Georgia Power (GPJA) 10-Q 30 Oct 24 2024 Q3 Quarterly report Financial data

Cover Page

Cover Page	9 Months Ended
	Sep. 30, 2024 shares
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2024
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)	1,095,684,180
Entity Central Index Key	0000092122
Amendment Flag	false
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Common Stock, par value $5 per share
Document Information [Line Items]
Title of 12(b) Security	Common Stock, par value $5 per share
Trading Symbol	SO
Security Exchange Name	NYSE
Series 2017B 5.25% Junior Subordinated Notes due 2077
Document Information [Line Items]
Title of 12(b) Security	Series 2017B 5.25% Junior Subordinated Notes due 2077
Trading Symbol	SOJC
Security Exchange Name	NYSE
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		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Operating Revenues:
Total operating revenues	$ 7,274	$ 6,980	$ 20,383	$ 19,208
Operating Expenses:
Other operations and maintenance	1,662	1,424	4,543	4,352
Depreciation and amortization	1,210	1,143	3,537	3,365
Taxes other than income taxes	375	341	1,155	1,076
Estimated loss on Plant Vogtle Units 3 and 4	0	160	(21)	160
Total operating expenses	4,906	4,870	14,373	14,589
Operating Income	2,368	2,110	6,010	4,619
Other Income and (Expense):
Allowance for equity funds used during construction	58	66	167	200
Earnings from equity method investments	31	32	107	110
Interest expense, net of amounts capitalized	(692)	(620)	(2,050)	(1,812)
Other income (expense), net	147	141	450	428
Total other income and (expense)	(456)	(381)	(1,326)	(1,074)
Earnings Before Income Taxes	1,912	1,729	4,684	3,545
Income taxes	377	297	890	492
Consolidated Net Income	1,535	1,432	3,794	3,053
Net income (loss) attributable to noncontrolling interests	0	10	(73)	(68)
Consolidated net income attributable to company	$ 1,535	$ 1,422	$ 3,867	$ 3,121
Earnings per share -
Basic (in dollars per share)	$ 1.40	$ 1.30	$ 3.53	$ 2.86
Diluted (in dollars per share)	$ 1.39	$ 1.29	$ 3.51	$ 2.84
Average number of shares of common stock outstanding — (in millions)
Basic (in shares)	1,097	1,092	1,096	1,092
Diluted (in shares)	1,103	1,099	1,102	1,098
Retail electric revenues
Operating Revenues:
Total operating revenues	$ 5,366	$ 5,139	$ 13,793	$ 12,597
Wholesale electric revenues
Operating Revenues:
Total operating revenues	721	727	1,919	1,930
Other electric revenues
Operating Revenues:
Total operating revenues	222	203	631	602
Natural Gas
Operating Revenues:
Total operating revenues	682	689	3,220	3,417
Other revenues
Operating Revenues:
Total operating revenues	283	222	820	662
Operating Expenses:
Total cost of sales	166	126	464	381
Fuel
Operating Expenses:
Total cost of sales	1,146	1,367	3,174	3,376
Purchased power
Operating Expenses:
Total cost of sales	249	207	669	680
Natural gas
Operating Expenses:
Total cost of sales	$ 98	$ 102	$ 852	$ 1,199

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Income (Unaudited) - Southern (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Total operating revenues	$ 7,274	$ 6,980	$ 20,383	$ 19,208
Alternative revenue programs
Total operating revenues	$ 1	$ 0	$ 46	$ 11

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - Southern - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Consolidated Net Income	$ 1,535	$ 1,432	$ 3,794	$ 3,053
Qualifying hedges:
Changes in fair value, net of tax	(2)	2	(5)	(34)
Reclassification adjustment for amounts included in net income, net of tax	(8)	36	39	70
Pension and other postretirement benefit plans:
Benefit plan net gain (loss), net of tax	0	0	3	0
Reclassification adjustment for amounts included in net income, net of tax	1	0	1	1
Total other comprehensive income (loss)	(9)	38	38	37
Comprehensive Income	1,526	1,470	3,832	3,090
Comprehensive income (loss) attributable to noncontrolling interests	0	10	(73)	(68)
Consolidated Comprehensive Income Attributable to Company	$ 1,526	$ 1,460	$ 3,905	$ 3,158

