SOUTHERN Co GAS (GAS) 10-Q 26 Apr 23 2023 Q1 Quarterly report Financial data

Cover Page

Cover Page	3 Months Ended
	Mar. 31, 2023 shares
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2023
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)	1,090,402,540
Entity Central Index Key	0000092122
Amendment Flag	false
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q1
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
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
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
	Mar. 31, 2023	Mar. 31, 2022
Operating Revenues:
Total operating revenues	$ 6,480	$ 6,648
Operating Expenses:
Other operations and maintenance	1,482	1,516
Depreciation and amortization	1,111	892
Taxes other than income taxes	394	372
Gain on dispositions, net	(42)	(23)
Total operating expenses	5,262	5,264
Operating Income	1,218	1,384
Other Income and (Expense):
Allowance for equity funds used during construction	65	51
Earnings from equity method investments	48	46
Interest expense, net of amounts capitalized	(582)	(462)
Other income (expense), net	147	145
Total other income and (expense)	(322)	(220)
Earnings Before Income Taxes	896	1,164
Income taxes (benefit)	97	173
Net Income	799	991
Dividends on preferred stock of subsidiaries	0	4
Net loss attributable to noncontrolling interests	(63)	(45)
Net Income	$ 862	$ 1,032
Earnings per share -
Basic (in dollars per share)	$ 0.79	$ 0.97
Diluted (in dollars per share)	$ 0.79	$ 0.97
Average number of shares of common stock outstanding — (in millions)
Basic (in shares)	1,091	1,063
Diluted (in shares)	1,098	1,069
Retail electric revenues
Operating Revenues:
Total operating revenues	$ 3,599	$ 3,613
Wholesale Electric
Operating Revenues:
Total operating revenues	599	664
Other electric revenues
Operating Revenues:
Total operating revenues	190	177
Natural Gas
Operating Revenues:
Total operating revenues	1,875	2,058
Natural gas
Operating Expenses:
Total cost of sales	898	1,095
Alternative revenue programs
Operating Revenues:
Total operating revenues	12	0
Other revenues
Operating Revenues:
Total operating revenues	217	136
Operating Expenses:
Total cost of sales	127	69
Fuel
Operating Expenses:
Total cost of sales	1,050	1,111
Purchased power
Operating Expenses:
Total cost of sales	$ 242	$ 232

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Income (Unaudited) - Southern (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Total operating revenues	$ 6,480	$ 6,648
Natural Gas
Total operating revenues	1,875	2,058
Alternative revenue programs
Total operating revenues	$ 12	$ 0

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - Southern - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 799	$ 991
Qualifying hedges:
Changes in fair value, net of tax	(63)	19
Reclassification adjustment for amounts included in net income, net of tax	19	20
Pension and other postretirement benefit plans:
Reclassification adjustment for amounts included in net income, net of tax	0	3
Total other comprehensive income (loss)	(44)	42
Comprehensive Income	755	1,033
Dividends on preferred stock of subsidiaries	0	4
Comprehensive loss attributable to noncontrolling interests	(63)	(45)
Comprehensive Income	$ 818	$ 1,074

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - Southern (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Statement of Comprehensive Income [Abstract]
Changes in fair value, tax	$ (23)	$ 8
Qualifying hedges, reclassification adjustment, tax	7	6
Reclassification adjustment for amounts included in net income, tax	$ 0	$ 1

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Cash Flows (Unaudited) - Southern - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating Activities:
Net income (loss)	$ 799	$ 991
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	1,233	989
Allowance for equity funds used during construction	(65)	(51)
Pension, postretirement, and other employee benefits	(126)	(123)
Settlement of asset retirement obligations	(113)	(87)
Stock based compensation expense	92	85
Natural gas cost under recovery – long-term	0	162
Retail fuel cost under recovery – long-term	454	(130)
Other, net	51	79
Changes in certain current assets and liabilities —
Receivables	319	(217)
Prepayments	(100)	(86)
Fossil fuel stock	(203)	39
Materials and supplies	(98)	(28)
Natural gas for sale, net of temporary LIFO liquidation	267	450
Other current assets	143	8
Accounts payable	(1,056)	132
Accrued taxes	(237)	(58)
Accrued compensation	(478)	(470)
Accrued interest	(127)	(128)
Natural gas cost over recovery	117	0
Other current liabilities	(28)	35
Net cash provided from operating activities	844	1,592
Investing Activities:
Property additions	(1,850)	(1,419)
Nuclear decommissioning trust fund purchases	(256)	(294)
Nuclear decommissioning trust fund sales	251	289
Proceeds from dispositions	103	91
Cost of removal, net of salvage	(135)	(227)
Construction payables	(140)	23
Other investing activities	(91)	(18)
Net cash used for investing activities	(2,118)	(1,555)
Financing Activities:
Increase in notes payable, net	187	137
Proceeds —
Long-term debt	1,979	700
Short-term borrowings	100	850
Common stock	15	38
Redemptions and repurchases —
Long-term debt	(575)	(977)
Short-term borrowings	(400)	(100)
Capital contributions from noncontrolling interests	21	73
Distributions to noncontrolling interests	(48)	(97)
Payment of common stock dividends	(742)	(702)
Other financing activities	(83)	(115)
Net cash provided from (used for) financing activities	454	(193)
Net Change in Cash, Cash Equivalents, and Restricted Cash	(820)	(156)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	2,037	1,829
Cash, Cash Equivalents, and Restricted Cash at End of Period	1,217	1,673
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	652	515
Income taxes, net	(9)	(8)
Noncash transactions —
Noncash transactions — Accrued property additions at end of period	833	863
Right-of-use assets obtained under operating leases	26	3
Right-of-use assets obtained under finance leases	1	0
Reassessment of right-of-use assets under operating leases	$ 0	$ 40

Condensed Consolidated Statem_6

Condensed Consolidated Statements of Cash Flows (Unaudited) - Southern (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Statement of Cash Flows [Abstract]
Net cash paid for capitalized interest	$ 32	$ 23

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - Southern - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Current Assets:
Cash and cash equivalents	$ 1,053	$ 1,917
Receivables —
Customer accounts	1,890	2,128
Unbilled revenues	596	1,012
Deferred under recovered fuel clause revenues	1,702	2,056
Other accounts and notes	510	637
Accumulated provision for uncollectible accounts	(80)	(71)
Materials and supplies	1,756	1,664
Fossil fuel for generation	778	575
Natural gas for sale	216	438
Prepaid expenses	626	347
Assets from risk management activities, net of collateral	53	115
Regulatory assets – asset retirement obligations	342	332
Natural gas cost under recovery	0	108
Other regulatory assets	936	860
Other current assets	395	344
Total current assets	9,555	10,416
Property, Plant, and Equipment:
In service	118,690	117,529
Less: Accumulated depreciation	35,990	35,297
Plant in service, net of depreciation	82,700	82,232
Other utility plant, net	571	599
Nuclear fuel, at amortized cost	849	843
Construction work in progress	11,510	10,896
Total property, plant, and equipment	95,630	94,570
Other Property and Investments:
Goodwill	5,161	5,161
Nuclear decommissioning trusts, at fair value	2,245	2,145
Equity investments in unconsolidated subsidiaries	1,408	1,443
Other intangible assets, net of amortization	397	406
Miscellaneous property and investments	616	602
Total other property and investments	9,827	9,757
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	1,505	1,531
Deferred charges related to income taxes	876	866
Prepaid pension costs	2,384	2,290
Unamortized loss on reacquired debt	234	238
Under recovered fuel clause revenues	484	10
Regulatory assets – asset retirement obligations, deferred	5,701	5,764
Other regulatory assets, deferred	5,886	5,918
Other deferred charges and assets	1,456	1,485
Total deferred charges and other assets	19,744	20,148
Total Assets	134,756	134,891
Current Liabilities:
Securities due within one year	4,363	4,285
Notes payable	2,554	2,609
Accounts payable	2,365	3,525
Customer deposits	475	502
Accrued taxes —
Accrued income taxes	52	60
Other accrued taxes	435	764
Accrued interest	487	614
Accrued compensation	617	1,127
Asset retirement obligations	709	694
Liabilities from risk management activities, net of collateral	318	178
Operating lease obligations	199	197
Natural gas cost over recovery	117	0
Other regulatory liabilities	287	382
Other current liabilities	915	787
Total current liabilities	13,893	15,724
Long-term Debt	52,060	50,656
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	10,488	10,036
Deferred credits related to income taxes	5,107	5,235
Accumulated deferred ITCs	2,112	2,133
Employee benefit obligations	1,222	1,238
Operating lease obligations, deferred	1,374	1,388
Asset retirement obligations, deferred	10,209	10,146
Other cost of removal obligations	1,921	1,903
Other regulatory liabilities, deferred	690	733
Other deferred credits and liabilities	1,118	1,167
Total deferred credits and other liabilities	34,241	33,979
Total Liabilities	100,194	100,359
Total Stockholders' Equity	34,562	34,532
Total Liabilities and Stockholders' Equity	$ 134,756	$ 134,891

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) - Southern (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Other intangible assets, amortization	$ 350	$ 340

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, 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
Beginning balance (in shares) at Dec. 31, 2022		1,090
Beginning balance (in shares) at Dec. 31, 2022			(1)
Beginning balance at Dec. 31, 2022	34,532	$ 5,417	$ (53)	13,673	11,538	(167)	4,124
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated net income (loss)	799				862		(63)
Other comprehensive income (loss)	(44)					(44)
Stock issued (in shares)		2
Stock issued	15	$ 4		11
Stock-based compensation	29			29
Cash dividends on common stock	(742)				(742)
Capital contributions from noncontrolling interests	21						21
Distributions to noncontrolling interests	(48)						(48)
Other	0		$ (2)	2
Ending balance (in shares) at Mar. 31, 2023		1,092
Ending balance (in shares) at Mar. 31, 2023			(1)
Ending balance at Mar. 31, 2023	$ 34,562	$ 5,421	$ (55)	$ 13,715	$ 11,658	$ (211)	$ 4,034

Condensed Consolidated Statem_8

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - Southern (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Statement of Stockholders' Equity [Abstract]
Cash dividends (in dollars per share)	$ 0.68	$ 0.66

Condensed Statements of Income

Condensed Statements of Income (Unaudited) - APC - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating Revenues:
Total operating revenues	$ 6,480	$ 6,648
Operating Expenses:
Other operations and maintenance	1,482	1,516
Depreciation and amortization	1,111	892
Taxes other than income taxes	394	372
Total operating expenses	5,262	5,264
Operating Income	1,218	1,384
Other Income and (Expense):
Allowance for equity funds used during construction	65	51
Interest expense, net of amounts capitalized	(582)	(462)
Total other income (expense), net	147	145
Total other income and (expense)	(322)	(220)
Earnings Before Income Taxes	896	1,164
Income taxes (benefit)	97	173
Net income	799	991
Dividends on preferred stock of subsidiaries	0	4
Net Income	862	1,032
Retail electric revenues
Operating Revenues:
Total operating revenues	3,599	3,613
Wholesale Electric
Operating Revenues:
Total operating revenues	599	664
Other electric revenues
Operating Revenues:
Total operating revenues	190	177
Natural Gas
Operating Revenues:
Total operating revenues	1,875	2,058
Other revenues
Operating Revenues:
Total operating revenues	217	136
Operating Expenses:
Total cost of sales	127	69
Fuel
Operating Expenses:
Total cost of sales	1,050	1,111
Purchased power
Operating Expenses:
Total cost of sales	242	232
Alabama Power
Operating Revenues:
Total operating revenues	1,647	1,649
Operating Expenses:
Other operations and maintenance	424	409
Depreciation and amortization	345	215
Taxes other than income taxes	115	104
Total operating expenses	1,352	1,154
Operating Income	295	495
Other Income and (Expense):
Allowance for equity funds used during construction	21	16
Interest expense, net of amounts capitalized	(103)	(89)
Total other income (expense), net	40	36
Total other income and (expense)	(42)	(37)
Earnings Before Income Taxes	253	458
Income taxes (benefit)	(2)	107
Net income	255	351
Dividends on preferred stock of subsidiaries	0	4
Net Income	255	347
Alabama Power | Retail electric revenues
Operating Revenues:
Total operating revenues	1,381	1,379
Alabama Power | Wholesale revenues, non-affiliates
Operating Revenues:
Total operating revenues	141	114
Alabama Power | Wholesale revenues, affiliates
Operating Revenues:
Total operating revenues	19	65
Alabama Power | Other revenues
Operating Revenues:
Total operating revenues	106	91
Alabama Power | Fuel
Operating Expenses:
Total cost of sales	308	333
Alabama Power | Purchased power
Operating Expenses:
Total cost of sales	101	67
Alabama Power | Purchased power, affiliates
Operating Expenses:
Total cost of sales	$ 59	$ 26

Condensed Statements of Compreh

Condensed Statements of Comprehensive Income (Unaudited) - APC - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Net income	$ 799	$ 991
Qualifying hedges:
Changes in fair value, net of tax	(63)	19
Reclassification adjustment for amounts included in net income, net of tax	19	20
Total other comprehensive income (loss)	(44)	42
Comprehensive Income	755	1,033
Alabama Power
Net income	255	351
Qualifying hedges:
Changes in fair value, net of tax	0	(1)
Reclassification adjustment for amounts included in net income, net of tax	0	1
Total other comprehensive income (loss)	0	0
Comprehensive Income	$ 255	$ 351

Condensed Statements of Compr_2

Condensed Statements of Comprehensive Income (Unaudited) - APC (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Changes in fair value, tax	$ (23)	$ 8
Qualifying hedges, reclassification adjustment, tax	7	6
Alabama Power
Changes in fair value, tax	0	(1)
Qualifying hedges, reclassification adjustment, tax	$ 0	$ 0

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows (Unaudited) - APC - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating Activities:
Net income (loss)	$ 799	$ 991
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	1,233	989
Pension, postretirement, and other employee benefits	(126)	(123)
Settlement of asset retirement obligations	(113)	(87)
Other, net	51	79
Changes in certain current assets and liabilities —
Receivables	319	(217)
Fossil fuel stock	(203)	39
Prepayments	(100)	(86)
Other current assets	143	8
Accounts payable	(1,056)	132
Accrued taxes	(237)	(58)
Accrued compensation	(478)	(470)
Other current liabilities	(28)	35
Net cash provided from operating activities	844	1,592
Investing Activities:
Property additions	(1,850)	(1,419)
Nuclear decommissioning trust fund purchases	(256)	(294)
Nuclear decommissioning trust fund sales	251	289
Cost of removal, net of salvage	(135)	(227)
Change in construction payables, net	(140)	23
Other investing activities	(91)	(18)
Net cash used for investing activities	(2,118)	(1,555)
Financing Activities:
Increase in notes payable, net	187	137
Payment of common stock dividends	(742)	(702)
Other financing activities	(83)	(115)
Net cash provided from (used for) financing activities	454	(193)
Net Change in Cash, Cash Equivalents, and Restricted Cash	(820)	(156)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	2,037	1,829
Cash, Cash Equivalents, and Restricted Cash at End of Period	1,217	1,673
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	652	515
Income taxes, net	(9)	(8)
Noncash transactions —
Noncash transactions — Accrued property additions at end of period	833	863
Right-of-use assets obtained under finance leases	1	0
Alabama Power
Operating Activities:
Net income (loss)	255	351
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	398	250
Deferred income taxes	(75)	35
Pension, postretirement, and other employee benefits	(51)	(48)
Settlement of asset retirement obligations	(52)	(38)
Retail fuel cost under recovery – long-term	100	(46)
Other, net	(3)	(27)
Changes in certain current assets and liabilities —
Receivables	90	(4)
Fossil fuel stock	(78)	23
Prepayments	(89)	(85)
Other current assets	(37)	(10)
Accounts payable	(400)	(237)
Accrued taxes	109	102
Accrued compensation	(102)	(99)
Other current liabilities	(35)	(13)
Net cash provided from operating activities	30	154
Investing Activities:
Property additions	(389)	(343)
Nuclear decommissioning trust fund purchases	(87)	(72)
Nuclear decommissioning trust fund sales	87	72
Cost of removal, net of salvage	(41)	(60)
Change in construction payables, net	(70)	39
Other investing activities	(9)	(1)
Net cash used for investing activities	(509)	(365)
Financing Activities:
Increase in notes payable, net	170	0
Proceeds — Senior notes	0	700
Other long-term debt	16	0
Senior notes	0	(550)
Capital contributions from parent company	325	625
Payment of common stock dividends	(285)	(254)
Other financing activities	(7)	(17)
Net cash provided from (used for) financing activities	219	504
Net Change in Cash, Cash Equivalents, and Restricted Cash	(260)	293
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	687	1,060
Cash, Cash Equivalents, and Restricted Cash at End of Period	427	1,353
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	138	110
Noncash transactions —
Noncash transactions — Accrued property additions at end of period	111	188
Right-of-use assets obtained under operating leases	13	1
Right-of-use assets obtained under finance leases	$ 1	$ 0

Condensed Statements of Cash _2

Condensed Statements of Cash Flows (Unaudited) - APC (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Net cash paid for capitalized interest	$ 32	$ 23
Alabama Power
Net cash paid for capitalized interest	$ 7	$ 4

Condensed Balance Sheets (Unaud

Condensed Balance Sheets (Unaudited) - APC - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Current Assets:
Cash and cash equivalents	$ 1,053	$ 1,917
Receivables —
Customer accounts	1,890	2,128
Unbilled revenues	596	1,012
Other accounts and notes	510	637
Accumulated provision for uncollectible accounts	(80)	(71)
Fossil fuel for generation	778	575
Materials and supplies	1,756	1,664
Prepaid expenses	626	347
Other regulatory assets	936	860
Other current assets	395	344
Total current assets	9,555	10,416
Property, Plant, and Equipment:
In service	118,690	117,529
Less: Accumulated depreciation	35,990	35,297
Plant in service, net of depreciation	82,700	82,232
Other utility plant, net	571	599
Nuclear fuel, at amortized cost	849	843
Construction work in progress	11,510	10,896
Total property, plant, and equipment	95,630	94,570
Other Property and Investments:
Nuclear decommissioning trusts, at fair value	2,245	2,145
Equity investments in unconsolidated subsidiaries	1,408	1,443
Miscellaneous property and investments	616	602
Total other property and investments	9,827	9,757
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	1,505	1,531
Deferred charges related to income taxes	876	866
Regulatory assets – asset retirement obligations, deferred	5,701	5,764
Other regulatory assets, deferred	5,886	5,918
Other deferred charges and assets	1,456	1,485
Total deferred charges and other assets	19,744	20,148
Total Assets	134,756	134,891
Current Liabilities:
Securities due within one year	4,363	4,285
Notes payable	2,554	2,609
Accounts payable —
Customer deposits	475	502
Accrued interest	487	614
Accrued compensation	617	1,127
Asset retirement obligations	709	694
Other regulatory liabilities	287	382
Other current liabilities	915	787
Total current liabilities	13,893	15,724
Long-term Debt	52,060	50,656
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	10,488	10,036
Deferred credits related to income taxes	5,107	5,235
Accumulated deferred ITCs	2,112	2,133
Employee benefit obligations	1,222	1,238
Operating lease obligations, deferred	1,374	1,388
Asset retirement obligations, deferred	10,209	10,146
Other regulatory liabilities, deferred	690	733
Other deferred credits and liabilities	1,118	1,167
Total deferred credits and other liabilities	34,241	33,979
Total Liabilities	100,194	100,359
Total Stockholders' Equity	34,562	34,532
Total Liabilities and Stockholders' Equity	134,756	134,891
Alabama Power
Current Assets:
Cash and cash equivalents	427	687
Receivables —
Customer accounts	446	431
Unbilled revenues	129	174
Affiliated	98	101
Other accounts and notes	86	153
Accumulated provision for uncollectible accounts	(15)	(14)
Fossil fuel for generation	307	229
Materials and supplies	586	557
Prepaid expenses	136	65
Other regulatory assets	485	474
Other current assets	48	67
Total current assets	2,733	2,924
Property, Plant, and Equipment:
In service	33,803	33,472
Less: Accumulated depreciation	10,664	10,470
Plant in service, net of depreciation	23,139	23,002
Other utility plant, net	571	599
Nuclear fuel, at amortized cost	238	239
Construction work in progress	1,510	1,526
Total property, plant, and equipment	25,458	25,366
Other Property and Investments:
Nuclear decommissioning trusts, at fair value	1,170	1,127
Equity investments in unconsolidated subsidiaries	55	57
Miscellaneous property and investments	125	124
Total other property and investments	1,350	1,308
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	81	71
Deferred charges related to income taxes	253	250
Prepaid pension and other postretirement benefit costs	689	657
Regulatory assets – asset retirement obligations, deferred	1,827	1,845
Other regulatory assets, deferred	2,034	2,107
Other deferred charges and assets	454	442
Total deferred charges and other assets	5,338	5,372
Total Assets	34,879	34,970
Current Liabilities:
Securities due within one year	323	301
Notes payable	170	0
Accounts payable —
Affiliated	242	443
Other	380	641
Customer deposits	105	106
Accrued taxes	148	57
Accrued interest	78	120
Accrued compensation	133	229
Asset retirement obligations	334	330
Other regulatory liabilities	74	96
Other current liabilities	132	91
Total current liabilities	2,119	2,414
Long-term Debt	10,322	10,329
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	3,997	3,981
Deferred credits related to income taxes	1,836	1,925
Accumulated deferred ITCs	79	81
Employee benefit obligations	149	145
Operating lease obligations, deferred	75	67
Asset retirement obligations, deferred	3,940	3,957
Other regulatory liabilities, deferred	300	315
Other deferred credits and liabilities	75	69
Total deferred credits and other liabilities	10,451	10,540
Total Liabilities	22,892	23,283
Total Stockholders' Equity	11,987	11,687
Total Liabilities and Stockholders' Equity	$ 34,879	$ 34,970

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, 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	1,032					347			347
Capital contributions from parent company						626		626
Cash dividends on common stock	(702)			(702)		(254)			(254)
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, 2022							31
Beginning balance at Dec. 31, 2022	34,532	5,417	13,673	11,538	(167)	11,687	$ 1,222	6,710	3,764	(9)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income after dividends on preferred stock	862					255			255
Capital contributions from parent company						330		330
Cash dividends on common stock	(742)			(742)		(285)			(285)
Ending balance (in shares) at Mar. 31, 2023							31
Ending balance at Mar. 31, 2023	$ 34,562	$ 5,421	$ 13,715	$ 11,658	$ (211)	$ 11,987	$ 1,222	$ 7,040	$ 3,734	$ (9)

Condensed Statements of Incom_2

Condensed Statements of Income (Unaudited) - GPC - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating Revenues:
Total operating revenues	$ 6,480	$ 6,648
Operating Expenses:
Other operations and maintenance	1,482	1,516
Depreciation and amortization	1,111	892
Taxes other than income taxes	394	372
Total operating expenses	5,262	5,264
Operating Income	1,218	1,384
Other Income and (Expense):
Allowance for equity funds used during construction	65	51
Interest expense, net of amounts capitalized	(582)	(462)
Other income (expense), net	147	145
Total other income and (expense)	(322)	(220)
Earnings Before Income Taxes	896	1,164
Income taxes (benefit)	97	173
Net Income	799	991
Retail electric revenues
Operating Revenues:
Total operating revenues	3,599	3,613
Wholesale Electric
Operating Revenues:
Total operating revenues	599	664
Other electric revenues
Operating Revenues:
Total operating revenues	190	177
Natural Gas
Operating Revenues:
Total operating revenues	1,875	2,058
Other revenues
Operating Revenues:
Total operating revenues	217	136
Operating Expenses:
Cost of Goods and Services Sold	127	69
Fuel
Operating Expenses:
Cost of Goods and Services Sold	1,050	1,111
Purchased power
Operating Expenses:
Cost of Goods and Services Sold	242	232
GEORGIA POWER CO
Operating Revenues:
Total operating revenues	2,176	2,208
Operating Expenses:
Other operations and maintenance	496	517
Depreciation and amortization	408	351
Taxes other than income taxes	131	125
Total operating expenses	1,766	1,768
Operating Income	410	440
Other Income and (Expense):
Allowance for equity funds used during construction	40	32
Interest expense, net of amounts capitalized	(146)	(107)
Other income (expense), net	45	50
Total other income and (expense)	(61)	(25)
Earnings Before Income Taxes	349	415
Income taxes (benefit)	53	30
Net Income	296	385
GEORGIA POWER CO | Retail electric revenues
Operating Revenues:
Total operating revenues	1,981	2,017
GEORGIA POWER CO | Wholesale Electric
Operating Revenues:
Total operating revenues	31	66
GEORGIA POWER CO | Other revenues
Operating Revenues:
Total operating revenues	164	125
GEORGIA POWER CO | Fuel
Operating Expenses:
Cost of Goods and Services Sold	402	419
GEORGIA POWER CO | Purchased power
Operating Expenses:
Cost of Goods and Services Sold	123	150
GEORGIA POWER CO | Purchased power, affiliates
Operating Expenses:
Cost of Goods and Services Sold	$ 206	$ 206

Condensed Statements of Compr_3

Condensed Statements of Comprehensive Income (Unaudited) - GPC - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Net income	$ 799	$ 991
Qualifying hedges:
Changes in fair value, net of tax	(63)	19
Reclassification adjustment for amounts included in net income, net of tax	19	20
Total other comprehensive income (loss)	(44)	42
Comprehensive Income	755	1,033
GEORGIA POWER CO
Net income	296	385
Qualifying hedges:
Changes in fair value, net of tax	(1)	9
Reclassification adjustment for amounts included in net income, net of tax	1	1
Total other comprehensive income (loss)	0	10
Comprehensive Income	$ 296	$ 395

Condensed Statements of Compr_4

Condensed Statements of Comprehensive Income (Unaudited) - GPC (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Changes in fair value, tax	$ (23)	$ 8
Qualifying hedges, reclassification adjustment, tax	7	6
GEORGIA POWER CO
Changes in fair value, tax	0	3
Qualifying hedges, reclassification adjustment, tax	$ 0	$ 1

Condensed Statements of Cash _3

Condensed Statements of Cash Flows (Unaudited) - GPC - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating Activities:
Net income (loss)	$ 799	$ 991
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	1,233	989
Allowance for equity funds used during construction	(65)	(51)
Pension, postretirement, and other employee benefits	(126)	(123)
Settlement of asset retirement obligations	(113)	(87)
Retail fuel cost under recovery – long-term	454	(130)
Other, net	51	79
Changes in certain current assets and liabilities —
Receivables	319	(217)
Fossil fuel stock	(203)	39
Materials and supplies	(98)	(28)
Other current assets	143	8
Accounts payable	(1,056)	132
Accrued taxes	(237)	(58)
Accrued compensation	(478)	(470)
Accrued interest	(127)	(128)
Other current liabilities	(28)	35
Net cash provided from operating activities	844	1,592
Investing Activities:
Property additions	(1,850)	(1,419)
Nuclear decommissioning trust fund purchases	(256)	(294)
Nuclear decommissioning trust fund sales	251	289
Cost of removal, net of salvage	(135)	(227)
Proceeds from dispositions	103	91
Other investing activities	(91)	(18)
Net cash used for investing activities	(2,118)	(1,555)
Financing Activities:
Increase in notes payable, net	187	137
Proceeds —
Short-term borrowings	100	850
Redemptions and repurchases —
Short-term borrowings	(400)	(100)
Payment of common stock dividends	(742)	(702)
Other financing activities	(83)	(115)
Net cash provided from (used for) financing activities	454	(193)
Net Change in Cash, Cash Equivalents, and Restricted Cash	(820)	(156)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	2,037	1,829
Cash, Cash Equivalents, and Restricted Cash at End of Period	1,217	1,673
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	652	515
Noncash transactions —
Noncash transactions — Accrued property additions at end of period	833	863
Right-of-use assets obtained under operating leases	26	3
GEORGIA POWER CO
Operating Activities:
Net income (loss)	296	385
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	455	397
Deferred income taxes	57	(6)
Allowance for equity funds used during construction	(40)	(32)
Pension, postretirement, and other employee benefits	(64)	(63)
Settlement of asset retirement obligations	(54)	(41)
Storm damage accruals	8	53
Retail fuel cost under recovery – long-term	354	(84)
Other, net	(40)	(54)
Changes in certain current assets and liabilities —
Receivables	(136)	0
Fossil fuel stock	(107)	18
Materials and supplies	(46)	(11)
Other current assets	6	(20)
Accounts payable	(293)	39
Accrued taxes	(266)	(78)
Accrued compensation	(85)	(79)
Customer refunds	(103)	2
Accrued interest	(23)	(43)
Other current liabilities	28	(22)
Net cash provided from operating activities	(53)	361
Investing Activities:
Property additions	(1,042)	(749)
Nuclear decommissioning trust fund purchases	(169)	(221)
Nuclear decommissioning trust fund sales	164	217
Cost of removal, net of salvage	(64)	(140)
Change in construction payables, net of joint owner portion	(27)	14
Proceeds from dispositions	56	56
Other investing activities	(35)	14
Net cash used for investing activities	(1,117)	(809)
Financing Activities:
Increase in notes payable, net	465	410
Proceeds —
Revenue bonds	229	0
Short-term borrowings	100	450
Redemptions and repurchases —
Senior notes	0	(400)
FFB loan	(21)	(24)
Short-term borrowings	(200)	0
Capital contributions from parent company	750	445
Payment of common stock dividends	(464)	(423)
Other financing activities	(9)	(17)
Net cash provided from (used for) financing activities	850	441
Net Change in Cash, Cash Equivalents, and Restricted Cash	(320)	(7)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	480	33
Cash, Cash Equivalents, and Restricted Cash at End of Period	160	26
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	159	139
Noncash transactions —
Noncash transactions — Accrued property additions at end of period	548	459
Right-of-use assets obtained under operating leases	$ 3	$ 1

