Fair Value Hedges of Existing Debt Southern Company parent 1,476 3.39% 1,250 1.88% September 2027 (243) Southern Company $ 2,040 € 1,750 $ (323)
Schedule of Derivative Category and Balance Sheet Location	The fair value of energy-related derivatives, interest rate derivatives, and foreign currency derivatives was reflected in the balance sheets as follows: At September 30, 2022 At December 31, 2021 Derivative Category and Balance Sheet Location Assets Liabilities Assets Liabilities (in millions) (in millions) Southern Company Energy-related derivatives designated as hedging instruments for regulatory purposes Assets from risk management activities/Other current liabilities $ 299 $ 70 $ 129 $ 30 Other deferred charges and assets/Other deferred credits and liabilities 150 59 72 6 Total derivatives designated as hedging instruments for regulatory purposes 449 129 201 36 Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Assets from risk management activities/Other current liabilities 27 13 7 5 Other deferred charges and assets/Other deferred credits and liabilities 7 1 1 — Interest rate derivatives: Assets from risk management activities/Other current liabilities — 44 19 — Other deferred charges and assets/Other deferred credits and liabilities — 266 — 29 Foreign currency derivatives: Assets from risk management activities/Other current liabilities — 37 — 39 Other deferred charges and assets/Other deferred credits and liabilities — 285 — 40 Total derivatives designated as hedging instruments in cash flow and fair value hedges 34 646 27 113 Energy-related derivatives not designated as hedging instruments Assets from risk management activities/Other current liabilities 19 18 9 4 Other deferred charges and assets/Other deferred credits and liabilities 2 1 1 — Total derivatives not designated as hedging instruments 21 19 10 4 Gross amounts recognized 504 794 238 153 Gross amounts offset (a) (113) (128) (25) (28) Net amounts recognized in the Balance Sheets (b) $ 391 $ 666 $ 213 $ 125 At September 30, 2022 At December 31, 2021 Derivative Category and Balance Sheet Location Assets Liabilities Assets Liabilities (in millions) (in millions) Alabama Power Energy-related derivatives designated as hedging instruments for regulatory purposes Other current assets/Other current liabilities $ 90 $ 12 $ 30 $ 9 Other deferred charges and assets/Other deferred credits and liabilities 57 23 25 2 Total derivatives designated as hedging instruments for regulatory purposes 147 35 55 11 Gross amounts offset (31) (31) (5) (5) Net amounts recognized in the Balance Sheets $ 116 $ 4 $ 50 $ 6 Georgia Power Energy-related derivatives designated as hedging instruments for regulatory purposes Assets from risk management activities/Other current liabilities $ 107 $ 28 $ 54 $ 6 Other deferred charges and assets/Other deferred credits and liabilities 38 23 21 2 Total derivatives designated as hedging instruments for regulatory purposes 145 51 75 8 Energy-related derivatives not designated as hedging instruments Other current assets/Other current liabilities 1 — — — Gross amounts recognized 146 51 75 8 Gross amounts offset (41) (41) (8) (8) Net amounts recognized in the Balance Sheets $ 105 $ 10 $ 67 $ — Mississippi Power Energy-related derivatives designated as hedging instruments for regulatory purposes Assets from risk management activities/Other current liabilities $ 78 $ 12 $ 30 $ 3 Other deferred charges and assets/Other deferred credits and liabilities 55 12 26 2 Total derivatives designated as hedging instruments for regulatory purposes 133 24 56 5 Gross amounts offset (20) (20) (4) (4) Net amounts recognized in the Balance Sheets $ 113 $ 4 $ 52 $ 1 At September 30, 2022 At December 31, 2021 Derivative Category and Balance Sheet Location Assets Liabilities Assets Liabilities (in millions) (in millions) Southern Power Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Other current assets/Other current liabilities $ — $ 10 $ 2 $ — Other deferred charges and assets/Other deferred credits and liabilities 5 1 1 — Foreign currency derivatives: Other current assets/Other current liabilities — 12 — 16 Other deferred charges and assets/Other deferred credits and liabilities — 68 — — Total derivatives designated as hedging instruments in cash flow and fair value hedges 5 91 3 16 Energy-related derivatives not designated as hedging instruments Other current assets/Other current liabilities 2 2 1 — Gross amounts recognized 7 93 4 16 Gross amounts offset (3) (3) — — Net amounts recognized in the Balance Sheets $ 4 $ 90 $ 4 $ 16 Southern Company Gas Energy-related derivatives designated as hedging instruments for regulatory purposes Other current assets/Other current liabilities $ 24 $ 17 $ 15 $ 12 Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Other current assets/Other current liabilities 26 3 5 5 Other deferred charges and assets/Other deferred credits and liabilities 3 — — — Interest rate derivatives: Other current assets/Other current liabilities — 13 6 — Other deferred charges and assets/Other deferred credits and liabilities — 74 — 6 Total derivatives designated as hedging instruments in cash flow and fair value hedges 29 90 11 11 Energy-related derivatives not designated as hedging instruments Other current assets/Other current liabilities 16 16 8 4 Other deferred charges and assets/Other deferred credits and liabilities 2 1 1 — Total derivatives not designated as hedging instruments 18 17 9 4 Gross amounts recognized 71 124 35 27 Gross amounts offset (a) (18) (33) (8) (11) Net amounts recognized in the Balance Sheets (b) $ 53 $ 91 $ 27 $ 16 (a) Gross amounts offset includes cash collateral held on deposit in broker margin accounts of $15 million and $3 million at September 30, 2022 and December 31, 2021, respectively. (b) Net amounts of derivative instruments outstanding exclude immaterial premium and intrinsic value associated with weather derivatives for all periods presented.
Schedule of Pre-tax Effects of Unrealized Derivative Gains (Losses)	At September 30, 2022 and December 31, 2021, the pre-tax effects of unrealized derivative gains (losses) arising from energy-related derivative instruments designated as regulatory hedging instruments and deferred were as follows: Regulatory Hedge Unrealized Gain (Loss) Recognized in the Balance Sheet Derivative Category and Balance Sheet Southern Alabama Georgia Mississippi Southern Company Gas (in millions) At September 30, 2022: Energy-related derivatives: Other regulatory assets, current $ (17) $ (2) $ (8) $ (3) $ (4) Other regulatory assets, deferred (6) (2) (3) (1) — Other regulatory liabilities, current 246 80 87 69 10 Other regulatory liabilities, deferred 98 36 18 44 — Total energy-related derivative gains (losses) $ 321 $ 112 $ 94 $ 109 $ 6 At December 31, 2021: Energy-related derivatives: Other regulatory assets, current $ (17) $ (6) $ — $ — $ (11) Other regulatory liabilities, current 107 28 48 27 4 Other regulatory liabilities, deferred 65 22 19 24 — Total energy-related derivative gains (losses) $ 155 $ 44 $ 67 $ 51 $ (7)
Schedule of Pre-Tax Effects of Hedging on AOCI	For the three and nine months ended September 30, 2022 and 2021, the pre-tax effects of cash flow and fair value hedge accounting on accumulated OCI were as follows: Gain (Loss) Recognized in OCI on Derivative For the Three Months Ended September 30, For the Nine Months Ended September 30, 2022 2021 2022 2021 (in millions) (in millions) Southern Company Cash flow hedges: Energy-related derivatives $ 11 $ 38 $ 51 $ 59 Interest rate derivatives 6 5 36 7 Foreign currency derivatives (35) (36) (137) (79) Fair value hedges () : Foreign currency derivatives 20 (4) 18 (4) Total $ 2 $ 3 $ (32) $ (17) Georgia Power Interest rate derivatives $ — $ — $ 31 $ — Southern Power Cash flow hedges: Energy-related derivatives $ (11) $ 8 $ (4) $ 16 Foreign currency derivatives (35) (36) (137) (79) Total $ (46) $ (28) $ (141) $ (63) Southern Company Gas Cash flow hedges: Energy-related derivatives $ 22 $ 30 $ 55 $ 43 Interest rate derivatives 5 — — — Total $ 27 $ 30 $ 55 $ 43 () Represents amounts excluded from the assessment of effectiveness for which the difference between changes in fair value and periodic amortization is recorded in OCI. For the three and nine months ended September 30, 2022 and 2021, the pre-tax effects of interest rate derivatives designated as cash flow hedging instruments on accumulated OCI were immaterial for the other Registrants.
Schedule of Pre-Tax Effects of Cash Flow and Fair Value Hedging on Income	For the three and nine months ended September 30, 2022 and 2021, the pre-tax effects of cash flow and fair value hedge accounting on income were as follows: Location and Amount of Gain (Loss) Recognized in Income on Cash Flow and Fair Value Hedging Relationships For the Three Months Ended September 30, For the Nine Months Ended September 30, 2022 2021 2022 2021 (in millions) (in millions) Southern Company Total cost of natural gas $ 294 $ 129 $ 1,840 $ 943 Gain (loss) on energy-related cash flow hedges (a) 9 2 28 — Total depreciation and amortization 922 896 2,728 2,658 Gain (loss) on energy-related cash flow hedges (a) (1) 3 5 6 Total interest expense, net of amounts capitalized (511) (451) (1,461) (1,352) Gain (loss) on interest rate cash flow hedges (a) (7) (7) (19) (20) Gain (loss) on foreign currency cash flow hedges (a) (3) (6) (16) (18) Gain (loss) on interest rate fair value hedges (b) (102) (4) (300) (16) Total other income (expense), net 132 131 414 290 Gain (loss) on foreign currency cash flow hedges (a)(c) (32) (34) (129) (76) Gain (loss) on foreign currency fair value hedges (59) (32) (180) (32) Amount excluded from effectiveness testing recognized in earnings (21) 4 (17) 4 Southern Power Total depreciation and amortization $ 133 $ 132 $ 384 $ 383 Gain (loss) on energy-related cash flow hedges (a) (1) 3 5 6 Total interest expense, net of amounts capitalized (32) (36) (105) (111) Gain (loss) on foreign currency cash flow hedges (a) (3) (6) (16) (18) Total other income (expense), net 3 2 5 10 Gain (loss) on foreign currency cash flow hedges (a)(c) (32) (34) (129) (76) Southern Company Gas Total cost of natural gas $ 294 $ 129 $ 1,840 $ 943 Gain (loss) on energy-related cash flow hedges (a) 9 2 28 — Total interest expense, net of amounts capitalized (65) (57) (187) (175) Gain (loss) on interest rate cash flow hedges (a) (2) (1) (3) (2) Gain (loss) on interest rate fair value hedges (b) (30) — (87) 2 (a) Reclassified from accumulated OCI into earnings. (b) For fair value hedges, changes in the fair value of the derivative contracts are generally equal to changes in the fair value of the underlying debt and have no material impact on income. (c) The reclassification from accumulated OCI into other income (expense), net completely offsets currency gains and losses arising from changes in the U.S. currency exchange rates used to record the euro-denominated notes.
Schedule of Cumulative Basis Adjustments for Fair Value Hedges	At September 30, 2022 and December 31, 2021, the following amounts were recorded on the balance sheets related to cumulative basis adjustments for fair value hedges: Carrying Amount of the Hedged Item Cumulative Amount of Fair Value Hedging Adjustment included in Carrying Amount of the Hedged Item Balance Sheet Location of Hedged Items At September 30, 2022 At December 31, 2021 At September 30, 2022 At December 31, 2021 (in millions) (in millions) Southern Company Long-term debt $ (2,788) $ (3,280) $ 306 $ 9 Southern Company Gas Long-term debt $ (411) $ (493) $ 86 $ 2
Schedule of Pre-tax Effect of Interest Rate and Energy Related Derivatives on Income	For the three and nine months ended September 30, 2022 and 2021, the pre-tax effects of energy-related derivatives not designated as hedging instruments on the statements of income of Southern Company and Southern Company Gas were as follows: Gain (Loss) Three Months Ended September 30, Nine Months Ended September 30, Derivatives in Non-Designated Hedging Relationships Statements of Income Location 2022 2021 2022 2021 (in millions) (in millions) Energy-related derivatives: Natural gas revenues () $ 3 $ (2) $ (10) $ (122) Cost of natural gas (2) 20 (7) 36 Total derivatives in non-designated hedging relationships $ 1 $ 18 $ (17) $ (86) () Excludes immaterial gains (losses) recorded in natural gas revenues associated with weather derivatives for all periods presented.

Acquisitions and Dispositions (

Acquisitions and Dispositions (Tables)	9 Months Ended
Acquisitions and Dispositions (Tables)	Sep. 30, 2022
Business Combination and Asset Acquisition [Abstract]
Schedule of Construction Projects	Project Facility Resource Approximate Nameplate Capacity ( MW ) Location COD PPA Contract Period Projects Completed During the Nine Months Ended September 30, 2022 Garland Solar Storage (a) Battery energy storage system 88 Kern County, CA September 2021 through February 2022 (b) 20 years Tranquillity Solar Storage (a) Battery energy storage system 72 Fresno County, CA November 2021 through March 2022 (c) 20 years (a) Southern Power consolidates each project's operating results in its financial statements and the tax equity partner and two other partners each own a noncontrolling interest. (b) The facility has a total capacity of 88 MWs, of which 73 MWs were placed in service in 2021 and 15 MWs were placed in service in February 2022. (c) The facility has a total capacity of 72 MWs, of which 32 MWs were placed in service in 2021 and 40 MWs were placed in service in March 2022.

Segment and Related Informati_2

Segment and Related Information (Tables)	9 Months Ended
Segment and Related Information (Tables)	Sep. 30, 2022
Segment Reporting [Abstract]
Schedule of Financial Data for Business Segments	Financial data for business segments and products and services for the three and nine months ended September 30, 2022 and 2021 was as follows: Electric Utilities Traditional Southern Eliminations Total Southern Company Gas All Eliminations Consolidated (in millions) Three Months Ended September 30, 2022 Operating revenues $ 6,938 $ 1,180 $ (691) $ 7,427 $ 857 $ 135 $ (41) $ 8,378 Segment net income (loss) (a)(b) 1,445 95 — 1,540 83 (152) 1 1,472 Nine Months Ended September 30, 2022 Operating revenues $ 16,716 $ 2,618 $ (1,391) $ 17,943 $ 3,998 $ 418 $ (127) $ 22,232 Segment net income (loss) (a)(b) 3,256 265 — 3,521 516 (415) (11) 3,611 At September 30, 2022 Goodwill $ — $ 2 $ — $ 2 $ 5,015 $ 263 $ — $ 5,280 Total assets 95,659 13,283 (748) 108,194 24,097 2,372 (658) 134,005 Three Months Ended September 30, 2021 Operating revenues $ 5,018 $ 679 $ (170) $ 5,527 $ 623 $ 124 $ (36) $ 6,238 Segment net income (loss) (a)(b)(c) 1,085 78 — 1,163 56 (121) 3 1,101 Nine Months Ended September 30, 2021 Operating revenues $ 12,813 $ 1,610 $ (372) $ 14,051 $ 2,994 $ 412 $ (111) $ 17,346 Segment net income (loss) (a)(b)(c)(d)(e) 2,352 211 — 2,563 389 (338) (6) 2,608 At December 31, 2021 Goodwill $ — $ 2 $ — $ 2 $ 5,015 $ 263 $ — $ 5,280 Total assets 89,051 13,390 (667) 101,774 23,560 2,975 (775) 127,534 (a) Attributable to Southern Company. (b) For the traditional electric operating companies, includes pre-tax charges (credits) to income at Georgia Power for the estimated probable loss associated with the construction of Plant Vogtle Units 3 and 4 of $(70) million ($(52) million after tax) and $(18) million ($(13) million after tax) for the three and nine months ended September 30, 2022, respectively, and $264 million ($197 million after tax) and $772 million ($576 million after tax) for the three and nine months ended September 30, 2021, respectively. See Note (B) and Note 2 to the financial statements in Item 8 of the Form 10-K under "Georgia Power – Nuclear Construction" for additional information. (c) For Southern Company Gas, includes a pre-tax gain of $121 million ($93 million after tax) related to its sale of Sequent, as well as the resulting $85 million of additional tax expense as a result of the sale. See Note 15 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K for additional information. (d) For Southern Power, includes gains on wind turbine equipment contributed to various equity method investments totaling approximately $37 million pre-tax ($28 million after tax). See Note 15 to the financial statements under "Southern Power – Development Projects" in Item 8 of the Form 10-K for additional information. (e) For Southern Company Gas, includes pre-tax impairment charges totaling $84 million ($67 million after tax) related to its equity method investment in the PennEast Pipeline project. See Note 7 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K for additional information. Business segment financial data for the three and nine months ended September 30, 2022 and 2021 was as follows: Gas Distribution Operations Gas Pipeline Investments Wholesale Gas Services (a) Gas Marketing Services Total All Other Eliminations Consolidated (in millions) Three Months Ended September 30, 2022 Operating revenues $ 751 $ 8 $ — $ 85 $ 844 $ 16 $ (3) $ 857 Segment net income (loss) 59 24 — (2) 81 2 — 83 Nine Months Ended September 30, 2022 Operating revenues $ 3,533 $ 24 $ — $ 420 $ 3,977 $ 43 $ (22) $ 3,998 Segment net income (loss) 365 76 — 65 506 10 — 516 Total assets at September 30, 2022 21,605 1,425 — 1,595 24,625 9,100 (9,628) 24,097 Three Months Ended September 30, 2021 Operating revenues $ 556 $ 8 $ — $ 52 $ 616 $ 11 $ (4) $ 623 Segment net income (loss) (b)(c) 45 10 94 (2) 147 (91) — 56 Nine Months Ended September 30, 2021 Operating revenues $ 2,466 $ 24 $ 188 $ 311 $ 2,989 $ 29 $ (24) $ 2,994 Segment net income (loss) (b)(c)(d) 308 3 108 60 479 (90) — 389 Total assets at December 31, 2021 20,917 1,467 31 1,556 23,971 12,114 (12,525) 23,560 (a) As a result of the sale of Sequent, wholesale gas services is no longer a reportable segment for the three and nine months ended September 30, 2022. Prior to the sale of Sequent, the revenues for wholesale gas services were netted with costs associated with its energy and risk management activities. A reconciliation of operating revenues and intercompany revenues is shown in the following table. Third Party Gross Revenues Intercompany Revenues Total Gross Revenues Less Gross Gas Costs Operating Revenues (in millions) Nine Months Ended September 30, 2021 $ 3,881 $ 90 $ 3,971 $ 3,783 $ 188 (b) For wholesale gas services, includes a pre-tax gain of $121 million ($93 million after tax) related to the sale of Sequent. See Note 15 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K for additional information. (c) For the "All Other" column, includes $85 million of additional tax expense as a result of the sale. See Note 15 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K for additional information. (d) For gas pipeline investments, includes pre-tax impairment charges totaling $84 million ($67 million after tax) related to the equity method investment in the PennEast Pipeline project. See Note 7 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K for additional information.
Schedule of Financial Data for Products and Services	Electric Utilities' Revenues Retail Wholesale Other Total (in millions) Three Months Ended September 30, 2022 $ 5,961 $ 1,197 $ 269 $ 7,427 Three Months Ended September 30, 2021 4,551 731 245 5,527 Nine Months Ended September 30, 2022 $ 14,363 $ 2,798 $ 782 $ 17,943 Nine Months Ended September 30, 2021 11,492 1,822 737 14,051 Southern Company Gas' Revenues Gas Wholesale Gas Services () Gas Other Total (in millions) Three Months Ended September 30, 2022 $ 748 $ — $ 85 $ 24 $ 857 Three Months Ended September 30, 2021 553 — 52 18 623 Nine Months Ended September 30, 2022 $ 3,513 $ — $ 420 $ 65 $ 3,998 Nine Months Ended September 30, 2021 2,451 188 311 44 2,994 () Prior to the sale of Sequent, the revenues for wholesale gas services were netted with costs associated with its energy and risk management activities. See "Southern Company Gas" herein and Note 15 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K for additional information.