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - Southern (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Changes in fair value, tax	$ (1)	$ 3	$ (2)	$ (11)
Qualifying hedges, reclassification adjustment, tax	(2)	12	14	25
Benefit plan net gain (loss), tax	0	0	1	0
Reclassification adjustment for amounts included in net income, tax	$ 0	$ 0	$ 0	$ 0

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Cash Flows (Unaudited) - Southern - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Operating Activities:
Consolidated Net Income	$ 3,794	$ 3,053
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	3,916	3,699
Deferred income taxes	520	(52)
Utilization of federal tax credit carryforward	87	195
Allowance for equity funds used during construction	(167)	(200)
Pension, postretirement, and other employee benefits	(391)	(397)
Settlement of asset retirement obligations	(405)	(444)
Stock based compensation expense	120	119
Estimated loss on Plant Vogtle Units 3 and 4	(21)	160
Retail fuel cost under recovery – long-term	0	(157)
Other, net	(100)	(26)
Changes in certain current assets and liabilities —
Receivables	(233)	524
Retail fuel cost under recovery	843	513
Fossil fuel for generation	143	(254)
Materials and supplies	(195)	(271)
Natural gas cost under recovery	0	108
Other current assets	(181)	(32)
Accounts payable	(161)	(1,031)
Accrued taxes	179	376
Accrued compensation	(90)	(197)
Customer refunds	(28)	(177)
Natural gas cost over recovery	12	165
Other current liabilities	(27)	66
Net cash provided from operating activities	7,615	5,740
Investing Activities:
Property additions	(6,206)	(6,561)
Nuclear decommissioning trust fund purchases	(1,070)	(885)
Nuclear decommissioning trust fund sales	1,070	879
Proceeds from dispositions	370	165
Cost of removal, net of salvage	(444)	(421)
Change in construction payables, net	(119)	241
Other investing activities	(279)	(139)
Net cash used for investing activities	(6,678)	(6,721)
Financing Activities:
Decrease in notes payable, net	(1,264)	(298)
Proceeds —
Long-term debt	5,321	7,812
Short-term borrowings	700	250
Common stock	112	26
Redemptions and repurchases —
Long-term debt	(2,167)	(3,567)
Short-term borrowings	(1,020)	(850)
Distributions to noncontrolling interests	(108)	(148)
Payment of common stock dividends	(2,220)	(2,271)
Other financing activities	(157)	(120)
Net cash provided from (used for) financing activities	(803)	834
Net Change in Cash, Cash Equivalents, and Restricted Cash	134	(147)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	921	2,037
Cash, Cash Equivalents, and Restricted Cash at End of Period	1,055	1,890
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	2,015	1,694
Income taxes, net	131	11
Noncash transactions —
Accrued property additions at end of period	937	1,224
Right-of-use assets obtained under operating leases	126	76
Right-of-use assets obtained under finance leases	1	3
Reassessment of right-of-use assets under operating leases	(7)	0
Issuance of common stock under dividend reinvestment plan	$ 123	$ 0

Condensed Consolidated Statem_6

Condensed Consolidated Statements of Cash Flows (Unaudited) - Southern (Parenthetical) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Statement of Cash Flows [Abstract]
Net cash paid for capitalized interest	$ 76	$ 97