Condensed Statements of Cash _4

Condensed Statements of Cash Flows (Unaudited) - GPC (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Net cash paid for capitalized interest	$ 32	$ 23
GEORGIA POWER CO
Net cash paid for capitalized interest	$ 21	$ 16

Condensed Balance Sheets (Una_2

Condensed Balance Sheets (Unaudited) - GPC - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Current Assets:
Cash and cash equivalents	$ 1,053	$ 1,917
Receivables —
Customer accounts	1,890	2,128
Unbilled revenues	596	1,012
Other accounts and notes	510	637
Fossil fuel for generation	778	575
Materials and supplies	1,756	1,664
Regulatory assets – asset retirement obligations	342	332
Assets from risk management activities	53	115
Other regulatory assets	936	860
Other current assets	395	344
Total current assets	9,555	10,416
Property, Plant, and Equipment:
In service	118,690	117,529
Less: Accumulated depreciation	35,990	35,297
Plant in service, net of depreciation	82,700	82,232
Nuclear fuel, at amortized cost	849	843
Construction work in progress	11,510	10,896
Total property, plant, and equipment	95,630	94,570
Other Property and Investments:
Nuclear decommissioning trusts, at fair value	2,245	2,145
Equity investments in unconsolidated subsidiaries	1,408	1,443
Miscellaneous property and investments	616	602
Total other property and investments	9,827	9,757
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	1,505	1,531
Deferred charges related to income taxes	876	866
Prepaid pension costs	2,384	2,290
Deferred under recovered fuel clause revenues	1,702	2,056
Regulatory assets – asset retirement obligations, deferred	5,701	5,764
Other regulatory assets, deferred	5,886	5,918
Other deferred charges and assets	1,456	1,485
Total deferred charges and other assets	19,744	20,148
Total Assets	134,756	134,891
Current Liabilities:
Securities due within one year	4,363	4,285
Notes payable	2,554	2,609
Accounts payable —
Customer deposits	475	502
Accrued interest	487	614
Accrued compensation	617	1,127
Operating lease obligations	199	197
Asset retirement obligations	709	694
Other regulatory liabilities	287	382
Other current liabilities	915	787
Total current liabilities	13,893	15,724
Long-term Debt	52,060	50,656
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	10,488	10,036
Deferred credits related to income taxes	5,107	5,235
Accumulated deferred ITCs	2,112	2,133
Employee benefit obligations	1,222	1,238
Operating lease obligations, deferred	1,374	1,388
Asset retirement obligations, deferred	10,209	10,146
Other deferred credits and liabilities	1,118	1,167
Total deferred credits and other liabilities	34,241	33,979
Total Liabilities	100,194	100,359
Total Stockholders' Equity	34,562	34,532
Total Liabilities and Stockholders' Equity	134,756	134,891
GEORGIA POWER CO
Current Assets:
Cash and cash equivalents	0	364
Receivables —
Customer accounts	597	735
Unbilled revenues	197	309
Under recovered fuel clause revenues	447	0
Joint owner accounts	100	128
Affiliated	59	53
Other accounts and notes	45	62
Fossil fuel for generation	399	291
Materials and supplies	774	729
Regulatory assets – asset retirement obligations	166	158
Other regulatory assets	377	324
Other current assets	264	246
Total current assets	3,425	3,399
Property, Plant, and Equipment:
In service	42,465	41,879
Less: Accumulated depreciation	13,383	13,115
Plant in service, net of depreciation	29,082	28,764
Nuclear fuel, at amortized cost	611	604
Construction work in progress	8,639	8,103
Total property, plant, and equipment	38,332	37,471
Other Property and Investments:
Nuclear decommissioning trusts, at fair value	1,075	1,018
Equity investments in unconsolidated subsidiaries	50	51
Miscellaneous property and investments	116	107
Total other property and investments	1,241	1,176
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	974	1,007
Deferred charges related to income taxes	592	583
Prepaid pension costs	771	738
Deferred under recovered fuel clause revenues	1,702	2,056
Regulatory assets – asset retirement obligations, deferred	3,635	3,671
Other regulatory assets, deferred	2,576	2,522
Other deferred charges and assets	489	540
Total deferred charges and other assets	10,739	11,117
Total Assets	53,737	53,163
Current Liabilities:
Securities due within one year	901	901
Notes payable	1,965	1,600
Accounts payable —
Affiliated	606	928
Other	1,099	1,076
Customer deposits	251	252
Accrued taxes	222	508
Accrued interest	133	157
Accrued compensation	133	254
Operating lease obligations	154	151
Asset retirement obligations	308	295
Other regulatory liabilities	47	170
Other current liabilities	426	286
Total current liabilities	6,245	6,578
Long-term Debt	14,219	14,009
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	3,818	3,707
Deferred credits related to income taxes	2,220	2,244
Accumulated deferred ITCs	316	319
Employee benefit obligations	310	318
Operating lease obligations, deferred	840	851
Asset retirement obligations, deferred	5,820	5,739
Other deferred credits and liabilities	506	540
Total deferred credits and other liabilities	13,830	13,718
Total Liabilities	34,294	34,305
Total Stockholders' Equity	19,443	18,858
Total Liabilities and Stockholders' Equity	$ 53,737	$ 53,163

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, 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	991					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)
Other	(7)		(7)	(2)
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, 2022							9
Beginning balance at Dec. 31, 2022	34,532	5,417	13,673	11,538	(167)	18,858	$ 398	15,626	2,846	(12)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	799					296			296
Capital contributions from parent company						752		752
Other comprehensive income (loss)	(44)				(44)
Cash dividends on common stock	(742)			(742)		(464)			(464)
Other	0		(2)			(1)			(1)
Ending balance (in shares) at Mar. 31, 2023							9
Ending balance at Mar. 31, 2023	$ 34,562	$ 5,421	$ 13,715	$ 11,658	$ (211)	$ 19,443	$ 398	$ 16,378	$ 2,679	$ (12)

Condensed Statements of Commo_3

Condensed Statements of Common Stockholders' Equity (Unaudited) - GPC (Parenthetical) - $ / shares	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Statement of Stockholders' Equity [Abstract]
Cash dividends (in dollars per share)	$ 0.68	$ 0.66

Condensed Statements of Incom_3

Condensed Statements of Income (Unaudited) - MPC - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating Revenues:
Total operating revenues	$ 6,480	$ 6,648
Operating Expenses:
Other operations and maintenance	1,482	1,516
Depreciation and amortization	1,111	892
Taxes other than income taxes	394	372
Total operating expenses	5,262	5,264
Operating Income	1,218	1,384
Other Income and (Expense):
Interest expense, net of amounts capitalized	(582)	(462)
Other income (expense), net	147	145
Total other income and (expense)	(322)	(220)
Earnings Before Income Taxes	896	1,164
Income taxes (benefit)	97	173
Net Income	799	991
Retail electric revenues
Operating Revenues:
Total operating revenues	3,599	3,613
Wholesale Electric
Operating Revenues:
Total operating revenues	599	664
Other electric revenues
Operating Revenues:
Total operating revenues	190	177
Natural Gas
Operating Revenues:
Total operating revenues	1,875	2,058
Other revenues
Operating Revenues:
Total operating revenues	217	136
Operating Expenses:
Total cost of sales	127	69
Mississippi Power
Operating Revenues:
Total operating revenues	390	335
Operating Expenses:
Other operations and maintenance	82	76
Depreciation and amortization	47	45
Taxes other than income taxes	32	29
Total operating expenses	312	282
Operating Income	78	53
Other Income and (Expense):
Interest expense, net of amounts capitalized	(16)	(13)
Other income (expense), net	9	10
Total other income and (expense)	(7)	(3)
Earnings Before Income Taxes	71	50
Income taxes (benefit)	13	8
Net Income	58	42
Mississippi Power | Retail electric revenues
Operating Revenues:
Total operating revenues	236	217
Mississippi Power | Wholesale revenues, non-affiliates
Operating Revenues:
Total operating revenues	68	68
Mississippi Power | Wholesale revenues, affiliates
Operating Revenues:
Total operating revenues	75	42
Mississippi Power | Other revenues
Operating Revenues:
Total operating revenues	11	8
Mississippi Power | Fuel and purchased power
Operating Expenses:
Total cost of sales	$ 151	$ 132

Condensed Statements of Cash _5

Condensed Statements of Cash Flows (Unaudited) - MPC - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating Activities:
Net income (loss)	$ 799	$ 991
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	1,233	989
Settlement of asset retirement obligations	(113)	(87)
Other, net	51	79
Changes in certain current assets and liabilities —
Receivables	319	(217)
Other current assets	143	8
Accounts payable	(1,056)	132
Accrued taxes	(237)	(58)
Accrued compensation	(478)	(470)
Other current liabilities	(28)	35
Net cash provided from operating activities	844	1,592
Investing Activities:
Property additions	(1,850)	(1,419)
Construction payables	(140)	23
Other investing activities	(91)	(18)
Net cash used for investing activities	(2,118)	(1,555)
Financing Activities:
Increase in notes payable, net	187	137
Payment of common stock dividends	(742)	(702)
Other financing activities	(83)	(115)
Net cash provided from (used for) financing activities	454	(193)
Net Change in Cash, Cash Equivalents, and Restricted Cash	(820)	(156)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	2,037	1,829
Cash, Cash Equivalents, and Restricted Cash at End of Period	1,217	1,673
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	652	515
Noncash transactions —
Noncash transactions — Accrued property additions at end of period	833	863
Right-of-use assets obtained under operating leases	26	3
Mississippi Power
Operating Activities:
Net income (loss)	58	42
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	58	55
Settlement of asset retirement obligations	(3)	(5)
Other, net	(5)	17
Changes in certain current assets and liabilities —
Receivables	73	(7)
Retail fuel cost under recovery	(23)	(11)
Other current assets	(1)	(11)
Accounts payable	(74)	(9)
Accrued taxes	(62)	(63)
Accrued compensation	(17)	(18)
Other current liabilities	(7)	(6)
Net cash provided from operating activities	(3)	(16)
Investing Activities:
Property additions	(94)	(45)
Construction payables	(9)	(8)
Payments pursuant to LTSAs	(8)	(8)
Other investing activities	(6)	(7)
Net cash used for investing activities	(117)	(68)
Financing Activities:
Increase in notes payable, net	126	25
Capital contributions from parent company	0	50
Payment of common stock dividends	(46)	(43)
Other financing activities	(1)	0
Net cash provided from (used for) financing activities	79	32
Net Change in Cash, Cash Equivalents, and Restricted Cash	(41)	(52)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	59	61
Cash, Cash Equivalents, and Restricted Cash at End of Period	18	9
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	25	22
Noncash transactions —
Noncash transactions — Accrued property additions at end of period	13	17
Right-of-use assets obtained under operating leases	$ 1	$ 0

Condensed Balance Sheets (Una_3

Condensed Balance Sheets (Unaudited) - MPC - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Current Assets:
Cash and cash equivalents	$ 1,053	$ 1,917
Receivables —
Customer accounts	1,890	2,128
Unbilled revenues	596	1,012
Other accounts and notes	510	637
Fossil fuel for generation	778	575
Materials and supplies	1,756	1,664
Assets from risk management activities	53	115
Other regulatory assets	936	860
Other current assets	395	344
Total current assets	9,555	10,416
Property, Plant, and Equipment:
In service	118,690	117,529
Less: Accumulated depreciation	35,990	35,297
Plant in service, net of depreciation	82,700	82,232
Construction work in progress	11,510	10,896
Total property, plant, and equipment	95,630	94,570
Other Property and Investments:
Total other property and investments	9,827	9,757
Deferred Charges and Other Assets:
Deferred charges related to income taxes	876	866
Regulatory assets – asset retirement obligations, deferred	5,701	5,764
Other regulatory assets, deferred	5,886	5,918
Other deferred charges and assets	1,456	1,485
Total deferred charges and other assets	19,744	20,148
Total Assets	134,756	134,891
Current Liabilities:
Securities due within one year	4,363	4,285
Notes payable	2,554	2,609
Accounts payable —
Accrued compensation	617	1,127
Asset retirement obligations	709	694
Other regulatory liabilities	287	382
Other current liabilities	915	787
Total current liabilities	13,893	15,724
Long-term Debt	52,060	50,656
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	10,488	10,036
Deferred credits related to income taxes	5,107	5,235
Employee benefit obligations	1,222	1,238
Asset retirement obligations, deferred	10,209	10,146
Other cost of removal obligations	1,921	1,903
Other regulatory liabilities, deferred	690	733
Other deferred credits and liabilities	1,118	1,167
Total deferred credits and other liabilities	34,241	33,979
Total Liabilities	100,194	100,359
Total Liabilities and Stockholders' Equity	134,756	134,891
Mississippi Power
Current Assets:
Cash and cash equivalents	18	59
Receivables —
Customer accounts	69	47
Unbilled revenues	37	47
Affiliated	26	82
Other accounts and notes	29	35
Fossil fuel for generation	51	44
Materials and supplies	80	80
Other regulatory assets	80	72
Other current assets	13	38
Total current assets	403	504
Property, Plant, and Equipment:
In service	5,319	5,254
Less: Accumulated depreciation	1,723	1,689
Plant in service, net of depreciation	3,596	3,565
Construction work in progress	225	208
Total property, plant, and equipment	3,821	3,773
Other Property and Investments:
Total other property and investments	165	167
Deferred Charges and Other Assets:
Deferred charges related to income taxes	29	30
Prepaid pension costs	114	109
Regulatory assets – asset retirement obligations, deferred	239	239
Other regulatory assets, deferred	253	249
Accumulated deferred income taxes	103	107
Other deferred charges and assets	89	94
Total deferred charges and other assets	827	828
Total Assets	5,216	5,272
Current Liabilities:
Securities due within one year	1	1
Notes payable	126	0
Accounts payable —
Affiliated	69	121
Other	75	106
Accrued taxes	62	124
Accrued compensation	20	37
Asset retirement obligations	35	37
Other regulatory liabilities	25	43
Other current liabilities	81	85
Total current liabilities	494	554
Long-term Debt	1,544	1,544
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	470	466
Deferred credits related to income taxes	247	253
Employee benefit obligations	69	69
Asset retirement obligations, deferred	143	142
Other cost of removal obligations	196	196
Other regulatory liabilities, deferred	84	96
Other deferred credits and liabilities	26	21
Total deferred credits and other liabilities	1,235	1,243
Total Liabilities	3,273	3,341
Total common stockholders' equity	1,943	1,931
Total Liabilities and Stockholders' Equity	$ 5,216	$ 5,272

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)
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)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,032					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)
Beginning balance (in shares) at Dec. 31, 2022							1
Beginning balance at Dec. 31, 2022	34,532	5,417	13,673	11,538	(167)	1,931	$ 38	4,652	(2,759)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	862					58			58
Cash dividends on common stock	(742)			(742)		(46)			(46)
Other	0		2
Ending balance (in shares) at Mar. 31, 2023							1
Ending balance at Mar. 31, 2023	$ 34,562	$ 5,421	$ 13,715	$ 11,658	$ (211)	$ 1,943	$ 38	$ 4,652	$ (2,747)

Condensed Consolidated Statem_9

Condensed Consolidated Statements of Income (Unaudited) - SPC - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating Revenues:
Total operating revenues	$ 6,480	$ 6,648
Operating Expenses:
Other operations and maintenance	1,482	1,516
Depreciation and amortization	1,111	892
Taxes other than income taxes	394	372
Gain on dispositions, net	(42)	(23)
Total operating expenses	5,262	5,264
Operating Income	1,218	1,384
Other Income and (Expense):
Interest expense, net of amounts capitalized	(582)	(462)
Other income (expense), net	147	145
Total other income and (expense)	(322)	(220)
Earnings Before Income Taxes	896	1,164
Income taxes (benefit)	97	173
Net Income	799	991
Net loss attributable to noncontrolling interests	(63)	(45)
Retail electric revenues
Operating Revenues:
Total operating revenues	3,599	3,613
Wholesale Electric
Operating Revenues:
Total operating revenues	599	664
Other electric revenues
Operating Revenues:
Total operating revenues	190	177
Natural Gas
Operating Revenues:
Total operating revenues	1,875	2,058
Other revenues
Operating Revenues:
Total operating revenues	217	136
Operating Expenses:
Total cost of sales	127	69
Fuel
Operating Expenses:
Total cost of sales	1,050	1,111
Purchased power
Operating Expenses:
Total cost of sales	242	232
SOUTHERN POWER CO
Operating Revenues:
Total operating revenues	508	539
Operating Expenses:
Other operations and maintenance	107	105
Depreciation and amortization	128	120
Taxes other than income taxes	13	13
Gain on dispositions, net	(20)	(2)
Total operating expenses	445	489
Operating Income	63	50
Other Income and (Expense):
Interest expense, net of amounts capitalized	(33)	(37)
Other income (expense), net	2	2
Total other income and (expense)	(31)	(35)
Earnings Before Income Taxes	32	15
Income taxes (benefit)	(7)	(12)
Net Income	39	27
Net loss attributable to noncontrolling interests	(63)	(45)
Net Income	102	72
SOUTHERN POWER CO | Wholesale revenues, non-affiliates
Operating Revenues:
Total operating revenues	362	426
SOUTHERN POWER CO | Wholesale revenues, affiliates
Operating Revenues:
Total operating revenues	135	105
SOUTHERN POWER CO | Other revenues
Operating Revenues:
Total operating revenues	11	8
SOUTHERN POWER CO | Fuel
Operating Expenses:
Total cost of sales	191	232
SOUTHERN POWER CO | Purchased power
Operating Expenses:
Total cost of sales	$ 26	$ 21

Condensed Consolidated State_10

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - SPC - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Net income	$ 799	$ 991
Qualifying hedges:
Changes in fair value, net of tax	(63)	19
Reclassification adjustment for amounts included in net income, net of tax	19	20
Total other comprehensive income (loss)	(44)	42
Comprehensive Income	755	1,033
Comprehensive loss attributable to noncontrolling interests	(63)	(45)
Comprehensive Income	818	1,074
SOUTHERN POWER CO
Net income	39	27
Qualifying hedges:
Changes in fair value, net of tax	(8)	(17)
Reclassification adjustment for amounts included in net income, net of tax	1	22
Total other comprehensive income (loss)	(7)	5
Comprehensive Income	32	32
Comprehensive loss attributable to noncontrolling interests	(63)	(45)
Comprehensive Income	$ 95	$ 77

Condensed Consolidated State_11

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - SPC (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Changes in fair value, tax	$ (23)	$ 8
Qualifying hedges, reclassification adjustment, tax	7	6
SOUTHERN POWER CO
Changes in fair value, tax	(3)	(6)
Qualifying hedges, reclassification adjustment, tax	$ 0	$ 7

Condensed Consolidated State_12

Condensed Consolidated Statements of Cash Flows (Unaudited) - SPC - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating Activities:
Net income (loss)	$ 799	$ 991
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	1,233	989
Other, net	51	79
Changes in certain current assets and liabilities —
Receivables	319	(217)
Other current assets	143	8
Accounts payable	(1,056)	132
Accrued compensation	(478)	(470)
Other current liabilities	(28)	35
Net cash provided from operating activities	844	1,592
Investing Activities:
Property additions	(1,850)	(1,419)
Other investing activities	(91)	(18)
Net cash used for investing activities	(2,118)	(1,555)
Financing Activities:
Capital contributions from noncontrolling interests	21	73
Distributions to noncontrolling interests	(48)	(97)
Payment of common stock dividends	(742)	(702)
Other financing activities	(83)	(115)
Net cash provided from (used for) financing activities	454	(193)
Net Change in Cash, Cash Equivalents, and Restricted Cash	(820)	(156)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	2,037	1,829
Cash, Cash Equivalents, and Restricted Cash at End of Period	1,217	1,673
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	652	515
Income taxes, net	(9)	(8)
Noncash transactions —
Noncash transactions — Accrued property additions at end of period	833	863
Reassessment of right-of-use assets under operating leases	0	40
SOUTHERN POWER CO
Operating Activities:
Net income (loss)	39	27
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	133	126
Deferred income taxes	3	12
Amortization of investment tax credits	(15)	(15)
Gain on dispositions, net	(20)	(2)
Other, net	(14)	(3)
Changes in certain current assets and liabilities —
Receivables	120	11
Prepaid income taxes	15	(8)
Other current assets	(13)	0
Accounts payable	(92)	(21)
Accrued compensation	(13)	(13)
Other current liabilities	(8)	3
Net cash provided from operating activities	135	117
Investing Activities:
Property additions	(11)	(19)
Proceeds from dispositions	46	29
Change in construction payables	(15)	(31)
Payments pursuant to LTSAs	(16)	(15)
Other investing activities	0	(1)
Net cash used for investing activities	4	(37)
Financing Activities:
Decrease in notes payable, net	(59)	(3)
Capital contributions from noncontrolling interests	21	73
Distributions to noncontrolling interests	(48)	(97)
Payment of common stock dividends	(63)	(49)
Other financing activities	3	0
Net cash provided from (used for) financing activities	(146)	(76)
Net Change in Cash, Cash Equivalents, and Restricted Cash	(7)	4
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	133	135
Cash, Cash Equivalents, and Restricted Cash at End of Period	126	139
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	30	29
Income taxes, net	(9)	(8)
Noncash transactions —
Noncash transactions — Accrued property additions at end of period	12	46
Reassessment of right-of-use assets under operating leases	$ 0	$ 40

Condensed Consolidated State_13

Condensed Consolidated Statements of Cash Flows (Unaudited) - SPC (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Net cash paid for capitalized interest	$ 32	$ 23

Condensed Consolidated Balanc_3

Condensed Consolidated Balance Sheets (Unaudited) - SPC - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Current Assets:
Cash and cash equivalents	$ 1,053	$ 1,917
Receivables —
Customer accounts	1,890	2,128
Other accounts and notes	510	637
Materials and supplies	1,756	1,664
Other current assets	395	344
Total current assets	9,555	10,416
Property, Plant, and Equipment:
In service	118,690	117,529
Less: Accumulated depreciation	35,990	35,297
Plant in service, net of depreciation	82,700	82,232
Construction work in progress	11,510	10,896
Total property, plant, and equipment	95,630	94,570
Other Property and Investments:
Equity investments in unconsolidated subsidiaries	1,408	1,443
Total other property and investments	9,827	9,757
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	1,505	1,531
Other deferred charges and assets	1,456	1,485
Total deferred charges and other assets	19,744	20,148
Total Assets	134,756	134,891
Current Liabilities:
Securities due within one year	4,363	4,285
Notes payable	2,554	2,609
Accounts payable —
Accrued interest	487	614
Other current liabilities	915	787
Total current liabilities	13,893	15,724
Long-term Debt	52,060	50,656
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	10,488	10,036
Accumulated deferred ITCs	2,112	2,133
Operating lease obligations, deferred	1,374	1,388
Other deferred credits and liabilities	1,118	1,167
Total deferred credits and other liabilities	34,241	33,979
Total Liabilities	100,194	100,359
Total Stockholders' Equity (See accompanying statements)	34,562	34,532
Total Liabilities and Stockholders' Equity	134,756	134,891
SOUTHERN POWER CO
Current Assets:
Cash and cash equivalents	123	131
Receivables —
Customer accounts	133	226
Affiliated	39	51
Other accounts and notes	71	70
Materials and supplies	85	88
Prepaid income taxes	291	5
Other current assets	59	50
Total current assets	801	621
Property, Plant, and Equipment:
In service	14,635	14,658
Less: Accumulated depreciation	3,760	3,661
Plant in service, net of depreciation	10,875	10,997
Construction work in progress	43	41
Total property, plant, and equipment	10,918	11,038
Other Property and Investments:
Intangible assets, net of amortization	258	263
Equity investments in unconsolidated subsidiaries	0	49
Net investment in sales-type leases	152	154
Total other property and investments	410	466
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	487	489
Prepaid LTSAs	208	193
Other deferred charges and assets	310	274
Total deferred charges and other assets	1,005	956
Total Assets	13,134	13,081
Current Liabilities:
Securities due within one year	291	290
Notes payable	165	225
Accounts payable —
Affiliated	71	139
Other	31	67
Accrued taxes	22	24
Accrued interest	27	28
Other current liabilities	90	111
Total current liabilities	697	884
Long-term Debt	2,700	2,689
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	581	279
Accumulated deferred ITCs	1,541	1,556
Operating lease obligations, deferred	510	514
Other deferred credits and liabilities	247	243
Total deferred credits and other liabilities	2,879	2,592
Total Liabilities	6,276	6,165
Total Stockholders' Equity (See accompanying statements)	6,858	6,916
Total Liabilities and Stockholders' Equity	$ 13,134	$ 13,081

Condensed Consolidated Balanc_4

Condensed Consolidated Balance Sheets (Unaudited) - SPC (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Other intangible assets, amortization	$ 350	$ 340
SOUTHERN POWER CO
Other intangible assets, amortization	$ 134	$ 129

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, 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	991					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)
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, 2022	34,532	13,673	11,538	(167)	4,124	6,916	2,792	1,069	1,741	(18)	4,124
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	799					39	102		102		(63)
Other comprehensive income (loss)	(44)			(44)		(7)	(7)			(7)
Cash dividends on common stock	(742)		(742)			(63)	(63)		(63)
Capital contributions from noncontrolling interests	21				21	21					21
Distributions to noncontrolling interests	(48)				(48)	(48)					(48)
Ending balance at Mar. 31, 2023	$ 34,562	$ 13,715	$ 11,658	$ (211)	$ 4,034	$ 6,858	$ 2,824	$ 1,069	$ 1,780	$ (25)	$ 4,034

Condensed Consolidated State_15

Condensed Consolidated Statements of Income (Unaudited) - GAS - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating Revenues:
Total operating revenues	$ 6,480	$ 6,648
Operating Expenses:
Other operations and maintenance	1,482	1,516
Depreciation and amortization	1,111	892
Taxes other than income taxes	394	372
Gain on dispositions, net	(42)	(23)
Total operating expenses	5,262	5,264
Operating Income	1,218	1,384
Other Income and (Expense):
Earnings from equity method investments	48	46
Interest expense, net of amounts capitalized	(582)	(462)
Other income (expense), net	147	145
Total other income and (expense)	(322)	(220)
Earnings Before Income Taxes	896	1,164
Income taxes (benefit)	97	173
Net Income	799	991
Retail electric revenues
Operating Revenues:
Total operating revenues	3,599	3,613
Wholesale Electric
Operating Revenues:
Total operating revenues	599	664
Other electric revenues
Operating Revenues:
Total operating revenues	190	177
Natural Gas
Operating Revenues:
Total operating revenues	1,875	2,058
Natural gas
Operating Expenses:
Total cost of sales	898	1,095
Alternative revenue programs
Operating Revenues:
Total operating revenues	12	0
Other revenues
Operating Revenues:
Total operating revenues	217	136
Operating Expenses:
Total cost of sales	127	69
SOUTHERN Co GAS
Operating Revenues:
Total operating revenues	$ 1,875	$ 2,058
Operating Expenses:
Cost, Product and Service [Extensible Enumeration]	Natural gas	Natural gas
Other operations and maintenance	$ 305	$ 305
Depreciation and amortization	141	137
Taxes other than income taxes	102	100
Total operating expenses	1,446	1,637
Operating Income	429	421
Other Income and (Expense):
Earnings from equity method investments	45	40
Interest expense, net of amounts capitalized	(76)	(61)
Other income (expense), net	14	16
Total other income and (expense)	(17)	(5)
Earnings Before Income Taxes	412	416
Income taxes (benefit)	103	97
Net Income	309	319
SOUTHERN Co GAS | Natural gas
Operating Revenues:
Total operating revenues	1,875	2,058
Operating Expenses:
Total cost of sales	$ 898	$ 1,095

Condensed Consolidated State_16

Condensed Consolidated Statements of Income (Unaudited) - GAS (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
SOUTHERN Co GAS
Revenue taxes collected	$ 66	$ 71

Condensed Consolidated State_17

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - GAS - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Net income	$ 799	$ 991
Qualifying hedges:
Changes in fair value, net of tax	(63)	19
Reclassification adjustment for amounts included in net income, net of tax	19	20
Total other comprehensive income (loss)	(44)	42
Comprehensive Income	755	1,033
SOUTHERN Co GAS
Net income	309	319
Qualifying hedges:
Changes in fair value, net of tax	(24)	26
Reclassification adjustment for amounts included in net income, net of tax	14	(6)
Total other comprehensive income (loss)	(10)	20
Comprehensive Income	$ 299	$ 339