Introduction - Schedule of Good

Introduction - Schedule of Goodwill (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Goodwill [Line Items]
Goodwill	$ 5,280	$ 5,280
SOUTHERN Co GAS
Goodwill [Line Items]
Goodwill	5,015	5,015
SOUTHERN Co GAS \| Gas distribution operations
Goodwill [Line Items]
Goodwill	4,034	4,034
SOUTHERN Co GAS \| Gas marketing services
Goodwill [Line Items]
Goodwill	$ 981	$ 981

Introduction - Schedule of Othe

Introduction - Schedule of Other Intangible Assets (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Other intangible assets subject to amortization:
Gross Carrying Amount	$ 671	$ 677
Accumulated Amortization	(331)	(307)
Other Intangible Assets, Net	340	370
Other intangible assets not subject to amortization:
Federal Communications Commission licenses	75	75
Total other intangible assets
Gross Carrying Amount	746	752
Accumulated Amortization	(331)	(307)
Other Intangible Assets, Net	415	445
Customer relationships
Other intangible assets subject to amortization:
Gross Carrying Amount	212	212
Accumulated Amortization	(159)	(150)
Other Intangible Assets, Net	53	62
Total other intangible assets
Accumulated Amortization	(159)	(150)
Trade names
Other intangible assets subject to amortization:
Gross Carrying Amount	64	64
Accumulated Amortization	(44)	(38)
Other Intangible Assets, Net	20	26
Total other intangible assets
Accumulated Amortization	(44)	(38)
PPA fair value adjustments
Other intangible assets subject to amortization:
Gross Carrying Amount	390	390
Accumulated Amortization	(124)	(109)
Other Intangible Assets, Net	266	281
Total other intangible assets
Accumulated Amortization	(124)	(109)
Other
Other intangible assets subject to amortization:
Gross Carrying Amount	5	11
Accumulated Amortization	(4)	(10)
Other Intangible Assets, Net	1	1
Total other intangible assets
Accumulated Amortization	(4)	(10)
SOUTHERN POWER CO
Other intangible assets subject to amortization:
Accumulated Amortization	(124)	(109)
Total other intangible assets
Accumulated Amortization	(124)	(109)
SOUTHERN POWER CO \| PPA fair value adjustments
Other intangible assets subject to amortization:
Gross Carrying Amount	390	390
Accumulated Amortization	(124)	(109)
Other Intangible Assets, Net	266	281
Total other intangible assets
Accumulated Amortization	(124)	(109)
SOUTHERN Co GAS
Other intangible assets subject to amortization:
Gross Carrying Amount	182	182
Accumulated Amortization	(154)	(145)
Other Intangible Assets, Net	28	37
Total other intangible assets
Accumulated Amortization	(154)	(145)
Other Intangible Assets, Net	28	37
SOUTHERN Co GAS \| Customer relationships
Other intangible assets subject to amortization:
Gross Carrying Amount	156	156
Accumulated Amortization	(137)	(130)
Other Intangible Assets, Net	19	26
Total other intangible assets
Accumulated Amortization	(137)	(130)
SOUTHERN Co GAS \| Trade names
Other intangible assets subject to amortization:
Gross Carrying Amount	26	26
Accumulated Amortization	(17)	(15)
Other Intangible Assets, Net	9	11
Total other intangible assets
Accumulated Amortization	$ (17)	$ (15)

Introduction - Schedule of Amor

Introduction - Schedule of Amortization of Other Intangible Assets (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2022
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 11	$ 30
Decrease in operating revenues	5	15
SOUTHERN POWER CO
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	5	15
SOUTHERN Co GAS
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 4	$ 9

Introduction - Schedule of Cash

Introduction - Schedule of Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021	Sep. 30, 2021	Dec. 31, 2020
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	$ 2,009	$ 1,798
Restricted cash:
Total cash, cash equivalents, and restricted cash	2,013	1,829	$ 2,101	$ 1,068
Other current assets
Restricted cash:
Restricted cash	2	2
Other deferred charges and assets
Restricted cash:
Restricted cash	3	29
SOUTHERN POWER CO
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	229	107
Restricted cash:
Total cash, cash equivalents, and restricted cash	231	135	213	183
SOUTHERN POWER CO \| Other current assets
Restricted cash:
Restricted cash	0	0
SOUTHERN POWER CO \| Other deferred charges and assets
Restricted cash:
Restricted cash	3	29
SOUTHERN POWER CO \| Tax Equity Contributions \| Garland
Restricted cash:
Restricted cash		19
SOUTHERN POWER CO \| Estimated Construction Completion Costs \| Deuel Harvest
Restricted cash:
Restricted cash	3	10
SOUTHERN Co GAS
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	26	45
Restricted cash:
Total cash, cash equivalents, and restricted cash	28	48	$ 32	$ 19
SOUTHERN Co GAS \| Other current assets
Restricted cash:
Restricted cash	2	2
SOUTHERN Co GAS \| Other deferred charges and assets
Restricted cash:
Restricted cash	$ 0	$ 0

Introduction - Depreciation and

Introduction - Depreciation and Amortization (Details)		12 Months Ended
Introduction - Depreciation and Amortization (Details)	Jan. 01, 2022	Dec. 31, 2021
Maximum \| Wind Generating Facility \| SOUTHERN POWER CO
Property, Plant and Equipment [Line Items]
Property, plant and equipment, useful life	35 years	30 years

Regulatory Matters - Schedule o

Regulatory Matters - Schedule of Cost Recovery Clauses (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Loss Contingencies [Line Items]
Natural gas cost under recovery	$ 390	$ 266
ALABAMA POWER CO \| Other regulatory assets, deferred
Loss Contingencies [Line Items]
Rate CNP Compliance	0	16
Rate CNP PPA	125	84
Retail Energy Cost Recovery	413	126
ALABAMA POWER CO \| Other regulatory liabilities, deferred
Loss Contingencies [Line Items]
Rate CNP Compliance	4	0
ALABAMA POWER CO \| Other regulatory assets, current
Loss Contingencies [Line Items]
Retail Energy Cost Recovery	93	0
GEORGIA POWER CO \| Other deferred charges and assets
Loss Contingencies [Line Items]
Fuel Cost Recovery	1,697	410
MISSISSIPPI POWER CO \| Other regulatory assets, deferred
Loss Contingencies [Line Items]
Ad Valorem Tax	22	37
MISSISSIPPI POWER CO \| Other customer accounts receivable
Loss Contingencies [Line Items]
Fuel Cost Recovery	13	4
MISSISSIPPI POWER CO \| Other regulatory assets, current
Loss Contingencies [Line Items]
Ad Valorem Tax	12	12
SOUTHERN Co GAS
Loss Contingencies [Line Items]
Natural gas cost under recovery	390	266
SOUTHERN Co GAS \| Other regulatory assets, deferred
Loss Contingencies [Line Items]
Natural gas cost under recovery	0	207
SOUTHERN Co GAS \| Other regulatory assets, current
Loss Contingencies [Line Items]
Natural gas cost under recovery	$ 390	$ 266

Regulatory Matters - APC Certif

Regulatory Matters - APC Certificate of Convenience and Necessity (Details) - USD ($) $ in Millions	Oct. 03, 2022	Sep. 30, 2022	Dec. 31, 2021	Dec. 31, 2020
Public Utilities, General Disclosures [Line Items]
Plant in service, net of depreciation		$ 81,314	$ 81,513
Other utility plant, net		602	0
Construction work in progress		10,773	8,771
Revision of Prior Period, Reclassification, Adjustment
Public Utilities, General Disclosures [Line Items]
Plant in service, net of depreciation		(600)
Other utility plant, net		600
ALABAMA POWER CO
Public Utilities, General Disclosures [Line Items]
Plant in service, net of depreciation		22,649	22,822
Other utility plant, net		602	0
Construction work in progress		1,524	$ 1,147
ALABAMA POWER CO \| Plant Barry Unit 8
Public Utilities, General Disclosures [Line Items]
Estimated in-service cost				$ 652
Construction work in progress		$ 484
Subsequent Event \| ALABAMA POWER CO
Public Utilities, General Disclosures [Line Items]
Increase to annual revenue requirement	$ 34
Increase to annual revenue requirement, percentage	0.60%

Regulatory Matters - APC Rate E

Regulatory Matters - APC Rate ECR (Details) - Alabama Power $ in Millions			1 Months Ended
	Jul. 12, 2022 USD ($) $ / KWH_Kilowatt_hour	Jul. 11, 2022 $ / KWH_Kilowatt_hour	Jan. 31, 2025 $ / KWH_Kilowatt_hour
Schedule of Regulatory Assets and Liabilities [Line Items]
Current billing rates under rate ECR (usd per KWH)	2.557	1.96
Current billing rates under rate ECR, amount \| $	$ 310
Scenario, Forecast
Schedule of Regulatory Assets and Liabilities [Line Items]
Current billing rates under rate ECR (usd per KWH)			5.91

Regulatory Matters - APC Rate N

Regulatory Matters - APC Rate NDR and Reliability Reserve Accounting Order (Details) - Alabama Power - USD ($)		6 Months Ended	12 Months Ended
	Jul. 12, 2022	Dec. 31, 2022	Dec. 31, 2023	Sep. 30, 2022
Public Utilities, General Disclosures [Line Items]
Maximum rate NDR charge per month, monthly nonresidential customer account	$ 5
Maximum rate NDR charge per month, monthly residential customer account	2.50
Natural disaster reserve balance				$ 103,000,000
Natural disaster reserve authorized limit	$ 35,000,000			75,000,000
Minimum natural disaster reserve balance, triggering establishment charge				$ 50,000,000
Minimum
Public Utilities, General Disclosures [Line Items]
Maximum period for recovery deferred stock related operations and maintenance costs and any future reserve deficits	24 months
Maximum
Public Utilities, General Disclosures [Line Items]
Maximum period for recovery deferred stock related operations and maintenance costs and any future reserve deficits	48 months
Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Natural disaster reserve, expected recovery amount		$ 6,000,000	$ 12,000,000

Regulatory Matters - APC Renewa

Regulatory Matters - APC Renewable Generation Certificate (Details) - ALABAMA POWER CO		1 Months Ended
	Oct. 04, 2022 project MW	Apr. 30, 2022 project MW	Sep. 30, 2022 MW
Public Utilities, General Disclosures [Line Items]
Renewable generation certificate, authorized generating capacity (in MWs)			500
Renewable generation certificate, number of projects terminated \| project		1
Renewable generation certificate, capacity restored (in MWs)		80
Renewable generation certificate, generating capacity owned by parent			330
Subsequent Event
Public Utilities, General Disclosures [Line Items]
Renewable generation certificate, number of projects approved \| project	2
Renewable generation certificate, generating capacity owned by parent	160

Regulatory Matters - GPC Base R

Regulatory Matters - GPC Base Rate Case (Details) $ in Millions	Jun. 24, 2022 USD ($)
Public Utilities, General Disclosures [Line Items]
Proposed alternate rate plan	3 years
GEORGIA POWER CO
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount, due in next fiscal year	$ 889
Requested rate increase (decrease), amount, due in 2024	107
Requested rate increase (decrease), amount, due in 2025	$ 45
Base rate case filing, measurement input, return on investment	11%
Base rate case filing, measurement input, maximum equity ratio	56%
Portion of actual earnings above approved ROE band refunded to customers	80%
Portion of actual earnings above approved ROE band retained by subsidiary company	20%
GEORGIA POWER CO \| Minimum
Public Utilities, General Disclosures [Line Items]
Retail rate of return on common equity	9.50%
GEORGIA POWER CO \| Maximum
Public Utilities, General Disclosures [Line Items]
Retail rate of return on common equity	12%

Regulatory Matters - GPC Tariff

Regulatory Matters - GPC Tariffs (Details) - GEORGIA POWER CO $ in Millions	Jun. 24, 2022 USD ($)
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount, due in next fiscal year	$ 889
Requested rate increase (decrease), amount, due in 2024	107
Requested rate increase (decrease), amount, due in 2025	45
Traditional base
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount, due in next fiscal year	762
Requested rate increase (decrease), amount, due in 2024	0
Requested rate increase (decrease), amount, due in 2025	0
Traditional
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount, due in next fiscal year	5
Requested rate increase (decrease), amount, due in 2024	0
Requested rate increase (decrease), amount, due in 2025	0
CCR ARO
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount, due in next fiscal year	64
Requested rate increase (decrease), amount, due in 2024	78
Requested rate increase (decrease), amount, due in 2025	47
DSM
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount, due in next fiscal year	37
Requested rate increase (decrease), amount, due in 2024	27
Requested rate increase (decrease), amount, due in 2025	(2)
Municipal Franchise Fee
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease), amount, due in next fiscal year	21
Requested rate increase (decrease), amount, due in 2024	2
Requested rate increase (decrease), amount, due in 2025	$ 1

Regulatory Matters - GPC Integr

Regulatory Matters - GPC Integrated Resource Plan (Details) - GEORGIA POWER CO $ in Millions						9 Months Ended	12 Months Ended
	Jan. 01, 2028 MW	Jan. 01, 2025 MW	Jan. 01, 2024 MW	Aug. 26, 2022 USD ($)	Jul. 21, 2022 agreement ashPond MW	Sep. 30, 2022 USD ($) MW	Dec. 31, 2026 MW
Public Utilities, General Disclosures [Line Items]
Approved capacity increase (in MWs)						970
Approved change in closure method, number of ash ponds \| ashPond					1
Number of approved Power Purchase Agreements \| agreement					6
Number of approved Approved Power Purchase Agreements \| agreement					5
Rejected additional generating capacity					88
Renewable Resources
Public Utilities, General Disclosures [Line Items]
Requested additional generating capacity					2,300
Energy Storage
Public Utilities, General Disclosures [Line Items]
Requested additional generating capacity					500
Biomass Generation
Public Utilities, General Disclosures [Line Items]
Requested additional generating capacity					140
Subsequent Event \| Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Approved capacity increase (in MWs)	228	380	1,567				265
Plant Wansley Units 1 and 2
Public Utilities, General Disclosures [Line Items]
Capacity of units approved for decertification and retirement of units					926
Approved amounts for decertification and retirement of units, percentage					53.50%
Plant Wansley Unit 1
Public Utilities, General Disclosures [Line Items]
Remaining net book value \| $						$ 299
Plant Wansley Unit 2
Public Utilities, General Disclosures [Line Items]
Remaining net book value \| $						277
Plant Scherer Unit 3
Public Utilities, General Disclosures [Line Items]
Capacity of units approved for decertification and retirement of units					614
Approved amounts for decertification and retirement of units, percentage					75%
Remaining net book value \| $						$ 608
Plant Gaston Units 1 through 4
Public Utilities, General Disclosures [Line Items]
Capacity of units approved for decertification and retirement of units					500
Approved amounts for decertification and retirement of units, percentage					50%
Plant Bowen Units 1 and 2
Public Utilities, General Disclosures [Line Items]
Capacity of units included in request for decertification of units					1,400
Plant Tugalo
Public Utilities, General Disclosures [Line Items]
Planned expenses to modernize plant \| $				$ 115