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets (Unaudited) - Southern - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Current Assets:
Cash and cash equivalents	$ 1,018	$ 748
Receivables —
Customer accounts	2,327	2,030
Unbilled revenues	556	786
Under recovered fuel clause revenues	689	696
Other accounts and notes	909	519
Accumulated provision for uncollectible accounts	(64)	(68)
Materials and supplies	2,169	1,989
Fossil fuel for generation	799	943
Natural gas for sale	417	420
Prepaid expenses	391	406
Regulatory assets – asset retirement obligations	390	274
Other regulatory assets	877	1,120
Other current assets	562	569
Total current assets	11,040	10,432
Property, Plant, and Equipment:
In service	134,889	128,428
Less: Accumulated depreciation	39,536	37,725
Plant in service, net of depreciation	95,353	90,703
Other utility plant, net	426	499
Nuclear fuel, at amortized cost	886	858
Construction work in progress	6,232	7,784
Total property, plant, and equipment	102,897	99,844
Other Property and Investments:
Goodwill	5,161	5,161
Nuclear decommissioning trusts, at fair value	2,650	2,424
Equity investments in unconsolidated subsidiaries	1,414	1,368
Other intangible assets, net of amortization	341	368
Miscellaneous property and investments	657	665
Total other property and investments	10,223	9,986
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	1,415	1,432
Deferred charges related to income taxes	874	886
Prepaid pension costs	2,375	2,079
Unamortized loss on reacquired debt	208	220
Deferred under recovered fuel clause revenues	632	1,261
Regulatory assets – asset retirement obligations, deferred	5,277	5,459
Other regulatory assets, deferred	7,531	6,264
Other deferred charges and assets	1,484	1,468
Total deferred charges and other assets	19,796	19,069
Total Assets	143,956	139,331
Current Liabilities:
Securities due within one year	1,642	2,476
Notes payable	722	2,314
Accounts payable	3,950	2,898
Customer deposits	491	503
Accrued taxes —
Accrued income taxes	37	8
Other accrued taxes	985	860
Accrued interest	570	652
Accrued compensation	1,065	1,151
Asset retirement obligations	763	744
Liabilities from risk management activities, net of collateral	199	294
Operating lease obligations	197	183
Natural gas cost over recovery	226	214
Other regulatory liabilities	214	141
Other current liabilities	1,104	1,029
Total current liabilities	12,165	13,467
Long-term Debt	61,254	57,210
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	11,727	10,990
Deferred credits related to income taxes	4,587	4,674
Accumulated deferred ITCs	2,003	2,067
Employee benefit obligations	1,064	1,115
Operating lease obligations, deferred	1,267	1,307
Asset retirement obligations, deferred	9,178	9,573
Other cost of removal obligations	2,006	1,957
Other regulatory liabilities, deferred	725	715
Other deferred credits and liabilities	1,075	1,031
Total deferred credits and other liabilities	33,632	33,429
Total Liabilities	107,051	104,106
Total Stockholders' Equity	36,905	35,225
Total Liabilities and Stockholders' Equity	$ 143,956	$ 139,331

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Unaudited) - Southern (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Other intangible assets, amortization	$ 403	$ 376

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 Other Comprehensive Income (Loss)	Noncontrolling Interests
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	(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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated net income (loss)	823				838		(15)
Other comprehensive income (loss)	43					43
Stock issued	7	$ 1		6
Stock-based compensation	19			19
Cash dividends	(764)				(764)
Distributions to noncontrolling interests	(42)						(42)
Other	0		$ (1)	2			(1)
Ending balance (in shares) at Jun. 30, 2023		1,092
Ending balance (in shares) at Jun. 30, 2023			(1)
Ending balance at Jun. 30, 2023	34,648	$ 5,422	$ (56)	13,742	11,732	(168)	3,976
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated net income (loss)	1,432				1,422		10
Other comprehensive income (loss)	38					38
Stock issued (in shares)		0
Stock issued	4	$ 0		4
Stock-based compensation	7			7
Cash dividends	(765)				(765)
Distributions to noncontrolling interests	(59)						(59)
Other	(1)		$ (1)	(2)	2	0
Ending balance (in shares) at Sep. 30, 2023		1,092
Ending balance (in shares) at Sep. 30, 2023			(1)
Ending balance at Sep. 30, 2023	35,304	$ 5,422	$ (57)	13,751	12,391	(130)	3,927
Beginning balance (in shares) at Dec. 31, 2023		1,092
Beginning balance (in shares) at Dec. 31, 2023			(1)
Beginning balance at Dec. 31, 2023	35,225	$ 5,423	$ (59)	13,775	12,482	(177)	3,781
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated net income (loss)	1,071				1,129		(58)
Other comprehensive income (loss)	37					37
Stock issued (in shares)		3
Stock issued	61	$ 8		53
Stock-based compensation	8			8
Cash dividends	(766)				(766)
Capital contributions from noncontrolling interests	9						9
Distributions to noncontrolling interests	(38)						(38)
Other	7		$ (2)	10	(1)
Ending balance (in shares) at Mar. 31, 2024		1,095
Ending balance (in shares) at Mar. 31, 2024			(1)
Ending balance at Mar. 31, 2024	35,614	$ 5,431	$ (61)	13,846	12,844	(140)	3,694
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated net income (loss)	1,188				1,203		(15)
Other comprehensive income (loss)	10					10
Stock issued (in shares)		1
Stock issued	90	$ 5		85
Stock-based compensation	13			13
Cash dividends	(788)				(788)
Capital contributions from noncontrolling interests	2						2
Distributions to noncontrolling interests	(19)						(19)
Other (in shares)		0	0
Other	1	$ 0	$ (2)	3	0	0	0
Ending balance (in shares) at Jun. 30, 2024		1,096
Ending balance (in shares) at Jun. 30, 2024			(1)
Ending balance at Jun. 30, 2024	36,111	$ 5,436	$ (63)	13,947	13,259	(130)	3,662
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated net income (loss)	1,535				1,535		0
Other comprehensive income (loss)	(9)					(9)
Stock issued (in shares)		1
Stock issued	84	$ 5		79
Stock-based compensation	24			24
Cash dividends	(789)				(789)
Distributions to noncontrolling interests	(55)						(55)
Other (in shares)		0	0
Other	4	$ 0	$ 6	(2)	0	0	0
Ending balance (in shares) at Sep. 30, 2024		1,097
Ending balance (in shares) at Sep. 30, 2024			(1)
Ending balance at Sep. 30, 2024	$ 36,905	$ 5,441	$ (57)	$ 14,048	$ 14,005	$ (139)	$ 3,607