Condensed Consolidated State_18

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - GAS (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Changes in fair value, tax	$ (23)	$ 8
Qualifying hedges, reclassification adjustment, tax	7	6
SOUTHERN Co GAS
Changes in fair value, tax	(10)	10
Qualifying hedges, reclassification adjustment, tax	$ 6	$ (2)

Condensed Consolidated State_19

Condensed Consolidated Statements of Cash Flows (Unaudited) - GAS - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating Activities:
Net income (loss)	$ 799	$ 991
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	1,233	989
Natural gas cost under recovery – long-term	0	162
Other, net	51	79
Changes in certain current assets and liabilities —
Receivables	319	(217)
Natural gas for sale, net of temporary LIFO liquidation	267	450
Other current assets	143	8
Accounts payable	(1,056)	132
Accrued taxes	(237)	(58)
Other current liabilities	(28)	35
Net cash provided from operating activities	844	1,592
Investing Activities:
Property additions	(1,850)	(1,419)
Cost of removal, net of salvage	(135)	(227)
Construction payables	(140)	23
Other investing activities	(91)	(18)
Net cash used for investing activities	(2,118)	(1,555)
Financing Activities:
Short-term borrowings	(400)	(100)
Payment of common stock dividends	(742)	(702)
Other financing activities	(83)	(115)
Net cash provided from (used for) financing activities	454	(193)
Net Change in Cash, Cash Equivalents, and Restricted Cash	(820)	(156)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	2,037	1,829
Cash, Cash Equivalents, and Restricted Cash at End of Period	1,217	1,673
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	652	515
Noncash transactions — Accrued property additions at end of period	833	863
SOUTHERN Co GAS
Operating Activities:
Net income (loss)	309	319
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	141	137
Deferred income taxes	27	5
Mark-to-market adjustments	13	(38)
Natural gas cost under recovery – long-term	0	162
Other, net	(15)	41
Changes in certain current assets and liabilities —
Receivables	266	(115)
Natural gas for sale, net of temporary LIFO liquidation	267	450
Prepaid income taxes	33	34
Other current assets	90	(1)
Accounts payable	(303)	(23)
Accrued taxes	36	54
Natural gas cost over recovery	117	0
Other current liabilities	(3)	(1)
Net cash provided from operating activities	978	1,024
Investing Activities:
Property additions	(299)	(247)
Cost of removal, net of salvage	(24)	(20)
Construction payables	(53)	(5)
Other investing activities	(3)	1
Net cash used for investing activities	(379)	(271)
Financing Activities:
Decrease in notes payable, net	(448)	(577)
Short-term borrowings	(200)	(100)
Capital contributions from parent company	192	39
Payment of common stock dividends	(146)	(130)
Other financing activities	9	0
Net cash provided from (used for) financing activities	(593)	(768)
Net Change in Cash, Cash Equivalents, and Restricted Cash	6	(15)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	83	48
Cash, Cash Equivalents, and Restricted Cash at End of Period	89	33
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	76	55
Noncash transactions — Accrued property additions at end of period	$ 124	$ 107

Condensed Consolidated State_20

Condensed Consolidated Statements of Cash Flows (Unaudited) - GAS (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Net cash paid for capitalized interest	$ 32	$ 23
SOUTHERN Co GAS
Net cash paid for capitalized interest	$ 4	$ 2

Condensed Consolidated Balanc_5

Condensed Consolidated Balance Sheets (Unaudited) - GAS - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Current Assets:
Cash and cash equivalents	$ 1,053	$ 1,917
Receivables —
Customer accounts	1,890	2,128
Unbilled revenues	596	1,012
Other accounts and notes	510	637
Accumulated provision for uncollectible accounts	(80)	(71)
Natural gas for sale	216	438
Prepaid expenses	626	347
Natural gas cost under recovery	0	108
Other regulatory assets	936	860
Other current assets	395	344
Total current assets	9,555	10,416
Property, Plant, and Equipment:
In service	118,690	117,529
Less: Accumulated depreciation	35,990	35,297
Plant in service, net of depreciation	82,700	82,232
Construction work in progress	11,510	10,896
Total property, plant, and equipment	95,630	94,570
Other Property and Investments:
Goodwill	5,161	5,161
Equity investments in unconsolidated subsidiaries	1,408	1,443
Other intangible assets, net of amortization	397	406
Miscellaneous property and investments	616	602
Total other property and investments	9,827	9,757
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	1,505	1,531
Prepaid pension costs	2,384	2,290
Other regulatory assets, deferred	5,886	5,918
Other deferred charges and assets	1,456	1,485
Total deferred charges and other assets	19,744	20,148
Total Assets	134,756	134,891
Current Liabilities:
Securities due within one year	4,363	4,285
Notes payable	2,554	2,609
Accounts payable —
Customer deposits	475	502
Accrued interest	487	614
Accrued compensation	617	1,127
Natural gas cost over recovery	117	0
Other regulatory liabilities	287	382
Other current liabilities	915	787
Total current liabilities	13,893	15,724
Long-term Debt	52,060	50,656
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	10,488	10,036
Deferred credits related to income taxes	5,107	5,235
Employee benefit obligations	1,222	1,238
Operating lease obligations, deferred	1,374	1,388
Other cost of removal obligations	1,921	1,903
Other deferred credits and liabilities	1,118	1,167
Total deferred credits and other liabilities	34,241	33,979
Total Liabilities	100,194	100,359
Total Stockholders' Equity	34,562	34,532
Total Liabilities and Stockholders' Equity	134,756	134,891
SOUTHERN Co GAS
Current Assets:
Cash and cash equivalents	88	81
Receivables —
Customer accounts	586	616
Unbilled revenues	218	453
Other accounts and notes	73	76
Accumulated provision for uncollectible accounts	(58)	(50)
Natural gas for sale	216	438
Prepaid expenses	74	93
Natural gas cost under recovery	0	108
Other regulatory assets	126	119
Other current assets	118	104
Total current assets	1,441	2,038
Property, Plant, and Equipment:
In service	19,918	19,723
Less: Accumulated depreciation	5,350	5,276
Plant in service, net of depreciation	14,568	14,447
Construction work in progress	996	909
Total property, plant, and equipment	15,564	15,356
Other Property and Investments:
Goodwill	5,015	5,015
Equity investments in unconsolidated subsidiaries	1,282	1,276
Other intangible assets, net of amortization	23	26
Miscellaneous property and investments	29	28
Total other property and investments	6,349	6,345
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	55	57
Prepaid pension costs	190	183
Other regulatory assets, deferred	478	497
Other deferred charges and assets	145	145
Total deferred charges and other assets	868	882
Total Assets	24,222	24,621
Current Liabilities:
Securities due within one year	401	400
Notes payable	120	768
Accounts payable —
Affiliated	91	104
Other	361	701
Customer deposits	99	125
Accrued taxes	113	77
Accrued interest	69	67
Accrued compensation	68	105
Temporary LIFO liquidation	45	0
Natural gas cost over recovery	117	0
Other regulatory liabilities	104	36
Other current liabilities	208	187
Total current liabilities	1,796	2,570
Long-term Debt	7,055	7,042
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	1,583	1,560
Deferred credits related to income taxes	781	788
Employee benefit obligations	112	120
Operating lease obligations, deferred	50	51
Other cost of removal obligations	1,725	1,707
Accrued environmental remediation	200	207
Other deferred credits and liabilities	167	179
Total deferred credits and other liabilities	4,618	4,612
Total Liabilities	13,469	14,224
Total Stockholders' Equity	10,753	10,397
Total Liabilities and Stockholders' Equity	$ 24,222	$ 24,621

Condensed Consolidated Balanc_6

Condensed Consolidated Balance Sheets (Unaudited) - GAS (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Other intangible assets, amortization	$ 350	$ 340
SOUTHERN Co GAS
Other intangible assets, amortization	$ 159	$ 156

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, 2021	$ 32,276	$ 11,950	$ 10,929	$ (237)	$ 9,916	$ 10,024	$ (132)	$ 24
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	991				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, 2022	34,532	13,673	11,538	(167)	10,397	10,445	(79)	31
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	799				309		309
Capital contributions from parent company					203	203
Other comprehensive income (loss)	(44)			(44)	(10)			(10)
Cash dividends on common stock	(742)		(742)		(146)		(146)
Other	0	2			0	1	(1)
Ending balance at Mar. 31, 2023	$ 34,562	$ 13,715	$ 11,658	$ (211)	$ 10,753	$ 10,649	$ 83	$ 21

Introduction

Introduction	3 Months Ended
	Mar. 31, 2023
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, 2022 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 March 31, 2023 and 2022. 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 March 31, 2023 and December 31, 2022 was as follows: Goodwill (in millions) Southern Company $ 5,161 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 March 31, 2023 At December 31, 2022 Gross Carrying Amount Accumulated Amortization Other Gross Carrying Amount Accumulated Amortization Other (in millions) (in millions) Southern Company Subject to amortization: Customer relationships $ 212 $ (164) $ 48 $ 212 $ (162) $ 50 Trade names 64 (47) 17 64 (44) 20 PPA fair value adjustments 390 (134) 256 390 (129) 261 Other 6 (5) 1 5 (5) — Total subject to amortization $ 672 $ (350) $ 322 $ 671 $ (340) $ 331 Not subject to amortization: FCC licenses 75 — 75 75 — 75 Total other intangible assets $ 747 $ (350) $ 397 $ 746 $ (340) $ 406 Southern Power (*) PPA fair value adjustments $ 390 $ (134) $ 256 $ 390 $ (129) $ 261 Southern Company Gas (*) Gas marketing services Customer relationships $ 156 $ (140) $ 16 $ 156 $ (139) $ 17 Trade names 26 (19) 7 26 (17) 9 Total other intangible assets $ 182 $ (159) $ 23 $ 182 $ (156) $ 26 (*) All subject to amortization. Amortization associated with other intangible assets was as follows: Three Months Ended March 31, 2023 March 31, 2022 (in millions) Southern Company (a) $ 10 $ 10 Southern Power (b) 5 5 Southern Company Gas 3 3 (a) Includes $5 million recorded as a reduction to operating revenues for both periods presented. (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 Company Georgia Power Southern Power Southern (in millions) At March 31, 2023 Cash and cash equivalents $ 1,053 $ — $ 123 $ 88 Restricted cash (a) : Other current assets 117 115 — 2 Other deferred charges and assets 47 45 3 — Total cash, cash equivalents, and restricted cash (b) $ 1,217 $ 160 $ 126 $ 89 At December 31, 2022 Cash and cash equivalents $ 1,917 $ 364 $ 131 $ 81 Restricted cash (a) : Other current assets 62 60 — 2 Other deferred charges and assets 58 56 3 — Total cash, cash equivalents, and restricted cash (b) $ 2,037 $ 480 $ 133 $ 83 (a) For Georgia Power, reflects $116 million at both March 31, 2023 and December 31, 2022 related to proceeds from the issuance of solid waste disposal facility revenue bonds in 2022 and $44 million at March 31, 2023 related to funds from a Georgia Housing and Finance Authority (GHFA) rental assistance program used to offset qualifying customers' past due balances, which expired on March 31, 2023 and will be returned to the GHFA. For Southern Power, reflects $3 million at both March 31, 2023 and December 31, 2022 held to fund estimated construction completion costs at the Deuel Harvest wind facility. 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' inventory decrement at March 31, 2023 is expected to be restored prior to year-end. Storm Damage Reserves See Note 1 to the financial statements in Item 8 of the Form 10-K under "Storm Damage and Reliability Reserves" for additional information. Storm damage reserve activity for the traditional electric operating companies during the three months ended March 31, 2023 was as follows: Southern Alabama Power Georgia Power Mississippi (in millions) Balance at December 31, 2022 $ 216 $ 97 $ 83 $ 36 Accrual 13 3 8 2 Weather-related damages (43) (12) (31) — Balance at March 31, 2023 $ 186 $ 88 $ 60 $ 38 Asset Retirement Obligations See Note 6 to the financial statements in Item 8 of the Form 10-K for additional information. Following initial criticality on March 6, 2023, Georgia Power recorded AROs of approximately $90 million related to Plant Vogtle Unit 3. See Note (B) under "Georgia Power – Nuclear Construction" for additional information on construction and start-up of Plant Vogtle Units 3 and 4.

Regulatory Matters

Regulatory Matters	3 Months Ended
	Mar. 31, 2023
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 March 31, 2023 and December 31, 2022 were as follows: Regulatory Clause Balance Sheet Line Item March 31, December 31, 2022 (in millions) Alabama Power Rate CNP Compliance Other regulatory assets, current $ 23 $ 47 Other regulatory assets, deferred 18 — Rate CNP PPA Other regulatory assets, current 17 18 Other regulatory assets, deferred 100 102 Retail Energy Cost Recovery Other regulatory assets, current 101 102 Other regulatory assets, deferred 420 520 Georgia Power Fuel Cost Recovery (*) Receivables – under recovered fuel clause revenues $ 447 $ — Deferred under recovered fuel clause revenues 1,702 2,056 Mississippi Power Fuel Cost Recovery Receivables – customer accounts, net $ 25 $ 1 Ad Valorem Tax Other regulatory assets, current 9 12 Other regulatory assets, deferred 19 19 Southern Company Gas Natural Gas Cost Recovery Natural gas cost under recovery $ — $ 108 Natural gas cost over recovery 117 — (*) See "Georgia Power – Fuel Cost Recovery" herein for additional information. Alabama Power Certificates of Convenience and Necessity In 2020, the Alabama PSC approved a certificate of convenience and necessity authorizing Alabama Power's construction of Plant Barry Unit 8 and the recovery of estimated actual in-service costs of $652 million. At March 31, 2023, project expenditures associated with Plant Barry Unit 8 totaled approximately $541 million, of which $536 million and $5 million was included in CWIP and property, plant, and equipment in service, respectively. 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 CNP New Plant On March 24, 2023, Alabama Power filed Rate CNP New Plant with the Alabama PSC to recover costs associated with the acquisition of the Central Alabama Generating Station. The filing reflected an annual increase in retail revenues of $78 million effective with June 2023 billings. Through May 2023, Alabama Power expects to recover substantially all costs associated with the Central Alabama Generating Station through Rate RSE, offset by revenues from a power sales agreement. See Note 15 to the financial statements under "Alabama Power" in Item 8 of the Form 10-K for additional information. 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. On April 4, 2023, the Alabama PSC approved two new solar PPAs totaling 160 MWs. Alabama Power has procured solar capacity totaling approximately 490 MWs under the RGC. Georgia Power Fuel Cost Recovery On February 28, 2023, Georgia Power filed a request with the Georgia PSC to increase fuel rates. On April 13, 2023, Georgia Power and the staff of the Georgia PSC reached a stipulated agreement that includes the following terms: (i) Georgia Power would update fuel rates from the original request for revised fuel costs and to reflect a three-year recovery period, starting June 1, 2023, for $2.2 billion of the under recovered fuel balance and (ii) Georgia Power would be required to file its next fuel case no later than February 28, 2026. On April 24, 2023, Georgia Power filed an updated request reflecting a 54% increase in fuel rates effective June 1, 2023, which is expected to increase annual billings by approximately $1.1 billion and includes recovery of the under recovered fuel balance described above. Changes in fuel rates have no significant effect on Georgia Power's net income but do impact the related operating cash flows. Georgia Power expects the Georgia PSC to make a final decision on this matter on May 16, 2023. The ultimate outcome of this matter cannot be determined at this time. Integrated Resource Plans In August 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. In November 2022, Georgia Power and the Georgia PSC both filed motions to dismiss the RCG petition. The ultimate outcome of this matter 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 currently 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 second quarter 2023 and the first quarter 2024, respectively, is as follows: (in millions) Base project capital cost forecast (a)(b) $ 10,553 Construction contingency estimate 40 Total project capital cost forecast (a)(b) 10,593 Net investment at March 31, 2023 (b) (9,747) Remaining estimate to complete $ 846 (a) Includes approximately $610 million of costs that are not shared with the other Vogtle Owners, including $33 million of construction monitoring costs approved for recovery by the Georgia PSC in its nineteenth VCM order, and approximately $407 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 $418 million, of which $334 million had been accrued through March 31, 2023. (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 $3.5 billion, of which $3.3 billion had been incurred through March 31, 2023. 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 start-up testing and related test results, engineering support, commodity installation, system turnovers, 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 March 6, 2023, Unit 3 achieved self-sustaining nuclear fission, commonly referred to as initial criticality, and, on April 1, 2023, the generator successfully synchronized to the power grid and generated electricity for the first time. Operators continue to perform tests at various power levels to help ensure the reactor performs as designed, and Southern Nuclear continues to remediate various equipment and component issues as they are identified. Based on the expected duration of start-up testing, Unit 3 is projected to be placed in service during May or June 2023. Hot functional testing for Unit 4 commenced on March 20, 2023, with fuel load projected to occur in the third quarter 2023. Unit 4 is projected to be placed in service during late fourth quarter 2023 or the first quarter 2024. During the first quarter 2023, established construction contingency totaling $20 million was assigned to the base capital cost forecast for costs primarily associated with additional craft and support resources. The projected schedule for Unit 3 primarily depends on the progression of pre-operational testing and start-up, which may be impacted by further equipment, component, and/or other operational challenges. The projected schedule for Unit 4 primarily depends on potential impacts arising from Unit 4 testing activities overlapping with Unit 3 start-up and commissioning; maintaining overall construction productivity and production levels, particularly in subcontractor scopes of work; and maintaining appropriate levels of craft laborers. As Unit 4 completes construction and transitions further into testing, ongoing and potential future challenges include the duration of hot functional testing; the timeframe and duration of other testing; the pace and quality of remaining commodities installation; the completion of documentation to support ITAAC submittals; the pace of remaining work package closures and system turnovers; and the availability of craft, supervisory, and technical support resources. Ongoing or future challenges for both units also include management of contractors and vendors; subcontractor performance; and/or related cost escalation. New challenges also may continue to arise, as Unit 3 completes start-up and commissioning and Unit 4 moves further into 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. With the receipt of the NRC's 103(g) finding in August 2022, Unit 3 is now subject to the NRC's operating reactor oversight process and must meet applicable technical and operational requirements contained in its 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 second quarter 2023 for Unit 3 or the first quarter 2024 for Unit 4, including the joint owner cost sharing and tender impacts 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, of which Georgia Power's share is $8.4 billion (VCM 19 Forecast Amount), 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 VCM 19 Forecast Amount (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 VCM 19 Forecast Amount (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 VCM 19 Forecast Amount 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 VCM 19 Forecast Amount 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 and all the Vogtle Owners 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. The other Vogtle Owners notified Georgia Power that they believe the project capital cost forecast approved by the Vogtle Owners in February 2022 triggered the tender provisions. In June 2022 and July 2022, OPC and Dalton, respectively, notified Georgia Power of their purported exercises of their tender options. Georgia Power did not accept these purported tender exercises. In June 2022, OPC and MEAG Power each filed a separate lawsuit against Georgia Power in the Superior Court of Fulton County, Georgia seeking a declaratory judgment that the starting dollar amount is $17.1 billion and that the cost-sharing and tender provisions had been triggered. The lawsuits also assert other claims, including breach of contract allegations, and seek, among other remedies, damages and injunctive relief requiring Georgia Power to track and allocate construction costs consistent with MEAG Power's and OPC's interpretations of the Global Amendments. In July 2022, Georgia Power filed its answers in the lawsuits filed by MEAG Power and OPC and included counterclaims seeking a declaratory judgment that the starting dollar amount is $18.38 billion and that costs related to force majeure events are excluded prior to calculating the cost-sharing and tender provisions and when calculating Georgia Power's related financial obligations. In September 2022, Dalton filed complaints in each of these lawsuits. Also in September 2022, Georgia Power and MEAG Power reached an agreement to resolve their dispute regarding the proper interpretation of the cost-sharing and tender provisions of the Global Amendments. Under the terms of the agreement, among other items, (i) MEAG Power will not exercise its tender option and will retain its full ownership interest in Plant Vogtle Units 3 and 4; (ii) Georgia Power will reimburse a portion of MEAG Power's costs of construction for Plant Vogtle Units 3 and 4 as such costs are incurred and with no further adjustment for force majeure costs, which payments will total approximately $92 million based on the current project capital cost forecast; and (iii) Georgia Power will reimburse 20% of MEAG Power's costs of construction with respect to any amounts over the current project capital cost forecast, with no further adjustment for force majeure costs. In addition, MEAG Power agreed to vote to continue construction upon occurrence of a Project Adverse Event unless the commercial operation date of either of Plant Vogtle Unit 3 or Unit 4 is not projected to occur by December 31, 2025. In October 2022, MEAG Power and Georgia Power filed a notice of settlement and voluntary dismissal of their pending litigation, including Georgia Power's counterclaim, and Dalton dismissed its related complaint. Georgia Power recorded pre-tax charges to income through the fourth quarter 2022 of $407 million ($304 million after tax) associated with the cost-sharing and tender provisions of the Global Amendments, including the settlement with MEAG Power. This total is included in the total project capital cost forecast and will not be recovered from retail customers. The settlement with MEAG Power does not resolve the separate pending litigation with OPC, including Dalton's associated complaint, described above. Georgia Power may be required to record further pre-tax charges to income of up to approximately $345 million associated with the cost-sharing and tender provisions of the Global Amendments for OPC and Dalton based on the current project capital cost forecast. Georgia Power's ownership interest in Plant Vogtle Units 3 and 4 continues to be 45.7%. Georgia Power believes the increases in the total project capital cost forecast through December 31, 2022 triggered the tender provisions, but Georgia Power disagrees with OPC and Dalton on the tender provisions trigger date. Valid notices of tender from OPC and Dalton would require Georgia Power to pay 100% of their respective remaining shares of the costs necessary to complete Plant Vogtle Units 3 and 4. Georgia Power's incremental ownership interest will be calculated and conveyed to Georgia Power after Plant Vogtle Units 3 and 4 are placed in service. The ultimate outcome of these matters cannot be determined at this time. Regulatory Matters In 2009, the Georgia PSC voted to certify construction of Plant Vogtle Units 3 and 4 with a certified capital cost of $4.418 billion. In addition, in 2009 the Georgia PSC approved inclusion of the Plant Vogtle Units 3 and 4 related CWIP accounts in rate base, and the State of Georgia enacted the Georgia Nuclear Energy Financing Act, which allows Georgia Power to recover financing costs for Plant Vogtle Units 3 and 4. Financing costs are recovered on all applicable certified costs through annual adjustments to the NCCR tariff up to the certified capital cost of $4.418 billion. At March 31, 2023, Georgia Power had recovered approximately $2.9 billion of financing costs. Financing costs related to capital costs above $4.418 billion are being recognized through AFUDC and are expected to be recovered through retail rates over the life of Plant Vogtle Units 3 and 4; however, Georgia Power is not recording AFUDC related to any capital costs in excess of the total deemed reasonable by the Georgia PSC (currently $7.3 billion) and not requested for rate recovery. In December 2022, the Georgia PSC approved Georgia Power's filing to increase the NCCR tariff by $36 million annually, effective January 1, 2023. Georgia Power is required to file semi-annual VCM reports with the Georgia PSC by February 28 and August 31 of each year. In 2013, in connection with the eighth VCM report, the Georgia PSC approved a stipulation between Georgia Power and the staff of the Georgia PSC to waive the requirement to amend the Plant Vogtle Units 3 and 4 certificate in accordance with the 2009 certification order until the completion of Plant Vogtle Unit 3, or earlier if deemed appropriate by the Georgia PSC and Georgia Power. In 2016, the Georgia PSC voted to approve a settlement agreement (Vogtle Cost Settlement Agreement) resolving certain prudency matters in connection with the fifteenth VCM report. In December 2017, the Georgia PSC voted to approve (and issued its related order on January 11, 2018) Georgia Power's seventeenth VCM report and modified the Vogtle Cost Settlement Agreement. The Vogtle Cost Settlement Agreement, as modified by the January 11, 2018 order, resolved the following regulatory matters related to Plant Vogtle Units 3 and 4: (i) none of the $3.3 billion of costs incurred through December 31, 2015 and reflected in the fourteenth VCM report should be disallowed from rate base on the basis of imprudence; (ii) the Contractor Settlement Agreement was reasonable and prudent and none of the $0.3 billion paid pursuant to the Contractor Settlement Agreement should be disallowed from rate base on the basis of imprudence; (iii) (a) capital costs incurred up to $5.68 billion would be presumed to be reasonable and prudent with the burden of proof on any party challenging such costs, (b) Georgia Power would have the burden to show that any capital costs above $5.68 billion were prudent, and (c) a revised capital cost forecast of $7.3 billion (after reflecting the impact of payments received under the Guarantee Settlement Agreement and related customer refunds) was found reasonable; (iv) construction of Plant Vogtle Units 3 and 4 should be completed, with Southern Nuclear serving as project manager and Bechtel as primary contractor; (v) approved and deemed reasonable Georgia Power's revised schedule placing Plant Vogtle Units 3 and 4 in service in November 2021 and November 2022, respectively; (vi) confirmed that the revised cost forecast does not represent a cost cap and that a prudence proceeding on cost recovery will occur following Unit 4 fuel load, consistent with applicable Georgia law; (vii) reduced the ROE used to calculate the NCCR tariff (a) from 10.95% (the ROE rate setting point authorized by the Georgia PSC at that time) to 10.00% effective January 1, 2016, (b) from 10.00% to 8.30%, effective January 1, 2020, and (c) from 8.30% to 5.30%, effective January 1, 2021 (provided that the ROE in no case will be less than Georgia Power's average cost of long-term debt); (viii) reduced the ROE used for AFUDC equity for Plant Vogtle Units 3 and 4 from 10.00% to Georgia Power's average cost of long-term debt, effective January 1, 2018; and (ix) agreed that effective the first month after Unit 3 reaches commercial operation, retail base rates would be adjusted to include the costs related to Unit 3 and common facilities deemed prudent in the Vogtle Cost Settlement Agreement (see Note 2 to the financial statements under "Georgia Power – Plant Vogtle Unit 3 and Common Facilities Rate Proceeding" in Item 8 of the Form 10-K for additional information). The January 11, 2018 order also stated that if Plant Vogtle Units 3 and 4 are not commercially operational by June 1, 2021 and June 1, 2022, respectively, the ROE used to calculate the NCCR tariff will be further reduced by 10 basis points each month (but not lower than Georgia Power's average cost of long-term debt) until the respective Unit is commercially operational. The ROE reductions negatively impacted earnings by approximately $300 million in 2022 and are estimated to have negative earnings impacts of approximately $270 million in 2023 and $60 million in 2024. In its January 11, 2018 order, the Georgia PSC also stated if other conditions change and assumptions upon which Georgia Power's seventeenth VCM report are based do not materialize, the Georgia PSC reserved the right to reconsider the decision to continue construction. In the August 2021 order approving the twenty-fourth VCM report, the Georgia PSC approved a stipulation addressing the following matters: (i) beginning with its twenty-fifth VCM report, Georgia Power will continue to report to the Georgia PSC all costs incurred during the period for review and will request for approval costs up to the $7.3 billion determined to be reasonable in the Georgia PSC's seventeenth VCM order and (ii) Georgia Power will not seek rate recovery of the $0.7 billion increase to the base capital cost forecast included in the nineteenth VCM report and charged to income by Georgia Power in the second quarter 2018. In addition, the stipulation confirms Georgia Power may request verification and approval of costs above $7.3 billion for inclusion in rate base at a later time, but no earlier than the prudence review contemplated by the seventeenth VCM order described previously. The Georgia PSC has approved 25 VCM reports covering periods through June 30, 2021. These reports reflect total construction capital costs incurred of $7.9 billion (net of $1.7 billion of payments received under the Guarantee Settlement Agreement and approximately $188 million in related customer refunds), of which the Georgia PSC has verified and approved $7.3 billion as described above. The Georgia PSC also has reviewed two additional VCM reports, which reflected $1.1 billion of additional construction capital costs incurred through June 30, 2022. Georgia Power filed its twenty-eighth VCM report with the Georgia PSC on February 16, 2023, which reflected the revised capital cost forecast descr

Contingencies

Contingencies	3 Months Ended
	Mar. 31, 2023
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. Alabama Power In September 2022, Mobile Baykeeper 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 prevent implementation of Alabama Power's closure plan and the development of a closure plan that satisfies regulations governing CCR requirements. On December 19, 2022, Alabama Power filed a motion to dismiss the case. On January 31, 2023, the EPA issued a Notice of Potential Violations associated with Alabama Power's plan to close the Plant Barry ash pond. Alabama Power submitted responses on March 20, 2023, March 24, 2023, and April 3, 2023 affirming its position that it is in compliance with CCR requirements. The ultimate outcome of these matters cannot be determined at this time but could have an impact on Alabama Power's ARO estimates. See Note 6 to the financial statements in Item 8 of the Form 10-K for a discussion of Alabama Power's ARO liabilities. Georgia Power Municipal Franchise Fees 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, which was denied on January 27, 2023. On February 6, 2023, the plaintiffs filed a motion for reconsideration with the Georgia Supreme Court, which was denied on February 16, 2023. This matter is now concluded. Plant Scherer In July 2020, a group of individual plaintiffs filed a complaint, which was amended in December 2022, in the Superior Court of Fulton County, Georgia against Georgia Power alleging that the construction and operation of Plant Scherer has impacted groundwater 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 December 2022, the Superior Court of Fulton County, Georgia granted Georgia Power's motion to transfer the case to the Superior Court of Monroe County, Georgia. In October 2021 and February 2022, a total of seven 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 sought an unspecified amount of monetary damages including punitive damages. In November 2021 and March 2022, Georgia Power removed these cases to the U.S. District Court for the Middle District of Georgia. In November 2022, the plaintiffs voluntarily dismissed their complaints without prejudice. Georgia Power anticipates that these plaintiffs will refile their complaints. On January 9, 2023, an additional complaint was filed in the Superior Court of Monroe County, Georgia against Georgia Power alleging that the construction and operation of Plant Scherer have impacted groundwater and air, resulting in alleged personal injuries. The plaintiff sought an unspecified amount of monetary damages, including punitive damages. On January 19, 2023, Georgia Power filed a notice to remove the case to the U.S. District Court for the Middle District of Georgia. On February 21, 2023, the plaintiff voluntarily dismissed the complaint without prejudice. Georgia Power anticipates that this plaintiff will refile the complaint. 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 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 $15 million at both March 31, 2023 and December 31, 2022. 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 $243 million and $256 million at March 31, 2023 and December 31, 2022, 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 Traditional Electric Operating Companies In April 2019, Bellsouth Telecommunications d/b/a AT&T Alabama (AT&T) filed a complaint against Alabama Power with the FCC alleging that the pole rental rate AT&T is required to pay pursuant to the parties' joint use agreement is unjust and unreasonable under federal law. The complaint sought a new rate and approximately $87 million in refunds of alleged overpayments for the preceding six years. In August 2019, the FCC stayed the case in favor of arbitration, which AT&T has not pursued. The ultimate outcome of this matter cannot be determined at this time, but an adverse outcome could have a material impact on the financial statements of Southern Company and Alabama Power. Georgia Power and Mississippi Power have joint use agreements with other AT&T affiliates.