Regulatory Matters - GPC Nuclea

Regulatory Matters - GPC Nuclear Construction (Details) - GEORGIA POWER CO $ in Millions	3 Months Ended		9 Months Ended	12 Months Ended
	Sep. 30, 2022 USD ($)	Jun. 30, 2022 USD ($)	Sep. 30, 2022 USD ($)	Dec. 31, 2012 utility MW	Aug. 31, 2018
Loss Contingencies [Line Items]
Estimated cost to complete, pre-tax charge to income	$ 32	$ 36
Estimated cost to complete, pre-tax charge to income, net of tax	$ 24	27
Plant Vogtle Units 3 And 4
Loss Contingencies [Line Items]
Proportionate ownership share	45.70%		45.70%
Number of construction units approved \| utility				2
Electric generating capacity in mega watts under consortium agreement \| MW				1,100
Estimated cost to complete, construction contingency estimate, financing costs	$ 3,400		$ 3,400
Estimated cost to complete, construction contingency estimate, financing costs, incurred to date	3,100		3,100
Construction contingency estimate	170		170
Estimated cost to complete, additional construction contingency estimate	32	$ 36	32
Base project capital cost forecast, monthly			15
Monthly AFUDC			$ 35
Percentage of ownership interest required for voting for continuing construction					90%
Plant Vogtle Units 3 And 4 \| Vogtle Owners
Loss Contingencies [Line Items]
Period of notice required in the event letters of credit are not renewed			30 days
Minimum \| Plant Vogtle Units 3 And 4 \| COVID-19
Loss Contingencies [Line Items]
Loss contingency, estimate of possible loss, loss of productivity, term			3 months
Estimate of possible loss	160		$ 160
Maximum \| Plant Vogtle Units 3 And 4 \| COVID-19
Loss Contingencies [Line Items]
Loss contingency, estimate of possible loss, loss of productivity, term			4 months
Estimate of possible loss	$ 200		$ 200

Regulatory Matters - GPC Nucl_2

Regulatory Matters - GPC Nuclear Construction Cost and Schedule (Details) - GEORGIA POWER CO - USD ($) $ in Millions	3 Months Ended			6 Months Ended	9 Months Ended
	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021	Sep. 30, 2022
Loss Contingencies [Line Items]
Pre-tax charge to income	$ (102)	$ 16	$ 440		$ 353
Plant Vogtle Units 3 And 4
Loss Contingencies [Line Items]
Base project capital cost forecast	10,334				10,334
Construction contingency estimate	49				49
Total project capital cost forecast	10,383				10,383
Net investment as of end of the period	(9,280)				(9,280)
Remaining estimate to complete	1,103				1,103
Estimated cost to complete, costs not shared with other owners	590				590
Expected capitalized costs					385
Capitalized interest accrued	$ 275				$ 275
Plant Vogtle Units 3 And 4 \| Twenty Fifth Vogtle Construction Monitoring Report
Loss Contingencies [Line Items]
Guarantor obligations				$ 1,700
Customer refund				$ 188

Regulatory Matters - GPC Amendm

Regulatory Matters - GPC Amendments to the Vogtle Joint Ownership Agreements (Details) - GEORGIA POWER CO - USD ($) $ in Thousands				3 Months Ended			9 Months Ended
	Oct. 04, 2022	Sep. 29, 2022	Jan. 11, 2018	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021	Sep. 30, 2022	Jul. 25, 2022	Jun. 18, 2022	Aug. 31, 2018
Public Utilities, General Disclosures [Line Items]
Pre-tax charge to income				$ (102,000)	$ 16,000	$ 440,000	$ 353,000
After tax charge to income				(76,000)	$ 12,000	$ 328,000
Plant Vogtle Units 3 And 4
Public Utilities, General Disclosures [Line Items]
Production tax credits, aggregate purchase price, maximum							300,000
Preliminary estimated cost to complete				$ 10,383,000			$ 10,383,000
Additional construction capital costs			$ 3,300,000
Remaining share of construction costs, agreement to pay, percentage							100%
Percentage of ownership interest required for voting for continuing construction										90%
Percentage of costs, disallowed for recovery							6%
Costs disallowed for recovery, period							6 months
Public utilities, extension project schedule, term							1 year
Proportionate ownership share				45.70%			45.70%
Plant Vogtle Units 3 And 4 \| Subsequent Event
Public Utilities, General Disclosures [Line Items]
Additional construction capital costs	$ 300,000
Plant Vogtle Units 3 And 4 \| Vogtle Owners
Public Utilities, General Disclosures [Line Items]
Additional construction capital costs							$ 100
Plant Vogtle Units 3 And 4 \| Vogtle Owners \| Tender Provision Dispute
Public Utilities, General Disclosures [Line Items]
Estimated cost to complete, starting dollar amount									$ 17,100,000
Plant Vogtle Units 3 And 4 \| Vogtle Owners \| Counterclaim Seeking Declaratory Judgement
Public Utilities, General Disclosures [Line Items]
Estimated cost to complete, starting dollar amount								$ 18,380,000
Plant Vogtle Units 3 And 4 \| MEAG Power
Public Utilities, General Disclosures [Line Items]
Payment of power costs		$ 79,000
Plant Vogtle Units 3 And 4 \| Minimum
Public Utilities, General Disclosures [Line Items]
Global amendments, tender provision, decision period after tender option triggered							120 days
Plant Vogtle Units 3 And 4 \| Maximum
Public Utilities, General Disclosures [Line Items]
Global amendments, tender provision, decision period after tender option triggered							194 days
Plant Vogtle Units 3 And 4 \| Category I
Public Utilities, General Disclosures [Line Items]
Preliminary estimated cost to complete				$ 8,400,000			$ 8,400,000
Additional construction capital costs, threshold							$ 800,000
Plant Vogtle Units 3 And 4 \| Category II
Public Utilities, General Disclosures [Line Items]
Percentage of construction costs, responsibility to pay							55.70%
Additional construction capital costs							$ 80,000
Plant Vogtle Units 3 And 4 \| Category II \| Vogtle Owners
Public Utilities, General Disclosures [Line Items]
Percentage of construction costs, responsibility to pay							44.30%
Plant Vogtle Units 3 And 4 \| Category II \| Minimum
Public Utilities, General Disclosures [Line Items]
Additional construction capital costs, threshold							$ 800,000
Plant Vogtle Units 3 And 4 \| Category II \| Maximum
Public Utilities, General Disclosures [Line Items]
Additional construction capital costs, threshold							$ 1,600,000
Plant Vogtle Units 3 And 4 \| Category III
Public Utilities, General Disclosures [Line Items]
Percentage of construction costs, responsibility to pay							65.70%
Additional construction capital costs							$ 100,000
Plant Vogtle Units 3 And 4 \| Category III \| Vogtle Owners
Public Utilities, General Disclosures [Line Items]
Percentage of construction costs, responsibility to pay							34.30%
Plant Vogtle Units 3 And 4 \| Category III \| Minimum
Public Utilities, General Disclosures [Line Items]
Additional construction capital costs, threshold							$ 1,600,000
Plant Vogtle Units 3 And 4 \| Category III \| Maximum
Public Utilities, General Disclosures [Line Items]
Additional construction capital costs, threshold							$ 2,100,000

Regulatory Matters - GPC Nucl_3

Regulatory Matters - GPC Nuclear Construction Regulatory Matters (Details) - Plant Vogtle Units 3 And 4 - GEORGIA POWER CO $ in Millions

6 Months Ended

9 Months Ended

12 Months Ended

Jan. 01, 2022 USD ($)

Jan. 01, 2021

Jan. 01, 2020

Jan. 11, 2018 USD ($)

Jan. 01, 2016

Jun. 30, 2022 USD ($)

Jun. 30, 2021 USD ($) report

Sep. 30, 2022 USD ($)

Dec. 31, 2023 USD ($)

Dec. 31, 2022 USD ($)

Dec. 31, 2021 USD ($)

Dec. 31, 2009 USD ($)

Jun. 30, 2018 USD ($)

Dec. 31, 2013

Public Utilities, General Disclosures [Line Items]

Estimated in-service capital cost

$ 4,418

Financing costs collected, net of tax

$ 2,800

Requested decrease in tariff

$ 78

Additional construction capital costs

$ 3,300

Payments for contractor settlement agreement

300

Amendment to estimated in-service capital cost

$ 5,680

Retail rate of return on common equity

10.95%

Public utilities, approved return on equity percentage

5.30%

8.30%

10%

Public utilities, approved return on equity, monthly percentage decrease

0.10%

Return on equity reduction, negative impact on earnings

$ 270

Increase to base capital cost forecast not seeking recovery

$ 700

Twenty Fourth Vogtle Construction Monitoring Report

Public Utilities, General Disclosures [Line Items]

Cost settlement agreement revised forecast, net of payments

$ 7,300

Twenty Fifth Vogtle Construction Monitoring Report

Public Utilities, General Disclosures [Line Items]

Number of approved construction management reports | report

Requested capital construction costs

$ 7,900

Guarantor obligations

1,700

Customer refund

$ 188

Twenty Sixth Vogtle Construction Monitoring Report

Public Utilities, General Disclosures [Line Items]

Requested capital construction costs

$ 584

Twenty Seventh Vogtle Construction Monitoring Report

Public Utilities, General Disclosures [Line Items]

Cost settlement agreement revised forecast, net of payments

$ 10,500

Requested capital construction costs

$ 522

Scenario, Forecast

Public Utilities, General Disclosures [Line Items]

Return on equity reduction, negative impact on earnings

$ 250

$ 300

Regulatory Matters - MPC (Detai

Regulatory Matters - MPC (Details) - MISSISSIPPI POWER CO $ in Millions	Jul. 15, 2022 USD ($)	Jun. 07, 2022 USD ($)	Sep. 30, 2022 MW	Aug. 26, 2022
Performance Evaluation Plan
Loss Contingencies [Line Items]
Approved rate increase (decrease)		$ 18
Approved rate increase, percentage		1.90%
Ad Valorem Tax Adjustment
Loss Contingencies [Line Items]
Approved rate increase (decrease)		$ 5
Municipal and Rural Associations Tariff
Loss Contingencies [Line Items]
Requested rate increase (decrease) amount	$ 23
Cooperative Energy
Loss Contingencies [Line Items]
Counterparty's option to decrease services, percentage				2.50%
Power being supplied to counterparty \| MW			400
Counterparty's electricity requirement at MRA delivery points				100%

Regulatory Matters - GAS Schedu

Regulatory Matters - GAS Schedule of Infrastructure Replacement Programs and Capital Projects (Details) - SOUTHERN Co GAS $ in Millions	9 Months Ended
	Sep. 30, 2022 USD ($)
Public Utilities, General Disclosures [Line Items]
Capital expenditures	$ 416
Investing in Illinois
Public Utilities, General Disclosures [Line Items]
Capital expenditures	311
SAVE
Public Utilities, General Disclosures [Line Items]
Capital expenditures	52
System Reinforcement Rider
Public Utilities, General Disclosures [Line Items]
Capital expenditures	51
Pipeline Replacement Program
Public Utilities, General Disclosures [Line Items]
Capital expenditures	$ 2

Regulatory Matters - GAS Atlant

Regulatory Matters - GAS Atlanta Gas Light (Details) $ in Millions	Jul. 01, 2022 USD ($)
SOUTHERN Co GAS
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease) amount	$ 53

Regulatory Matters - GAS Virgin

Regulatory Matters - GAS Virginia Natural Gas (Details) - Virginia Natural Gas $ in Millions	Aug. 01, 2022 USD ($)
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease) amount	$ 69
Public utilities, requested rate increase amount recovery of investments	$ 15
Public utilities, approved return on equity percentage	10.35%
Public utilities, approved equity capital structure percentage	53.20%

Contingencies - General Litigat

Contingencies - General Litigation Matters (Details) $ in Millions			1 Months Ended		12 Months Ended
	Jun. 09, 2022 USD ($)	Feb. 07, 2022 claim	Oct. 31, 2021 claim	Mar. 31, 2019 plaintiff	Dec. 31, 2018 USD ($) plaintiff defendant	Mar. 09, 2022 claim	Dec. 31, 2017 claim
Pending Litigation \| Shareholder Derivative Lawsuits
Loss Contingencies [Line Items]
Pending number of claims							2
Settled Litigation \| Shareholder Derivative Lawsuits
Loss Contingencies [Line Items]
Settlement expense \| $	$ 4.5
GEORGIA POWER CO \| Pending Litigation \| Class Action Lawsuit
Loss Contingencies [Line Items]
Pending number of claims						4
Complaints filed		4	3
MISSISSIPPI POWER CO \| Pending Litigation \| Purported Violations of Mississippi Consumer Protection Act
Loss Contingencies [Line Items]
Number of plaintiffs \| plaintiff					10
Number of defendants \| defendant					3
Number of additional plaintiffs \| plaintiff				4
Underpayment of refunds \| $					$ 23.5

Contingencies - Environmental R

Contingencies - Environmental Remediation (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
GEORGIA POWER CO
Loss Contingencies [Line Items]
Environmental remediation liability, current and former sites	$ 16	$ 17
SOUTHERN Co GAS
Loss Contingencies [Line Items]
Environmental remediation liability, current and former sites	$ 270	$ 249

Contingencies - Other Matters (

Contingencies - Other Matters (Details)			12 Months Ended	60 Months Ended
Contingencies - Other Matters (Details)	Aug. 31, 2022 USD ($)	Jul. 12, 2022 USD ($) claim	Dec. 31, 2019 USD ($)	Jan. 15, 2024 USD ($)
MISSISSIPPI POWER CO
Loss Contingencies [Line Items]
Estimate of possible loss	$ 28,000,000
Plant Daniel Unit, Primary \| MISSISSIPPI POWER CO
Loss Contingencies [Line Items]
Plant units \| claim		1
Plant Daniel Units 1 And 2 \| GULF POWER CO
Loss Contingencies [Line Items]
Percent ownership in individual unit		100%
Plant Daniel Units 1 And 2 \| MISSISSIPPI POWER CO
Loss Contingencies [Line Items]
Plant units \| claim		2
Scenario, Forecast \| Plant Daniel Units 1 And 2 \| MISSISSIPPI POWER CO
Loss Contingencies [Line Items]
Payments to acquire businesses				$ 1
Business combination, option to purchase, period				120 days
Disposal Group, Disposed of by Sale \| GULF POWER CO
Loss Contingencies [Line Items]
Proceeds from divestiture of businesses, amount held back		$ 75,000,000	$ 75,000,000