Condensed Consolidated Statem_8

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - Southern (Parenthetical) - $ / shares	3 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023
Statement of Stockholders' Equity [Abstract]
Cash dividends (in dollars per share)	$ 0.72	$ 0.72	$ 0.70	$ 0.70	$ 0.70	$ 0.68

Condensed Statements of Income

Condensed Statements of Income (Unaudited) - APC - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Operating Revenues:
Total operating revenues	$ 7,274	$ 6,980	$ 20,383	$ 19,208
Operating Expenses:
Other operations and maintenance	1,662	1,424	4,543	4,352
Depreciation and amortization	1,210	1,143	3,537	3,365
Taxes other than income taxes	375	341	1,155	1,076
Total operating expenses	4,906	4,870	14,373	14,589
Operating Income	2,368	2,110	6,010	4,619
Other Income and (Expense):
Allowance for equity funds used during construction	58	66	167	200
Interest expense, net of amounts capitalized	(692)	(620)	(2,050)	(1,812)
Total other income (expense), net	147	141	450	428
Total other income and (expense)	(456)	(381)	(1,326)	(1,074)
Earnings Before Income Taxes	1,912	1,729	4,684	3,545
Income taxes	377	297	890	492
Consolidated Net Income	1,535	1,432	3,794	3,053
Retail revenues
Operating Revenues:
Total operating revenues	5,366	5,139	13,793	12,597
Other revenues
Operating Revenues:
Total operating revenues	283	222	820	662
Operating Expenses:
Total cost of sales	166	126	464	381
Fuel
Operating Expenses:
Total cost of sales	1,146	1,367	3,174	3,376
Purchased power, non-affiliates
Operating Expenses:
Total cost of sales	249	207	669	680
Alabama Power
Operating Revenues:
Total operating revenues	2,138	2,083	5,803	5,420
Operating Expenses:
Other operations and maintenance	493	411	1,335	1,275
Depreciation and amortization	366	351	1,091	1,045
Taxes other than income taxes	108	110	347	333
Total operating expenses	1,448	1,396	4,105	4,056
Operating Income	690	687	1,698	1,364
Other Income and (Expense):
Allowance for equity funds used during construction	15	23	40	65
Interest expense, net of amounts capitalized	(113)	(104)	(337)	(311)
Total other income (expense), net	36	38	116	117
Total other income and (expense)	(62)	(43)	(181)	(129)
Earnings Before Income Taxes	628	644	1,517	1,235
Income taxes	135	79	322	103
Consolidated Net Income	493	565	1,195	1,132
Alabama Power | Retail revenues
Operating Revenues:
Total operating revenues	1,904	1,860	5,117	4,708
Alabama Power | Wholesale revenues, non-affiliates
Operating Revenues:
Total operating revenues	89	106	259	358
Alabama Power | Wholesale revenues, affiliates
Operating Revenues:
Total operating revenues	34	14	103	43
Alabama Power | Other revenues
Operating Revenues:
Total operating revenues	111	103	324	311
Alabama Power | Fuel
Operating Expenses:
Total cost of sales	384	402	1,050	1,013
Alabama Power | Purchased power, non-affiliates
Operating Expenses:
Total cost of sales	49	42	148	197
Alabama Power | Purchased power, affiliates
Operating Expenses:
Total cost of sales	$ 48	$ 80	$ 134	$ 193