Revenue from Contracts with Cus

Revenue from Contracts with Customers and Lease Income	3 Months Ended
	Mar. 31, 2023
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 months ended March 31, 2023 and 2022: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Three Months Ended March 31, 2023 Operating revenues Retail electric revenues Residential $ 1,525 $ 659 $ 801 $ 65 $ — $ — Commercial 1,251 430 753 68 — — Industrial 789 398 313 78 — — Other 27 3 22 2 — — Total retail electric revenues 3,592 1,490 1,889 213 — — Natural gas distribution revenues Residential 896 — — — — 896 Commercial 232 — — — — 232 Transportation 319 — — — — 319 Industrial 23 — — — — 23 Other 117 — — — — 117 Total natural gas distribution revenues 1,587 — — — — 1,587 Wholesale electric revenues PPA energy revenues 284 72 12 4 202 — PPA capacity revenues 190 60 11 32 89 — Non-PPA revenues 36 20 3 107 103 — Total wholesale electric revenues 510 152 26 143 394 — Other natural gas revenues Gas marketing services 231 — — — — 231 Other natural gas revenues 11 — — — — 11 Total natural gas revenues 242 — — — — 242 Other revenues 310 54 132 11 11 — Total revenue from contracts with customers 6,241 1,696 2,047 367 405 1,829 Other revenue sources (*) 239 (49) 129 23 103 46 Total operating revenues $ 6,480 $ 1,647 $ 2,176 $ 390 $ 508 $ 1,875 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Three Months Ended March 31, 2022 Operating revenues Retail electric revenues Residential $ 1,525 $ 634 $ 821 $ 70 $ — $ — Commercial 1,178 375 738 65 — — Industrial 727 323 334 70 — — Other 26 4 20 2 — — Total retail electric revenues 3,456 1,336 1,913 207 — — Natural gas distribution revenues Residential 1,016 — — — — 1,016 Commercial 270 — — — — 270 Transportation 337 — — — — 337 Industrial 32 — — — — 32 Other 129 — — — — 129 Total natural gas distribution revenues 1,784 — — — — 1,784 Wholesale electric revenues PPA energy revenues 342 59 32 3 251 — PPA capacity revenues 134 39 12 3 81 — Non-PPA revenues 58 64 9 102 73 — Total wholesale electric revenues 534 162 53 108 405 — Other natural gas revenues Gas marketing services 243 — — — — 243 Other natural gas revenues 16 — — — — 16 Total natural gas revenues 259 — — — — 259 Other revenues 225 48 95 9 8 — Total revenue from contracts with customers 6,258 1,546 2,061 324 413 2,043 Other revenue sources (*) 390 103 147 11 126 15 Total operating revenues $ 6,648 $ 1,649 $ 2,208 $ 335 $ 539 $ 2,058 (*) 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. Contract Balances The following table reflects the closing balances of receivables, contract assets, and contract liabilities related to revenues from contracts with customers at March 31, 2023 and December 31, 2022: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Accounts Receivable At March 31, 2023 $ 2,433 $ 622 $ 672 $ 79 $ 119 $ 853 At December 31, 2022 3,123 696 922 92 237 1,107 Contract Assets At March 31, 2023 $ 160 $ 3 $ 74 $ — $ — $ 19 At December 31, 2022 156 2 89 — — — Contract Liabilities At March 31, 2023 $ 61 $ 2 $ 14 $ 1 $ 1 $ — At December 31, 2022 45 4 9 — 1 — Contract assets for Georgia Power primarily relate 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 primarily relate to cash collections recognized in advance of revenue for unregulated service agreements. At March 31, 2023, Southern Company Gas' contract assets relate to work performed on an energy efficiency enhancement and upgrade contract with the U.S. General Services Administration. Southern Company Gas receives cash advances from a third-party financial institution to fund work performed, of which approximately $30 million had been received at March 31, 2023. These advances have been accounted for as long-term debt on the balance sheets. See Note 1 to the financial statements under "Affiliate Transactions" in Item 8 of the Form 10-K for additional information regarding the construction contract. At March 31, 2023 and December 31, 2022, Southern Company's unregulated distributed generation business had contract assets of $64 million and $65 million, respectively, and contract liabilities of $44 million and $32 million, respectively, for outstanding performance obligations. Revenues recognized in the three months ended March 31, 2023, which were included in contract liabilities at December 31, 2022, were $19 million for Southern Company and immaterial for the other Registrants. Remaining Performance Obligations The Subsidiary Registrants may enter into long-term contracts with customers in which revenues are recognized as performance obligations are satisfied over the contract term. For Alabama Power, Georgia Power, 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 primarily relate to the U.S. General Services Administration contract described above. 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 March 31, 2023 are expected to be recognized as follows: 2023 (remaining) 2024 2025 2026 2027 Thereafter (in millions) Southern Company $ 632 $ 553 $ 347 $ 315 $ 319 $ 2,089 Alabama Power 17 7 6 — — — Georgia Power 68 60 25 13 14 23 Southern Power 268 345 302 303 310 2,077 Southern Company Gas 15 29 — — — — Lease Income Lease income for the three months ended March 31, 2023 and 2022 is as follows: Southern Alabama Power Georgia Power Mississippi Southern Power Southern Company Gas (in millions) For the Three Months Ended March 31, 2023 Lease income - interest income on sales-type leases $ 6 $ — $ — $ 4 $ 2 $ — Lease income - operating leases 49 18 7 1 21 9 Variable lease income 69 — — — 75 — Total lease income $ 124 $ 18 $ 7 $ 5 $ 98 $ 9 For the Three Months Ended March 31, 2022 Lease income - interest income on sales-type leases $ 6 $ — $ — $ 4 $ 2 $ — Lease income - operating leases 51 20 8 — 21 9 Variable lease income 84 — — — 90 — Total lease income $ 141 $ 20 $ 8 $ 4 $ 113 $ 9 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	3 Months Ended
	Mar. 31, 2023
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 March 31, 2023 and December 31, 2022, SP Solar had total assets of $5.8 billion and $5.9 billion, respectively, total liabilities of $0.4 billion, and noncontrolling interests of $1.0 billion and $1.1 billion, respectively. 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 March 31, 2023 and December 31, 2022, SP Wind had total assets of $2.2 billion, total liabilities of $172 million and $169 million, respectively, and noncontrolling interests of $39 million. 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 March 31, 2023 and December 31, 2022, the other VIEs had total assets of $1.8 billion, total liabilities of $0.2 billion, and noncontrolling interests of $0.8 billion. 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 December 31, 2022, Southern Power had equity method investments in wind and battery energy storage projects totaling $49 million. During the first quarter 2023, Southern Power sold its remaining equity method investments in the projects and received proceeds of $50 million. Earnings (loss) from these investments, including the gains associated with the sales, were immaterial for the three months ended March 31, 2023 and 2022. Southern Company Gas Equity Method Investments The carrying amounts of Southern Company Gas' equity method investments at March 31, 2023 and December 31, 2022 and related earnings from those investments for the three months ended March 31, 2023 and 2022 were as follows: Investment Balance March 31, 2023 December 31, 2022 (in millions) SNG $ 1,249 $ 1,243 Other 33 33 Total $ 1,282 $ 1,276 Three Months Ended March 31, Earnings from Equity Method Investments 2023 2022 (in millions) SNG $ 44 $ 39 Other 1 1 Total $ 45 $ 40

Financing and Leases

Financing and Leases	3 Months Ended
	Mar. 31, 2023
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 March 31, 2023, 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 — 275 225 — Southern Power (a) — — — 600 600 587 — 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 $ 7,564 $ 280 (a) Does not include Southern Power Company's $75 million and $100 million continuing letter of credit facilities for standby letters of credit, expiring in 2025 and 2026, respectively, of which $9 million and $16 million, respectively, was unused at March 31, 2023. In March 2023, Southern Power amended the $100 million letter of credit facility, which, among other things, extended the expiration date from 2025 to 2026 and increased the amount from $75 million. 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 under a $250 million credit arrangement expiring in 2023. 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 March 31, 2023, 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. A portion of the unused credit with banks is allocated to provide liquidity support to the revenue bonds of the traditional electric operating companies and the commercial paper programs of the Registrants, Nicor Gas, and SEGCO. The amount of variable rate revenue bonds of the traditional electric operating companies outstanding requiring liquidity support at March 31, 2023 was approximately $1.7 billion (comprised of approximately $789 million at Alabama Power, $819 million at Georgia Power, and $69 million at Mississippi Power). In addition, at March 31, 2023, Alabama Power and Georgia Power had approximately $120 million and $285 million, respectively, of fixed rate revenue bonds outstanding that are required to be remarketed within the next 12 months. Convertible Senior Notes In February 2023, Southern Company issued $1.5 billion aggregate principal amount of Series 2023A 3.875% Convertible Senior Notes due December 15, 2025 (Series 2023A Convertible Senior Notes). In March 2023, Southern Company issued an additional $225 million aggregate principal amount of the Series 2023A Convertible Senior Notes upon the exercise by the initial purchasers of their over-allotment option. Interest on the Series 2023A Convertible Senior Notes is payable semiannually, beginning June 15, 2023. The Series 2023A Convertible Senior Notes will mature on December 15, 2025, unless earlier converted or repurchased, but are not redeemable at the option of Southern Company. The Series 2023A Convertible Senior Notes are direct, unsecured, and unsubordinated obligations of Southern Company, ranking equally with all of Southern Company's other unsecured and unsubordinated indebtedness from time to time outstanding, and are effectively subordinated to all secured indebtedness of Southern Company. Holders may convert their Series 2023A Convertible Senior Notes at their option prior to the close of business on the business day preceding September 15, 2025, but only under the following circumstances: • during any calendar quarter (and only during such calendar quarter), if the last reported sale price of Southern Company's common stock for at least 20 trading days (whether or not consecutive) during the period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day as determined by Southern Company; • during the five business day period after any 10 consecutive trading day period (Measurement Period) in which the trading price per $1,000 principal amount of Series 2023A Convertible Senior Notes for each trading day of the Measurement Period was less than 98% of the product of the last reported sale price of the common stock and the conversion rate on each such trading day; or • upon the occurrence of certain corporate events specified in the indenture governing the Series 2023A Convertible Senior Notes. On or after September 15, 2025, a holder may convert all or any portion of its Series 2023A Convertible Senior Notes at any time prior to the close of business on the second scheduled trading day immediately preceding the maturity date regardless of the foregoing conditions. Southern Company will settle conversions of the Series 2023A Convertible Senior Notes by paying cash up to the aggregate principal amount of the Series 2023A Convertible Senior Notes to be converted and paying or delivering, as the case may be, cash, shares of common stock or a combination of cash and shares of common stock, at Southern Company's election, in respect of the remainder, if any, of Southern Company's conversion obligation in excess of the aggregate principal amount of the Series 2023A Convertible Senior Notes being converted. The Series 2023A Convertible Senior Notes are initially convertible at a rate of 11.8818 shares of common stock per $1,000 principal amount converted, which is approximately equal to $84.16 per share of common stock. The conversion rate will be subject to adjustment upon the occurrence of certain specified events but will not be adjusted for accrued and unpaid interest. In addition, upon the occurrence of a make-whole fundamental change (as defined in the indenture governing the Series 2023A Convertible Senior Notes), Southern Company will, in certain circumstances, increase the conversion rate by a number of additional shares of common stock for conversions in connection with the make-whole fundamental change. Upon the occurrence of a fundamental change (as defined in the indenture governing the Series 2023A Convertible Senior Notes), holders of the Series 2023A Convertible Senior Notes may require Southern Company to purchase all or a portion of their Series 2023A Convertible Senior Notes, in principal amounts equal to $1,000 or an integral multiple thereof, for cash at a price equal to 100% of the principal amount of the Series 2023A Convertible Senior Notes to be purchased plus any accrued and unpaid interest. Earnings per Share For Southern Company, the only difference in computing basic and diluted earnings per share (EPS) is attributable to awards outstanding under stock-based compensation plans and the Series 2023A Convertible Senior Notes. EPS dilution resulting from stock-based compensation plans is determined using the treasury stock method and EPS dilution resulting from the Series 2023A Convertible Senior Notes is determined using the net share settlement method. See Note 12 to the financial statements in Item 8 of the Form 10-K and "Convertible Senior Notes" herein for additional information. Shares used to compute diluted EPS were as follows: Three Months Ended March 31, 2023 2022 (in millions) As reported shares 1,091 1,063 Effect of stock-based compensation 7 6 Diluted shares 1,098 1,069 For the three months ended March 31, 2023, there were no anti-dilutive shares. For the three months ended March 31, 2022, an immaterial number of stock-based compensation awards was excluded from the diluted EPS calculation because the awards were anti-dilutive. For both periods presented, there was no dilution resulting from the Series 2023A Convertible Senior Notes. 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. In June 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. Subsequently, the lessee failed to make the semi-annual lease payment due in December 2022. As a result, the Southern Holdings subsidiary was unable to make its corresponding payment to the holders of the underlying non-recourse debt related to the generation assets. The parties to the lease have entered into a forbearance agreement which suspends the related contractual rights of the parties while they continue restructuring negotiations, 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. Southern Company will continue to monitor the operational performance of the underlying assets and evaluate the ability of the lessee to continue to make the required lease payments and meet its obligations associated with a future closure or retirement of the generation assets and associated properties, including the dry ash landfill.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2023
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 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 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 10.8% for the three months ended March 31, 2023 compared to 14.9% for the corresponding period in 2022. The effective tax rate decrease was primarily due to an increase in the flowback of certain excess deferred income taxes at Alabama Power in 2023, partially offset by the flowback of certain excess deferred income taxes ending in 2022 at Georgia Power. Alabama Power Alabama Power's effective tax benefit rate was (0.8)% for the three months ended March 31, 2023 compared to an effective tax rate of 23.3% for the corresponding period in 2022. The effective tax rate decrease was primarily due to an increase in the flowback of certain excess deferred income taxes in 2023. See Note 2 to the financial statements under "Alabama Power – Excess Accumulated Deferred Income Tax Accounting Order" in Item 8 of the Form 10-K for additional information. Georgia Power Georgia Power's effective tax rate was 15.1% for the three months ended March 31, 2023 compared to 7.3% for the corresponding period in 2022. The effective tax rate increase was primarily due to the flowback of certain excess deferred income taxes ending in 2022. Southern Power Southern Power's effective tax benefit rate was (20.7)% for the three months ended March 31, 2023 compared to (80.0)% for the corresponding period in 2022. The effective tax rate increase was primarily due to higher pre-tax earnings and the impacts of noncontrolling interests.

Retirement Benefits

Retirement Benefits	3 Months Ended
	Mar. 31, 2023
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, 2023. 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. 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 months ended March 31, 2023 and 2022 are presented in the following tables. Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) Three Months Ended March 31, 2023 Pension Plans Service cost $ 69 $ 16 $ 17 $ 3 $ 2 $ 6 Interest cost 156 36 48 7 2 11 Expected return on plan assets (307) (74) (96) (14) (4) (22) Amortization: Prior service costs — — — — — (1) Regulatory asset — — — — — 4 Net (gain) loss 8 2 3 — — (1) Net periodic pension income $ (74) $ (20) $ (28) $ (4) $ — $ (3) Postretirement Benefits Service cost $ 4 $ 1 $ 1 $ — $ — $ — Interest cost 18 4 6 1 — 2 Expected return on plan assets (21) (8) (7) (1) — (2) Amortization: Regulatory asset — — — — — 2 Net gain (3) (1) (1) — — (1) Net periodic postretirement benefit cost (income) $ (2) $ (4) $ (1) $ — $ — $ 1 Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) Three Months Ended March 31, 2022 Pension Plans Service cost $ 103 $ 25 $ 26 $ 4 $ 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 — — — — — 4 Net loss 60 16 18 3 1 2 Net periodic pension cost (income) $ (51) $ (12) $ (24) $ (3) $ 1 $ (1) Postretirement Benefits Service cost $ 6 $ 1 $ 2 $ — $ — $ — Interest cost 10 3 4 — — 1 Expected return on plan assets (20) (8) (7) — — (2) Amortization: Regulatory asset — — — — — 2 Net periodic postretirement benefit cost (income) $ (4) $ (4) $ (1) $ — $ — $ 1

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2023
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS At March 31, 2023, 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 March 31, 2023 Quoted Prices Significant Significant Net Asset Value as a Practical Expedient (NAV) Total (in millions) Southern Company Assets: Energy-related derivatives (a) $ 4 $ 100 $ — $ — $ 104 Interest rate derivatives — 2 — — 2 Investments in trusts: (b)(c) Domestic equity 680 192 — — 872 Foreign equity 138 162 — — 300 U.S. Treasury and government agency securities — 316 — — 316 Municipal bonds — 48 — — 48 Pooled funds – fixed income — 7 — — 7 Corporate bonds — 403 — — 403 Mortgage and asset backed securities — 90 — — 90 Private equity — — — 160 160 Cash and cash equivalents 2 — — — 2 Other 40 12 — 9 61 Cash equivalents 433 13 — — 446 Other investments 9 29 8 — 46 Total $ 1,306 $ 1,374 $ 8 $ 169 $ 2,857 Liabilities: Energy-related derivatives (a) $ 40 $ 354 $ — $ — $ 394 Interest rate derivatives — 261 — — 261 Foreign currency derivatives — 218 — — 218 Contingent consideration — — 12 — 12 Other — 13 — — 13 Total $ 40 $ 846 $ 12 $ — $ 898 Fair Value Measurements Using: At March 31, 2023 Quoted Prices Significant Significant Net Asset Value as a Practical Expedient (NAV) Total (in millions) Alabama Power Assets: Energy-related derivatives $ — $ 32 $ — $ — $ 32 Nuclear decommissioning trusts: (b) Domestic equity 404 185 — — 589 Foreign equity 138 — — — 138 U.S. Treasury and government agency securities — 19 — — 19 Municipal bonds — 1 — — 1 Corporate bonds — 223 — — 223 Mortgage and asset backed securities — 22 — — 22 Private equity — — — 160 160 Other 7 — — 9 16 Cash equivalents 193 13 — — 206 Other investments — 29 — — 29 Total $ 742 $ 524 $ — $ 169 $ 1,435 Liabilities: Energy-related derivatives $ — $ 96 $ — $ — $ 96 Georgia Power Assets: Energy-related derivatives $ — $ 22 $ — $ — $ 22 Nuclear decommissioning trusts: (b)(c) Domestic equity 276 1 — — 277 Foreign equity — 161 — — 161 U.S. Treasury and government agency securities — 297 — — 297 Municipal bonds — 47 — — 47 Corporate bonds — 180 — — 180 Mortgage and asset backed securities — 68 — — 68 Other 33 12 — — 45 Total $ 309 $ 788 $ — $ — $ 1,097 Liabilities: Energy-related derivatives $ — $ 132 $ — $ — $ 132 Interest rate derivatives — 1 — — 1 Total $ — $ 133 $ — $ — $ 133 Fair Value Measurements Using: At March 31, 2023 Quoted Prices Significant Significant Net Asset Value as a Practical Expedient (NAV) Total (in millions) Mississippi Power Assets: Energy-related derivatives $ — $ 35 $ — $ — $ 35 Cash equivalents 3 — — — 3 Total $ 3 $ 35 $ — $ — $ 38 Liabilities: Energy-related derivatives $ — $ 62 $ — $ — $ 62 Southern Power Assets: Energy-related derivatives $ — $ 5 $ — $ — $ 5 Cash equivalents 13 — — — 13 Total $ 13 $ 5 $ — $ — $ 18 Liabilities: Energy-related derivatives $ — $ 14 $ — $ — $ 14 Foreign currency derivatives — 47 — — 47 Contingent consideration — — 12 — 12 Other — 13 — — 13 Total $ — $ 74 $ 12 $ — $ 86 Southern Company Gas Assets: Energy-related derivatives (a) $ 4 $ 6 $ — $ — $ 10 Interest rate derivatives — 1 — — 1 Non-qualified deferred compensation trusts: Domestic equity — 6 — — 6 Foreign equity — 1 — — 1 Pooled funds – fixed income — 7 — — 7 Cash equivalents 2 — — — 2 Cash equivalents and restricted cash 55 — — — 55 Total $ 61 $ 21 $ — $ — $ 82 Liabilities: Energy-related derivatives (a) $ 40 $ 50 $ — $ — $ 90 Interest rate derivatives — 72 — — 72 Total $ 40 $ 122 $ — $ — $ 162 (a) Excludes cash collateral of $60 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 March 31, 2023, approximately $37 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 months ended March 31, 2023 and 2022. The changes were recorded as a change to the regulatory assets and liabilities related to AROs for Georgia Power and Alabama Power, respectively. Three Months Ended Fair value increases (decreases) March 31, 2023 March 31, 2022 (in millions) Southern Company $ 102 $ (150) Alabama Power 45 (67) Georgia Power 57 (83) 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" primarily includes 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 March 31, 2023, the fair value measurements of private market 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 $169 million and unfunded commitments related to the private market investments totaled $75 million. Private market investments include high-quality private equity funds across several market sectors, funds that invest in real estate assets, and a private credit fund. Private market funds do not have redemption rights. Distributions from these funds will be received as the underlying investments in the funds are liquidated. At March 31, 2023, 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 $ 56.1 $ 10.6 $ 14.9 $ 1.5 $ 3.0 $ 7.5 Fair value 51.6 9.5 13.7 1.3 2.9 6.7 (*) 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	3 Months Ended
	Mar. 31, 2023
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. 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. 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 March 31, 2023, 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 (*) 437 2030 2028 Alabama Power 111 2026 2023 Georgia Power 122 2026 2023 Mississippi Power 86 2027 2023 Southern Power 11 2030 2023 Southern Company Gas (*) 107 2028 2028 (*) 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 113.6 million mmBtu and short natural gas positions of 6.6 million mmBtu at March 31, 2023, 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 22 million mmBtu for Southern Company, which includes 6 million mmBtu for Alabama Power, 8 million mmBtu for Georgia Power, 3 million mmBtu for Mississippi Power, and 5 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 March 31, 2024 are $(42) million for Southern Company, $(12) million for Southern Power, $(30) 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 March 31, 2023, the following interest rate derivatives were outstanding: Notional Weighted Interest Hedge Fair Value Gain (Loss) at March 31, 2023 (in millions) (in millions) Cash Flow Hedges of Forecasted Debt Georgia Power $ 750 3.63% N/A February 2033 $ (1) Southern Company parent 500 3.47% N/A June — Southern Company Gas 250 3.40% N/A August 1 Fair Value Hedges of Existing Debt Southern Company parent 400 1-month LIBOR + 0.68% 1.75% March 2028 (45) Southern Company parent 1,000 1-month LIBOR + 2.36% 3.70% April (142) Southern Company Gas 500 1-month LIBOR + 0.38% 1.75% January 2031 (71) Southern Company $ 3,400 $ (258) 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 March 31, 2024 are $(15) 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 March 31, 2023, the following foreign currency derivatives were outstanding: Pay Notional Pay Receive Notional Receive Hedge Fair Value Gain (Loss) at March 31, 2023 (in millions) (in millions) (in millions) Cash Flow Hedges of Existing Debt Southern Power $ 564 3.78% € 500 1.85% June 2026 $ (47) Fair Value Hedges of Existing Debt Southern Company parent 1,476 3.39% 1,250 1.88% September 2027 (171) Southern Company $ 2,040 € 1,750 $ (218) 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 March 31, 2024 are $11 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 March 31, 2023 At December 31, 2022 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/Liabilities from risk management activities $ 41 $ 230 $ 123 $ 121 Other deferred charges and assets/Other deferred credits and liabilities 53 113 52 44 Total derivatives designated as hedging instruments for regulatory purposes 94 343 175 165 Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Assets from risk management activities/Liabilities from risk management activities — 38 3 27 Other deferred charges and assets/Other deferred credits and liabilities 4 4 6 4 Interest rate derivatives: Assets from risk management activities/Liabilities from risk management activities 2 71 12 62 Other deferred charges and assets/Other deferred credits and liabilities — 191 — 240 Foreign currency derivatives: Assets from risk management activities/Liabilities from risk management activities — 35 — 34 Other deferred charges and assets/Other deferred credits and liabilities — 183 — 182 Total derivatives designated as hedging instruments in cash flow and fair value hedges 6 522 21 549 Energy-related derivatives not designated as hedging instruments Assets from risk management activities/Liabilities from risk management activities 4 8 13 13 Other deferred charges and assets/Other deferred credits and liabilities 2 1 2 1 Total derivatives not designated as hedging instruments 6 9 15 14 Gross amounts recognized 106 874 211 728 Gross amounts offset (a) (57) (118) (70) (111) Net amounts recognized in the Balance Sheets (b) $ 49 $ 756 $ 141 $ 617 At March 31, 2023 At December 31, 2022 Derivative Category and Balance Sheet Location Assets Liabilities Assets Liabilities (in millions) (in millions) Alabama Power (c) Energy-related derivatives designated as hedging instruments for regulatory purposes Other current assets/Other current liabilities $ 14 $ 54 $ 42 $ 21 Other deferred charges and assets/Other deferred credits and liabilities 18 42 20 18 Total derivatives designated as hedging instruments for regulatory purposes 32 96 62 39 Gross amounts offset (28) (28) (24) (24) Net amounts recognized in the Balance Sheets $ 4 $ 68 $ 38 $ 15 Georgia Power Energy-related derivatives designated as hedging instruments for regulatory purposes Assets from risk management activities/Other current liabilities $ 10 $ 86 $ 36 $ 43 Other deferred charges and assets/Other deferred credits and liabilities 11 45 6 18 Total derivatives designated as hedging instruments for regulatory purposes 21 131 42 61 Interest rate derivatives designated as hedging instruments in cash flow and fair value hedges Assets from risk management activities/Other current liabilities — 1 — — Energy-related derivatives not designated as hedging instruments Other current assets/Other current liabilities 1 1 — 1 Gross amounts recognized 22 133 42 62 Gross amounts offset (19) (19) (21) (21) Net amounts recognized in the Balance Sheets $ 3 $ 114 $ 21 $ 41 Mississippi Power (c) Energy-related derivatives designated as hedging instruments for regulatory purposes Assets from risk management activities/Other current liabilities $ 11 $ 37 $ 33 $ 24 Other deferred charges and assets/Other deferred credits and liabilities 24 25 26 8 Total derivatives designated as hedging instruments for regulatory purposes 35 62 59 32 Gross amounts offset (25) (25) (17) (17) Net amounts recognized in the Balance Sheets $ 10 $ 37 $ 42 $ 15 At March 31, 2023 At December 31, 2022 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 $ — $ 12 $ — $ 12 Other deferred charges and assets/Other deferred credits and liabilities 4 — 5 — Foreign currency derivatives: Other current assets/Other current liabilities — 11 — 11 Other deferred charges and assets/Other deferred credits and liabilities — 36 — 36 Total derivatives designated as hedging instruments in cash flow and fair value hedges 4 59 5 59 Energy-related derivatives not designated as hedging instruments Other current assets/Other current liabilities — 2 2 — Other deferred charges and assets/Other deferred credits and liabilities 1 — 1 — Total derivatives not designated as hedging instruments 1 2 3 — Gross amounts recognized 5 61 8 59 Net amounts recognized in the Balance Sheets $ 5 $ 61 $ 8 $ 59 At March 31, 2023 At December 31, 2022 Derivative Category and Balance Sheet Location Assets Liabilities Assets Liabilities (in millions) (in millions) Southern Company Gas Energy-related derivatives designated as hedging instruments for regulatory purposes Other current assets/Other current liabilities $ 6 $ 53 $ 12 $ 33 Other deferred charges and assets/Other deferred credits and liabilities — 1 — — Total derivatives designated as hedging instruments for regulatory purposes 6 54 12 33 Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Other current assets/Other current liabilities — 26 3 15 Other deferred charges and assets/Other deferred credits and liabilities — 4 1 4 Interest rate derivatives: Other current assets/Other current liabilities 1 19 — 14 Other deferred charges and assets/Other deferred credits and liabilities — 53 — 72 Total derivatives designated as hedging instruments in cash flow and fair value hedges 1 102 4 105 Energy-related derivatives not designated as hedging instruments Other current assets/Other current liabilities 3 5 11 12 Other deferred charges and assets/Other deferred credits and liabilities 1 1 1 1 Total derivatives not designated as hedging instruments 4 6 12 13 Gross amounts recognized 11 162 28 151 Gross amounts offset (a) 18 (43) — (41) Net amounts recognized in the Balance Sheets (b) $ 29 $ 119 $ 28 $ 110 (a) Gross amounts offset includes cash collateral held on deposit in broker margin accounts of $60 million and $41 million at March 31, 2023 and December 31, 2022, respectively. (b) Net amounts of derivative instruments outstanding exclude immaterial premium and intrinsic value associated with weather derivatives for both periods presented. (c) Energy-related derivatives not designated as hedging instruments were immaterial for Alabama Power and Mississippi Power for both periods presented. At March 31, 2023 and December 31, 2022, 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 March 31, 2023: Energy-related derivatives: Other regulatory assets, current $ (198) $ (44) $ (78) $ (29) $ (47) Other regulatory assets, deferred (67) (24) (35) (8) — Other regulatory liabilities, current 19 3 2 3 11 Other regulatory liabilities, deferred 9 1 1 7 — Total energy-related derivative gains (losses) $ (237) $ (64) $ (110) $ (27) $ (36) At December 31, 2022: Energy-related derivatives: Other regulatory assets, current $ (71) $ (8) $ (26) $ (13) $ (24) Other regulatory assets, deferred (23) (7) (14) (2) — Other regulatory liabilities, current 72 29 19 22 2 Other regulatory liabilities, deferred 31 9 2 20 — Total energy-related derivative gains (losses) $ 9 $ 23 $ (19) $ 27 $ (22) For the three months ended March 31, 2023 and 2022, the pre-tax effects of cash flow and fair value hedge accounting on accumulated OCI for the applicable Registrants were as follows: Gain (Loss) Recognized in OCI on Derivatives For the Three Months Ended March 31, 2023 2022 (in millions) Southern Company Cash flow hedges: Energy-related derivatives $ (45) $ 42 Interest rate derivatives (13) 9 Foreign currency derivatives — (28) Fair value hedges (*) : Foreign currency derivatives (28) 4 Total $ (86) $ 27 Georgia Power Cash flow hedges: Interest rate derivatives $ (1) $ 12 Southern Power Cash flow hedges: Energy-related derivatives $ (11) $ 5 Foreign currency derivatives — (28) Total $ (11) $ (23) Southern Company Gas Cash flow hedges: Energy-related derivatives $ (34) $ 37 Interest rate derivatives 1 — Total $ (33) $ 37 (*) 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 months ended March 31, 2023, the pre-tax effects of energy-related derivatives designated as cash flow hedging instruments on accumulated OCI were immaterial for Alabama Power and Mississippi Power. There were no such instruments for Alabama Power and Mississippi Power at March 31, 2022. For the three months ended March 31, 2023 and 2022, 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 March 31, 2023 2022 (in millions) Southern Company Total cost of natural gas $ 898 $ 1,095 Gain (loss) on energy-related cash flow hedges (a) (20) 9 Total depreciation and amortization 1,111 892 Gain (loss) on energy-related cash flow hedges (a) (9) 2 Total interest expense, net of amounts capitalized (582) (462) Gain (loss) on interest rate cash flow hedges (a) (4) (7) Gain (loss) on foreign currency cash flow hedges (a) (3) (6) Gain (loss) on interest rate fair value hedges (b) 43 (123) Total other income (expense), net 147 145 Gain (loss) on foreign currency cash flow hedges (a)(c) 10 (25) Gain (loss) on foreign currency fair value hedges (2) (24) Amount excluded from effectiveness testing recognized in earnings 28 (4) Southern Power Total depreciation and amortization $ 128 $ 120 Gain (loss) on energy-related cash flow hedges (a) (9) 2 Total interest expense, net of amounts capitalized (33) (37) Gain (loss) on foreign currency cash flow hedges (a) (3) (6) Total other income (expense), net 2 2 Gain (loss) on foreign currency cash flow hedges (a)(c) 10 (25) Southern Company Gas Total cost of natural gas $ 898 $ 1,095 Gain (loss) on energy-related cash flow hedges (a) (20) 9 Total interest expense, net of amounts capitalized (76) (61) Gain (loss) on interest rate cash flow hedges (a) (1) (1) Gain (loss) on interest rate fair value hedges (b) 13 (36) (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. The pre-tax effects of cash flow and fair value hedge accounting on income for energy-related derivatives and interest rate derivatives were immaterial for the traditional electric operating companies for both periods presented. At March 31, 2023 and December 31, 2022, 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 March 31, 2023 At December 31, 2022 At March 31, 2023 At December 31, 2022 (in millions) (in millions) Southern Company Long-term debt $ (3,007) $ (2,927) $ 228 $ 282 Southern Company Gas Long-term debt $ (428) $ (415) $ 69 $ 81 For the three months ended March 31, 2023 and 2022, 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 March 31, Derivatives in Non-Designated Hedging Relationships Statements of Income Location 2023 2022 (in millions) Energy-related derivatives: Natural gas revenues (*) $ — $ 2 Cost of natural gas 13 21 Total derivatives in non-designated hedging relationships $ 13 $ 23 (*) Excludes immaterial gains (losses) recorded in natural gas revenues associated with weather derivatives for both periods presented. For the three months ended March 31, 2023 and 2022, 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 March 31, 2023, 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 $73 million and $23 million, respectively, at March 31, 2023. 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 March 31, 2023. 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. 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 March 31, 2023, cash collateral posted in these accounts was $15 million for Southern Power and immaterial for Alabama Power. 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 March 31, 2023, cash collateral held on deposit in broker margin accounts was $60 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.