Revenue from Contracts with C_3

Revenue from Contracts with Customers and Lease Income - Schedule of Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 7,116	$ 5,732	$ 19,599	$ 18,066
Total operating revenues	8,378	6,238	22,232	17,346
Retail electric revenues
Disaggregation of Revenue [Line Items]
Total operating revenues	5,961	4,551	14,363	11,492
Retail electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	4,951	4,332	12,477	11,006
Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	2,104	1,974	5,282	4,910
Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,637	1,432	4,202	3,727
Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,183	902	2,914	2,299
Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	27	24	79	70
Natural Gas
Disaggregation of Revenue [Line Items]
Total operating revenues	857	623	3,998	2,994
Natural gas distribution revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	744	549	3,490	2,432
Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	331	218	1,821	1,143
Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	93	55	493	298
Transportation
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	259	239	872	775
Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	12	6	60	29
Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	49	31	244	187
Other natural gas revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	99	56	458	2,498
Wholesale gas services
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers				2,168
Gas marketing services
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	84	45	417	303
Other natural gas revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	15	11	41	27
Other revenue sources
Disaggregation of Revenue [Line Items]
Other revenues	1,262	506	2,633	2,979
Other adjustments
Disaggregation of Revenue [Line Items]
Other revenues				(3,699)
Wholesale Electric
Disaggregation of Revenue [Line Items]
Total operating revenues	1,197	731	2,798	1,822
Wholesale electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,045	547	2,364	1,338
PPA energy revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	812	359	1,739	782
PPA capacity revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	175	125	443	375
Non-PPA revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	58	63	182	181
Other revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	277	248	810	792
ALABAMA POWER CO
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	2,128	1,801	5,315	4,708
Total operating revenues	2,444	1,904	6,023	5,019
ALABAMA POWER CO \| Retail electric revenues
Disaggregation of Revenue [Line Items]
Total operating revenues	2,008	1,651	5,015	4,357
ALABAMA POWER CO \| Retail electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,753	1,619	4,487	4,221
ALABAMA POWER CO \| Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	799	750	2,049	1,931
ALABAMA POWER CO \| Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	499	471	1,285	1,229
ALABAMA POWER CO \| Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	452	394	1,143	1,048
ALABAMA POWER CO \| Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	3	4	10	13
ALABAMA POWER CO \| Natural gas distribution revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
ALABAMA POWER CO \| Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
ALABAMA POWER CO \| Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
ALABAMA POWER CO \| Transportation
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
ALABAMA POWER CO \| Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
ALABAMA POWER CO \| Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
ALABAMA POWER CO \| Other natural gas revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
ALABAMA POWER CO \| Wholesale gas services
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers				0
ALABAMA POWER CO \| Gas marketing services
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
ALABAMA POWER CO \| Other natural gas revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
ALABAMA POWER CO \| Other revenue sources
Disaggregation of Revenue [Line Items]
Other revenues	316	103	708	311
ALABAMA POWER CO \| Other adjustments
Disaggregation of Revenue [Line Items]
Other revenues				0
ALABAMA POWER CO \| Wholesale electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	310	129	655	337
ALABAMA POWER CO \| PPA energy revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	187	61	354	143
ALABAMA POWER CO \| PPA capacity revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	56	14	135	86
ALABAMA POWER CO \| Non-PPA revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	67	54	166	108
ALABAMA POWER CO \| Other revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	65	53	173	150
GEORGIA POWER CO
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	3,093	2,636	7,767	6,631
Total operating revenues	3,889	2,856	9,218	7,050
GEORGIA POWER CO \| Retail electric revenues
Disaggregation of Revenue [Line Items]
Total operating revenues	3,703	2,652	8,629	6,465
GEORGIA POWER CO \| Retail electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	2,927	2,466	7,274	6,143
GEORGIA POWER CO \| Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,212	1,138	2,995	2,765
GEORGIA POWER CO \| Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,051	882	2,688	2,293
GEORGIA POWER CO \| Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	642	428	1,529	1,034
GEORGIA POWER CO \| Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	22	18	62	51
GEORGIA POWER CO \| Natural gas distribution revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
GEORGIA POWER CO \| Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
GEORGIA POWER CO \| Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
GEORGIA POWER CO \| Transportation
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
GEORGIA POWER CO \| Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
GEORGIA POWER CO \| Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
GEORGIA POWER CO \| Other natural gas revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
GEORGIA POWER CO \| Wholesale gas services
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers				0
GEORGIA POWER CO \| Gas marketing services
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
GEORGIA POWER CO \| Other natural gas revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
GEORGIA POWER CO \| Other revenue sources
Disaggregation of Revenue [Line Items]
Other revenues	796	220	1,451	419
GEORGIA POWER CO \| Other adjustments
Disaggregation of Revenue [Line Items]
Other revenues				0
GEORGIA POWER CO \| Wholesale Electric
Disaggregation of Revenue [Line Items]
Total operating revenues	56	63	186	143
GEORGIA POWER CO \| Wholesale electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	56	58	166	126
GEORGIA POWER CO \| PPA energy revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	40	41	112	71
GEORGIA POWER CO \| PPA capacity revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	12	14	35	41
GEORGIA POWER CO \| Non-PPA revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	4	3	19	14
GEORGIA POWER CO \| Other revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	110	112	327	362
MISSISSIPPI POWER CO
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	531	378	1,276	960
Total operating revenues	510	378	1,279	988
MISSISSIPPI POWER CO \| Retail electric revenues
Disaggregation of Revenue [Line Items]
Total operating revenues	250	248	718	670
MISSISSIPPI POWER CO \| Retail electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	271	247	716	642
MISSISSIPPI POWER CO \| Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	93	86	238	214
MISSISSIPPI POWER CO \| Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	87	79	229	205
MISSISSIPPI POWER CO \| Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	89	80	242	217
MISSISSIPPI POWER CO \| Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	2	2	7	6
MISSISSIPPI POWER CO \| Natural gas distribution revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
MISSISSIPPI POWER CO \| Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
MISSISSIPPI POWER CO \| Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
MISSISSIPPI POWER CO \| Transportation
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
MISSISSIPPI POWER CO \| Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
MISSISSIPPI POWER CO \| Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
MISSISSIPPI POWER CO \| Other natural gas revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
MISSISSIPPI POWER CO \| Wholesale gas services
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers				0
MISSISSIPPI POWER CO \| Gas marketing services
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
MISSISSIPPI POWER CO \| Other natural gas revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
MISSISSIPPI POWER CO \| Other revenue sources
Disaggregation of Revenue [Line Items]
Other revenues	(21)	0	3	28
MISSISSIPPI POWER CO \| Other adjustments
Disaggregation of Revenue [Line Items]
Other revenues				0
MISSISSIPPI POWER CO \| Wholesale electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	247	123	526	296
MISSISSIPPI POWER CO \| PPA energy revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	4	2	11	9
MISSISSIPPI POWER CO \| PPA capacity revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1	1	4	4
MISSISSIPPI POWER CO \| Non-PPA revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	242	120	511	283
MISSISSIPPI POWER CO \| Other revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	13	8	34	22
SOUTHERN POWER CO
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,010	501	2,157	1,113
Total operating revenues	1,180	679	2,618	1,610
SOUTHERN POWER CO \| Retail electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
SOUTHERN POWER CO \| Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
SOUTHERN POWER CO \| Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
SOUTHERN POWER CO \| Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
SOUTHERN POWER CO \| Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
SOUTHERN POWER CO \| Natural gas distribution revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
SOUTHERN POWER CO \| Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
SOUTHERN POWER CO \| Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
SOUTHERN POWER CO \| Transportation
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
SOUTHERN POWER CO \| Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
SOUTHERN POWER CO \| Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
SOUTHERN POWER CO \| Other natural gas revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
SOUTHERN POWER CO \| Wholesale gas services
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers				0
SOUTHERN POWER CO \| Gas marketing services
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
SOUTHERN POWER CO \| Other natural gas revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
SOUTHERN POWER CO \| Other revenue sources
Disaggregation of Revenue [Line Items]
Other revenues	170	178	461	497
SOUTHERN POWER CO \| Other adjustments
Disaggregation of Revenue [Line Items]
Other revenues				0
SOUTHERN POWER CO \| Wholesale electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,001	492	2,130	1,095
SOUTHERN POWER CO \| PPA energy revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	591	261	1,285	575
SOUTHERN POWER CO \| PPA capacity revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	107	97	273	247
SOUTHERN POWER CO \| Non-PPA revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	303	134	572	273
SOUTHERN POWER CO \| Other revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	9	9	27	18
SOUTHERN Co GAS
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	843	605	3,948	4,930
Total operating revenues	857	623	3,998	2,994
SOUTHERN Co GAS \| Retail electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
SOUTHERN Co GAS \| Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
SOUTHERN Co GAS \| Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
SOUTHERN Co GAS \| Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
SOUTHERN Co GAS \| Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
SOUTHERN Co GAS \| Natural gas distribution revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	744	549	3,490	2,432
SOUTHERN Co GAS \| Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	331	218	1,821	1,143
SOUTHERN Co GAS \| Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	93	55	493	298
SOUTHERN Co GAS \| Transportation
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	259	239	872	775
SOUTHERN Co GAS \| Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	12	6	60	29
SOUTHERN Co GAS \| Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	49	31	244	187
SOUTHERN Co GAS \| Other natural gas revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	99	56	458	2,498
SOUTHERN Co GAS \| Wholesale gas services
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers				2,168
SOUTHERN Co GAS \| Gas marketing services
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	84	45	417	303
SOUTHERN Co GAS \| Other natural gas revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	15	11	41	27
SOUTHERN Co GAS \| Other revenue sources
Disaggregation of Revenue [Line Items]
Other revenues	14	18	50	1,763
SOUTHERN Co GAS \| Other adjustments
Disaggregation of Revenue [Line Items]
Other revenues				(3,699)
SOUTHERN Co GAS \| Wholesale electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
SOUTHERN Co GAS \| PPA energy revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
SOUTHERN Co GAS \| PPA capacity revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
SOUTHERN Co GAS \| Non-PPA revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
SOUTHERN Co GAS \| Other revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 0	$ 0	$ 0	$ 0

Revenue from Contracts with C_4

Revenue from Contracts with Customers and Lease Income - Schedule of Contract Balances (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Disaggregation of Revenue [Line Items]
Accounts Receivable	$ 2,760	$ 2,504
Contract Assets	178	117
Contract Liabilities	56	57
ALABAMA POWER CO
Disaggregation of Revenue [Line Items]
Accounts Receivable	800	589
Contract Assets	5	2
Contract Liabilities	5	4
GEORGIA POWER CO
Disaggregation of Revenue [Line Items]
Accounts Receivable	1,035	736
Contract Assets	114	63
Contract Liabilities	6	14
MISSISSIPPI POWER CO
Disaggregation of Revenue [Line Items]
Accounts Receivable	98	73
Contract Assets	0	0
Contract Liabilities	7	0
SOUTHERN POWER CO
Disaggregation of Revenue [Line Items]
Accounts Receivable	264	149
Contract Assets	0	1
Contract Liabilities	2	1
SOUTHERN Co GAS
Disaggregation of Revenue [Line Items]
Accounts Receivable	433	753
Contract Assets	0	0
Contract Liabilities	$ 0	$ 0

Revenue from Contracts with C_5

Revenue from Contracts with Customers and Lease Income - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2022	Dec. 31, 2021
Disaggregation of Revenue [Line Items]
Contract assets	$ 178	$ 178	$ 117
Contract liabilities	56	56	57
Revenue from contracts with customers recognized	13	32
Unregulated Distributed Generation
Disaggregation of Revenue [Line Items]
Contract assets	59	59	50
Contract liabilities	$ 37	$ 37	$ 39

Revenue from Contracts with C_6

Revenue from Contracts with Customers and Lease Income - Schedule of Remaining Performance Obligations (Details) $ in Millions	Sep. 30, 2022 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 243
Performance obligation, expected timing of satisfaction	3 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	$ 619
Performance obligation, expected timing of satisfaction	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	$ 434
Performance obligation, expected timing of satisfaction	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	$ 322
Performance obligation, expected timing of satisfaction	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	$ 307
Performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 2,340
Performance obligation, expected timing of satisfaction
ALABAMA POWER CO \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 8
Performance obligation, expected timing of satisfaction	3 months
ALABAMA POWER CO \| 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	$ 24
Performance obligation, expected timing of satisfaction	1 year
ALABAMA POWER CO \| 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	$ 7
Performance obligation, expected timing of satisfaction	1 year
ALABAMA POWER CO \| 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	$ 5
Performance obligation, expected timing of satisfaction	1 year
ALABAMA POWER CO \| 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	$ 0
Performance obligation, expected timing of satisfaction	1 year
ALABAMA POWER CO \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 0
Performance obligation, expected timing of satisfaction
GEORGIA POWER CO \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 20
Performance obligation, expected timing of satisfaction	3 months
GEORGIA POWER CO \| 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	$ 70
Performance obligation, expected timing of satisfaction	1 year
GEORGIA POWER CO \| 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	$ 34
Performance obligation, expected timing of satisfaction	1 year
GEORGIA POWER CO \| 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	$ 22
Performance obligation, expected timing of satisfaction	1 year
GEORGIA POWER CO \| 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	$ 11
Performance obligation, expected timing of satisfaction	1 year
GEORGIA POWER CO \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 21
Performance obligation, expected timing of satisfaction
SOUTHERN POWER CO \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 80
Performance obligation, expected timing of satisfaction	3 months
SOUTHERN POWER CO \| 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	$ 341
Performance obligation, expected timing of satisfaction	1 year
SOUTHERN POWER CO \| 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	$ 344
Performance obligation, expected timing of satisfaction	1 year
SOUTHERN POWER CO \| 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	$ 294
Performance obligation, expected timing of satisfaction	1 year
SOUTHERN POWER CO \| 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	$ 299
Performance obligation, expected timing of satisfaction	1 year
SOUTHERN POWER CO \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 2,334
Performance obligation, expected timing of satisfaction
SOUTHERN Co GAS \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 12
Performance obligation, expected timing of satisfaction	3 months
SOUTHERN Co GAS \| 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	$ 29
Performance obligation, expected timing of satisfaction	1 year
SOUTHERN Co GAS \| 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	$ 29
Performance obligation, expected timing of satisfaction	1 year
SOUTHERN Co GAS \| 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	$ 0
Performance obligation, expected timing of satisfaction	1 year
SOUTHERN Co GAS \| 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	$ 0
Performance obligation, expected timing of satisfaction	1 year
SOUTHERN Co GAS \| Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 0
Performance obligation, expected timing of satisfaction

Revenue from Contracts with C_7

Revenue from Contracts with Customers and Lease Income - Schedule of Lease Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Lessor, Lease, Description [Line Items]
Lease income - interest income on sales-type leases	$ 7	$ 4	$ 19	$ 11
Lease income - operating leases	50	56	149	168
Variable lease income	139	143	355	355
Total lease income	196	203	523	534
ALABAMA POWER CO
Lessor, Lease, Description [Line Items]
Lease income - interest income on sales-type leases	0	0	0	0
Lease income - operating leases	19	21	58	62
Variable lease income	0	0	1	0
Total lease income	19	21	59	62
GEORGIA POWER CO
Lessor, Lease, Description [Line Items]
Lease income - interest income on sales-type leases	0	0	0	0
Lease income - operating leases	8	11	24	31
Variable lease income	0	0	0	0
Total lease income	8	11	24	31
MISSISSIPPI POWER CO
Lessor, Lease, Description [Line Items]
Lease income - interest income on sales-type leases	4	4	11	10
Lease income - operating leases	1	0	1	1
Variable lease income	0	0	0	0
Total lease income	5	4	12	11
SOUTHERN POWER CO
Lessor, Lease, Description [Line Items]
Lease income - interest income on sales-type leases	3	0	8	0
Lease income - operating leases	21	21	64	64
Variable lease income	145	151	372	379
Total lease income	169	172	444	443
SOUTHERN Co GAS
Lessor, Lease, Description [Line Items]
Lease income - interest income on sales-type leases	0	0	0	0
Lease income - operating leases	9	9	27	26
Variable lease income	0	0	0	0
Total lease income	$ 9	$ 9	$ 27	$ 26

Consolidated Entities and Equ_3

Consolidated Entities and Equity Method Investments - Narrative (Details) $ in Millions	9 Months Ended
	Sep. 30, 2022 USD ($) investor	Dec. 31, 2021 USD ($)
Schedule of Equity Method Investments [Line Items]
Assets	$ 134,005	$ 127,534
Liabilities	98,287	94,967
Equity investments in unconsolidated subsidiaries	1,292	1,282
SOUTHERN POWER CO
Schedule of Equity Method Investments [Line Items]
Assets	13,283	13,390
Liabilities	6,403	6,792
Equity investments in unconsolidated subsidiaries	49	86
Proceeds from sale of equity method investments	$ 38
SP Solar Holdings I, LP \| SOUTHERN POWER CO
Schedule of Equity Method Investments [Line Items]
Distribution made to limited partner, cash distributions paid, percentage	67%
SP Solar Holdings I, LP \| Global Atlantic
Schedule of Equity Method Investments [Line Items]
Distribution made to limited partner, cash distributions paid, percentage	33%
Variable Interest Entity, Primary Beneficiary \| SP Solar Holdings I, LP \| SOUTHERN POWER CO
Schedule of Equity Method Investments [Line Items]
Assets	$ 6,000	6,100
Liabilities	400	400
Noncontrolling interests related to other partners' interests	1,100	1,100
Variable Interest Entity, Primary Beneficiary \| SP Wind \| SOUTHERN POWER CO
Schedule of Equity Method Investments [Line Items]
Assets	2,300	2,300
Liabilities	191	130
Noncontrolling interests related to other partners' interests	$ 40	41
Distribution made to limited partner, cash distributions paid, percentage	60%
Number of financial investors \| investor	3
Variable Interest Entity, Primary Beneficiary \| SP Wind \| Financial Investors
Schedule of Equity Method Investments [Line Items]
Distribution made to limited partner, cash distributions paid, percentage	40%
Variable Interest Entity, Primary Beneficiary \| Other Variable Interest Entities \| SOUTHERN POWER CO
Schedule of Equity Method Investments [Line Items]
Assets	$ 1,900	1,900
Liabilities	200	300
Noncontrolling interests related to other partners' interests	$ 800	$ 900

Consolidated Entities and Equ_4

Consolidated Entities and Equity Method Investments - Schedule of Equity Method Investments (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Schedule of Equity Method Investments [Line Items]
Investment Balance	$ 1,292	$ 1,282
SOUTHERN Co GAS
Schedule of Equity Method Investments [Line Items]
Investment Balance	1,125	1,173
SOUTHERN Co GAS \| SNG
Schedule of Equity Method Investments [Line Items]
Investment Balance	1,091	1,129
SOUTHERN Co GAS \| Other
Schedule of Equity Method Investments [Line Items]
Investment Balance	34	$ 44
SOUTHERN Co GAS \| PennEast Pipeline
Schedule of Equity Method Investments [Line Items]
Distribution	$ 11