Condensed Statements of Compreh

Condensed Statements of Comprehensive Income (Unaudited) - APC - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Net income	$ 1,535	$ 1,432	$ 3,794	$ 3,053
Qualifying hedges:
Changes in fair value, net of tax	(2)	2	(5)	(34)
Reclassification adjustment for amounts included in net income, net of tax	(8)	36	39	70
Total other comprehensive income (loss)	(9)	38	38	37
Comprehensive Income	1,526	1,470	3,832	3,090
Alabama Power
Net income	493	565	1,195	1,132
Qualifying hedges:
Changes in fair value, net of tax	0	0	0	1
Reclassification adjustment for amounts included in net income, net of tax	0	1	1	1
Total other comprehensive income (loss)	0	1	1	2
Comprehensive Income	$ 493	$ 566	$ 1,196	$ 1,134

Condensed Statements of Compr_2

Condensed Statements of Comprehensive Income (Unaudited) - APC (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Changes in fair value, tax	$ (1)	$ 3	$ (2)	$ (11)
Qualifying hedges, reclassification adjustment, tax	(2)	12	14	25
Alabama Power
Changes in fair value, tax	0	0	0	0
Qualifying hedges, reclassification adjustment, tax	$ 0	$ 0	$ 1	$ 0

Condensed Statements of Cash Fl

Condensed Statements of Cash Flows (Unaudited) - APC - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Operating Activities:
Net income	$ 3,794	$ 3,053
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	3,916	3,699
Deferred income taxes	520	(52)
Pension, postretirement, and other employee benefits	(391)	(397)
Settlement of asset retirement obligations	(405)	(444)
Other, net	(100)	(26)
Changes in certain current assets and liabilities —
Receivables	(233)	524
Fossil fuel stock	143	(254)
Retail fuel cost under recovery	843	513
Other current assets	(181)	(32)
Accounts payable	(161)	(1,031)
Accrued taxes	179	376
Accrued compensation	(90)	(197)
Other current liabilities	(27)	66
Net cash provided from operating activities	7,615	5,740
Investing Activities:
Property additions	(6,206)	(6,561)
Nuclear decommissioning trust fund purchases	(1,070)	(885)
Nuclear decommissioning trust fund sales	1,070	879
Cost of removal, net of salvage	(444)	(421)
Change in construction payables, net of joint owner portion	(119)	241
Other investing activities	(279)	(139)
Net cash used for investing activities	(6,678)	(6,721)
Financing Activities:
Increase (decrease) in notes payable, net	(1,264)	(298)
Proceeds —
Short-term borrowings	700	250
Redemptions —
Short-term borrowings	(1,020)	(850)
Payment of common stock dividends	(2,220)	(2,271)
Other financing activities	(157)	(120)
Net cash provided from (used for) financing activities	(803)	834
Net Change in Cash, Cash Equivalents, and Restricted Cash	134	(147)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	921	2,037
Cash, Cash Equivalents, and Restricted Cash at End of Period	1,055	1,890
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	2,015	1,694
Income taxes, net	131	11
Noncash transactions —
Accrued property additions at end of period	937	1,224
Right-of-use assets obtained under finance leases	1	3
Alabama Power
Operating Activities:
Net income	1,195	1,132
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	1,201	1,158
Deferred income taxes	(79)	(210)
Pension, postretirement, and other employee benefits	(151)	(148)
Settlement of asset retirement obligations	(184)	(188)
Other, net	24	(22)
Changes in certain current assets and liabilities —
Receivables	(115)	(108)
Fossil fuel stock	46	(113)
Prepayments	(44)	(30)
Retail fuel cost under recovery	236	334
Other current assets	(32)	(93)
Accounts payable	(304)	(358)
Accrued taxes	235	271
Accrued compensation	(26)	(46)