Segment and Related Information

Segment and Related Information	3 Months Ended
	Mar. 31, 2023
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. Southern Company's reportable business segments are the sale of electricity by the traditional electric operating companies, the sale of electricity in the competitive wholesale market by Southern Power, and the sale of natural gas and other complementary products and services by Southern Company Gas. Revenues from sales by Southern Power to the traditional electric operating companies were $135 million and $105 million for the three months ended March 31, 2023 and 2022, respectively. Revenues from sales of natural gas from Southern Company Gas to the traditional electric operating companies and Southern Power were immaterial for both periods presented. The "All Other" column includes the Southern Company parent entity, which does not allocate operating expenses to business segments. Also, this category includes segments below the quantitative threshold for separate disclosure. These segments include providing distributed energy and resilience solutions and deploying microgrids for commercial, industrial, governmental, and utility customers, as well as investments in telecommunications and, for the three months ended March 31, 2022, leveraged lease projects. All other inter-segment revenues are not material. Financial data for business segments and products and services for the three months ended March 31, 2023 and 2022 was as follows: Electric Utilities Traditional Southern Eliminations Total Southern Company Gas All Eliminations Consolidated (in millions) Three Months Ended March 31, 2023 Operating revenues $ 4,113 $ 508 $ (138) $ 4,483 $ 1,875 $ 166 $ (44) $ 6,480 Segment net income (loss) (a)(b) 610 102 — 712 309 (154) (5) 862 At March 31, 2023 Goodwill $ — $ 2 $ — $ 2 $ 5,015 $ 144 $ — $ 5,161 Total assets 96,223 13,134 (575) 108,782 24,222 2,606 (854) 134,756 Three Months Ended March 31, 2022 Operating revenues $ 4,191 $ 539 $ (221) $ 4,509 $ 2,058 $ 123 $ (42) $ 6,648 Segment net income (loss) (a) 774 72 — 846 319 (125) (8) 1,032 At December 31, 2022 Goodwill $ — $ 2 $ — $ 2 $ 5,015 $ 144 $ — $ 5,161 Total assets 95,861 13,081 (659) 108,283 24,621 2,665 (678) 134,891 (a) Attributable to Southern Company. (b) For Southern Power, includes a $16 million pre-tax gain ($12 million after tax) on the sale of spare parts. Products and Services Electric Utilities' Revenues Retail Wholesale Other Total (in millions) Three Months Ended March 31, 2023 $ 3,599 $ 599 $ 285 $ 4,483 Three Months Ended March 31, 2022 3,613 664 232 4,509 Southern Company Gas' Revenues Gas Gas Other Total (in millions) Three Months Ended March 31, 2023 $ 1,610 $ 246 $ 19 $ 1,875 Three Months Ended March 31, 2022 1,791 243 24 2,058 Southern Company Gas Southern Company Gas manages its business through three reportable segments – gas distribution operations, gas pipeline investments, and gas marketing services. The non-reportable segments are combined and presented as all other. 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. See Note 7 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K for additional information. 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. The all other column included a natural gas storage facility in Texas through its sale in November 2022. See Note 15 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K for additional information, including the sale of a natural gas storage facility in California expected to be completed later in 2023. Business segment financial data for the three months ended March 31, 2023 and 2022 was as follows: Gas Distribution Operations Gas Gas Marketing Services Total All Other Eliminations Consolidated (in millions) Three Months Ended March 31, 2023 Operating revenues $ 1,618 $ 8 $ 246 $ 1,872 $ 12 $ (9) $ 1,875 Segment net income 221 31 50 302 7 — 309 Total assets at March 31, 2023 22,223 1,583 1,596 25,402 9,598 (10,778) 24,222 Three Months Ended March 31, 2022 Operating revenues $ 1,803 $ 8 $ 243 $ 2,054 $ 16 $ (12) $ 2,058 Segment net income 214 29 66 309 10 — 319 Total assets at December 31, 2022 22,040 1,577 1,616 25,233 8,943 (9,555) 24,621

Introduction (Policies)

Introduction (Policies)	3 Months Ended
	Mar. 31, 2023
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, 2022 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 March 31, 2023 and 2022. 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. 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. 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. 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)	3 Months Ended
	Mar. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Goodwill	Goodwill at March 31, 2023 and December 31, 2022 was as follows: Goodwill (in millions) Southern Company $ 5,161 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 March 31, 2023 At December 31, 2022 Gross Carrying Amount Accumulated Amortization Other Gross Carrying Amount Accumulated Amortization Other (in millions) (in millions) Southern Company Subject to amortization: Customer relationships $ 212 $ (164) $ 48 $ 212 $ (162) $ 50 Trade names 64 (47) 17 64 (44) 20 PPA fair value adjustments 390 (134) 256 390 (129) 261 Other 6 (5) 1 5 (5) — Total subject to amortization $ 672 $ (350) $ 322 $ 671 $ (340) $ 331 Not subject to amortization: FCC licenses 75 — 75 75 — 75 Total other intangible assets $ 747 $ (350) $ 397 $ 746 $ (340) $ 406 Southern Power (*) PPA fair value adjustments $ 390 $ (134) $ 256 $ 390 $ (129) $ 261 Southern Company Gas (*) Gas marketing services Customer relationships $ 156 $ (140) $ 16 $ 156 $ (139) $ 17 Trade names 26 (19) 7 26 (17) 9 Total other intangible assets $ 182 $ (159) $ 23 $ 182 $ (156) $ 26 (*) All subject to amortization.
Schedule of Other Intangible Assets, Finite-Lived	Other intangible assets were as follows: At March 31, 2023 At December 31, 2022 Gross Carrying Amount Accumulated Amortization Other Gross Carrying Amount Accumulated Amortization Other (in millions) (in millions) Southern Company Subject to amortization: Customer relationships $ 212 $ (164) $ 48 $ 212 $ (162) $ 50 Trade names 64 (47) 17 64 (44) 20 PPA fair value adjustments 390 (134) 256 390 (129) 261 Other 6 (5) 1 5 (5) — Total subject to amortization $ 672 $ (350) $ 322 $ 671 $ (340) $ 331 Not subject to amortization: FCC licenses 75 — 75 75 — 75 Total other intangible assets $ 747 $ (350) $ 397 $ 746 $ (340) $ 406 Southern Power (*) PPA fair value adjustments $ 390 $ (134) $ 256 $ 390 $ (129) $ 261 Southern Company Gas (*) Gas marketing services Customer relationships $ 156 $ (140) $ 16 $ 156 $ (139) $ 17 Trade names 26 (19) 7 26 (17) 9 Total other intangible assets $ 182 $ (159) $ 23 $ 182 $ (156) $ 26 (*) All subject to amortization.
Schedule of Amortization of Other Intangible Assets	Amortization associated with other intangible assets was as follows: Three Months Ended March 31, 2023 March 31, 2022 (in millions) Southern Company (a) $ 10 $ 10 Southern Power (b) 5 5 Southern Company Gas 3 3 (a) Includes $5 million recorded as a reduction to operating revenues for both periods presented. (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 Company Georgia Power Southern Power Southern (in millions) At March 31, 2023 Cash and cash equivalents $ 1,053 $ — $ 123 $ 88 Restricted cash (a) : Other current assets 117 115 — 2 Other deferred charges and assets 47 45 3 — Total cash, cash equivalents, and restricted cash (b) $ 1,217 $ 160 $ 126 $ 89 At December 31, 2022 Cash and cash equivalents $ 1,917 $ 364 $ 131 $ 81 Restricted cash (a) : Other current assets 62 60 — 2 Other deferred charges and assets 58 56 3 — Total cash, cash equivalents, and restricted cash (b) $ 2,037 $ 480 $ 133 $ 83 (a) For Georgia Power, reflects $116 million at both March 31, 2023 and December 31, 2022 related to proceeds from the issuance of solid waste disposal facility revenue bonds in 2022 and $44 million at March 31, 2023 related to funds from a Georgia Housing and Finance Authority (GHFA) rental assistance program used to offset qualifying customers' past due balances, which expired on March 31, 2023 and will be returned to the GHFA. For Southern Power, reflects $3 million at both March 31, 2023 and December 31, 2022 held to fund estimated construction completion costs at the Deuel Harvest wind facility. 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 Company Georgia Power Southern Power Southern (in millions) At March 31, 2023 Cash and cash equivalents $ 1,053 $ — $ 123 $ 88 Restricted cash (a) : Other current assets 117 115 — 2 Other deferred charges and assets 47 45 3 — Total cash, cash equivalents, and restricted cash (b) $ 1,217 $ 160 $ 126 $ 89 At December 31, 2022 Cash and cash equivalents $ 1,917 $ 364 $ 131 $ 81 Restricted cash (a) : Other current assets 62 60 — 2 Other deferred charges and assets 58 56 3 — Total cash, cash equivalents, and restricted cash (b) $ 2,037 $ 480 $ 133 $ 83 (a) For Georgia Power, reflects $116 million at both March 31, 2023 and December 31, 2022 related to proceeds from the issuance of solid waste disposal facility revenue bonds in 2022 and $44 million at March 31, 2023 related to funds from a Georgia Housing and Finance Authority (GHFA) rental assistance program used to offset qualifying customers' past due balances, which expired on March 31, 2023 and will be returned to the GHFA. For Southern Power, reflects $3 million at both March 31, 2023 and December 31, 2022 held to fund estimated construction completion costs at the Deuel Harvest wind facility. 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 Storm Damage Reserve Activity	Storm damage reserve activity for the traditional electric operating companies during the three months ended March 31, 2023 was as follows: Southern Alabama Power Georgia Power Mississippi (in millions) Balance at December 31, 2022 $ 216 $ 97 $ 83 $ 36 Accrual 13 3 8 2 Weather-related damages (43) (12) (31) — Balance at March 31, 2023 $ 186 $ 88 $ 60 $ 38

Regulatory Matters (Tables)

Regulatory Matters (Tables)	3 Months Ended
	Mar. 31, 2023
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 March 31, 2023 and December 31, 2022 were as follows: Regulatory Clause Balance Sheet Line Item March 31, December 31, 2022 (in millions) Alabama Power Rate CNP Compliance Other regulatory assets, current $ 23 $ 47 Other regulatory assets, deferred 18 — Rate CNP PPA Other regulatory assets, current 17 18 Other regulatory assets, deferred 100 102 Retail Energy Cost Recovery Other regulatory assets, current 101 102 Other regulatory assets, deferred 420 520 Georgia Power Fuel Cost Recovery (*) Receivables – under recovered fuel clause revenues $ 447 $ — Deferred under recovered fuel clause revenues 1,702 2,056 Mississippi Power Fuel Cost Recovery Receivables – customer accounts, net $ 25 $ 1 Ad Valorem Tax Other regulatory assets, current 9 12 Other regulatory assets, deferred 19 19 Southern Company Gas Natural Gas Cost Recovery Natural gas cost under recovery $ — $ 108 Natural gas cost over recovery 117 — (*) See "Georgia Power – Fuel Cost Recovery" herein for additional information.
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 second quarter 2023 and the first quarter 2024, respectively, is as follows: (in millions) Base project capital cost forecast (a)(b) $ 10,553 Construction contingency estimate 40 Total project capital cost forecast (a)(b) 10,593 Net investment at March 31, 2023 (b) (9,747) Remaining estimate to complete $ 846 (a) Includes approximately $610 million of costs that are not shared with the other Vogtle Owners, including $33 million of construction monitoring costs approved for recovery by the Georgia PSC in its nineteenth VCM order, and approximately $407 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 $418 million, of which $334 million had been accrued through March 31, 2023. (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	Capital expenditures incurred under specific infrastructure replacement programs and capital projects during the first three months of 2023 were as follows: Utility Program Three Months Ended March 31, 2023 (in millions) Nicor Gas Investing in Illinois $ 62 Virginia Natural Gas SAVE 20 Atlanta Gas Light System Reinforcement Rider 32 Chattanooga Gas Pipeline Replacement Program 1 Total $ 115

Revenue from Contracts with C_2

Revenue from Contracts with Customers and Lease Income (Tables)	3 Months Ended
	Mar. 31, 2023
Revenue from Contract with Customer [Abstract]
Schedule of Disaggregation of Revenue	The following table disaggregates revenue from contracts with customers for the three months ended March 31, 2023 and 2022: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Three Months Ended March 31, 2023 Operating revenues Retail electric revenues Residential $ 1,525 $ 659 $ 801 $ 65 $ — $ — Commercial 1,251 430 753 68 — — Industrial 789 398 313 78 — — Other 27 3 22 2 — — Total retail electric revenues 3,592 1,490 1,889 213 — — Natural gas distribution revenues Residential 896 — — — — 896 Commercial 232 — — — — 232 Transportation 319 — — — — 319 Industrial 23 — — — — 23 Other 117 — — — — 117 Total natural gas distribution revenues 1,587 — — — — 1,587 Wholesale electric revenues PPA energy revenues 284 72 12 4 202 — PPA capacity revenues 190 60 11 32 89 — Non-PPA revenues 36 20 3 107 103 — Total wholesale electric revenues 510 152 26 143 394 — Other natural gas revenues Gas marketing services 231 — — — — 231 Other natural gas revenues 11 — — — — 11 Total natural gas revenues 242 — — — — 242 Other revenues 310 54 132 11 11 — Total revenue from contracts with customers 6,241 1,696 2,047 367 405 1,829 Other revenue sources (*) 239 (49) 129 23 103 46 Total operating revenues $ 6,480 $ 1,647 $ 2,176 $ 390 $ 508 $ 1,875 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Three Months Ended March 31, 2022 Operating revenues Retail electric revenues Residential $ 1,525 $ 634 $ 821 $ 70 $ — $ — Commercial 1,178 375 738 65 — — Industrial 727 323 334 70 — — Other 26 4 20 2 — — Total retail electric revenues 3,456 1,336 1,913 207 — — Natural gas distribution revenues Residential 1,016 — — — — 1,016 Commercial 270 — — — — 270 Transportation 337 — — — — 337 Industrial 32 — — — — 32 Other 129 — — — — 129 Total natural gas distribution revenues 1,784 — — — — 1,784 Wholesale electric revenues PPA energy revenues 342 59 32 3 251 — PPA capacity revenues 134 39 12 3 81 — Non-PPA revenues 58 64 9 102 73 — Total wholesale electric revenues 534 162 53 108 405 — Other natural gas revenues Gas marketing services 243 — — — — 243 Other natural gas revenues 16 — — — — 16 Total natural gas revenues 259 — — — — 259 Other revenues 225 48 95 9 8 — Total revenue from contracts with customers 6,258 1,546 2,061 324 413 2,043 Other revenue sources (*) 390 103 147 11 126 15 Total operating revenues $ 6,648 $ 1,649 $ 2,208 $ 335 $ 539 $ 2,058 (*) 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.
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 March 31, 2023 and December 31, 2022: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Accounts Receivable At March 31, 2023 $ 2,433 $ 622 $ 672 $ 79 $ 119 $ 853 At December 31, 2022 3,123 696 922 92 237 1,107 Contract Assets At March 31, 2023 $ 160 $ 3 $ 74 $ — $ — $ 19 At December 31, 2022 156 2 89 — — — Contract Liabilities At March 31, 2023 $ 61 $ 2 $ 14 $ 1 $ 1 $ — At December 31, 2022 45 4 9 — 1 —
Schedule of Remaining Performance Obligations	Revenues from contracts with customers related to these performance obligations remaining at March 31, 2023 are expected to be recognized as follows: 2023 (remaining) 2024 2025 2026 2027 Thereafter (in millions) Southern Company $ 632 $ 553 $ 347 $ 315 $ 319 $ 2,089 Alabama Power 17 7 6 — — — Georgia Power 68 60 25 13 14 23 Southern Power 268 345 302 303 310 2,077 Southern Company Gas 15 29 — — — —
Schedule of Lease Income	Lease income for the three months ended March 31, 2023 and 2022 is as follows: Southern Alabama Power Georgia Power Mississippi Southern Power Southern Company Gas (in millions) For the Three Months Ended March 31, 2023 Lease income - interest income on sales-type leases $ 6 $ — $ — $ 4 $ 2 $ — Lease income - operating leases 49 18 7 1 21 9 Variable lease income 69 — — — 75 — Total lease income $ 124 $ 18 $ 7 $ 5 $ 98 $ 9 For the Three Months Ended March 31, 2022 Lease income - interest income on sales-type leases $ 6 $ — $ — $ 4 $ 2 $ — Lease income - operating leases 51 20 8 — 21 9 Variable lease income 84 — — — 90 — Total lease income $ 141 $ 20 $ 8 $ 4 $ 113 $ 9

Consolidated Entities and Equ_2

Consolidated Entities and Equity Method Investments (Tables)	3 Months Ended
	Mar. 31, 2023
Regulated Operations [Abstract]
Schedule of Equity Method Investments	The carrying amounts of Southern Company Gas' equity method investments at March 31, 2023 and December 31, 2022 and related earnings from those investments for the three months ended March 31, 2023 and 2022 were as follows: Investment Balance March 31, 2023 December 31, 2022 (in millions) SNG $ 1,249 $ 1,243 Other 33 33 Total $ 1,282 $ 1,276
Schedule of Earnings (Loss) from Equity Method Investments	Three Months Ended March 31, Earnings from Equity Method Investments 2023 2022 (in millions) SNG $ 44 $ 39 Other 1 1 Total $ 45 $ 40

Financing and Leases (Tables)

Financing and Leases (Tables)	3 Months Ended
	Mar. 31, 2023
Debt Disclosure [Abstract]
Schedule of Credit Arrangements	At March 31, 2023, 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 — 275 225 — Southern Power (a) — — — 600 600 587 — 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 $ 7,564 $ 280 (a) Does not include Southern Power Company's $75 million and $100 million continuing letter of credit facilities for standby letters of credit, expiring in 2025 and 2026, respectively, of which $9 million and $16 million, respectively, was unused at March 31, 2023. In March 2023, Southern Power amended the $100 million letter of credit facility, which, among other things, extended the expiration date from 2025 to 2026 and increased the amount from $75 million. 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 under a $250 million credit arrangement expiring in 2023.
Schedule of Shares Used to Compute Diluted Earnings Per Share	Shares used to compute diluted EPS were as follows: Three Months Ended March 31, 2023 2022 (in millions) As reported shares 1,091 1,063 Effect of stock-based compensation 7 6 Diluted shares 1,098 1,069

Retirement Benefits (Tables)

Retirement Benefits (Tables)	3 Months Ended
	Mar. 31, 2023
Retirement Benefits [Abstract]
Schedule of Pension Plans and Postretirement Plans	Components of the net periodic benefit costs for the three months ended March 31, 2023 and 2022 are presented in the following tables. Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) Three Months Ended March 31, 2023 Pension Plans Service cost $ 69 $ 16 $ 17 $ 3 $ 2 $ 6 Interest cost 156 36 48 7 2 11 Expected return on plan assets (307) (74) (96) (14) (4) (22) Amortization: Prior service costs — — — — — (1) Regulatory asset — — — — — 4 Net (gain) loss 8 2 3 — — (1) Net periodic pension income $ (74) $ (20) $ (28) $ (4) $ — $ (3) Postretirement Benefits Service cost $ 4 $ 1 $ 1 $ — $ — $ — Interest cost 18 4 6 1 — 2 Expected return on plan assets (21) (8) (7) (1) — (2) Amortization: Regulatory asset — — — — — 2 Net gain (3) (1) (1) — — (1) Net periodic postretirement benefit cost (income) $ (2) $ (4) $ (1) $ — $ — $ 1 Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) Three Months Ended March 31, 2022 Pension Plans Service cost $ 103 $ 25 $ 26 $ 4 $ 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 — — — — — 4 Net loss 60 16 18 3 1 2 Net periodic pension cost (income) $ (51) $ (12) $ (24) $ (3) $ 1 $ (1) Postretirement Benefits Service cost $ 6 $ 1 $ 2 $ — $ — $ — Interest cost 10 3 4 — — 1 Expected return on plan assets (20) (8) (7) — — (2) Amortization: Regulatory asset — — — — — 2 Net periodic postretirement benefit cost (income) $ (4) $ (4) $ (1) $ — $ — $ 1