Consolidated Entities and Equ_5

Consolidated Entities and Equity Method Investments - Schedule of Earnings (Loss) from Equity Method Investments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Schedule of Equity Method Investments [Line Items]
Earnings (Loss) from Equity Method Investments	$ 28	$ 30	$ 109	$ 35
SOUTHERN Co GAS
Schedule of Equity Method Investments [Line Items]
Earnings (Loss) from Equity Method Investments	34	25	105	14
Impairment of PennEast Pipeline investment			0	84
SOUTHERN Co GAS \| SNG
Schedule of Equity Method Investments [Line Items]
Earnings (Loss) from Equity Method Investments	34	27	104	93
SOUTHERN Co GAS \| PennEast Pipeline
Schedule of Equity Method Investments [Line Items]
Earnings (Loss) from Equity Method Investments	0	(2)	0	(81)
Impairment of PennEast Pipeline investment		84		84
Asset impairment charges, net of tax		67		67
SOUTHERN Co GAS \| Other
Schedule of Equity Method Investments [Line Items]
Earnings (Loss) from Equity Method Investments	$ 0	$ 0	$ 1	$ 2

Financing and Leases - Schedule

Financing and Leases - Schedule of Credit Arrangements (Details)	9 Months Ended
	Sep. 30, 2022 USD ($) letter_of_credit
Line of Credit Facility [Line Items]
Expires, 2023	$ 280,000,000
Expires, 2024	700,000,000
Expires, 2025	125,000,000
Expires, 2026	6,550,000,000
Total	7,655,000,000
Unused	7,596,000,000
Expires within One Year	280,000,000
Southern Company parent
Line of Credit Facility [Line Items]
Expires, 2023	0
Expires, 2024	0
Expires, 2025	0
Expires, 2026	2,000,000,000
Total	2,000,000,000
Unused	1,998,000,000
Expires within One Year	0
ALABAMA POWER CO
Line of Credit Facility [Line Items]
Expires, 2023	0
Expires, 2024	550,000,000
Expires, 2025	0
Expires, 2026	700,000,000
Total	1,250,000,000
Unused	1,250,000,000
Expires within One Year	0
GEORGIA POWER CO
Line of Credit Facility [Line Items]
Expires, 2023	0
Expires, 2024	0
Expires, 2025	0
Expires, 2026	1,750,000,000
Total	1,750,000,000
Unused	1,726,000,000
Expires within One Year	0
MISSISSIPPI POWER CO
Line of Credit Facility [Line Items]
Expires, 2023	0
Expires, 2024	150,000,000
Expires, 2025	125,000,000
Expires, 2026	0
Total	275,000,000
Unused	275,000,000
Expires within One Year	0
SOUTHERN POWER CO
Line of Credit Facility [Line Items]
Expires, 2023	0
Expires, 2024	0
Expires, 2025	0
Expires, 2026	600,000,000
Total	600,000,000
Unused	569,000,000
Expires within One Year	$ 0
Letter of credits not included \| letter_of_credit	2
SOUTHERN POWER CO \| Continuing Letter of Credit Facility A
Line of Credit Facility [Line Items]
Expires, 2023	$ 75,000,000
Expires, 2025	75,000,000
Unused	11,000,000
SOUTHERN POWER CO \| Continuing Letter of Credit Facility B
Line of Credit Facility [Line Items]
Unused	5,000,000
SOUTHERN Co GAS
Line of Credit Facility [Line Items]
Expires, 2023	250,000,000
Expires, 2024	0
Expires, 2025	0
Expires, 2026	1,500,000,000
Total	1,750,000,000
Unused	1,748,000,000
Expires within One Year	250,000,000
SEGCO
Line of Credit Facility [Line Items]
Expires, 2023	30,000,000
Expires, 2024	0
Expires, 2025	0
Expires, 2026	0
Total	30,000,000
Unused	30,000,000
Expires within One Year	30,000,000
Southern Company Gas Capital
Line of Credit Facility [Line Items]
Expires, 2026	800,000,000
Nicor Gas
Line of Credit Facility [Line Items]
Expires, 2026	$ 700,000,000

Financing and Leases - Narrativ

Financing and Leases - Narrative (Details) - USD ($)	Sep. 30, 2022	Mar. 31, 2022
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 7,655,000,000
Variable rate pollution control revenue bonds outstanding	1,400,000,000
MISSISSIPPI POWER CO
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	275,000,000
Variable rate pollution control revenue bonds outstanding	34,000,000
MISSISSIPPI POWER CO \| Line of Credit \| Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity		$ 125,000,000
ALABAMA POWER CO
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	1,250,000,000
Variable rate pollution control revenue bonds outstanding	789,000,000
GEORGIA POWER CO
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	1,750,000,000
Variable rate pollution control revenue bonds outstanding	619,000,000
Fixed rate pollution control revenue bonds outstanding	$ 288,000,000

Financing and Leases - Equity U

Financing and Leases - Equity Units (Details) - USD ($) $ in Thousands		9 Months Ended
	Aug. 01, 2022	Sep. 30, 2022	Sep. 30, 2021	May 31, 2022
Debt Instrument [Line Items]
Proceeds from issuance of common stock		$ 1,803,000	$ 62,000
Series 2019A Remarketable Junior Subordinated Notes \| Junior Subordinated Debt
Debt Instrument [Line Items]
Remarketed principal amount				$ 862,500
Interest rate				4.475%
Series 2019B Remarketable Junior Subordinated Notes \| Junior Subordinated Debt
Debt Instrument [Line Items]
Remarketed principal amount				$ 862,500
Interest rate				5.113%
2019 Series A Equity Units \| Junior Subordinated Debt
Debt Instrument [Line Items]
Common stock issued to settle purchase contracts (in shares)	25,200,000
Proceeds from issuance of common stock	$ 1,725,000

Financing and Leases - Schedu_2

Financing and Leases - Schedule of Shares Used to Compute Diluted Earnings Per Share (Details) - shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Debt Disclosure [Abstract]
As reported shares (in shares)	1,082	1,061	1,070	1,060
Effect of stock-based compensation (in shares)	6	7	6	7
Diluted (in shares)	1,088	1,068	1,076	1,067

Financing and Leases - Georgia

Financing and Leases - Georgia Power Lease Modification (Details) - USD ($) $ in Millions	Sep. 30, 2022	Jul. 31, 2022	Dec. 31, 2021
Lessor, Lease, Description [Line Items]
Operating lease right-of-use assets, net of amortization	$ 1,560		$ 1,701
Revision of Prior Period, Adjustment
Lessor, Lease, Description [Line Items]
Operating lease right-of-use assets, net of amortization		$ (17)
Lease obligations		(18)
Finance lease ROU assets, net		112
Finance lease obligations		$ 113

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Millions	9 Months Ended
Income Taxes - Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Income Tax Contingency [Line Items]
Effective tax (benefit) rate	20%	17.50%
Unrecognized tax positions	$ 79		$ 47
ITC and PTC carryforwards
Income Tax Contingency [Line Items]
Deferred tax assets	$ 1,000		$ 1,200
GEORGIA POWER CO
Income Tax Contingency [Line Items]
Effective tax (benefit) rate	18.50%	7.30%
MISSISSIPPI POWER CO
Income Tax Contingency [Line Items]
Effective tax (benefit) rate	20.10%	14.30%
SOUTHERN POWER CO
Income Tax Contingency [Line Items]
Effective tax (benefit) rate	18.80%	(1.60%)
SOUTHERN Co GAS
Income Tax Contingency [Line Items]
Effective tax (benefit) rate	23.70%	36.60%
Unrecognized tax positions	$ 32

Retirement Benefits (Details)

Retirement Benefits (Details) - USD ($)	3 Months Ended		9 Months Ended
Retirement Benefits (Details) - USD ($)	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, expected future employer contributions, remainder of fiscal year	$ 0		$ 0
Pension Plans and Postretirement Plans
Service cost	103,000,000	$ 109,000,000	309,000,000	$ 326,000,000
Interest cost	102,000,000	87,000,000	306,000,000	260,000,000
Expected return on plan assets	(316,000,000)	(298,000,000)	(949,000,000)	(893,000,000)
Amortization:
Prior service costs	0	0	0	0
Regulatory asset	0	0	0	0
Net loss	60,000,000	78,000,000	180,000,000	235,000,000
Net periodic pension cost (income)	(51,000,000)	(24,000,000)	(154,000,000)	(72,000,000)
Pension Plans \| ALABAMA POWER CO
Pension Plans and Postretirement Plans
Service cost	25,000,000	26,000,000	74,000,000	77,000,000
Interest cost	24,000,000	20,000,000	72,000,000	61,000,000
Expected return on plan assets	(77,000,000)	(72,000,000)	(229,000,000)	(215,000,000)
Amortization:
Prior service costs	0	0	0	0
Regulatory asset	0	0	0	0
Net loss	16,000,000	21,000,000	47,000,000	62,000,000
Net periodic pension cost (income)	(12,000,000)	(5,000,000)	(36,000,000)	(15,000,000)
Pension Plans \| GEORGIA POWER CO
Pension Plans and Postretirement Plans
Service cost	26,000,000	28,000,000	78,000,000	84,000,000
Interest cost	31,000,000	26,000,000	92,000,000	78,000,000
Expected return on plan assets	(99,000,000)	(94,000,000)	(298,000,000)	(282,000,000)
Amortization:
Prior service costs	0	0	1,000,000	1,000,000
Regulatory asset	0	0	0	0
Net loss	18,000,000	25,000,000	55,000,000	75,000,000
Net periodic pension cost (income)	(24,000,000)	(15,000,000)	(72,000,000)	(44,000,000)
Pension Plans \| MISSISSIPPI POWER CO
Pension Plans and Postretirement Plans
Service cost	5,000,000	4,000,000	13,000,000	13,000,000
Interest cost	5,000,000	4,000,000	14,000,000	12,000,000
Expected return on plan assets	(15,000,000)	(14,000,000)	(44,000,000)	(41,000,000)
Amortization:
Prior service costs	0	0	0	0
Regulatory asset	0	0	0	0
Net loss	2,000,000	4,000,000	9,000,000	11,000,000
Net periodic pension cost (income)	(3,000,000)	(2,000,000)	(8,000,000)	(5,000,000)
Pension Plans \| SOUTHERN POWER CO
Pension Plans and Postretirement Plans
Service cost	2,000,000	2,000,000	7,000,000	7,000,000
Interest cost	2,000,000	2,000,000	5,000,000	4,000,000
Expected return on plan assets	(4,000,000)	(4,000,000)	(12,000,000)	(11,000,000)
Amortization:
Prior service costs	0	0	0	0
Regulatory asset	0	0	0	0
Net loss	1,000,000	1,000,000	2,000,000	3,000,000
Net periodic pension cost (income)	1,000,000	1,000,000	2,000,000	3,000,000
Pension Plans \| SOUTHERN Co GAS
Pension Plans and Postretirement Plans
Service cost	9,000,000	10,000,000	26,000,000	28,000,000
Interest cost	7,000,000	6,000,000	21,000,000	18,000,000
Expected return on plan assets	(22,000,000)	(21,000,000)	(68,000,000)	(64,000,000)
Amortization:
Prior service costs	(1,000,000)	(1,000,000)	(2,000,000)	(2,000,000)
Regulatory asset	3,000,000	3,000,000	11,000,000	11,000,000
Net loss	2,000,000	3,000,000	5,000,000	9,000,000
Net periodic pension cost (income)	(2,000,000)	0	(7,000,000)	0
Postretirement Benefits
Pension Plans and Postretirement Plans
Service cost	6,000,000	6,000,000	17,000,000	18,000,000
Interest cost	10,000,000	9,000,000	31,000,000	26,000,000
Expected return on plan assets	(20,000,000)	(19,000,000)	(60,000,000)	(57,000,000)
Amortization:
Prior service costs	(1,000,000)		(1,000,000)	(1,000,000)
Regulatory asset	0	0	0	0
Net loss	1,000,000	1,000,000	1,000,000	3,000,000
Net periodic pension cost (income)	(4,000,000)	(3,000,000)	(12,000,000)	(11,000,000)
Postretirement Benefits \| ALABAMA POWER CO
Pension Plans and Postretirement Plans
Service cost	2,000,000	2,000,000	5,000,000	5,000,000
Interest cost	3,000,000	2,000,000	8,000,000	6,000,000
Expected return on plan assets	(9,000,000)	(8,000,000)	(25,000,000)	(22,000,000)
Amortization:
Prior service costs	0		0	0
Regulatory asset	0	0	0	0
Net loss	0	0	0	0
Net periodic pension cost (income)	(4,000,000)	(4,000,000)	(12,000,000)	(11,000,000)
Postretirement Benefits \| GEORGIA POWER CO
Pension Plans and Postretirement Plans
Service cost	2,000,000	2,000,000	5,000,000	5,000,000
Interest cost	4,000,000	3,000,000	11,000,000	9,000,000
Expected return on plan assets	(8,000,000)	(7,000,000)	(21,000,000)	(20,000,000)
Amortization:
Prior service costs	0		0	0
Regulatory asset	0	0	0	0
Net loss	0	1,000,000	1,000,000	2,000,000
Net periodic pension cost (income)	(2,000,000)	(1,000,000)	(4,000,000)	(4,000,000)
Postretirement Benefits \| MISSISSIPPI POWER CO
Pension Plans and Postretirement Plans
Service cost	1,000,000	1,000,000	1,000,000	1,000,000
Interest cost	0	0	1,000,000	1,000,000
Expected return on plan assets	0	(1,000,000)	(1,000,000)	(2,000,000)
Amortization:
Prior service costs	0		0	0
Regulatory asset	0	0	0	0
Net loss	0	0	0	0
Net periodic pension cost (income)	1,000,000	0	1,000,000	0
Postretirement Benefits \| SOUTHERN POWER CO
Pension Plans and Postretirement Plans
Service cost	1,000,000	1,000,000	1,000,000	1,000,000
Interest cost	0	0	0	0
Expected return on plan assets	0	0	0	0
Amortization:
Prior service costs	0		0	0
Regulatory asset	0	0	0	0
Net loss	0	0	0	0
Net periodic pension cost (income)	1,000,000	1,000,000	1,000,000	1,000,000
Postretirement Benefits \| SOUTHERN Co GAS
Pension Plans and Postretirement Plans
Service cost	0	0	1,000,000	1,000,000
Interest cost	1,000,000	1,000,000	4,000,000	3,000,000
Expected return on plan assets	(2,000,000)	(2,000,000)	(6,000,000)	(6,000,000)
Amortization:
Prior service costs	0		0	0
Regulatory asset	2,000,000	2,000,000	5,000,000	5,000,000
Net loss	(1,000,000)	(1,000,000)	(2,000,000)	(2,000,000)
Net periodic pension cost (income)	$ 0	$ 0	$ 2,000,000	$ 1,000,000

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Assets:
Derivatives	$ 391	$ 213
Liabilities:
Derivatives	666	125
Other	13
Collateral already posted, assets, aggregate fair value	15
Quoted Prices in Active Markets for Identical Assets (Level 1)
Liabilities:
Other	0
Significant Other Observable Inputs (Level 2)
Liabilities:
Other	13
Significant Unobservable Inputs (Level 3)
Liabilities:
Other	0
ALABAMA POWER CO
Assets:
Derivatives	116	50
Liabilities:
Derivatives	4	6
GEORGIA POWER CO
Assets:
Derivatives	105	67
Investments in trusts	46
Liabilities:
Derivatives	10	0
MISSISSIPPI POWER CO
Assets:
Derivatives	113	52
Liabilities:
Derivatives	4	1
SOUTHERN POWER CO
Assets:
Derivatives	4	4
Liabilities:
Derivatives	90	16
Other	13
SOUTHERN POWER CO \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Liabilities:
Other	0
SOUTHERN POWER CO \| Significant Other Observable Inputs (Level 2)
Liabilities:
Other	13
SOUTHERN POWER CO \| Significant Unobservable Inputs (Level 3)
Liabilities:
Other	0
SOUTHERN Co GAS
Assets:
Derivatives	53	27
Liabilities:
Derivatives	91	16
Total
Collateral already posted, assets, aggregate fair value	15	$ 3
Fair Value, Measurements, Recurring
Assets:
Cash equivalents	1,420
Other investments	35
Total	4,008
Liabilities:
Contingent consideration	14
Total	822
Fair Value, Measurements, Recurring \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Cash equivalents	1,402
Other investments	9
Total	2,202
Liabilities:
Contingent consideration	0
Total	20
Fair Value, Measurements, Recurring \| Significant Other Observable Inputs (Level 2)
Assets:
Cash equivalents	18
Other investments	26
Total	1,650
Liabilities:
Contingent consideration	0
Total	788
Fair Value, Measurements, Recurring \| Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents	0
Other investments	0
Total	0
Liabilities:
Contingent consideration	14
Total	14
Fair Value, Measurements, Recurring \| Net Asset Value as a Practical Expedient (NAV)
Assets:
Total	156
Fair Value, Measurements, Recurring \| Energy-related derivatives
Assets:
Derivatives	503
Liabilities:
Derivatives	161
Fair Value, Measurements, Recurring \| Energy-related derivatives \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Derivatives	49
Liabilities:
Derivatives	20
Fair Value, Measurements, Recurring \| Energy-related derivatives \| Significant Other Observable Inputs (Level 2)
Assets:
Derivatives	454
Liabilities:
Derivatives	141
Fair Value, Measurements, Recurring \| Energy-related derivatives \| Significant Unobservable Inputs (Level 3)
Assets:
Derivatives	0
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring \| Interest rate derivatives
Liabilities:
Derivatives	311
Fair Value, Measurements, Recurring \| Interest rate derivatives \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring \| Interest rate derivatives \| Significant Other Observable Inputs (Level 2)
Liabilities:
Derivatives	311
Fair Value, Measurements, Recurring \| Interest rate derivatives \| Significant Unobservable Inputs (Level 3)
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring \| Domestic equity
Assets:
Investments in trusts	771
Fair Value, Measurements, Recurring \| Domestic equity \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	610
Fair Value, Measurements, Recurring \| Domestic equity \| Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	161
Fair Value, Measurements, Recurring \| Domestic equity \| Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| Foreign equity
Assets:
Investments in trusts	240
Fair Value, Measurements, Recurring \| Foreign equity \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	111
Fair Value, Measurements, Recurring \| Foreign equity \| Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	129
Fair Value, Measurements, Recurring \| Foreign equity \| Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| U.S. Treasury and government agency securities
Assets:
Investments in trusts	265
Fair Value, Measurements, Recurring \| U.S. Treasury and government agency securities \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| U.S. Treasury and government agency securities \| Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	265
Fair Value, Measurements, Recurring \| U.S. Treasury and government agency securities \| Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| Municipal bonds
Assets:
Investments in trusts	52
Fair Value, Measurements, Recurring \| Municipal bonds \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| Municipal bonds \| Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	52
Fair Value, Measurements, Recurring \| Municipal bonds \| Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| Pooled funds – fixed income
Assets:
Investments in trusts	7
Fair Value, Measurements, Recurring \| Pooled funds – fixed income \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| Pooled funds – fixed income \| Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	7
Fair Value, Measurements, Recurring \| Pooled funds – fixed income \| Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| Corporate bonds
Assets:
Investments in trusts	438
Fair Value, Measurements, Recurring \| Corporate bonds \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| Corporate bonds \| Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	438
Fair Value, Measurements, Recurring \| Corporate bonds \| Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| Mortgage and asset backed securities
Assets:
Investments in trusts	87
Fair Value, Measurements, Recurring \| Mortgage and asset backed securities \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| Mortgage and asset backed securities \| Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	87
Fair Value, Measurements, Recurring \| Mortgage and asset backed securities \| Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| Private equity
Assets:
Investments in trusts	156
Fair Value, Measurements, Recurring \| Private equity \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| Private equity \| Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| Private equity \| Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| Private equity \| Net Asset Value as a Practical Expedient (NAV)
Assets:
Investments in trusts	156
Fair Value, Measurements, Recurring \| Cash and cash equivalents
Assets:
Investments in trusts	4
Fair Value, Measurements, Recurring \| Cash and cash equivalents \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	4
Fair Value, Measurements, Recurring \| Cash and cash equivalents \| Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| Cash and cash equivalents \| Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| Other
Assets:
Investments in trusts	30
Fair Value, Measurements, Recurring \| Other \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	17
Fair Value, Measurements, Recurring \| Other \| Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	13
Fair Value, Measurements, Recurring \| Other \| Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| Foreign currency derivatives
Liabilities:
Derivatives	323
Fair Value, Measurements, Recurring \| Foreign currency derivatives \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring \| Foreign currency derivatives \| Significant Other Observable Inputs (Level 2)
Liabilities:
Derivatives	323
Fair Value, Measurements, Recurring \| Foreign currency derivatives \| Significant Unobservable Inputs (Level 3)
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring \| ALABAMA POWER CO
Assets:
Cash equivalents	1,243
Other investments	26
Total	2,482
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Cash equivalents	1,225
Other investments	0
Total	1,716
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Significant Other Observable Inputs (Level 2)
Assets:
Cash equivalents	18
Other investments	26
Total	610
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents	0
Other investments	0
Total	0
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Net Asset Value as a Practical Expedient (NAV)
Assets:
Total	156
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Energy-related derivatives
Assets:
Derivatives	147
Liabilities:
Derivatives	35
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Energy-related derivatives \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Derivatives	0
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Energy-related derivatives \| Significant Other Observable Inputs (Level 2)
Assets:
Derivatives	147
Liabilities:
Derivatives	35
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Energy-related derivatives \| Significant Unobservable Inputs (Level 3)
Assets:
Derivatives	0
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Domestic equity
Assets:
Investments in trusts	522
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Domestic equity \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	370
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Domestic equity \| Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	152
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Domestic equity \| Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Foreign equity
Assets:
Investments in trusts	111
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Foreign equity \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	111
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Foreign equity \| Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Foreign equity \| Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| U.S. Treasury and government agency securities
Assets:
Investments in trusts	15
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| U.S. Treasury and government agency securities \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| U.S. Treasury and government agency securities \| Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	15
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| U.S. Treasury and government agency securities \| Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Municipal bonds
Assets:
Investments in trusts	2
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Municipal bonds \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Municipal bonds \| Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	2
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Municipal bonds \| Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Corporate bonds
Assets:
Investments in trusts	230
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Corporate bonds \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Corporate bonds \| Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	230
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Corporate bonds \| Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Mortgage and asset backed securities
Assets:
Investments in trusts	20
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Mortgage and asset backed securities \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Mortgage and asset backed securities \| Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	20
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Mortgage and asset backed securities \| Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Private equity
Assets:
Investments in trusts	156
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Private equity \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Private equity \| Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Private equity \| Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Private equity \| Net Asset Value as a Practical Expedient (NAV)
Assets:
Investments in trusts	156
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Other
Assets:
Investments in trusts	10
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Other \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	10
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Other \| Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| ALABAMA POWER CO \| Other \| Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| GEORGIA POWER CO
Assets:
Total	1,109
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Total	247
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Significant Other Observable Inputs (Level 2)
Assets:
Total	862
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Significant Unobservable Inputs (Level 3)
Assets:
Total	0
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Energy-related derivatives
Assets:
Derivatives	145
Liabilities:
Derivatives	51
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Energy-related derivatives \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Derivatives	0
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Energy-related derivatives \| Significant Other Observable Inputs (Level 2)
Assets:
Derivatives	145
Liabilities:
Derivatives	51
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Energy-related derivatives \| Significant Unobservable Inputs (Level 3)
Assets:
Derivatives	0
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Domestic equity
Assets:
Investments in trusts	241
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Domestic equity \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	240
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Domestic equity \| Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	1
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Domestic equity \| Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Foreign equity
Assets:
Investments in trusts	128
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Foreign equity \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Foreign equity \| Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	128
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Foreign equity \| Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| U.S. Treasury and government agency securities
Assets:
Investments in trusts	250
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| U.S. Treasury and government agency securities \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| U.S. Treasury and government agency securities \| Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	250
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| U.S. Treasury and government agency securities \| Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Municipal bonds
Assets:
Investments in trusts	50
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Municipal bonds \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Municipal bonds \| Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	50
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Municipal bonds \| Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Corporate bonds
Assets:
Investments in trusts	208
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Corporate bonds \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Corporate bonds \| Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	208
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Corporate bonds \| Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Mortgage and asset backed securities
Assets:
Investments in trusts	67
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Mortgage and asset backed securities \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Mortgage and asset backed securities \| Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	67
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Mortgage and asset backed securities \| Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Other
Assets:
Investments in trusts	20
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Other \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	7
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Other \| Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	13
Fair Value, Measurements, Recurring \| GEORGIA POWER CO \| Other \| Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring \| MISSISSIPPI POWER CO
Assets:
Cash equivalents	30
Total	163
Fair Value, Measurements, Recurring \| MISSISSIPPI POWER CO \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Cash equivalents	30
Total	30
Fair Value, Measurements, Recurring \| MISSISSIPPI POWER CO \| Significant Other Observable Inputs (Level 2)
Assets:
Cash equivalents	0
Total	133
Fair Value, Measurements, Recurring \| MISSISSIPPI POWER CO \| Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents	0
Total	0
Fair Value, Measurements, Recurring \| MISSISSIPPI POWER CO \| Energy-related derivatives
Assets:
Derivatives	133
Liabilities:
Derivatives	24
Fair Value, Measurements, Recurring \| MISSISSIPPI POWER CO \| Energy-related derivatives \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Derivatives	0
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring \| MISSISSIPPI POWER CO \| Energy-related derivatives \| Significant Other Observable Inputs (Level 2)
Assets:
Derivatives	133
Liabilities:
Derivatives	24
Fair Value, Measurements, Recurring \| MISSISSIPPI POWER CO \| Energy-related derivatives \| Significant Unobservable Inputs (Level 3)
Assets:
Derivatives	0
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring \| SOUTHERN POWER CO
Liabilities:
Contingent consideration	14
Total	120
Fair Value, Measurements, Recurring \| SOUTHERN POWER CO \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Liabilities:
Contingent consideration	0
Total	0
Fair Value, Measurements, Recurring \| SOUTHERN POWER CO \| Significant Other Observable Inputs (Level 2)
Liabilities:
Contingent consideration	0
Total	106
Fair Value, Measurements, Recurring \| SOUTHERN POWER CO \| Significant Unobservable Inputs (Level 3)
Liabilities:
Contingent consideration	14
Total	14
Fair Value, Measurements, Recurring \| SOUTHERN POWER CO \| Energy-related derivatives
Assets:
Derivatives	7
Liabilities:
Derivatives	13
Fair Value, Measurements, Recurring \| SOUTHERN POWER CO \| Energy-related derivatives \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Derivatives	0
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring \| SOUTHERN POWER CO \| Energy-related derivatives \| Significant Other Observable Inputs (Level 2)
Assets:
Derivatives	7
Liabilities:
Derivatives	13
Fair Value, Measurements, Recurring \| SOUTHERN POWER CO \| Energy-related derivatives \| Significant Unobservable Inputs (Level 3)
Assets:
Derivatives	0
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring \| SOUTHERN POWER CO \| Foreign currency derivatives
Liabilities:
Derivatives	80
Fair Value, Measurements, Recurring \| SOUTHERN POWER CO \| Foreign currency derivatives \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring \| SOUTHERN POWER CO \| Foreign currency derivatives \| Significant Other Observable Inputs (Level 2)
Liabilities:
Derivatives	80
Fair Value, Measurements, Recurring \| SOUTHERN POWER CO \| Foreign currency derivatives \| Significant Unobservable Inputs (Level 3)
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring \| SOUTHERN Co GAS
Assets:
Total	91
Liabilities:
Total	124
Fair Value, Measurements, Recurring \| SOUTHERN Co GAS \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Total	53
Liabilities:
Total	20
Fair Value, Measurements, Recurring \| SOUTHERN Co GAS \| Significant Other Observable Inputs (Level 2)
Assets:
Total	38
Liabilities:
Total	104
Fair Value, Measurements, Recurring \| SOUTHERN Co GAS \| Significant Unobservable Inputs (Level 3)
Assets:
Total	0
Liabilities:
Total	0
Fair Value, Measurements, Recurring \| SOUTHERN Co GAS \| Energy-related derivatives
Assets:
Derivatives	71
Liabilities:
Derivatives	37
Fair Value, Measurements, Recurring \| SOUTHERN Co GAS \| Energy-related derivatives \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Derivatives	49
Liabilities:
Derivatives	20
Fair Value, Measurements, Recurring \| SOUTHERN Co GAS \| Energy-related derivatives \| Significant Other Observable Inputs (Level 2)
Assets:
Derivatives	22
Liabilities:
Derivatives	17
Fair Value, Measurements, Recurring \| SOUTHERN Co GAS \| Energy-related derivatives \| Significant Unobservable Inputs (Level 3)
Assets:
Derivatives	0
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring \| SOUTHERN Co GAS \| Interest rate derivatives
Liabilities:
Derivatives	87
Fair Value, Measurements, Recurring \| SOUTHERN Co GAS \| Interest rate derivatives \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring \| SOUTHERN Co GAS \| Interest rate derivatives \| Significant Other Observable Inputs (Level 2)
Liabilities:
Derivatives	87
Fair Value, Measurements, Recurring \| SOUTHERN Co GAS \| Interest rate derivatives \| Significant Unobservable Inputs (Level 3)
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring \| SOUTHERN Co GAS \| Domestic equity
Assets:
Non-qualified deferred compensation trusts	8
Fair Value, Measurements, Recurring \| SOUTHERN Co GAS \| Domestic equity \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Non-qualified deferred compensation trusts	0
Fair Value, Measurements, Recurring \| SOUTHERN Co GAS \| Domestic equity \| Significant Other Observable Inputs (Level 2)
Assets:
Non-qualified deferred compensation trusts	8
Fair Value, Measurements, Recurring \| SOUTHERN Co GAS \| Domestic equity \| Significant Unobservable Inputs (Level 3)
Assets:
Non-qualified deferred compensation trusts	0
Fair Value, Measurements, Recurring \| SOUTHERN Co GAS \| Foreign equity
Assets:
Non-qualified deferred compensation trusts	1
Fair Value, Measurements, Recurring \| SOUTHERN Co GAS \| Foreign equity \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Non-qualified deferred compensation trusts	0
Fair Value, Measurements, Recurring \| SOUTHERN Co GAS \| Foreign equity \| Significant Other Observable Inputs (Level 2)
Assets:
Non-qualified deferred compensation trusts	1
Fair Value, Measurements, Recurring \| SOUTHERN Co GAS \| Foreign equity \| Significant Unobservable Inputs (Level 3)
Assets:
Non-qualified deferred compensation trusts	0
Fair Value, Measurements, Recurring \| SOUTHERN Co GAS \| Pooled funds – fixed income
Assets:
Non-qualified deferred compensation trusts	7
Fair Value, Measurements, Recurring \| SOUTHERN Co GAS \| Pooled funds – fixed income \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Non-qualified deferred compensation trusts	0
Fair Value, Measurements, Recurring \| SOUTHERN Co GAS \| Pooled funds – fixed income \| Significant Other Observable Inputs (Level 2)
Assets:
Non-qualified deferred compensation trusts	7
Fair Value, Measurements, Recurring \| SOUTHERN Co GAS \| Pooled funds – fixed income \| Significant Unobservable Inputs (Level 3)
Assets:
Non-qualified deferred compensation trusts	0
Fair Value, Measurements, Recurring \| SOUTHERN Co GAS \| Cash equivalents
Assets:
Non-qualified deferred compensation trusts	4
Fair Value, Measurements, Recurring \| SOUTHERN Co GAS \| Cash equivalents \| Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Non-qualified deferred compensation trusts	4
Fair Value, Measurements, Recurring \| SOUTHERN Co GAS \| Cash equivalents \| Significant Other Observable Inputs (Level 2)
Assets:
Non-qualified deferred compensation trusts	0
Fair Value, Measurements, Recurring \| SOUTHERN Co GAS \| Cash equivalents \| Significant Unobservable Inputs (Level 3)
Assets:
Non-qualified deferred compensation trusts	$ 0

Fair Value Measurements - Sch_2

Fair Value Measurements - Schedule of Increase (Decrease) In Fair Value Of Funds (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Fair Value, Option, Quantitative Disclosures [Line Items]
Increase (decrease) in fair value of funds	$ (106)	$ 9	$ (486)	$ 173
ALABAMA POWER CO
Fair Value, Option, Quantitative Disclosures [Line Items]
Increase (decrease) in fair value of funds	(53)	15	(245)	133
GEORGIA POWER CO
Fair Value, Option, Quantitative Disclosures [Line Items]
Increase (decrease) in fair value of funds	$ (53)	$ (6)	$ (241)	$ 40

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) - ALABAMA POWER CO - Private equity $ in Millions	Sep. 30, 2022 USD ($)
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value	$ 156
Unfunded commitments	$ 84

Fair Value Measurements - Sch_3

Fair Value Measurements - Schedule of Financial Instruments for which Carrying Amount did not Equal Fair Value (Details) $ in Millions	Sep. 30, 2022 USD ($)
Long-term debt, including securities due within one year:
Carrying amount	$ 53,400
Fair value	46,400
ALABAMA POWER CO
Long-term debt, including securities due within one year:
Carrying amount	10,800
Fair value	9,300
GEORGIA POWER CO
Long-term debt, including securities due within one year:
Carrying amount	14,500
Fair value	12,600
MISSISSIPPI POWER CO
Long-term debt, including securities due within one year:
Carrying amount	1,500
Fair value	1,200
SOUTHERN POWER CO
Long-term debt, including securities due within one year:
Carrying amount	2,900
Fair value	2,700
SOUTHERN Co GAS
Long-term debt, including securities due within one year:
Carrying amount	7,400
Fair value	$ 6,300