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2023
Fair Value Disclosures [Abstract]
Schedule of Assets and Liabilities Measured at Fair Value	At March 31, 2023, 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 March 31, 2023 Quoted Prices Significant Significant Net Asset Value as a Practical Expedient (NAV) Total (in millions) Southern Company Assets: Energy-related derivatives (a) $ 4 $ 100 $ — $ — $ 104 Interest rate derivatives — 2 — — 2 Investments in trusts: (b)(c) Domestic equity 680 192 — — 872 Foreign equity 138 162 — — 300 U.S. Treasury and government agency securities — 316 — — 316 Municipal bonds — 48 — — 48 Pooled funds – fixed income — 7 — — 7 Corporate bonds — 403 — — 403 Mortgage and asset backed securities — 90 — — 90 Private equity — — — 160 160 Cash and cash equivalents 2 — — — 2 Other 40 12 — 9 61 Cash equivalents 433 13 — — 446 Other investments 9 29 8 — 46 Total $ 1,306 $ 1,374 $ 8 $ 169 $ 2,857 Liabilities: Energy-related derivatives (a) $ 40 $ 354 $ — $ — $ 394 Interest rate derivatives — 261 — — 261 Foreign currency derivatives — 218 — — 218 Contingent consideration — — 12 — 12 Other — 13 — — 13 Total $ 40 $ 846 $ 12 $ — $ 898 Fair Value Measurements Using: At March 31, 2023 Quoted Prices Significant Significant Net Asset Value as a Practical Expedient (NAV) Total (in millions) Alabama Power Assets: Energy-related derivatives $ — $ 32 $ — $ — $ 32 Nuclear decommissioning trusts: (b) Domestic equity 404 185 — — 589 Foreign equity 138 — — — 138 U.S. Treasury and government agency securities — 19 — — 19 Municipal bonds — 1 — — 1 Corporate bonds — 223 — — 223 Mortgage and asset backed securities — 22 — — 22 Private equity — — — 160 160 Other 7 — — 9 16 Cash equivalents 193 13 — — 206 Other investments — 29 — — 29 Total $ 742 $ 524 $ — $ 169 $ 1,435 Liabilities: Energy-related derivatives $ — $ 96 $ — $ — $ 96 Georgia Power Assets: Energy-related derivatives $ — $ 22 $ — $ — $ 22 Nuclear decommissioning trusts: (b)(c) Domestic equity 276 1 — — 277 Foreign equity — 161 — — 161 U.S. Treasury and government agency securities — 297 — — 297 Municipal bonds — 47 — — 47 Corporate bonds — 180 — — 180 Mortgage and asset backed securities — 68 — — 68 Other 33 12 — — 45 Total $ 309 $ 788 $ — $ — $ 1,097 Liabilities: Energy-related derivatives $ — $ 132 $ — $ — $ 132 Interest rate derivatives — 1 — — 1 Total $ — $ 133 $ — $ — $ 133 Fair Value Measurements Using: At March 31, 2023 Quoted Prices Significant Significant Net Asset Value as a Practical Expedient (NAV) Total (in millions) Mississippi Power Assets: Energy-related derivatives $ — $ 35 $ — $ — $ 35 Cash equivalents 3 — — — 3 Total $ 3 $ 35 $ — $ — $ 38 Liabilities: Energy-related derivatives $ — $ 62 $ — $ — $ 62 Southern Power Assets: Energy-related derivatives $ — $ 5 $ — $ — $ 5 Cash equivalents 13 — — — 13 Total $ 13 $ 5 $ — $ — $ 18 Liabilities: Energy-related derivatives $ — $ 14 $ — $ — $ 14 Foreign currency derivatives — 47 — — 47 Contingent consideration — — 12 — 12 Other — 13 — — 13 Total $ — $ 74 $ 12 $ — $ 86 Southern Company Gas Assets: Energy-related derivatives (a) $ 4 $ 6 $ — $ — $ 10 Interest rate derivatives — 1 — — 1 Non-qualified deferred compensation trusts: Domestic equity — 6 — — 6 Foreign equity — 1 — — 1 Pooled funds – fixed income — 7 — — 7 Cash equivalents 2 — — — 2 Cash equivalents and restricted cash 55 — — — 55 Total $ 61 $ 21 $ — $ — $ 82 Liabilities: Energy-related derivatives (a) $ 40 $ 50 $ — $ — $ 90 Interest rate derivatives — 72 — — 72 Total $ 40 $ 122 $ — $ — $ 162 (a) Excludes cash collateral of $60 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 March 31, 2023, approximately $37 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 months ended March 31, 2023 and 2022. The changes were recorded as a change to the regulatory assets and liabilities related to AROs for Georgia Power and Alabama Power, respectively. Three Months Ended Fair value increases (decreases) March 31, 2023 March 31, 2022 (in millions) Southern Company $ 102 $ (150) Alabama Power 45 (67) Georgia Power 57 (83)
Schedule of Financial Instruments for which Carrying Amount Did Not Equal Fair Value	At March 31, 2023, 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 $ 56.1 $ 10.6 $ 14.9 $ 1.5 $ 3.0 $ 7.5 Fair value 51.6 9.5 13.7 1.3 2.9 6.7 (*) 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)	3 Months Ended
	Mar. 31, 2023
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Energy-Related Derivatives	At March 31, 2023, 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 (*) 437 2030 2028 Alabama Power 111 2026 2023 Georgia Power 122 2026 2023 Mississippi Power 86 2027 2023 Southern Power 11 2030 2023 Southern Company Gas (*) 107 2028 2028 (*) 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 113.6 million mmBtu and short natural gas positions of 6.6 million mmBtu at March 31, 2023, which is also included in Southern Company's total volume.
Schedule of Interest Rate Derivatives	At March 31, 2023, the following interest rate derivatives were outstanding: Notional Weighted Interest Hedge Fair Value Gain (Loss) at March 31, 2023 (in millions) (in millions) Cash Flow Hedges of Forecasted Debt Georgia Power $ 750 3.63% N/A February 2033 $ (1) Southern Company parent 500 3.47% N/A June — Southern Company Gas 250 3.40% N/A August 1 Fair Value Hedges of Existing Debt Southern Company parent 400 1-month LIBOR + 0.68% 1.75% March 2028 (45) Southern Company parent 1,000 1-month LIBOR + 2.36% 3.70% April (142) Southern Company Gas 500 1-month LIBOR + 0.38% 1.75% January 2031 (71) Southern Company $ 3,400 $ (258)
Schedule of Foreign Currency Derivatives	At March 31, 2023, the following foreign currency derivatives were outstanding: Pay Notional Pay Receive Notional Receive Hedge Fair Value Gain (Loss) at March 31, 2023 (in millions) (in millions) (in millions) Cash Flow Hedges of Existing Debt Southern Power $ 564 3.78% € 500 1.85% June 2026 $ (47) Fair Value Hedges of Existing Debt Southern Company parent 1,476 3.39% 1,250 1.88% September 2027 (171) Southern Company $ 2,040 € 1,750 $ (218)
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 March 31, 2023 At December 31, 2022 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/Liabilities from risk management activities $ 41 $ 230 $ 123 $ 121 Other deferred charges and assets/Other deferred credits and liabilities 53 113 52 44 Total derivatives designated as hedging instruments for regulatory purposes 94 343 175 165 Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Assets from risk management activities/Liabilities from risk management activities — 38 3 27 Other deferred charges and assets/Other deferred credits and liabilities 4 4 6 4 Interest rate derivatives: Assets from risk management activities/Liabilities from risk management activities 2 71 12 62 Other deferred charges and assets/Other deferred credits and liabilities — 191 — 240 Foreign currency derivatives: Assets from risk management activities/Liabilities from risk management activities — 35 — 34 Other deferred charges and assets/Other deferred credits and liabilities — 183 — 182 Total derivatives designated as hedging instruments in cash flow and fair value hedges 6 522 21 549 Energy-related derivatives not designated as hedging instruments Assets from risk management activities/Liabilities from risk management activities 4 8 13 13 Other deferred charges and assets/Other deferred credits and liabilities 2 1 2 1 Total derivatives not designated as hedging instruments 6 9 15 14 Gross amounts recognized 106 874 211 728 Gross amounts offset (a) (57) (118) (70) (111) Net amounts recognized in the Balance Sheets (b) $ 49 $ 756 $ 141 $ 617 At March 31, 2023 At December 31, 2022 Derivative Category and Balance Sheet Location Assets Liabilities Assets Liabilities (in millions) (in millions) Alabama Power (c) Energy-related derivatives designated as hedging instruments for regulatory purposes Other current assets/Other current liabilities $ 14 $ 54 $ 42 $ 21 Other deferred charges and assets/Other deferred credits and liabilities 18 42 20 18 Total derivatives designated as hedging instruments for regulatory purposes 32 96 62 39 Gross amounts offset (28) (28) (24) (24) Net amounts recognized in the Balance Sheets $ 4 $ 68 $ 38 $ 15 Georgia Power Energy-related derivatives designated as hedging instruments for regulatory purposes Assets from risk management activities/Other current liabilities $ 10 $ 86 $ 36 $ 43 Other deferred charges and assets/Other deferred credits and liabilities 11 45 6 18 Total derivatives designated as hedging instruments for regulatory purposes 21 131 42 61 Interest rate derivatives designated as hedging instruments in cash flow and fair value hedges Assets from risk management activities/Other current liabilities — 1 — — Energy-related derivatives not designated as hedging instruments Other current assets/Other current liabilities 1 1 — 1 Gross amounts recognized 22 133 42 62 Gross amounts offset (19) (19) (21) (21) Net amounts recognized in the Balance Sheets $ 3 $ 114 $ 21 $ 41 Mississippi Power (c) Energy-related derivatives designated as hedging instruments for regulatory purposes Assets from risk management activities/Other current liabilities $ 11 $ 37 $ 33 $ 24 Other deferred charges and assets/Other deferred credits and liabilities 24 25 26 8 Total derivatives designated as hedging instruments for regulatory purposes 35 62 59 32 Gross amounts offset (25) (25) (17) (17) Net amounts recognized in the Balance Sheets $ 10 $ 37 $ 42 $ 15 At March 31, 2023 At December 31, 2022 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 $ — $ 12 $ — $ 12 Other deferred charges and assets/Other deferred credits and liabilities 4 — 5 — Foreign currency derivatives: Other current assets/Other current liabilities — 11 — 11 Other deferred charges and assets/Other deferred credits and liabilities — 36 — 36 Total derivatives designated as hedging instruments in cash flow and fair value hedges 4 59 5 59 Energy-related derivatives not designated as hedging instruments Other current assets/Other current liabilities — 2 2 — Other deferred charges and assets/Other deferred credits and liabilities 1 — 1 — Total derivatives not designated as hedging instruments 1 2 3 — Gross amounts recognized 5 61 8 59 Net amounts recognized in the Balance Sheets $ 5 $ 61 $ 8 $ 59 At March 31, 2023 At December 31, 2022 Derivative Category and Balance Sheet Location Assets Liabilities Assets Liabilities (in millions) (in millions) Southern Company Gas Energy-related derivatives designated as hedging instruments for regulatory purposes Other current assets/Other current liabilities $ 6 $ 53 $ 12 $ 33 Other deferred charges and assets/Other deferred credits and liabilities — 1 — — Total derivatives designated as hedging instruments for regulatory purposes 6 54 12 33 Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Other current assets/Other current liabilities — 26 3 15 Other deferred charges and assets/Other deferred credits and liabilities — 4 1 4 Interest rate derivatives: Other current assets/Other current liabilities 1 19 — 14 Other deferred charges and assets/Other deferred credits and liabilities — 53 — 72 Total derivatives designated as hedging instruments in cash flow and fair value hedges 1 102 4 105 Energy-related derivatives not designated as hedging instruments Other current assets/Other current liabilities 3 5 11 12 Other deferred charges and assets/Other deferred credits and liabilities 1 1 1 1 Total derivatives not designated as hedging instruments 4 6 12 13 Gross amounts recognized 11 162 28 151 Gross amounts offset (a) 18 (43) — (41) Net amounts recognized in the Balance Sheets (b) $ 29 $ 119 $ 28 $ 110 (a) Gross amounts offset includes cash collateral held on deposit in broker margin accounts of $60 million and $41 million at March 31, 2023 and December 31, 2022, respectively. (b) Net amounts of derivative instruments outstanding exclude immaterial premium and intrinsic value associated with weather derivatives for both periods presented. (c) Energy-related derivatives not designated as hedging instruments were immaterial for Alabama Power and Mississippi Power for both periods presented.
Schedule of Pre-tax Effects of Unrealized Derivative Gains (Losses)	At March 31, 2023 and December 31, 2022, 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 March 31, 2023: Energy-related derivatives: Other regulatory assets, current $ (198) $ (44) $ (78) $ (29) $ (47) Other regulatory assets, deferred (67) (24) (35) (8) — Other regulatory liabilities, current 19 3 2 3 11 Other regulatory liabilities, deferred 9 1 1 7 — Total energy-related derivative gains (losses) $ (237) $ (64) $ (110) $ (27) $ (36) At December 31, 2022: Energy-related derivatives: Other regulatory assets, current $ (71) $ (8) $ (26) $ (13) $ (24) Other regulatory assets, deferred (23) (7) (14) (2) — Other regulatory liabilities, current 72 29 19 22 2 Other regulatory liabilities, deferred 31 9 2 20 — Total energy-related derivative gains (losses) $ 9 $ 23 $ (19) $ 27 $ (22)
Schedule of Pre-Tax Effects of Hedging on AOCI	For the three months ended March 31, 2023 and 2022, the pre-tax effects of cash flow and fair value hedge accounting on accumulated OCI for the applicable Registrants were as follows: Gain (Loss) Recognized in OCI on Derivatives For the Three Months Ended March 31, 2023 2022 (in millions) Southern Company Cash flow hedges: Energy-related derivatives $ (45) $ 42 Interest rate derivatives (13) 9 Foreign currency derivatives — (28) Fair value hedges (*) : Foreign currency derivatives (28) 4 Total $ (86) $ 27 Georgia Power Cash flow hedges: Interest rate derivatives $ (1) $ 12 Southern Power Cash flow hedges: Energy-related derivatives $ (11) $ 5 Foreign currency derivatives — (28) Total $ (11) $ (23) Southern Company Gas Cash flow hedges: Energy-related derivatives $ (34) $ 37 Interest rate derivatives 1 — Total $ (33) $ 37 (*) Represents amounts excluded from the assessment of effectiveness for which the difference between changes in fair value and periodic amortization is recorded in OCI.
Schedule of Pre-Tax Effects of Cash Flow and Fair Value Hedging on Income	For the three months ended March 31, 2023 and 2022, 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 March 31, 2023 2022 (in millions) Southern Company Total cost of natural gas $ 898 $ 1,095 Gain (loss) on energy-related cash flow hedges (a) (20) 9 Total depreciation and amortization 1,111 892 Gain (loss) on energy-related cash flow hedges (a) (9) 2 Total interest expense, net of amounts capitalized (582) (462) Gain (loss) on interest rate cash flow hedges (a) (4) (7) Gain (loss) on foreign currency cash flow hedges (a) (3) (6) Gain (loss) on interest rate fair value hedges (b) 43 (123) Total other income (expense), net 147 145 Gain (loss) on foreign currency cash flow hedges (a)(c) 10 (25) Gain (loss) on foreign currency fair value hedges (2) (24) Amount excluded from effectiveness testing recognized in earnings 28 (4) Southern Power Total depreciation and amortization $ 128 $ 120 Gain (loss) on energy-related cash flow hedges (a) (9) 2 Total interest expense, net of amounts capitalized (33) (37) Gain (loss) on foreign currency cash flow hedges (a) (3) (6) Total other income (expense), net 2 2 Gain (loss) on foreign currency cash flow hedges (a)(c) 10 (25) Southern Company Gas Total cost of natural gas $ 898 $ 1,095 Gain (loss) on energy-related cash flow hedges (a) (20) 9 Total interest expense, net of amounts capitalized (76) (61) Gain (loss) on interest rate cash flow hedges (a) (1) (1) Gain (loss) on interest rate fair value hedges (b) 13 (36) (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 March 31, 2023 and December 31, 2022, 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 March 31, 2023 At December 31, 2022 At March 31, 2023 At December 31, 2022 (in millions) (in millions) Southern Company Long-term debt $ (3,007) $ (2,927) $ 228 $ 282 Southern Company Gas Long-term debt $ (428) $ (415) $ 69 $ 81
Schedule of Pre-tax Effect of Interest Rate and Energy Related Derivatives on Income	For the three months ended March 31, 2023 and 2022, 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 March 31, Derivatives in Non-Designated Hedging Relationships Statements of Income Location 2023 2022 (in millions) Energy-related derivatives: Natural gas revenues (*) $ — $ 2 Cost of natural gas 13 21 Total derivatives in non-designated hedging relationships $ 13 $ 23 (*) Excludes immaterial gains (losses) recorded in natural gas revenues associated with weather derivatives for both periods presented.

Segment and Related Informati_2

Segment and Related Information (Tables)	3 Months Ended
	Mar. 31, 2023
Segment Reporting [Abstract]
Schedule of Financial Data for Business Segments	Financial data for business segments and products and services for the three months ended March 31, 2023 and 2022 was as follows: Electric Utilities Traditional Southern Eliminations Total Southern Company Gas All Eliminations Consolidated (in millions) Three Months Ended March 31, 2023 Operating revenues $ 4,113 $ 508 $ (138) $ 4,483 $ 1,875 $ 166 $ (44) $ 6,480 Segment net income (loss) (a)(b) 610 102 — 712 309 (154) (5) 862 At March 31, 2023 Goodwill $ — $ 2 $ — $ 2 $ 5,015 $ 144 $ — $ 5,161 Total assets 96,223 13,134 (575) 108,782 24,222 2,606 (854) 134,756 Three Months Ended March 31, 2022 Operating revenues $ 4,191 $ 539 $ (221) $ 4,509 $ 2,058 $ 123 $ (42) $ 6,648 Segment net income (loss) (a) 774 72 — 846 319 (125) (8) 1,032 At December 31, 2022 Goodwill $ — $ 2 $ — $ 2 $ 5,015 $ 144 $ — $ 5,161 Total assets 95,861 13,081 (659) 108,283 24,621 2,665 (678) 134,891 (a) Attributable to Southern Company. (b) For Southern Power, includes a $16 million pre-tax gain ($12 million after tax) on the sale of spare parts. Business segment financial data for the three months ended March 31, 2023 and 2022 was as follows: Gas Distribution Operations Gas Gas Marketing Services Total All Other Eliminations Consolidated (in millions) Three Months Ended March 31, 2023 Operating revenues $ 1,618 $ 8 $ 246 $ 1,872 $ 12 $ (9) $ 1,875 Segment net income 221 31 50 302 7 — 309 Total assets at March 31, 2023 22,223 1,583 1,596 25,402 9,598 (10,778) 24,222 Three Months Ended March 31, 2022 Operating revenues $ 1,803 $ 8 $ 243 $ 2,054 $ 16 $ (12) $ 2,058 Segment net income 214 29 66 309 10 — 319 Total assets at December 31, 2022 22,040 1,577 1,616 25,233 8,943 (9,555) 24,621
Schedule of Financial Data for Products and Services	Electric Utilities' Revenues Retail Wholesale Other Total (in millions) Three Months Ended March 31, 2023 $ 3,599 $ 599 $ 285 $ 4,483 Three Months Ended March 31, 2022 3,613 664 232 4,509 Southern Company Gas' Revenues Gas Gas Other Total (in millions) Three Months Ended March 31, 2023 $ 1,610 $ 246 $ 19 $ 1,875 Three Months Ended March 31, 2022 1,791 243 24 2,058

Introduction - Schedule of Good

Introduction - Schedule of Goodwill (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Goodwill [Line Items]
Goodwill	$ 5,161	$ 5,161
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	Mar. 31, 2023	Dec. 31, 2022
Subject to amortization:
Gross Carrying Amount	$ 672	$ 671
Accumulated Amortization	(350)	(340)
Other Intangible Assets, Net	322	331
Not subject to amortization:
FCC licenses	75	75
Total other intangible assets
Gross Carrying Amount	747	746
Accumulated Amortization	(350)	(340)
Other Intangible Assets, Net	397	406
Customer relationships
Subject to amortization:
Gross Carrying Amount	212	212
Accumulated Amortization	(164)	(162)
Other Intangible Assets, Net	48	50
Total other intangible assets
Accumulated Amortization	(164)	(162)
Trade names
Subject to amortization:
Gross Carrying Amount	64	64
Accumulated Amortization	(47)	(44)
Other Intangible Assets, Net	17	20
Total other intangible assets
Accumulated Amortization	(47)	(44)
PPA fair value adjustments
Subject to amortization:
Gross Carrying Amount	390	390
Accumulated Amortization	(134)	(129)
Other Intangible Assets, Net	256	261
Total other intangible assets
Accumulated Amortization	(134)	(129)
Other
Subject to amortization:
Gross Carrying Amount	6	5
Accumulated Amortization	(5)	(5)
Other Intangible Assets, Net	1	0
Total other intangible assets
Accumulated Amortization	(5)	(5)
SOUTHERN POWER CO
Subject to amortization:
Accumulated Amortization	(134)	(129)
Total other intangible assets
Accumulated Amortization	(134)	(129)
SOUTHERN POWER CO | PPA fair value adjustments
Subject to amortization:
Gross Carrying Amount	390	390
Accumulated Amortization	(134)	(129)
Other Intangible Assets, Net	256	261
Total other intangible assets
Accumulated Amortization	(134)	(129)
SOUTHERN Co GAS
Subject to amortization:
Gross Carrying Amount	182	182
Accumulated Amortization	(159)	(156)
Other Intangible Assets, Net	23	26
Total other intangible assets
Accumulated Amortization	(159)	(156)
Other Intangible Assets, Net	23	26
SOUTHERN Co GAS | Customer relationships
Subject to amortization:
Gross Carrying Amount	156	156
Accumulated Amortization	(140)	(139)
Other Intangible Assets, Net	16	17
Total other intangible assets
Accumulated Amortization	(140)	(139)
SOUTHERN Co GAS | Trade names
Subject to amortization:
Gross Carrying Amount	26	26
Accumulated Amortization	(19)	(17)
Other Intangible Assets, Net	7	9
Total other intangible assets
Accumulated Amortization	$ (19)	$ (17)

Introduction - Schedule of Amor

Introduction - Schedule of Amortization of Other Intangible Assets (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 10	$ 10
Decrease in operating revenues	5	5
SOUTHERN POWER CO
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	5	5
SOUTHERN Co GAS
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 3	$ 3

Introduction - Schedule of Cash

Introduction - Schedule of Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022	Mar. 31, 2022	Dec. 31, 2021
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	$ 1,053	$ 1,917
Restricted cash:
Total cash, cash equivalents, and restricted cash	1,217	2,037	$ 1,673	$ 1,829
Other current assets
Restricted cash:
Restricted cash	117	62
Other deferred charges and assets
Restricted cash:
Restricted cash	47	58
GEORGIA POWER CO
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	0	364
Restricted cash:
Total cash, cash equivalents, and restricted cash	160	480	26	33
GEORGIA POWER CO | Other current assets
Restricted cash:
Restricted cash	115	60
GEORGIA POWER CO | Other deferred charges and assets
Restricted cash:
Restricted cash	45	56
GEORGIA POWER CO | Proceeds From Issuance Of Solid Waste Disposal Facility Revenue Bonds
Restricted cash:
Restricted cash	116	116
GEORGIA POWER CO | Funds From Georgia Housing And Finance Authority
Restricted cash:
Restricted cash	44
SOUTHERN POWER CO
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	123	131
Restricted cash:
Total cash, cash equivalents, and restricted cash	126	133	139	135
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	3
SOUTHERN POWER CO | Estimated Construction Completion Costs | Deuel Harvest
Restricted cash:
Restricted cash	3	3
SOUTHERN Co GAS
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	88	81
Restricted cash:
Total cash, cash equivalents, and restricted cash	89	83	$ 33	$ 48
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 - Storm Damage Res

Introduction - Storm Damage Reserves (Details) $ in Millions	3 Months Ended
	Mar. 31, 2023 USD ($)
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance at December 31, 2022	$ 216
Balance at March 31, 2023	186
Accrued Storm Reserve
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Accrual	13
Storm Reserve
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Weather-related damages	(43)
ALABAMA POWER CO
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance at December 31, 2022	97
Balance at March 31, 2023	88
ALABAMA POWER CO | Accrued Storm Reserve
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Accrual	3
ALABAMA POWER CO | Storm Reserve
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Weather-related damages	(12)
GEORGIA POWER CO
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance at December 31, 2022	83
Balance at March 31, 2023	60
GEORGIA POWER CO | Accrued Storm Reserve
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Accrual	8
GEORGIA POWER CO | Storm Reserve
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Weather-related damages	(31)
MISSISSIPPI POWER CO
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance at December 31, 2022	36
Balance at March 31, 2023	38
MISSISSIPPI POWER CO | Accrued Storm Reserve
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Accrual	2
MISSISSIPPI POWER CO | Storm Reserve
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Weather-related damages	$ 0

Introduction - Asset Retirement

Introduction - Asset Retirement Obligations (Details) $ in Millions	Mar. 06, 2023 USD ($)
Plant Vogtle Unit 3
Schedule of Asset Retirement Obligation [Line Items]
Asset retirement obligations	$ 90

Regulatory Matters - Schedule o

Regulatory Matters - Schedule of Cost Recovery Clauses (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Loss Contingencies [Line Items]
Natural gas cost under recovery	$ 0	$ 108
ALABAMA POWER CO | Other regulatory assets, current
Loss Contingencies [Line Items]
Rate CNP Compliance	23	47
Rate CNP PPA	17	18
Retail Energy Cost Recovery	101	102
ALABAMA POWER CO | Other regulatory assets, deferred
Loss Contingencies [Line Items]
Rate CNP Compliance	18	0
Rate CNP PPA	100	102
Retail Energy Cost Recovery	420	520
GEORGIA POWER CO | Receivables – under recovered fuel clause revenues
Loss Contingencies [Line Items]
Fuel Cost Recovery(*)	447	0
GEORGIA POWER CO | Deferred under recovered fuel clause revenues
Loss Contingencies [Line Items]
Fuel Cost Recovery(*)	1,702	2,056
MISSISSIPPI POWER CO | Other regulatory assets, current
Loss Contingencies [Line Items]
Ad Valorem Tax	9	12
MISSISSIPPI POWER CO | Other regulatory assets, deferred
Loss Contingencies [Line Items]
Ad Valorem Tax	19	19
MISSISSIPPI POWER CO | Receivables – customer accounts, net
Loss Contingencies [Line Items]
Fuel Cost Recovery(*)	25	1
SOUTHERN Co GAS
Loss Contingencies [Line Items]
Natural gas cost under recovery	0	108
SOUTHERN Co GAS | Other regulatory assets, current
Loss Contingencies [Line Items]
Natural gas cost under recovery	0	108
SOUTHERN Co GAS | Natural gas cost over recovery
Loss Contingencies [Line Items]
Natural gas cost under recovery	$ 117	$ 0

Regulatory Matters - APC Certif

Regulatory Matters - APC Certificate of Convenience and Necessity (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022	Dec. 31, 2020
Public Utilities, General Disclosures [Line Items]
Construction work in progress	$ 11,510	$ 10,896
Plant in service, net of depreciation	82,700	82,232
ALABAMA POWER CO
Public Utilities, General Disclosures [Line Items]
Construction work in progress	1,510	1,526
Plant in service, net of depreciation	23,139	$ 23,002
ALABAMA POWER CO | Plant Barry Unit 8
Public Utilities, General Disclosures [Line Items]
Estimated in-service cost			$ 652
Construction work in progress	541
Construction in progress, work in progress amount	536
Plant in service, net of depreciation	$ 5

Regulatory Matters - APC Rate C

Regulatory Matters - APC Rate CNP New Plant (Details) $ in Millions	Mar. 24, 2023 USD ($)
ALABAMA POWER CO
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease) amount	$ 78

Regulatory Matters - APC Renewa

Regulatory Matters - APC Renewable Generation Certificate (Details)	Apr. 04, 2023 claim MW	Mar. 31, 2023 MW
Subsequent Event
Public Utilities, General Disclosures [Line Items]
Renewable generation certificate, number of new solar power purchase agreements | claim	2
ALABAMA POWER CO
Public Utilities, General Disclosures [Line Items]
Renewable generation certificate, authorized generating capacity (in MWs)		500
ALABAMA POWER CO | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Renewable generation certificate, additional generating capacity procured (in MWs)	160
Renewable generation certificate, generating capacity (in MWs)	490

Regulatory Matters - GPC Fuel C

Regulatory Matters - GPC Fuel Cost Recovery (Details) $ in Billions	Feb. 28, 2023 USD ($)
Public Utilities, General Disclosures [Line Items]
Under recovered fuel balance to be recovered	$ 2.2
GEORGIA POWER CO
Public Utilities, General Disclosures [Line Items]
Under recovered fuel balance to be recovered, period of recovery	3 years
Requested revenues increase (decrease) percentage	54%
Requested rate increase (decrease) amount	$ 1.1

Regulatory Matters - GPC Integr

Regulatory Matters - GPC Integrated Resource Plan (Details) $ in Millions	1 Months Ended
	Aug. 31, 2022 USD ($)
GEORGIA POWER CO | 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 - Plant Vogtle Units 3 And 4 $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2023 USD ($)	Dec. 31, 2012 utility MW	Aug. 31, 2018
Loss Contingencies [Line Items]
Proportionate ownership share	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	$ 3,500
Estimated cost to complete, construction contingency estimate, financing costs, incurred to date	3,300
Construction contingency estimate	20
Base project capital cost forecast, monthly	15
Monthly AFUDC	$ 35
Percentage of ownership interest required for voting for continuing construction			90%
Vogtle Owners
Loss Contingencies [Line Items]
Period of notice required in the event letters of credit are not renewed	30 days
Minimum | COVID-19
Loss Contingencies [Line Items]
Loss contingency, estimate of possible loss, loss of productivity, term	3 months
Estimate of possible loss	$ 160
Maximum | COVID-19
Loss Contingencies [Line Items]
Loss contingency, estimate of possible loss, loss of productivity, term	4 months
Estimate of possible loss	$ 200