Derivatives - Schedule of Energ

Derivatives - Schedule of Energy-Related Derivatives (Details) - Energy-related, Natural Gas MMBTU in Millions	Sep. 30, 2022 MMBTU
Energy-related derivative contracts
Net Purchased mmBtu	399
ALABAMA POWER CO
Energy-related derivative contracts
Net Purchased mmBtu	105
GEORGIA POWER CO
Energy-related derivative contracts
Net Purchased mmBtu	116
MISSISSIPPI POWER CO
Energy-related derivative contracts
Net Purchased mmBtu	82
SOUTHERN POWER CO
Energy-related derivative contracts
Net Purchased mmBtu	11
SOUTHERN Co GAS
Energy-related derivative contracts
Net Purchased mmBtu	85
SOUTHERN Co GAS \| Energy-related derivatives not designated as hedging instruments \| Long
Energy-related derivative contracts
Derivative nonmonetary notional amount net long short position volume	95.7
SOUTHERN Co GAS \| Energy-related derivatives not designated as hedging instruments \| Short
Energy-related derivative contracts
Derivative nonmonetary notional amount net long short position volume	10.6

Derivatives - Narrative (Detail

Derivatives - Narrative (Details) MMBTU in Millions	9 Months Ended
Derivatives - Narrative (Details) MMBTU in Millions	Sep. 30, 2022 USD ($) MMBTU	Dec. 31, 2021 USD ($)
Derivative [Line Items]
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints \| MMBTU	15
Energy-related derivative hedge gain (loss) to be reclassified within twelve months	$ 17,000,000
Collateral already posted, assets, aggregate fair value	15,000,000
Derivatives	666,000,000	$ 125,000,000
Interest rate derivatives
Derivative [Line Items]
Cash flow hedge gain (loss) to be reclassified within twelve months	(17,000,000)
Derivatives	$ 156,000,000
ALABAMA POWER CO
Derivative [Line Items]
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints \| MMBTU	4
Derivatives	$ 4,000,000	6,000,000
GEORGIA POWER CO
Derivative [Line Items]
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints \| MMBTU	5
Derivatives	$ 10,000,000	0
MISSISSIPPI POWER CO
Derivative [Line Items]
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints \| MMBTU	2
Derivatives	$ 4,000,000	1,000,000
SOUTHERN POWER CO
Derivative [Line Items]
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints \| MMBTU	4
Foreign currency cash flow hedge gain (loss) to be reclassified during next 12 months	$ (12,000,000)
Derivatives	90,000,000	16,000,000
SOUTHERN POWER CO \| Interest rate derivatives
Derivative [Line Items]
Derivatives	38,000,000
Registrants \| Derivative Counterparties
Derivative [Line Items]
Collateral already posted, assets, aggregate fair value	0
SOUTHERN Co GAS
Derivative [Line Items]
Energy-related derivative hedge gain (loss) to be reclassified within twelve months	26,000,000
Collateral already posted, assets, aggregate fair value	15,000,000	3,000,000
Derivatives	$ 91,000,000	$ 16,000,000

Derivatives - Schedule of Inter

Derivatives - Schedule of Interest Rate Derivatives (Details) - Interest rate derivatives $ in Millions	9 Months Ended
	Sep. 30, 2022 USD ($)
Derivative [Line Items]
Notional Amount	$ 2,250
Fair Value Gain (Loss)	(311)
Southern Company parent \| Cash Flow Hedges of Existing Debt
Derivative [Line Items]
Notional Amount	$ 175
Interest Rate Received	0%
Fair Value Gain (Loss)	$ 0
Southern Company parent \| Cash Flow Hedges of Existing Debt \| September 2025
Derivative [Line Items]
Weighted Average Interest Rate Paid	4.25%
Southern Company parent \| Cash Flow Hedges of Existing Debt \| August 2032
Derivative [Line Items]
Weighted Average Interest Rate Paid	3.83%
Southern Company parent \| Fair Value Hedges of Existing Debt \| March 2028
Derivative [Line Items]
Notional Amount	$ 400
Interest Rate Received	1.75%
Fair Value Gain (Loss)	$ (57)
Southern Company parent \| Fair Value Hedges of Existing Debt \| April 2030
Derivative [Line Items]
Notional Amount	$ 1,000
Interest Rate Received	3.70%
Fair Value Gain (Loss)	$ (167)
SOUTHERN Co GAS \| Fair Value Hedges of Existing Debt
Derivative [Line Items]
Notional Amount	$ 500
Interest Rate Received	1.75%
Fair Value Gain (Loss)	$ (87)
London Interbank Offered Rate (LIBOR) \| Southern Company parent \| Fair Value Hedges of Existing Debt \| March 2028
Derivative [Line Items]
Weighted Average Interest Rate Paid	0.68%
London Interbank Offered Rate (LIBOR) \| Southern Company parent \| Fair Value Hedges of Existing Debt \| April 2030
Derivative [Line Items]
Weighted Average Interest Rate Paid	2.36%
London Interbank Offered Rate (LIBOR) \| SOUTHERN Co GAS \| Fair Value Hedges of Existing Debt
Derivative [Line Items]
Weighted Average Interest Rate Paid	0.38%

Derivatives - Schedule of Forei

Derivatives - Schedule of Foreign Currency Derivatives (Details) - 9 months ended Sep. 30, 2022 - Foreign currency derivatives € in Millions, $ in Millions	USD ($)	EUR (€)
Derivative [Line Items]
Pay Notional	$ 2,040
Receive Notional \| €		€ 1,750
Fair Value Gain (Loss)	(323)
Cash Flow Hedges of Existing Debt \| SOUTHERN POWER CO
Derivative [Line Items]
Pay Notional	$ 564
Pay Rate	3.78%
Receive Notional \| €		500
Receive Rate	1.85%
Fair Value Gain (Loss)	$ (80)
Fair Value Hedges of Existing Debt \| Southern Company parent \| April 2030
Derivative [Line Items]
Pay Notional	$ 1,476
Pay Rate	3.39%
Receive Notional \| €		€ 1,250
Receive Rate	1.88%
Fair Value Gain (Loss)	$ (243)

Derivatives - Schedule of Deriv

Derivatives - Schedule of Derivative Category and Balance Sheet Location (Details) - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	$ 504	$ 238
Derivative asset, Gross amounts offset	(113)	(25)
Derivative asset, net amounts recognized in the balance sheets	391	213
Derivative liability, gross amount recognized	794	153
Derivative liability, Gross amounts offset	(128)	(28)
Derivative liability, net amounts recognized in the balance sheets	666	125
Collateral already posted, assets, aggregate fair value	15
Interest rate derivatives
Derivatives, Fair Value [Line Items]
Derivative liability, net amounts recognized in the balance sheets	156
Energy-related derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	21	10
Derivative liability, gross amount recognized	19	4
Energy-related derivatives not designated as hedging instruments \| Energy-related derivatives \| Assets from risk management activities
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	19	9
Energy-related derivatives not designated as hedging instruments \| Energy-related derivatives \| Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	18	4
Energy-related derivatives not designated as hedging instruments \| Energy-related derivatives \| Other deferred charges and assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	2	1
Energy-related derivatives not designated as hedging instruments \| Energy-related derivatives \| Other deferred credits and liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	1	0
Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives designated as hedging instruments for regulatory purposes
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	449	201
Derivative liability, gross amount recognized	129	36
Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Assets from risk management activities
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	299	129
Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	70	30
Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Other deferred charges and assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	150	72
Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Other deferred credits and liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	59	6
Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	34	27
Derivative liability, gross amount recognized	646	113
Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Assets from risk management activities
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	27	7
Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	13	5
Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Other deferred charges and assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	7	1
Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Other deferred credits and liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	1	0
Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Interest rate derivatives \| Assets from risk management activities
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	0	19
Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Interest rate derivatives \| Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	44	0
Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Interest rate derivatives \| Other deferred charges and assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	0	0
Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Interest rate derivatives \| Other deferred credits and liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	266	29
Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Foreign currency derivatives \| Assets from risk management activities
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	0	0
Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Foreign currency derivatives \| Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	37	39
Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Foreign currency derivatives \| Other deferred charges and assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	0	0
Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Foreign currency derivatives \| Other deferred credits and liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	285	40
ALABAMA POWER CO
Derivatives, Fair Value [Line Items]
Derivative asset, Gross amounts offset	(31)	(5)
Derivative asset, net amounts recognized in the balance sheets	116	50
Derivative liability, Gross amounts offset	(31)	(5)
Derivative liability, net amounts recognized in the balance sheets	4	6
ALABAMA POWER CO \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives designated as hedging instruments for regulatory purposes
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	147	55
Derivative liability, gross amount recognized	35	11
ALABAMA POWER CO \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Other current assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	90	30
ALABAMA POWER CO \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	12	9
ALABAMA POWER CO \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Other deferred charges and assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	57	25
ALABAMA POWER CO \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Other deferred credits and liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	23	2
GEORGIA POWER CO
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	146	75
Derivative asset, Gross amounts offset	(41)	(8)
Derivative asset, net amounts recognized in the balance sheets	105	67
Derivative liability, gross amount recognized	51	8
Derivative liability, Gross amounts offset	(41)	(8)
Derivative liability, net amounts recognized in the balance sheets	10	0
GEORGIA POWER CO \| Energy-related derivatives not designated as hedging instruments \| Energy-related derivatives \| Other current assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	1	0
GEORGIA POWER CO \| Energy-related derivatives not designated as hedging instruments \| Energy-related derivatives \| Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	0	0
GEORGIA POWER CO \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives designated as hedging instruments for regulatory purposes
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	145	75
Derivative liability, gross amount recognized	51	8
GEORGIA POWER CO \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Assets from risk management activities
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	107	54
GEORGIA POWER CO \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	28	6
GEORGIA POWER CO \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Other deferred charges and assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	38	21
GEORGIA POWER CO \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Other deferred credits and liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	23	2
MISSISSIPPI POWER CO
Derivatives, Fair Value [Line Items]
Derivative asset, Gross amounts offset	(20)	(4)
Derivative asset, net amounts recognized in the balance sheets	113	52
Derivative liability, Gross amounts offset	(20)	(4)
Derivative liability, net amounts recognized in the balance sheets	4	1
MISSISSIPPI POWER CO \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives designated as hedging instruments for regulatory purposes
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	133	56
Derivative liability, gross amount recognized	24	5
MISSISSIPPI POWER CO \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Assets from risk management activities
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	78	30
MISSISSIPPI POWER CO \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	12	3
MISSISSIPPI POWER CO \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Other deferred charges and assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	55	26
MISSISSIPPI POWER CO \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Other deferred credits and liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	12	2
SOUTHERN POWER CO
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	7	4
Derivative asset, Gross amounts offset	(3)	0
Derivative asset, net amounts recognized in the balance sheets	4	4
Derivative liability, gross amount recognized	93	16
Derivative liability, Gross amounts offset	(3)	0
Derivative liability, net amounts recognized in the balance sheets	90	16
SOUTHERN POWER CO \| Interest rate derivatives
Derivatives, Fair Value [Line Items]
Derivative liability, net amounts recognized in the balance sheets	38
SOUTHERN POWER CO \| Energy-related derivatives not designated as hedging instruments \| Energy-related derivatives \| Other current assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	2	1
SOUTHERN POWER CO \| Energy-related derivatives not designated as hedging instruments \| Energy-related derivatives \| Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	2	0
SOUTHERN POWER CO \| Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	5	3
Derivative liability, gross amount recognized	91	16
SOUTHERN POWER CO \| Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Other current assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	0	2
SOUTHERN POWER CO \| Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	10	0
SOUTHERN POWER CO \| Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Other deferred charges and assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	5	1
SOUTHERN POWER CO \| Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Other deferred credits and liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	1	0
SOUTHERN POWER CO \| Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Foreign currency derivatives \| Other current assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	0	0
SOUTHERN POWER CO \| Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Foreign currency derivatives \| Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	12	16
SOUTHERN POWER CO \| Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Foreign currency derivatives \| Other deferred charges and assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	0	0
SOUTHERN POWER CO \| Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Foreign currency derivatives \| Other deferred credits and liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	68	0
SOUTHERN Co GAS
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	71	35
Derivative asset, Gross amounts offset	(18)	(8)
Derivative asset, net amounts recognized in the balance sheets	53	27
Derivative liability, gross amount recognized	124	27
Derivative liability, Gross amounts offset	(33)	(11)
Derivative liability, net amounts recognized in the balance sheets	91	16
Collateral already posted, assets, aggregate fair value	15	3
SOUTHERN Co GAS \| Energy-related derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	18	9
Derivative liability, gross amount recognized	17	4
SOUTHERN Co GAS \| Energy-related derivatives not designated as hedging instruments \| Energy-related derivatives \| Other current assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	16	8
SOUTHERN Co GAS \| Energy-related derivatives not designated as hedging instruments \| Energy-related derivatives \| Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	16	4
SOUTHERN Co GAS \| Energy-related derivatives not designated as hedging instruments \| Energy-related derivatives \| Other deferred charges and assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	2	1
SOUTHERN Co GAS \| Energy-related derivatives not designated as hedging instruments \| Energy-related derivatives \| Other deferred credits and liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	1	0
SOUTHERN Co GAS \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Other current assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	24	15
SOUTHERN Co GAS \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	17	12
SOUTHERN Co GAS \| Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	29	11
Derivative liability, gross amount recognized	90	11
SOUTHERN Co GAS \| Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Other current assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	26	5
SOUTHERN Co GAS \| Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	3	5
SOUTHERN Co GAS \| Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Other deferred charges and assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	3	0
SOUTHERN Co GAS \| Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Energy-related derivatives \| Other deferred credits and liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	0	0
SOUTHERN Co GAS \| Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Interest rate derivatives \| Other current assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	0	6
SOUTHERN Co GAS \| Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Interest rate derivatives \| Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	13	0
SOUTHERN Co GAS \| Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Interest rate derivatives \| Other deferred charges and assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	0	0
SOUTHERN Co GAS \| Derivatives designated as hedging instruments in cash flow and fair value hedges \| Energy-related derivatives designated as hedging instruments for regulatory purposes \| Interest rate derivatives \| Other deferred credits and liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	$ 74	$ 6

Derivatives - Schedule of Pre-t

Derivatives - Schedule of Pre-tax Effects of Unrealized Derivative Gains (Losses) (Details) - Energy-related derivatives - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	$ 321	$ 155
Other regulatory assets, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(17)	(17)
Other regulatory assets, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(6)
Other regulatory liabilities, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	246	107
Other regulatory liabilities, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	98	65
ALABAMA POWER CO
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	112	44
ALABAMA POWER CO \| Other regulatory assets, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(2)	(6)
ALABAMA POWER CO \| Other regulatory assets, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(2)
ALABAMA POWER CO \| Other regulatory liabilities, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	80	28
ALABAMA POWER CO \| Other regulatory liabilities, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	36	22
GEORGIA POWER CO
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	94	67
GEORGIA POWER CO \| Other regulatory assets, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(8)	0
GEORGIA POWER CO \| Other regulatory assets, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(3)
GEORGIA POWER CO \| Other regulatory liabilities, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	87	48
GEORGIA POWER CO \| Other regulatory liabilities, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	18	19
MISSISSIPPI POWER CO
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	109	51
MISSISSIPPI POWER CO \| Other regulatory assets, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(3)	0
MISSISSIPPI POWER CO \| Other regulatory assets, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(1)
MISSISSIPPI POWER CO \| Other regulatory liabilities, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	69	27
MISSISSIPPI POWER CO \| Other regulatory liabilities, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	44	24
SOUTHERN Co GAS
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	6	(7)
SOUTHERN Co GAS \| Other regulatory assets, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(4)	(11)
SOUTHERN Co GAS \| Other regulatory assets, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	0
SOUTHERN Co GAS \| Other regulatory liabilities, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	10	4
SOUTHERN Co GAS \| Other regulatory liabilities, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	$ 0	$ 0

Derivatives - Schedule of Pre_2

Derivatives - Schedule of Pre-Tax Effects of Hedging on AOCI (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative	$ 2	$ 3	$ (32)	$ (17)
Cash Flow Hedging \| Energy-related derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative	11	38	51	59
Cash Flow Hedging \| Interest rate derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative	6	5	36	7
Cash Flow Hedging \| Foreign currency derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative	(35)	(36)	(137)	(79)
Fair Value Hedging \| Foreign currency derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative	20	(4)	18	(4)
GEORGIA POWER CO \| Cash Flow Hedging \| Interest rate derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative	0	0	31	0
SOUTHERN POWER CO
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative	(46)	(28)	(141)	(63)
SOUTHERN POWER CO \| Cash Flow Hedging \| Energy-related derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative	(11)	8	(4)	16
SOUTHERN POWER CO \| Cash Flow Hedging \| Foreign currency derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative	(35)	(36)	(137)	(79)
SOUTHERN Co GAS
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative	27	30	55	43
SOUTHERN Co GAS \| Cash Flow Hedging \| Energy-related derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative	22	30	55	43
SOUTHERN Co GAS \| Cash Flow Hedging \| Interest rate derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivative	$ 5	$ 0	$ 0	$ 0

Derivatives - Schedule of Pre_3

Derivatives - Schedule of Pre-Tax Effects of Cash Flow and Fair Value Hedging on Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Derivative [Line Items]
Depreciation and amortization	$ 922	$ 896	$ 2,728	$ 2,658
Total interest expense, net of amounts capitalized	(511)	(451)	(1,461)	(1,352)
Total other income (expense), net	132	131	414	290
Natural gas
Derivative [Line Items]
Total cost of sales	294	129	1,840	943
Other Income (Expense)
Derivative [Line Items]
Amount excluded from effectiveness testing recognized in earnings	(21)	4	(17)	4
Cash Flow Hedging \| Energy-related derivatives \| Cost of Sales
Derivative [Line Items]
Gain (loss) on hedges	9	2	28	0
Cash Flow Hedging \| Energy-related derivatives \| Depreciation and Amortization
Derivative [Line Items]
Gain (loss) on hedges	(1)	3	5	6
Cash Flow Hedging \| Interest rate derivatives \| Interest Expense
Derivative [Line Items]
Gain (loss) on hedges	(7)	(7)	(19)	(20)
Cash Flow Hedging \| Foreign currency derivatives \| Interest Expense
Derivative [Line Items]
Gain (loss) on hedges	(3)	(6)	(16)	(18)
Cash Flow Hedging \| Foreign currency derivatives \| Other Income (Expense)
Derivative [Line Items]
Gain (loss) on hedges	(32)	(34)	(129)	(76)
Fair Value Hedging \| Interest rate derivatives \| Interest Expense
Derivative [Line Items]
Gain (loss) on hedges	(102)	(4)	(300)	(16)
Fair Value Hedging \| Foreign currency derivatives \| Other Income (Expense)
Derivative [Line Items]
Gain (loss) on hedges	(59)	(32)	(180)	(32)
SOUTHERN POWER CO
Derivative [Line Items]
Depreciation and amortization	133	132	384	383
Total interest expense, net of amounts capitalized	(32)	(36)	(105)	(111)
Total other income (expense), net	3	2	5	10
SOUTHERN POWER CO \| Cash Flow Hedging \| Energy-related derivatives \| Depreciation and Amortization
Derivative [Line Items]
Gain (loss) on hedges	(1)	3	5	6
SOUTHERN POWER CO \| Cash Flow Hedging \| Foreign currency derivatives \| Interest Expense
Derivative [Line Items]
Gain (loss) on hedges	(3)	(6)	(16)	(18)
SOUTHERN POWER CO \| Cash Flow Hedging \| Foreign currency derivatives \| Other Income (Expense)
Derivative [Line Items]
Gain (loss) on hedges	(32)	(34)	(129)	(76)
SOUTHERN Co GAS
Derivative [Line Items]
Depreciation and amortization	140	133	414	396
Total interest expense, net of amounts capitalized	(65)	(57)	(187)	(175)
Total other income (expense), net	15	13	47	(66)
SOUTHERN Co GAS \| Natural gas
Derivative [Line Items]
Total cost of sales	294	129	1,840	943
SOUTHERN Co GAS \| Cash Flow Hedging \| Energy-related derivatives \| Cost of Sales
Derivative [Line Items]
Gain (loss) on hedges	9	2	28	0
SOUTHERN Co GAS \| Cash Flow Hedging \| Interest rate derivatives \| Interest Expense
Derivative [Line Items]
Gain (loss) on hedges	(2)	(1)	(3)	(2)
SOUTHERN Co GAS \| Fair Value Hedging \| Interest rate derivatives \| Interest Expense
Derivative [Line Items]
Gain (loss) on hedges	$ (30)	$ 0	$ (87)	$ 2

Derivatives - Schedule of Cumul

Derivatives - Schedule of Cumulative Basis Adjustments for Fair Value Hedges (Details) - Fair Value Hedging - Long-term debt - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Derivative [Line Items]
Carrying Amount of the Hedged Item	$ (2,788)	$ (3,280)
Cumulative Amount of Fair Value Hedging Adjustment included in Carrying Amount of the Hedged Item	306	9
SOUTHERN Co GAS
Derivative [Line Items]
Carrying Amount of the Hedged Item	(411)	(493)
Cumulative Amount of Fair Value Hedging Adjustment included in Carrying Amount of the Hedged Item	$ 86	$ 2

Derivatives - Schedule of Pre_4

Derivatives - Schedule of Pre-tax Effect of Interest Rate and Energy Related Derivatives on Income (Details) - Energy-related derivatives not designated as hedging instruments - Energy-related derivatives - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments not designated as hedging instruments, gain (loss), net	$ 1	$ 18	$ (17)	$ (86)
Natural gas revenues
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments not designated as hedging instruments, gain (loss), net	3	(2)	(10)	(122)
Cost of natural gas
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments not designated as hedging instruments, gain (loss), net	$ (2)	$ 20	$ (7)	$ 36

Acquisitions and Dispositions -

Acquisitions and Dispositions - Alabama Power Narrative (Details) - USD ($) $ in Millions		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2022	Sep. 30, 2021
Business Acquisition [Line Items]
Net assets recorded within property, plant, and equipment		$ 5,502	$ 5,222
ALABAMA POWER CO
Business Acquisition [Line Items]
Net assets recorded within property, plant, and equipment		$ 1,483	$ 1,235
ALABAMA POWER CO \| Calhoun Generating Station
Business Acquisition [Line Items]
Purchase price	$ 179
Net assets recorded within property, plant, and equipment	$ 171

Acquisitions and Dispositions_2

Acquisitions and Dispositions - Southern Power Narrative (Details) - SOUTHERN POWER CO - MW	1 Months Ended		9 Months Ended	12 Months Ended
	Mar. 31, 2022	Feb. 28, 2022	Sep. 30, 2022	Dec. 31, 2021
Tranquillity Solar Storage
Business Acquisition [Line Items]
Nameplate capacity placed in service (in MWs)	40		40	32
Garland Solar Storage
Business Acquisition [Line Items]
Nameplate capacity placed in service (in MWs)		15	15	73

Acquisitions and Dispositions_3

Acquisitions and Dispositions - Schedule of Construction Projects (Details) - SOUTHERN POWER CO - MW	1 Months Ended		5 Months Ended	6 Months Ended	9 Months Ended	12 Months Ended
	Mar. 31, 2022	Feb. 28, 2022	Mar. 31, 2022	Feb. 28, 2022	Sep. 30, 2022	Dec. 31, 2021
Garland Solar Storage
Business Acquisition [Line Items]
Approximate Nameplate Capacity (MW)					88
PPA Contract Period				20 years
Nameplate capacity placed in service (in MWs)		15			15	73
Tranquillity Solar Storage
Business Acquisition [Line Items]
Approximate Nameplate Capacity (MW)					72
PPA Contract Period			20 years
Nameplate capacity placed in service (in MWs)	40				40	32

Acquisitions and Dispositions_4

Acquisitions and Dispositions - Southern Company Gas (Details) $ in Millions		3 Months Ended	9 Months Ended
	May 20, 2022 USD ($)	Dec. 31, 2022 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Sep. 07, 2022 USD ($) storageFacility
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale			$ 41	$ 171
SOUTHERN Co GAS
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale			$ 5	$ 127
SOUTHERN Co GAS \| Natural Gas Storage Facilities \| Disposal Group, Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Number of natural gas storage facilities sold \| storageFacility					2
Purchase price					$ 186
SOUTHERN Co GAS \| Natural Gas Storage Facilities \| Disposal Group, Disposed of by Sale \| Scenario, Forecast
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain on sale		$ (125)
Gain (loss) on dispositions, after tax		$ (95)
SOUTHERN Co GAS \| Pivotal LNG \| Disposal Group, Disposed of by Sale
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from divestiture of businesses, amount held back	$ 5

Segment and Related Informati_3

Segment and Related Information - Narrative (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022 USD ($) state	Sep. 30, 2021 USD ($)	Sep. 30, 2022 USD ($) state segment	Sep. 30, 2021 USD ($)
Segment Reporting Information [Line Items]
Number of states in which entity operates \| state	3		3
Operating revenues	$ 7,116	$ 5,732	$ 19,599	$ 18,066
SOUTHERN POWER CO
Segment Reporting Information [Line Items]
Operating revenues	$ 1,010	501	$ 2,157	1,113
SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Number of states in which entity operates \| state	4		4
Operating revenues	$ 843	605	$ 3,948	4,930
Number of reportable segments \| segment			3
SOUTHERN Co GAS \| Southern Natural Gas Company, LLC
Segment Reporting Information [Line Items]
Ownership percentage, equity method investment	50%		50%
SOUTHERN Co GAS \| Dalton Pipeline
Segment Reporting Information [Line Items]
Ownership percentage, equity method investment	50%		50%
SOUTHERN Co GAS \| PennEast Pipeline
Segment Reporting Information [Line Items]
Ownership percentage, equity method investment	20%		20%
Traditional Electric Operating Companies \| Wholesale revenues, affiliates \| SOUTHERN POWER CO
Segment Reporting Information [Line Items]
Operating revenues	$ 336	$ 167	$ 673	361
SOUTHERN POWER CO \| Natural gas \| SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues				$ 18

Segment and Related Informati_4

Segment and Related Information - Schedule of Financial Data for Business Segments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Segment Reporting Information [Line Items]
Operating revenues	$ 8,378	$ 6,238	$ 22,232	$ 17,346
Segment net income (loss)	1,472	1,101	3,611	2,608
Goodwill	5,280		5,280		$ 5,280
Total assets	134,005		134,005		127,534
Estimated loss on Plant Vogtle Units 3 and 4	(70)	264	(18)	772
Gain on sale			41	171
GEORGIA POWER CO
Segment Reporting Information [Line Items]
Operating revenues	3,889	2,856	9,218	7,050
Total assets	52,546		52,546		48,461
Estimated loss on Plant Vogtle Units 3 and 4	(70)	264	(18)	772
Estimated loss on Plant Vogtle Units 3 and 4, net of tax	(52)	197	(13)	576
SOUTHERN POWER CO
Segment Reporting Information [Line Items]
Operating revenues	1,180	679	2,618	1,610
Segment net income (loss)	95	78	265	211
Total assets	13,283		13,283		13,390
Gain on sale			2	39
SOUTHERN POWER CO \| Wind Generating Facility
Segment Reporting Information [Line Items]
Gain on sale				37
Gain on sale, net of tax				28
SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues	857	623	3,998	2,994
Segment net income (loss)	83	56	516	389
Goodwill	5,015		5,015		5,015
Total assets	24,097		24,097		23,560
Gain on sale			5	127
Impairment of PennEast Pipeline investment			0	84
SOUTHERN Co GAS \| Disposal Group, Disposed of by Sale \| Sequent
Segment Reporting Information [Line Items]
Gain on sale			121
Gain (loss) on dispositions, after tax			93
Deferred tax expense, increase from change in appointment rate			85	85
Asset impairment charges, net of tax			93
SOUTHERN Co GAS \| PennEast Pipeline
Segment Reporting Information [Line Items]
Impairment of PennEast Pipeline investment		84		84
Asset impairment charges, net of tax		67		67
Electric Utilities
Segment Reporting Information [Line Items]
Operating revenues	7,427	5,527	17,943	14,051
SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues	857	623	3,998	2,994
Gas distribution operations \| SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Goodwill	4,034		4,034		4,034
Wholesale Gas Services \| SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues				188
Gas marketing services \| SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Goodwill	981		981		981
Operating Segments \| SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues	844	616	3,977	2,989
Segment net income (loss)	81	147	506	479
Total assets	24,625		24,625		23,971
Operating Segments \| Electric Utilities
Segment Reporting Information [Line Items]
Operating revenues	7,427	5,527	17,943	14,051
Segment net income (loss)	1,540	1,163	3,521	2,563
Goodwill	2		2		2
Total assets	108,194		108,194		101,774
Operating Segments \| Traditional Electric Operating Companies
Segment Reporting Information [Line Items]
Operating revenues	6,938	5,018	16,716	12,813
Segment net income (loss)	1,445	1,085	3,256	2,352
Goodwill	0		0		0
Total assets	95,659		95,659		89,051
Operating Segments \| SOUTHERN POWER CO
Segment Reporting Information [Line Items]
Operating revenues	1,180	679	2,618	1,610
Segment net income (loss)	95	78	265	211
Goodwill	2		2		2
Total assets	13,283		13,283		13,390
Operating Segments \| SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues	857	623	3,998	2,994
Segment net income (loss)	83	56	516	389
Goodwill	5,015		5,015		5,015
Total assets	24,097		24,097		23,560
Operating Segments \| Gas distribution operations \| SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues	751	556	3,533	2,466
Segment net income (loss)	59	45	365	308
Total assets	21,605		21,605		20,917
Operating Segments \| Gas Pipeline Investments \| SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues	8	8	24	24
Segment net income (loss)	24	10	76	3
Total assets	1,425		1,425		1,467
Operating Segments \| Wholesale Gas Services \| SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues	0	0	0	188
Segment net income (loss)	0	94	0	108
Total assets	0		0		31
Operating Segments \| Gas marketing services \| SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues	85	52	420	311
Segment net income (loss)	(2)	(2)	65	60
Total assets	1,595		1,595		1,556
Operating Segments \| All Other
Segment Reporting Information [Line Items]
Operating revenues	135	124	418	412
Segment net income (loss)	(152)	(121)	(415)	(338)
Goodwill	263		263		263
Total assets	2,372		2,372		2,975
Operating Segments \| All Other \| SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues	16	11	43	29
Segment net income (loss)	2	(91)	10	(90)
Total assets	9,100		9,100		12,114
Eliminations
Segment Reporting Information [Line Items]
Operating revenues	(41)	(36)	(127)	(111)
Segment net income (loss)	1	3	(11)	(6)
Goodwill	0		0		0
Total assets	(658)		(658)		(775)
Eliminations \| SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues	(3)	(4)	(22)	(24)
Segment net income (loss)	0	0	0	0
Total assets	(9,628)		(9,628)		(12,525)
Eliminations \| Electric Utilities
Segment Reporting Information [Line Items]
Operating revenues	(691)	(170)	(1,391)	(372)
Segment net income (loss)	0	$ 0	0	$ 0
Goodwill	0		0		0
Total assets	$ (748)		$ (748)		$ (667)

Segment and Related Informati_5

Segment and Related Information - Schedule of Financial Data for Products and Services (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Concentration Risk [Line Items]
Operating revenues	$ 8,378	$ 6,238	$ 22,232	$ 17,346
Gain on sale			41	171
Retail
Concentration Risk [Line Items]
Operating revenues	5,961	4,551	14,363	11,492
Wholesale Electric
Concentration Risk [Line Items]
Operating revenues	1,197	731	2,798	1,822
Natural Gas
Concentration Risk [Line Items]
Operating revenues	857	623	3,998	2,994
Electric Utilities
Concentration Risk [Line Items]
Operating revenues	7,427	5,527	17,943	14,051
Electric Utilities \| Retail
Concentration Risk [Line Items]
Operating revenues	5,961	4,551	14,363	11,492
Electric Utilities \| Wholesale Electric
Concentration Risk [Line Items]
Operating revenues	1,197	731	2,798	1,822
Electric Utilities \| Other Revenue
Concentration Risk [Line Items]
Operating revenues	269	245	782	737
Southern Company Gas' Revenues
Concentration Risk [Line Items]
Operating revenues	857	623	3,998	2,994
Southern Company Gas' Revenues \| Gas Distribution Operations
Concentration Risk [Line Items]
Operating revenues	748	553	3,513	2,451
Southern Company Gas' Revenues \| Wholesale Gas Services
Concentration Risk [Line Items]
Operating revenues	0	0	0	188
Southern Company Gas' Revenues \| Gas marketing services
Concentration Risk [Line Items]
Operating revenues	85	52	420	311
Southern Company Gas' Revenues \| Other
Concentration Risk [Line Items]
Operating revenues	24	18	65	44
Southern Company Gas' Revenues
Concentration Risk [Line Items]
Operating revenues	$ 857	623	3,998	2,994
Gain on sale			5	127
Southern Company Gas' Revenues \| PennEast Pipeline
Concentration Risk [Line Items]
Asset impairment charges, net of tax		$ 67		67
Southern Company Gas' Revenues \| Disposal Group, Disposed of by Sale \| Sequent
Concentration Risk [Line Items]
Gain on sale			121
Asset impairment charges, net of tax			93
Deferred tax expense, increase from change in appointment rate			$ 85	85
Southern Company Gas' Revenues \| Wholesale Gas Services
Concentration Risk [Line Items]
Operating revenues				188
Less Gross Gas Costs				3,783
Third Party Gross Revenues \| Southern Company Gas' Revenues \| Wholesale Gas Services
Concentration Risk [Line Items]
Operating revenues				3,881
Intercompany Revenues \| Southern Company Gas' Revenues \| Wholesale Gas Services
Concentration Risk [Line Items]
Operating revenues				90
Total Gross Revenues \| Southern Company Gas' Revenues \| Wholesale Gas Services
Concentration Risk [Line Items]
Operating revenues				$ 3,971