Regulatory Matters - GPC Nucl_2

Regulatory Matters - GPC Nuclear Construction Cost and Schedule (Details) - GEORGIA POWER CO - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Loss Contingencies [Line Items]
Pre-tax charge to income		$ 407
Plant Vogtle Units 3 And 4
Loss Contingencies [Line Items]
Base project capital cost forecast	$ 10,553
Construction contingency estimate	40
Total project capital cost forecast	10,593
Net investment as of end of the period	(9,747)
Remaining estimate to complete	846
Estimated cost to complete, costs not shared with other owners	610
Estimated cost to complete, construction monitoring costs approved for recovery	33
Expected capitalized costs	418
Capitalized interest accrued	334
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) - USD ($) $ in Thousands		1 Months Ended	3 Months Ended
	Jan. 11, 2018	Sep. 30, 2022	Mar. 31, 2023	Dec. 31, 2022	Jul. 31, 2022	Jun. 30, 2022	Aug. 31, 2018
Public Utilities, General Disclosures [Line Items]
Agreement with third party, amount of costs over projected forecast to be paid by company		20%
GEORGIA POWER CO
Public Utilities, General Disclosures [Line Items]
Pre-tax charge to income				$ 407,000
After tax charge to income				304,000
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO
Public Utilities, General Disclosures [Line Items]
Production tax credits, aggregate purchase price, maximum			$ 300,000
Preliminary estimated cost to complete			$ 10,593,000
Additional construction capital costs	$ 3,300,000			$ 345,000
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
Estimated cost to complete, starting dollar amount					$ 18,380,000
Proportionate ownership share			45.70%
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO | Vogtle Owners
Public Utilities, General Disclosures [Line Items]
Additional construction capital costs			$ 100
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO | 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 | GEORGIA POWER CO | MEAG Power
Public Utilities, General Disclosures [Line Items]
Payment of power costs		$ 92,000
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO | Category I
Public Utilities, General Disclosures [Line Items]
Preliminary estimated cost to complete			8,400,000
Additional construction capital costs, threshold			$ 800,000
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO | 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 | GEORGIA POWER CO | 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 | GEORGIA POWER CO | Category II | Minimum
Public Utilities, General Disclosures [Line Items]
Additional construction capital costs, threshold			$ 800,000
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO | Category II | Maximum
Public Utilities, General Disclosures [Line Items]
Additional construction capital costs, threshold			$ 1,600,000
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO | 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 | GEORGIA POWER CO | 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 | GEORGIA POWER CO | Category III | Minimum
Public Utilities, General Disclosures [Line Items]
Additional construction capital costs, threshold			$ 1,600,000
Plant Vogtle Units 3 And 4 | GEORGIA POWER CO | 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

3 Months Ended

6 Months Ended

12 Months Ended

Feb. 16, 2023 USD ($)

Jan. 01, 2023 USD ($)

Jan. 01, 2021

Jan. 01, 2020

Jan. 11, 2018 USD ($)

Jan. 01, 2016

Mar. 31, 2023 USD ($)

Dec. 31, 2022 USD ($)

Jun. 30, 2022 USD ($) report

Dec. 31, 2024 USD ($)

Dec. 31, 2023 USD ($)

Dec. 31, 2022 USD ($)

Dec. 31, 2009 USD ($)

Dec. 31, 2021 USD ($)

Jun. 30, 2021 report

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

$ 2,900

Requested decrease in tariff

$ 36

Additional construction capital costs

$ 3,300

$ 345

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

$ 300

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

$ 7,300

Twenty Fifth Vogtle Construction Monitoring Report

Public Utilities, General Disclosures [Line Items]

Number of approved construction management reports | report

25

Requested capital construction costs

7,900

Guarantor obligations

1,700

Customer refund

$ 188

Number of additional reports reviewed | report

2

Twenty Sixth Vogtle Construction Monitoring Report

Public Utilities, General Disclosures [Line Items]

Requested capital construction costs

$ 1,100

Twenty Seventh Vogtle Construction Monitoring Report

Public Utilities, General Disclosures [Line Items]

Requested capital construction costs

$ 461

Scenario, Forecast

Public Utilities, General Disclosures [Line Items]

Return on equity reduction, negative impact on earnings

$ 60

$ 270

Regulatory Matters - MPC (Detai

Regulatory Matters - MPC (Details) - USD ($) $ in Millions	Apr. 04, 2023	Apr. 03, 2023	Mar. 31, 2023
Subsequent Event
Loss Contingencies [Line Items]
Minimum annual accrual, amount		$ 8
MISSISSIPPI POWER CO | Subsequent Event
Loss Contingencies [Line Items]
Approved rate increase (decrease)	$ 12
MISSISSIPPI POWER CO | Ad Valorem Tax Adjustment
Loss Contingencies [Line Items]
Requested rate increase (decrease) amount			$ 7
MISSISSIPPI POWER CO | ECO Plan | Subsequent Event
Loss Contingencies [Line Items]
Approved rate increase (decrease)	$ 3

Regulatory Matters - GAS Schedu

Regulatory Matters - GAS Schedule of Infrastructure Replacement Programs and Capital Projects (Details) - SOUTHERN Co GAS $ in Millions	3 Months Ended
	Mar. 31, 2023 USD ($)
Public Utilities, General Disclosures [Line Items]
Capital expenditures	$ 115
Investing in Illinois
Public Utilities, General Disclosures [Line Items]
Capital expenditures	62
SAVE
Public Utilities, General Disclosures [Line Items]
Capital expenditures	20
System Reinforcement Rider
Public Utilities, General Disclosures [Line Items]
Capital expenditures	32
Pipeline Replacement Program
Public Utilities, General Disclosures [Line Items]
Capital expenditures	$ 1

Contingencies - General Litigat

Contingencies - General Litigation Matters (Details) - Pending Litigation $ in Millions	1 Months Ended	5 Months Ended	6 Months Ended
	Mar. 31, 2019 plaintiff	Feb. 28, 2022 claim	Jun. 30, 2019 USD ($) defendant plaintiff
GEORGIA POWER CO | Class Action Lawsuit
Loss Contingencies [Line Items]
Complaints filed | claim		7
MISSISSIPPI POWER CO | Purported Violations of Mississippi Consumer Protection Act
Loss Contingencies [Line Items]
Number of plaintiffs			10
Number of defendants | defendant			3
Number of additional plaintiffs	4
Underpayment of refunds | $			$ 23.5

Contingencies - Environmental R

Contingencies - Environmental Remediation (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
GEORGIA POWER CO
Loss Contingencies [Line Items]
Environmental remediation liability, current and former sites	$ 15	$ 15
SOUTHERN Co GAS
Loss Contingencies [Line Items]
Environmental remediation liability, current and former sites	$ 243	$ 256

Contingencies - Other Matters (

Contingencies - Other Matters (Details) - USD ($) $ in Millions	1 Months Ended
	Aug. 31, 2022	Apr. 30, 2019
Loss Contingencies [Line Items]
Estimated additional interest expense	$ 1
ALABAMA POWER CO | AT&T
Loss Contingencies [Line Items]
Potential refund amount owed		$ 87
Refund payment period		6 years
MISSISSIPPI POWER CO
Loss Contingencies [Line Items]
Estimate of possible loss	$ 28

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
	Mar. 31, 2023	Mar. 31, 2022
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 6,241	$ 6,258
Total operating revenues	6,480	6,648
Retail electric revenues
Disaggregation of Revenue [Line Items]
Total operating revenues	3,599	3,613
Retail electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	3,592	3,456
Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,525	1,525
Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,251	1,178
Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	789	727
Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	27	26
Natural Gas
Disaggregation of Revenue [Line Items]
Total operating revenues	1,875	2,058
Natural gas distribution revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,587	1,784
Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	896	1,016
Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	232	270
Transportation
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	319	337
Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	23	32
Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	117	129
Other natural gas revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	242	259
Gas marketing services
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	231	243
Other natural gas revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	11	16
Other revenue sources
Disaggregation of Revenue [Line Items]
Other revenues	239	390
Wholesale Electric
Disaggregation of Revenue [Line Items]
Total operating revenues	599	664
Wholesale electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	510	534
PPA energy revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	284	342
PPA capacity revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	190	134
Non-PPA revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	36	58
Other revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	310	225
ALABAMA POWER CO
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,696	1,546
Total operating revenues	1,647	1,649
ALABAMA POWER CO | Retail electric revenues
Disaggregation of Revenue [Line Items]
Total operating revenues	1,381	1,379
ALABAMA POWER CO | Retail electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,490	1,336
ALABAMA POWER CO | Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	659	634
ALABAMA POWER CO | Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	430	375
ALABAMA POWER CO | Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	398	323
ALABAMA POWER CO | Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	3	4
ALABAMA POWER CO | Natural gas distribution revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
ALABAMA POWER CO | Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
ALABAMA POWER CO | Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
ALABAMA POWER CO | Transportation
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
ALABAMA POWER CO | Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
ALABAMA POWER CO | Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
ALABAMA POWER CO | Other natural gas revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
ALABAMA POWER CO | Gas marketing services
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
ALABAMA POWER CO | Other natural gas revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
ALABAMA POWER CO | Other revenue sources
Disaggregation of Revenue [Line Items]
Other revenues	(49)	103
ALABAMA POWER CO | Wholesale electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	152	162
ALABAMA POWER CO | PPA energy revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	72	59
ALABAMA POWER CO | PPA capacity revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	60	39
ALABAMA POWER CO | Non-PPA revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	20	64
ALABAMA POWER CO | Other revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	54	48
GEORGIA POWER CO
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	2,047	2,061
Total operating revenues	2,176	2,208
GEORGIA POWER CO | Retail electric revenues
Disaggregation of Revenue [Line Items]
Total operating revenues	1,981	2,017
GEORGIA POWER CO | Retail electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,889	1,913
GEORGIA POWER CO | Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	801	821
GEORGIA POWER CO | Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	753	738
GEORGIA POWER CO | Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	313	334
GEORGIA POWER CO | Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	22	20
GEORGIA POWER CO | Natural gas distribution revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
GEORGIA POWER CO | Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
GEORGIA POWER CO | Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
GEORGIA POWER CO | Transportation
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
GEORGIA POWER CO | Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
GEORGIA POWER CO | Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
GEORGIA POWER CO | Other natural gas revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
GEORGIA POWER CO | Gas marketing services
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
GEORGIA POWER CO | Other natural gas revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
GEORGIA POWER CO | Other revenue sources
Disaggregation of Revenue [Line Items]
Other revenues	129	147
GEORGIA POWER CO | Wholesale Electric
Disaggregation of Revenue [Line Items]
Total operating revenues	31	66
GEORGIA POWER CO | Wholesale electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	26	53
GEORGIA POWER CO | PPA energy revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	12	32
GEORGIA POWER CO | PPA capacity revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	11	12
GEORGIA POWER CO | Non-PPA revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	3	9
GEORGIA POWER CO | Other revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	132	95
MISSISSIPPI POWER CO
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	367	324
Total operating revenues	390	335
MISSISSIPPI POWER CO | Retail electric revenues
Disaggregation of Revenue [Line Items]
Total operating revenues	236	217
MISSISSIPPI POWER CO | Retail electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	213	207
MISSISSIPPI POWER CO | Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	65	70
MISSISSIPPI POWER CO | Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	68	65
MISSISSIPPI POWER CO | Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	78	70
MISSISSIPPI POWER CO | Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	2	2
MISSISSIPPI POWER CO | Natural gas distribution revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
MISSISSIPPI POWER CO | Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
MISSISSIPPI POWER CO | Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
MISSISSIPPI POWER CO | Transportation
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
MISSISSIPPI POWER CO | Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
MISSISSIPPI POWER CO | Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
MISSISSIPPI POWER CO | Other natural gas revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
MISSISSIPPI POWER CO | Gas marketing services
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
MISSISSIPPI POWER CO | Other natural gas revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
MISSISSIPPI POWER CO | Other revenue sources
Disaggregation of Revenue [Line Items]
Other revenues	23	11
MISSISSIPPI POWER CO | Wholesale electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	143	108
MISSISSIPPI POWER CO | PPA energy revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	4	3
MISSISSIPPI POWER CO | PPA capacity revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	32	3
MISSISSIPPI POWER CO | Non-PPA revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	107	102
MISSISSIPPI POWER CO | Other revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	11	9
SOUTHERN POWER CO
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	405	413
Total operating revenues	508	539
SOUTHERN POWER CO | Retail electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
SOUTHERN POWER CO | Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
SOUTHERN POWER CO | Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
SOUTHERN POWER CO | Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
SOUTHERN POWER CO | Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
SOUTHERN POWER CO | Natural gas distribution revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
SOUTHERN POWER CO | Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
SOUTHERN POWER CO | Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
SOUTHERN POWER CO | Transportation
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
SOUTHERN POWER CO | Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
SOUTHERN POWER CO | Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
SOUTHERN POWER CO | Other natural gas revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
SOUTHERN POWER CO | Gas marketing services
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
SOUTHERN POWER CO | Other natural gas revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
SOUTHERN POWER CO | Other revenue sources
Disaggregation of Revenue [Line Items]
Other revenues	103	126
SOUTHERN POWER CO | Wholesale electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	394	405
SOUTHERN POWER CO | PPA energy revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	202	251
SOUTHERN POWER CO | PPA capacity revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	89	81
SOUTHERN POWER CO | Non-PPA revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	103	73
SOUTHERN POWER CO | Other revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	11	8
SOUTHERN Co GAS
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,829	2,043
Total operating revenues	1,875	2,058
SOUTHERN Co GAS | Retail electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
SOUTHERN Co GAS | Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
SOUTHERN Co GAS | Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
SOUTHERN Co GAS | Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
SOUTHERN Co GAS | Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
SOUTHERN Co GAS | Natural gas distribution revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,587	1,784
SOUTHERN Co GAS | Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	896	1,016
SOUTHERN Co GAS | Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	232	270
SOUTHERN Co GAS | Transportation
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	319	337
SOUTHERN Co GAS | Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	23	32
SOUTHERN Co GAS | Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	117	129
SOUTHERN Co GAS | Other natural gas revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	242	259
SOUTHERN Co GAS | Gas marketing services
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	231	243
SOUTHERN Co GAS | Other natural gas revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	11	16
SOUTHERN Co GAS | Other revenue sources
Disaggregation of Revenue [Line Items]
Other revenues	46	15
SOUTHERN Co GAS | Wholesale electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
SOUTHERN Co GAS | PPA energy revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
SOUTHERN Co GAS | PPA capacity revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
SOUTHERN Co GAS | Non-PPA revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0
SOUTHERN Co GAS | Other revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 0	$ 0

Revenue from Contracts with C_4

Revenue from Contracts with Customers and Lease Income - Schedule of Contract Balances (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Disaggregation of Revenue [Line Items]
Accounts Receivable	$ 2,433	$ 3,123
Contract Assets	160	156
Contract Liabilities	61	45
ALABAMA POWER CO
Disaggregation of Revenue [Line Items]
Accounts Receivable	622	696
Contract Assets	3	2
Contract Liabilities	2	4
GEORGIA POWER CO
Disaggregation of Revenue [Line Items]
Accounts Receivable	672	922
Contract Assets	74	89
Contract Liabilities	14	9
MISSISSIPPI POWER CO
Disaggregation of Revenue [Line Items]
Accounts Receivable	79	92
Contract Assets	0	0
Contract Liabilities	1	0
SOUTHERN POWER CO
Disaggregation of Revenue [Line Items]
Accounts Receivable	119	237
Contract Assets	0	0
Contract Liabilities	1	1
SOUTHERN Co GAS
Disaggregation of Revenue [Line Items]
Accounts Receivable	853	1,107
Contract Assets	19	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
	Mar. 31, 2023	Dec. 31, 2022
Disaggregation of Revenue [Line Items]
Contract liabilities	$ 61	$ 45
Contract assets	160	156
Revenue from contracts with customers recognized	19
GEORGIA POWER CO
Disaggregation of Revenue [Line Items]
Contract liabilities	14	9
Contract assets	74	89
SOUTHERN Co GAS
Disaggregation of Revenue [Line Items]
Contract liabilities	0	0
Contract assets	$ 19	0
Retail Customer Fixed Bill Programs | GEORGIA POWER CO
Disaggregation of Revenue [Line Items]
Contract term	1 year
Energy Efficiency Enhancement And Upgrade | SOUTHERN Co GAS
Disaggregation of Revenue [Line Items]
Contract liabilities	$ 30
Unregulated Distributed Generation
Disaggregation of Revenue [Line Items]
Contract liabilities	44	32
Contract assets	$ 64	$ 65

Revenue from Contracts with C_6

Revenue from Contracts with Customers and Lease Income - Schedule of Remaining Performance Obligations (Details) $ in Millions	Mar. 31, 2023 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 632
Performance obligation, expected timing of satisfaction	9 months
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	$ 553
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	$ 347
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	$ 315
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	$ 319
Performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 2,089
Performance obligation, expected timing of satisfaction
ALABAMA POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 17
Performance obligation, expected timing of satisfaction	9 months
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	$ 6
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	1 year
ALABAMA POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-01-01
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]: 2023-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 68
Performance obligation, expected timing of satisfaction	9 months
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	$ 60
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	$ 25
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	$ 13
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	$ 14
Performance obligation, expected timing of satisfaction	1 year
GEORGIA POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 23
Performance obligation, expected timing of satisfaction
SOUTHERN POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 268
Performance obligation, expected timing of satisfaction	9 months
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	$ 345
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	$ 302
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	$ 303
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	$ 310
Performance obligation, expected timing of satisfaction	1 year
SOUTHERN POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 2,077
Performance obligation, expected timing of satisfaction
SOUTHERN Co GAS | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 15
Performance obligation, expected timing of satisfaction	9 months
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	1 year
SOUTHERN Co GAS | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2028-01-01
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
	Mar. 31, 2023	Mar. 31, 2022
Lessor, Lease, Description [Line Items]
Lease income - interest income on sales-type leases	$ 6	$ 6
Lease income - operating leases	49	51
Variable lease income	69	84
Total lease income	124	141
ALABAMA POWER CO
Lessor, Lease, Description [Line Items]
Lease income - interest income on sales-type leases	0	0
Lease income - operating leases	18	20
Variable lease income	0	0
Total lease income	18	20
GEORGIA POWER CO
Lessor, Lease, Description [Line Items]
Lease income - interest income on sales-type leases	0	0
Lease income - operating leases	7	8
Variable lease income	0	0
Total lease income	7	8
MISSISSIPPI POWER CO
Lessor, Lease, Description [Line Items]
Lease income - interest income on sales-type leases	4	4
Lease income - operating leases	1	0
Variable lease income	0	0
Total lease income	5	4
SOUTHERN POWER CO
Lessor, Lease, Description [Line Items]
Lease income - interest income on sales-type leases	2	2
Lease income - operating leases	21	21
Variable lease income	75	90
Total lease income	98	113
SOUTHERN Co GAS
Lessor, Lease, Description [Line Items]
Lease income - interest income on sales-type leases	0	0
Lease income - operating leases	9	9
Variable lease income	0	0
Total lease income	$ 9	$ 9

Consolidated Entities and Equ_3

Consolidated Entities and Equity Method Investments - Narrative (Details) $ in Millions	3 Months Ended
	Mar. 31, 2023 USD ($) investor	Dec. 31, 2022 USD ($)
Schedule of Equity Method Investments [Line Items]
Equity investments in unconsolidated subsidiaries	$ 1,408	$ 1,443
Assets	134,756	134,891
Liabilities	100,194	100,359
Southern Holdings Company
Schedule of Equity Method Investments [Line Items]
Equity investments in unconsolidated subsidiaries	120	112
SOUTHERN POWER CO
Schedule of Equity Method Investments [Line Items]
Equity investments in unconsolidated subsidiaries	0	49
Assets	13,134	13,081
Liabilities	6,276	6,165
Proceeds from sale of equity method investments	$ 50
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	$ 5,800	5,900
Liabilities	400	400
Noncontrolling interests related to other partners' interests	1,000	1,100
Variable Interest Entity, Primary Beneficiary | SP Wind | SOUTHERN POWER CO
Schedule of Equity Method Investments [Line Items]
Assets	2,200	2,200
Liabilities	172	169
Noncontrolling interests related to other partners' interests	$ 39	39
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	$ 1,800	1,800
Liabilities	200	200
Noncontrolling interests related to other partners' interests	$ 800	$ 800

Consolidated Entities and Equ_4

Consolidated Entities and Equity Method Investments - Schedule of Equity Method Investments (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Schedule of Equity Method Investments [Line Items]
Investment Balance	$ 1,408	$ 1,443
SOUTHERN Co GAS
Schedule of Equity Method Investments [Line Items]
Investment Balance	1,282	1,276
SOUTHERN Co GAS | SNG
Schedule of Equity Method Investments [Line Items]
Investment Balance	1,249	1,243
SOUTHERN Co GAS | Other
Schedule of Equity Method Investments [Line Items]
Investment Balance	$ 33	$ 33

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
	Mar. 31, 2023	Mar. 31, 2022
Schedule of Equity Method Investments [Line Items]
Earnings from Equity Method Investments	$ 48	$ 46
SOUTHERN Co GAS
Schedule of Equity Method Investments [Line Items]
Earnings from Equity Method Investments	45	40
SOUTHERN Co GAS | SNG
Schedule of Equity Method Investments [Line Items]
Earnings from Equity Method Investments	44	39
SOUTHERN Co GAS | Other
Schedule of Equity Method Investments [Line Items]
Earnings from Equity Method Investments	$ 1	$ 1

Financing and Leases - Schedule

Financing and Leases - Schedule of Credit Arrangements (Details)	Mar. 31, 2023 USD ($)
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	7,564,000,000
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	225,000,000
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	587,000,000
Expires within One Year	0
SOUTHERN POWER CO | Continuing Letter of Credit Facility A
Line of Credit Facility [Line Items]
Expires, 2025	75,000,000
Expires, 2026	100,000,000
Unused	9,000,000
SOUTHERN POWER CO | Continuing Letter of Credit Facility B
Line of Credit Facility [Line Items]
Unused	16,000,000
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, 2027	800,000,000
Nicor Gas
Line of Credit Facility [Line Items]
Expires, 2027	$ 700,000,000

Financing and Leases - Narrativ

Financing and Leases - Narrative (Details) $ in Millions	Mar. 31, 2023 USD ($)
Debt Instrument [Line Items]
Variable rate pollution control revenue bonds outstanding	$ 1,700
MISSISSIPPI POWER CO
Debt Instrument [Line Items]
Variable rate pollution control revenue bonds outstanding	69
ALABAMA POWER CO
Debt Instrument [Line Items]
Variable rate pollution control revenue bonds outstanding	789
Fixed rate pollution control revenue bonds outstanding	120
GEORGIA POWER CO
Debt Instrument [Line Items]
Variable rate pollution control revenue bonds outstanding	819
Fixed rate pollution control revenue bonds outstanding	$ 285

Financing and Leases - Converti

Financing and Leases - Convertible Senior Notes (Details) - Series 2023A Convertible Senior Notes Due 2025 - Convertible Debt $ / shares in Units, $ in Millions		1 Months Ended
	Feb. 28, 2023 USD ($) $ / shares	Feb. 28, 2023 USD ($) d $ / shares	Mar. 31, 2023 USD ($)
Debt Instrument [Line Items]
Aggregate principal amount | $	$ 1,500	$ 1,500	$ 225
Interest rate	3.875%	3.875%
Conversion ratio		0.0118818
Conversion price (in dollars per share) | $ / shares	$ 84.16	$ 84.16
Redemption price	100%
Debt Conversion Terms One
Debt Instrument [Line Items]
Trading day threshold		20
Consecutive trading day threshold		30
Stock price trigger threshold, percentage		130%
Debt Conversion Terms Two
Debt Instrument [Line Items]
Trading day threshold		5
Consecutive trading day threshold		10
Stock price trigger threshold, percentage		98%

Financing and Leases - Schedu_2

Financing and Leases - Schedule of Shares Used to Compute Diluted Earnings Per Share (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Debt Disclosure [Abstract]
As reported shares (in shares)	1,091,000	1,063,000
Effect of stock-based compensation (in shares)	7,000	6,000
Diluted (in shares)	1,098,000	1,069,000
Antidilutive securities excluded from computation of earnings per share (in shares)	0	0

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Income Tax Contingency [Line Items]
Effective tax (benefit) rate	10.80%	14.90%
ALABAMA POWER CO
Income Tax Contingency [Line Items]
Effective tax (benefit) rate	(0.80%)	23.30%
GEORGIA POWER CO
Income Tax Contingency [Line Items]
Effective tax (benefit) rate	15.10%	7.30%
SOUTHERN POWER CO
Income Tax Contingency [Line Items]
Effective tax (benefit) rate	(20.70%)	(80.00%)

Retirement Benefits (Details)

Retirement Benefits (Details) - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, expected future employer contributions, remainder of fiscal year	$ 0
Pension Plans and Postretirement Plans
Service cost	69,000,000	$ 103,000,000
Interest cost	156,000,000	102,000,000
Expected return on plan assets	(307,000,000)	(316,000,000)
Amortization:
Prior service costs	0	0
Regulatory asset	0	0
Net gain	8,000,000	60,000,000
Net periodic pension cost (income)	(74,000,000)	(51,000,000)
Pension Plans | ALABAMA POWER CO
Pension Plans and Postretirement Plans
Service cost	16,000,000	25,000,000
Interest cost	36,000,000	24,000,000
Expected return on plan assets	(74,000,000)	(77,000,000)
Amortization:
Prior service costs	0	0
Regulatory asset	0	0
Net gain	2,000,000	16,000,000
Net periodic pension cost (income)	(20,000,000)	(12,000,000)
Pension Plans | GEORGIA POWER CO
Pension Plans and Postretirement Plans
Service cost	17,000,000	26,000,000
Interest cost	48,000,000	31,000,000
Expected return on plan assets	(96,000,000)	(99,000,000)
Amortization:
Prior service costs	0	0
Regulatory asset	0	0
Net gain	3,000,000	18,000,000
Net periodic pension cost (income)	(28,000,000)	(24,000,000)
Pension Plans | MISSISSIPPI POWER CO
Pension Plans and Postretirement Plans
Service cost	3,000,000	4,000,000
Interest cost	7,000,000	5,000,000
Expected return on plan assets	(14,000,000)	(15,000,000)
Amortization:
Prior service costs	0	0
Regulatory asset	0	0
Net gain	0	3,000,000
Net periodic pension cost (income)	(4,000,000)	(3,000,000)
Pension Plans | SOUTHERN POWER CO
Pension Plans and Postretirement Plans
Service cost	2,000,000	2,000,000
Interest cost	2,000,000	2,000,000
Expected return on plan assets	(4,000,000)	(4,000,000)
Amortization:
Prior service costs	0	0
Regulatory asset	0	0
Net gain	0	1,000,000
Net periodic pension cost (income)	0	1,000,000
Pension Plans | SOUTHERN Co GAS
Pension Plans and Postretirement Plans
Service cost	6,000,000	9,000,000
Interest cost	11,000,000	7,000,000
Expected return on plan assets	(22,000,000)	(22,000,000)
Amortization:
Prior service costs	(1,000,000)	(1,000,000)
Regulatory asset	4,000,000	4,000,000
Net gain	(1,000,000)	2,000,000
Net periodic pension cost (income)	(3,000,000)	(1,000,000)
Postretirement Benefits
Pension Plans and Postretirement Plans
Service cost	4,000,000	6,000,000
Interest cost	18,000,000	10,000,000
Expected return on plan assets	(21,000,000)	(20,000,000)
Amortization:
Regulatory asset	0	0
Net gain	(3,000,000)
Net periodic pension cost (income)	(2,000,000)	(4,000,000)
Postretirement Benefits | ALABAMA POWER CO
Pension Plans and Postretirement Plans
Service cost	1,000,000	1,000,000
Interest cost	4,000,000	3,000,000
Expected return on plan assets	(8,000,000)	(8,000,000)
Amortization:
Regulatory asset	0	0
Net gain	(1,000,000)
Net periodic pension cost (income)	(4,000,000)	(4,000,000)
Postretirement Benefits | GEORGIA POWER CO
Pension Plans and Postretirement Plans
Service cost	1,000,000	2,000,000
Interest cost	6,000,000	4,000,000
Expected return on plan assets	(7,000,000)	(7,000,000)
Amortization:
Regulatory asset	0	0
Net gain	(1,000,000)
Net periodic pension cost (income)	(1,000,000)	(1,000,000)
Postretirement Benefits | MISSISSIPPI POWER CO
Pension Plans and Postretirement Plans
Service cost	0	0
Interest cost	1,000,000	0
Expected return on plan assets	(1,000,000)	0
Amortization:
Regulatory asset	0	0
Net gain	0
Net periodic pension cost (income)	0	0
Postretirement Benefits | SOUTHERN POWER CO
Pension Plans and Postretirement Plans
Service cost	0	0
Interest cost	0	0
Expected return on plan assets	0	0
Amortization:
Regulatory asset	0	0
Net gain	0
Net periodic pension cost (income)	0	0
Postretirement Benefits | SOUTHERN Co GAS
Pension Plans and Postretirement Plans
Service cost	0	0
Interest cost	2,000,000	1,000,000
Expected return on plan assets	(2,000,000)	(2,000,000)
Amortization:
Regulatory asset	2,000,000	2,000,000
Net gain	(1,000,000)
Net periodic pension cost (income)	$ 1,000,000	$ 1,000,000

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Assets:
Derivatives	$ 49	$ 141
Liabilities:
Derivatives	756	617
Other	13
Collateral already posted, assets, aggregate fair value	60
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	4	38
Liabilities:
Derivatives	68	15
Collateral already posted, assets, aggregate fair value	0
GEORGIA POWER CO
Assets:
Derivatives	3	21
Investments in trusts	37
Liabilities:
Derivatives	114	41
MISSISSIPPI POWER CO
Assets:
Derivatives	10	42
Liabilities:
Derivatives	37	15
SOUTHERN POWER CO
Assets:
Derivatives	5	8
Liabilities:
Derivatives	61	59
Other	13
Collateral already posted, assets, aggregate fair value	15
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	29	28
Liabilities:
Derivatives	119	110
Total
Collateral already posted, assets, aggregate fair value	60	$ 41
Fair Value, Measurements, Recurring
Assets:
Cash equivalents	446
Other investments	46
Total	2,857
Liabilities:
Contingent consideration	12
Total	898
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Cash equivalents	433
Other investments	9
Total	1,306
Liabilities:
Contingent consideration	0
Total	40
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Assets:
Cash equivalents	13
Other investments	29
Total	1,374
Liabilities:
Contingent consideration	0
Total	846
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents	0
Other investments	8
Total	8
Liabilities:
Contingent consideration	12
Total	12
Fair Value, Measurements, Recurring | Net Asset Value as a Practical Expedient (NAV)
Assets:
Total	169
Fair Value, Measurements, Recurring | Energy-related derivatives
Assets:
Derivatives	104
Liabilities:
Derivatives	394
Fair Value, Measurements, Recurring | Energy-related derivatives | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Derivatives	4
Liabilities:
Derivatives	40
Fair Value, Measurements, Recurring | Energy-related derivatives | Significant Other Observable Inputs (Level 2)
Assets:
Derivatives	100
Liabilities:
Derivatives	354
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
Assets:
Derivatives	2
Liabilities:
Derivatives	261
Fair Value, Measurements, Recurring | Interest rate derivatives | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Derivatives	0
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring | Interest rate derivatives | Significant Other Observable Inputs (Level 2)
Assets:
Derivatives	2
Liabilities:
Derivatives	261
Fair Value, Measurements, Recurring | Interest rate derivatives | Significant Unobservable Inputs (Level 3)
Assets:
Derivatives	0
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring | Domestic equity
Assets:
Investments in trusts	872
Fair Value, Measurements, Recurring | Domestic equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	680
Fair Value, Measurements, Recurring | Domestic equity | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	192
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	300
Fair Value, Measurements, Recurring | Foreign equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	138
Fair Value, Measurements, Recurring | Foreign equity | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	162
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	316
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	316
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	48
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	48
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	403
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	403
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	90
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	90
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	160
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	160
Fair Value, Measurements, Recurring | Cash and cash equivalents
Assets:
Investments in trusts	2
Fair Value, Measurements, Recurring | Cash and cash equivalents | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	2
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	61
Fair Value, Measurements, Recurring | Other | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	40
Fair Value, Measurements, Recurring | Other | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	12
Fair Value, Measurements, Recurring | Other | Significant Unobservable Inputs (Level 3)
Assets:
Investments in trusts	0
Fair Value, Measurements, Recurring | Other | Net Asset Value as a Practical Expedient (NAV)
Assets:
Investments in trusts	9
Fair Value, Measurements, Recurring | Foreign currency derivatives
Liabilities:
Derivatives	218
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	218
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	206
Other investments	29
Total	1,435
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Cash equivalents	193
Other investments	0
Total	742
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Significant Other Observable Inputs (Level 2)
Assets:
Cash equivalents	13
Other investments	29
Total	524
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	169
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Energy-related derivatives
Assets:
Derivatives	32
Liabilities:
Derivatives	96
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	32
Liabilities:
Derivatives	96
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	589
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Domestic equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	404
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Domestic equity | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	185
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	138
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Foreign equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	138
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	19
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	19
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	1
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	1
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	223
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	223
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	22
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	22
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	160
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	160
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Other
Assets:
Investments in trusts	16
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Other | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	7
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 | ALABAMA POWER CO | Other | Net Asset Value as a Practical Expedient (NAV)
Assets:
Investments in trusts	9
Fair Value, Measurements, Recurring | GEORGIA POWER CO
Assets:
Total	1,097
Liabilities:
Total	133
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Total	309
Liabilities:
Total	0
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Significant Other Observable Inputs (Level 2)
Assets:
Total	788
Liabilities:
Total	133
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Significant Unobservable Inputs (Level 3)
Assets:
Total	0
Liabilities:
Total	0
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Energy-related derivatives
Assets:
Derivatives	22
Liabilities:
Derivatives	132
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	22
Liabilities:
Derivatives	132
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 | Interest rate derivatives
Liabilities:
Derivatives	1
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Interest rate derivatives | Quoted Prices in Active Markets for Identical Assets (Level 1)
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Interest rate derivatives | Significant Other Observable Inputs (Level 2)
Liabilities:
Derivatives	1
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Interest rate derivatives | Significant Unobservable Inputs (Level 3)
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Domestic equity
Assets:
Investments in trusts	277
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Domestic equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	276
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	161
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	161
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	297
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	297
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	47
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	47
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	180
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	180
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	68
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	68
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	45
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Other | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	33
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Other | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	12
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	3
Total	38
Fair Value, Measurements, Recurring | MISSISSIPPI POWER CO | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Cash equivalents	3
Total	3
Fair Value, Measurements, Recurring | MISSISSIPPI POWER CO | Significant Other Observable Inputs (Level 2)
Assets:
Cash equivalents	0
Total	35
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	35
Liabilities:
Derivatives	62
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	35
Liabilities:
Derivatives	62
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
Assets:
Cash equivalents	13
Total	18
Liabilities:
Contingent consideration	12
Total	86
Fair Value, Measurements, Recurring | SOUTHERN POWER CO | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Cash equivalents	13
Total	13
Liabilities:
Contingent consideration	0
Total	0
Fair Value, Measurements, Recurring | SOUTHERN POWER CO | Significant Other Observable Inputs (Level 2)
Assets:
Cash equivalents	0
Total	5
Liabilities:
Contingent consideration	0
Total	74
Fair Value, Measurements, Recurring | SOUTHERN POWER CO | Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents	0
Total	0
Liabilities:
Contingent consideration	12
Total	12
Fair Value, Measurements, Recurring | SOUTHERN POWER CO | Energy-related derivatives
Assets:
Derivatives	5
Liabilities:
Derivatives	14
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	5
Liabilities:
Derivatives	14
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	47
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	47
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:
Cash equivalents	55
Total	82
Liabilities:
Total	162
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Cash equivalents	55
Total	61
Liabilities:
Total	40
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Significant Other Observable Inputs (Level 2)
Assets:
Cash equivalents	0
Total	21
Liabilities:
Total	122
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents	0
Total	0
Liabilities:
Total	0
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Energy-related derivatives
Assets:
Derivatives	10
Liabilities:
Derivatives	90
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Energy-related derivatives | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Derivatives	4
Liabilities:
Derivatives	40
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Energy-related derivatives | Significant Other Observable Inputs (Level 2)
Assets:
Derivatives	6
Liabilities:
Derivatives	50
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
Assets:
Derivatives	1
Liabilities:
Derivatives	72
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Interest rate derivatives | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Derivatives	0
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Interest rate derivatives | Significant Other Observable Inputs (Level 2)
Assets:
Derivatives	1
Liabilities:
Derivatives	72
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Interest rate derivatives | Significant Unobservable Inputs (Level 3)
Assets:
Derivatives	0
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Domestic equity
Assets:
Non-qualified deferred compensation trusts	6
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	6
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	2
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	2
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
	Mar. 31, 2023	Mar. 31, 2022
Fair Value, Option, Quantitative Disclosures [Line Items]
Increase (decrease) in fair value of funds	$ 102	$ (150)
ALABAMA POWER CO
Fair Value, Option, Quantitative Disclosures [Line Items]
Increase (decrease) in fair value of funds	45	(67)
GEORGIA POWER CO
Fair Value, Option, Quantitative Disclosures [Line Items]
Increase (decrease) in fair value of funds	$ 57	$ (83)

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) - ALABAMA POWER CO - Private equity $ in Millions	Mar. 31, 2023 USD ($)
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value	$ 169
Unfunded commitments	$ 75

Fair Value Measurements - Sch_3

Fair Value Measurements - Schedule of Financial Instruments for which Carrying Amount did not Equal Fair Value (Details) $ in Millions	Mar. 31, 2023 USD ($)
Long-term debt, including securities due within one year:
Carrying amount	$ 56,100
Fair value	51,600
ALABAMA POWER CO
Long-term debt, including securities due within one year:
Carrying amount	10,600
Fair value	9,500
GEORGIA POWER CO
Long-term debt, including securities due within one year:
Carrying amount	14,900
Fair value	13,700
MISSISSIPPI POWER CO
Long-term debt, including securities due within one year:
Carrying amount	1,500
Fair value	1,300
SOUTHERN POWER CO
Long-term debt, including securities due within one year:
Carrying amount	3,000
Fair value	2,900
SOUTHERN Co GAS
Long-term debt, including securities due within one year:
Carrying amount	7,500
Fair value	$ 6,700

Derivatives - Schedule of Energ

Derivatives - Schedule of Energy-Related Derivatives (Details) - Energy-related, Natural Gas MMBTU in Millions	Mar. 31, 2023 MMBTU
Energy-related derivative contracts
Net Purchased mmBtu	437
ALABAMA POWER CO
Energy-related derivative contracts
Net Purchased mmBtu	111
GEORGIA POWER CO
Energy-related derivative contracts
Net Purchased mmBtu	122
MISSISSIPPI POWER CO
Energy-related derivative contracts
Net Purchased mmBtu	86
SOUTHERN POWER CO
Energy-related derivative contracts
Net Purchased mmBtu	11
SOUTHERN Co GAS
Energy-related derivative contracts
Net Purchased mmBtu	107
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	113.6
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	6.6

Derivatives - Narrative (Detail

Derivatives - Narrative (Details) MMBTU in Millions	3 Months Ended
	Mar. 31, 2023 USD ($) MMBTU	Dec. 31, 2022 USD ($)
Derivative [Line Items]
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints | MMBTU	22
Energy-related derivative hedge gain (loss) to be reclassified within twelve months	$ (42,000,000)
Collateral already posted, assets, aggregate fair value	60,000,000
Derivatives	756,000,000	$ 617,000,000
Interest rate derivatives
Derivative [Line Items]
Cash flow hedge gain (loss) to be reclassified within twelve months	(15,000,000)
Derivatives	$ 73,000,000
SOUTHERN POWER CO
Derivative [Line Items]
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints | MMBTU	5
Energy-related derivative hedge gain (loss) to be reclassified within twelve months	$ (12,000,000)
Foreign currency cash flow hedge gain (loss) to be reclassified during next 12 months	(11,000,000)
Collateral already posted, assets, aggregate fair value	15,000,000
Derivatives	61,000,000	59,000,000
SOUTHERN POWER CO | Interest rate derivatives
Derivative [Line Items]
Derivatives	23,000,000
SOUTHERN Co GAS
Derivative [Line Items]
Energy-related derivative hedge gain (loss) to be reclassified within twelve months	(30,000,000)
Collateral already posted, assets, aggregate fair value	60,000,000	41,000,000
Derivatives	$ 119,000,000	110,000,000
ALABAMA POWER CO
Derivative [Line Items]
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints | MMBTU	6
Energy-related derivative hedge gain (loss) to be reclassified within twelve months	$ 0
Collateral already posted, assets, aggregate fair value	0
Derivatives	$ 68,000,000	15,000,000
GEORGIA POWER CO
Derivative [Line Items]
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints | MMBTU	8
Energy-related derivative hedge gain (loss) to be reclassified within twelve months	$ 0
Derivatives	$ 114,000,000	41,000,000
MISSISSIPPI POWER CO
Derivative [Line Items]
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints | MMBTU	3
Energy-related derivative hedge gain (loss) to be reclassified within twelve months	$ 0
Derivatives	37,000,000	$ 15,000,000
Registrants | Derivative Counterparties
Derivative [Line Items]
Collateral already posted, assets, aggregate fair value	$ 0

Derivatives - Schedule of Inter

Derivatives - Schedule of Interest Rate Derivatives (Details) - Interest rate derivatives $ in Millions	3 Months Ended
	Mar. 31, 2023 USD ($)
Derivative [Line Items]
Notional Amount	$ 3,400
Fair Value Gain (Loss)	(258)
GEORGIA POWER CO | Cash Flow Hedges of Forecasted Debt
Derivative [Line Items]
Notional Amount	$ 750
Weighted Average Interest Rate Paid	3.63%
Fair Value Gain (Loss)	$ (1)
Southern Company parent | Cash Flow Hedges of Forecasted Debt
Derivative [Line Items]
Notional Amount	$ 500
Weighted Average Interest Rate Paid	3.47%
Fair Value Gain (Loss)	$ 0
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)	$ (45)
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)	$ (142)
SOUTHERN Co GAS | Cash Flow Hedges of Forecasted Debt
Derivative [Line Items]
Notional Amount	$ 250
Weighted Average Interest Rate Paid	3.40%
Fair Value Gain (Loss)	$ 1
SOUTHERN Co GAS | Fair Value Hedges of Existing Debt
Derivative [Line Items]
Notional Amount	$ 500
Interest Rate Received	1.75%
Fair Value Gain (Loss)	$ (71)
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) - 3 months ended Mar. 31, 2023 - Foreign currency derivatives € in Millions, $ in Millions	USD ($)	EUR (€)
Derivative [Line Items]
Pay Notional	$ 2,040
Receive Notional | €		€ 1,750
Fair Value Gain (Loss)	(218)
Cash Flow Hedges of Forecasted 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)	$ (47)
Fair Value Hedges of Existing Debt | Southern Company parent
Derivative [Line Items]
Pay Notional	$ 1,476
Pay Rate	3.39%
Receive Notional | €		€ 1,250
Receive Rate	1.88%
Fair Value Gain (Loss)	$ (171)

Derivatives - Schedule of Deriv

Derivatives - Schedule of Derivative Category and Balance Sheet Location (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	$ 106	$ 211
Derivative asset, Gross amounts offset	(57)	(70)
Derivative asset, net amounts recognized in the balance sheets	49	141
Derivative liability, gross amount recognized	874	728
Derivative liability, Gross amounts offset	(118)	(111)
Derivative liability, net amounts recognized in the balance sheets	756	617
Collateral already posted, assets, aggregate fair value	60
Interest rate derivatives
Derivatives, Fair Value [Line Items]
Derivative liability, net amounts recognized in the balance sheets	73
Energy-related derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	6	15
Derivative liability, gross amount recognized	9	14
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	4	13
Energy-related derivatives not designated as hedging instruments | Energy-related derivatives | Liabilities from risk management activities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	8	13
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	2
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	1
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	94	175
Derivative liability, gross amount recognized	343	165
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	41	123
Energy-related derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Liabilities from risk management activities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	230	121
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	53	52
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	113	44
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	6	21
Derivative liability, gross amount recognized	522	549
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	0	3
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 | Liabilities from risk management activities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	38	27
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	4	6
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	4	4
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	2	12
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 | Liabilities from risk management activities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	71	62
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	191	240
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 | Liabilities from risk management activities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	35	34
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	183	182
ALABAMA POWER CO
Derivatives, Fair Value [Line Items]
Derivative asset, Gross amounts offset	(28)	(24)
Derivative asset, net amounts recognized in the balance sheets	4	38
Derivative liability, Gross amounts offset	(28)	(24)
Derivative liability, net amounts recognized in the balance sheets	68	15
Collateral already posted, assets, aggregate fair value	0
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	32	62
Derivative liability, gross amount recognized	96	39
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	14	42
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	54	21
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	18	20
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	42	18
GEORGIA POWER CO
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	22	42
Derivative asset, Gross amounts offset	(19)	(21)
Derivative asset, net amounts recognized in the balance sheets	3	21
Derivative liability, gross amount recognized	133	62
Derivative liability, Gross amounts offset	(19)	(21)
Derivative liability, net amounts recognized in the balance sheets	114	41
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	1	1
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	21	42
Derivative liability, gross amount recognized	131	61
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	10	36
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	86	43
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	11	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 credits and liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	45	18
GEORGIA POWER CO | 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	0
GEORGIA POWER CO | 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	1	0
MISSISSIPPI POWER CO
Derivatives, Fair Value [Line Items]
Derivative asset, Gross amounts offset	(25)	(17)
Derivative asset, net amounts recognized in the balance sheets	10	42
Derivative liability, Gross amounts offset	(25)	(17)
Derivative liability, net amounts recognized in the balance sheets	37	15
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	35	59
Derivative liability, gross amount recognized	62	32
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	11	33
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	37	24
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	24	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	25	8
SOUTHERN POWER CO
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	5	8
Derivative asset, net amounts recognized in the balance sheets	5	8
Derivative liability, gross amount recognized	61	59
Derivative liability, net amounts recognized in the balance sheets	61	59
Collateral already posted, assets, aggregate fair value	15
SOUTHERN POWER CO | Interest rate derivatives
Derivatives, Fair Value [Line Items]
Derivative liability, net amounts recognized in the balance sheets	23
SOUTHERN POWER CO | Energy-related derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	1	3
Derivative liability, gross amount recognized	2	0
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	0	2
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 | 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	1	1
SOUTHERN POWER CO | 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	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
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	4	5
Derivative liability, gross amount recognized	59	59
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	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 current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	12	12
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	4	5
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	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 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	11	11
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	36	36
SOUTHERN Co GAS
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	11	28
Derivative asset, Gross amounts offset	18	0
Derivative asset, net amounts recognized in the balance sheets	29	28
Derivative liability, gross amount recognized	162	151
Derivative liability, Gross amounts offset	(43)	(41)
Derivative liability, net amounts recognized in the balance sheets	119	110
Collateral already posted, assets, aggregate fair value	60	41
SOUTHERN Co GAS | Energy-related derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	4	12
Derivative liability, gross amount recognized	6	13
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	3	11
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	5	12
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	1	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	1
SOUTHERN Co GAS | 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	6	12
Derivative liability, gross amount recognized	54	33
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	6	12
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	53	33
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 deferred charges and assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	0	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 deferred credits and liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	1	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
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	1	4
Derivative liability, gross amount recognized	102	105
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	0	3
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	26	15
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	0	1
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	4	4
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	1	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 liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	19	14
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	$ 53	$ 72

Derivatives - Schedule of Pre-t

Derivatives - Schedule of Pre-tax Effects of Unrealized Derivative Gains (Losses) (Details) - Energy-related derivatives - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	$ (237)	$ 9
Other regulatory assets, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(198)	(71)
Other regulatory assets, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(67)	(23)
Other regulatory liabilities, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	19	72
Other regulatory liabilities, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	9	31
ALABAMA POWER CO
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(64)	23
ALABAMA POWER CO | Other regulatory assets, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(44)	(8)
ALABAMA POWER CO | Other regulatory assets, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(24)	(7)
ALABAMA POWER CO | Other regulatory liabilities, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	3	29
ALABAMA POWER CO | Other regulatory liabilities, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	1	9
GEORGIA POWER CO
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(110)	(19)
GEORGIA POWER CO | Other regulatory assets, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(78)	(26)
GEORGIA POWER CO | Other regulatory assets, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(35)	(14)
GEORGIA POWER CO | Other regulatory liabilities, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	2	19
GEORGIA POWER CO | Other regulatory liabilities, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	1	2
MISSISSIPPI POWER CO
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(27)	27
MISSISSIPPI POWER CO | Other regulatory assets, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(29)	(13)
MISSISSIPPI POWER CO | Other regulatory assets, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(8)	(2)
MISSISSIPPI POWER CO | Other regulatory liabilities, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	3	22
MISSISSIPPI POWER CO | Other regulatory liabilities, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	7	20
SOUTHERN Co GAS
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(36)	(22)
SOUTHERN Co GAS | Other regulatory assets, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(47)	(24)
SOUTHERN Co GAS | Other regulatory assets, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	0	0
SOUTHERN Co GAS | Other regulatory liabilities, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	11	2
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
	Mar. 31, 2023	Mar. 31, 2022
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	$ (86)	$ 27
Cash Flow Hedging | Energy-related derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	(45)	42
Cash Flow Hedging | Interest rate derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	(13)	9
Cash Flow Hedging | Foreign currency derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	0	(28)
Fair Value Hedging | Foreign currency derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	(28)	4
GEORGIA POWER CO | Cash Flow Hedging | Interest rate derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	(1)	12
SOUTHERN POWER CO
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	(11)	(23)
SOUTHERN POWER CO | Cash Flow Hedging | Energy-related derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	(11)	5
SOUTHERN POWER CO | Cash Flow Hedging | Foreign currency derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	0	(28)
SOUTHERN Co GAS
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	(33)	37
SOUTHERN Co GAS | Cash Flow Hedging | Energy-related derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	(34)	37
SOUTHERN Co GAS | Cash Flow Hedging | Interest rate derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	$ 1	$ 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
	Mar. 31, 2023	Mar. 31, 2022
Derivative [Line Items]
Depreciation and amortization	$ 1,111	$ 892
Total interest expense, net of amounts capitalized	(582)	(462)
Total other income (expense), net	147	145
Natural gas
Derivative [Line Items]
Total cost of sales	898	1,095
Other Income (Expense)
Derivative [Line Items]
Amount excluded from effectiveness testing recognized in earnings	28	(4)
Cash Flow Hedging | Energy-related derivatives | Cost of Sales
Derivative [Line Items]
Gain (loss) on hedges	(20)	9
Cash Flow Hedging | Energy-related derivatives | Depreciation and Amortization
Derivative [Line Items]
Gain (loss) on hedges	(9)	2
Cash Flow Hedging | Interest rate derivatives | Interest Expense
Derivative [Line Items]
Gain (loss) on hedges	(4)	(7)
Cash Flow Hedging | Foreign currency derivatives | Interest Expense
Derivative [Line Items]
Gain (loss) on hedges	(3)	(6)
Cash Flow Hedging | Foreign currency derivatives | Other Income (Expense)
Derivative [Line Items]
Gain (loss) on hedges	10	(25)
Fair Value Hedging | Interest rate derivatives | Interest Expense
Derivative [Line Items]
Gain (loss) on hedges	43	(123)
Fair Value Hedging | Foreign currency derivatives | Other Income (Expense)
Derivative [Line Items]
Gain (loss) on hedges	(2)	(24)
SOUTHERN POWER CO
Derivative [Line Items]
Depreciation and amortization	128	120
Total interest expense, net of amounts capitalized	(33)	(37)
Total other income (expense), net	2	2
SOUTHERN POWER CO | Cash Flow Hedging | Energy-related derivatives | Depreciation and Amortization
Derivative [Line Items]
Gain (loss) on hedges	(9)	2
SOUTHERN POWER CO | Cash Flow Hedging | Foreign currency derivatives | Interest Expense
Derivative [Line Items]
Gain (loss) on hedges	(3)	(6)
SOUTHERN POWER CO | Cash Flow Hedging | Foreign currency derivatives | Other Income (Expense)
Derivative [Line Items]
Gain (loss) on hedges	10	(25)
SOUTHERN Co GAS
Derivative [Line Items]
Depreciation and amortization	141	137
Total interest expense, net of amounts capitalized	(76)	(61)
Total other income (expense), net	14	16
SOUTHERN Co GAS | Natural gas
Derivative [Line Items]
Total cost of sales	898	1,095
SOUTHERN Co GAS | Cash Flow Hedging | Energy-related derivatives | Cost of Sales
Derivative [Line Items]
Gain (loss) on hedges	(20)	9
SOUTHERN Co GAS | Cash Flow Hedging | Interest rate derivatives | Interest Expense
Derivative [Line Items]
Gain (loss) on hedges	(1)	(1)
SOUTHERN Co GAS | Fair Value Hedging | Interest rate derivatives | Interest Expense
Derivative [Line Items]
Gain (loss) on hedges	$ 13	$ (36)

Derivatives - Schedule of Cumul

Derivatives - Schedule of Cumulative Basis Adjustments for Fair Value Hedges (Details) - Fair Value Hedging - Long-term debt - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Derivative [Line Items]
Carrying Amount of the Hedged Item	$ (3,007)	$ (2,927)
Cumulative Amount of Fair Value Hedging Adjustment included in Carrying Amount of the Hedged Item	228	282
SOUTHERN Co GAS
Derivative [Line Items]
Carrying Amount of the Hedged Item	(428)	(415)
Cumulative Amount of Fair Value Hedging Adjustment included in Carrying Amount of the Hedged Item	$ 69	$ 81

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
	Mar. 31, 2023	Mar. 31, 2022
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments not designated as hedging instruments, gain (loss), net	$ 13	$ 23
Natural gas revenues
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments not designated as hedging instruments, gain (loss), net	0	2
Cost of natural gas
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments not designated as hedging instruments, gain (loss), net	$ 13	$ 21

Segment and Related Informati_3

Segment and Related Information - Narrative (Details) $ in Millions	3 Months Ended
	Mar. 31, 2023 USD ($) state segment	Mar. 31, 2022 USD ($)
Segment Reporting Information [Line Items]
Number of states in which entity operates | state	3
Operating revenues	$ 6,241	$ 6,258
SOUTHERN POWER CO
Segment Reporting Information [Line Items]
Operating revenues	$ 405	413
SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Number of states in which entity operates | state	4
Operating revenues	$ 1,829	2,043
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%
SOUTHERN Co GAS | Dalton Pipeline
Segment Reporting Information [Line Items]
Ownership percentage, equity method investment	50%
Traditional Electric Operating Companies | Wholesale revenues, affiliates | SOUTHERN POWER CO
Segment Reporting Information [Line Items]
Operating revenues	$ 135	$ 105

Segment and Related Informati_4

Segment and Related Information - Schedule of Financial Data for Business Segments (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2022
Segment Reporting Information [Line Items]
Operating revenues	$ 6,480	$ 6,648
Net income	862	1,032
Goodwill	5,161			$ 5,161
Total assets	134,756			134,891
SOUTHERN POWER CO
Segment Reporting Information [Line Items]
Operating revenues	508	539
Total assets	13,134			13,081
SOUTHERN POWER CO | Disposal Group, Disposed of by Sale | Spare Parts
Segment Reporting Information [Line Items]
Gain on sale	16
Gain on sale, after tax			$ 12
SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues	1,875	2,058
Net income	309	319
Goodwill	5,015			5,015
Total assets	24,222			24,621
Electric Utilities
Segment Reporting Information [Line Items]
Operating revenues	4,483	4,509
SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues	1,875	2,058
Gas distribution operations | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Goodwill	4,034			4,034
Gas marketing services | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Goodwill	981			981
Operating Segments | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues	1,872	2,054
Net income	302	309
Total assets	25,402			25,233
Operating Segments | Electric Utilities
Segment Reporting Information [Line Items]
Operating revenues	4,483	4,509
Net income	712	846
Goodwill	2			2
Total assets	108,782			108,283
Operating Segments | Traditional Electric Operating Companies
Segment Reporting Information [Line Items]
Operating revenues	4,113	4,191
Net income	610	774
Goodwill	0			0
Total assets	96,223			95,861
Operating Segments | SOUTHERN POWER CO
Segment Reporting Information [Line Items]
Operating revenues	508	539
Net income	102	72
Goodwill	2			2
Total assets	13,134			13,081
Operating Segments | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues	1,875	2,058
Net income	309	319
Goodwill	5,015			5,015
Total assets	24,222			24,621
Operating Segments | Gas distribution operations | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues	1,618	1,803
Net income	221	214
Total assets	22,223			22,040
Operating Segments | Gas Pipeline Investments | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues	8	8
Net income	31	29
Total assets	1,583			1,577
Operating Segments | Gas marketing services | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues	246	243
Net income	50	66
Total assets	1,596			1,616
Operating Segments | All Other
Segment Reporting Information [Line Items]
Operating revenues	166	123
Net income	(154)	(125)
Goodwill	144			144
Total assets	2,606			2,665
Operating Segments | All Other | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues	12	16
Net income	7	10
Total assets	9,598			8,943
Eliminations
Segment Reporting Information [Line Items]
Operating revenues	(44)	(42)
Net income	(5)	(8)
Goodwill	0			0
Total assets	(854)			(678)
Eliminations | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues	(9)	(12)
Net income	0	0
Total assets	(10,778)			(9,555)
Eliminations | Electric Utilities
Segment Reporting Information [Line Items]
Operating revenues	(138)	(221)
Net income	0	$ 0
Goodwill	0			0
Total assets	$ (575)			$ (659)

Segment and Related Informati_5

Segment and Related Information - Schedule of Financial Data for Products and Services (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Concentration Risk [Line Items]
Operating revenues	$ 6,480	$ 6,648
Electric Utilities
Concentration Risk [Line Items]
Operating revenues	4,483	4,509
Southern Company Gas' Revenues
Concentration Risk [Line Items]
Operating revenues	1,875	2,058
Retail
Concentration Risk [Line Items]
Operating revenues	3,599	3,613
Retail | Electric Utilities
Concentration Risk [Line Items]
Operating revenues	3,599	3,613
Wholesale Electric
Concentration Risk [Line Items]
Operating revenues	599	664
Wholesale Electric | Electric Utilities
Concentration Risk [Line Items]
Operating revenues	599	664
Other Revenue | Electric Utilities
Concentration Risk [Line Items]
Operating revenues	285	232
Natural Gas
Concentration Risk [Line Items]
Operating revenues	1,875	2,058
Gas Distribution Operations | Southern Company Gas' Revenues
Concentration Risk [Line Items]
Operating revenues	1,610	1,791
Gas marketing services | Southern Company Gas' Revenues
Concentration Risk [Line Items]
Operating revenues	246	243
Other | Southern Company Gas' Revenues
Concentration Risk [Line Items]
Operating revenues	$ 19	$ 24