Other current liabilities	(19)	(57)
Net cash provided from operating activities	1,983	1,522
Investing Activities:
Property additions	(1,279)	(1,377)
Nuclear decommissioning trust fund purchases	(448)	(226)
Nuclear decommissioning trust fund sales	448	226
Cost of removal, net of salvage	(123)	(128)
Change in construction payables, net of joint owner portion	(32)	(68)
Other investing activities	(26)	27
Net cash used for investing activities	(1,460)	(1,546)
Financing Activities:
Increase (decrease) in notes payable, net	(40)
Increase in notes payable, net		0
Proceeds —
Senior notes	0	200
Revenue bonds	0	326
Short-term borrowings	50	0
Other long-term debt	6	28
Redemptions —
Revenue bonds	(21)	0
Short-term borrowings	(50)	0
Capital contributions from parent company	488	380
Payment of common stock dividends	(886)	(856)
Other financing activities	(3)	(12)
Net cash provided from (used for) financing activities	(456)	66
Net Change in Cash, Cash Equivalents, and Restricted Cash	67	42
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	409	687
Cash, Cash Equivalents, and Restricted Cash at End of Period	476	729
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	356	329
Income taxes, net	288	152
Noncash transactions —
Accrued property additions at end of period	106	114
Right-of-use assets obtained under operating leases	11	28
Right-of-use assets obtained under finance leases	$ 0	$ 3

Condensed Statements of Cash _2

Condensed Statements of Cash Flows (Unaudited) - APC (Parenthetical) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Net cash paid for capitalized interest	$ 76	$ 97
Alabama Power
Net cash paid for capitalized interest	$ 13	$ 21

Condensed Balance Sheets (Unaud

Condensed Balance Sheets (Unaudited) - APC - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Current Assets:
Cash and cash equivalents	$ 1,018	$ 748
Receivables —
Customer accounts and affiliated	2,327	2,030
Unbilled revenues	556	786
Other accounts and notes	909	519
Accumulated provision for uncollectible accounts	(64)	(68)
Fossil fuel stock	799	943
Materials and supplies	2,169	1,989
Prepaid expenses	391	406
Other regulatory assets	877	1,120
Other current assets	562	569
Total current assets	11,040	10,432
Property, Plant, and Equipment:
In service	134,889	128,428
Less: Accumulated depreciation	39,536	37,725
Plant in service, net of depreciation	95,353	90,703
Other utility plant, net	426	499
Nuclear fuel, at amortized cost	886	858
Construction work in progress	6,232	7,784
Total property, plant, and equipment	102,897	99,844
Other Property and Investments:
Nuclear decommissioning trusts, at fair value	2,650	2,424
Equity investments in unconsolidated subsidiaries	1,414	1,368
Miscellaneous property and investments	657	665
Total other property and investments	10,223	9,986
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	1,415	1,432
Deferred charges related to income taxes	874	886
Regulatory assets – asset retirement obligations	5,277	5,459
Other regulatory assets, deferred	7,531	6,264
Other deferred charges and assets	1,484	1,468
Total deferred charges and other assets	19,796	19,069
Total Assets	143,956	139,331
Current Liabilities:
Securities due within one year	1,642	2,476
Notes payable	722	2,314
Accounts payable —
Customer deposits	491	503
Accrued interest	570	652
Accrued compensation	1,065	1,151
Asset retirement obligations	763	744
Other regulatory liabilities	214	141
Other current liabilities	1,104	1,029
Total current liabilities	12,165	13,467
Long-term Debt	61,254	57,210
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	11,727	10,990
Deferred credits related to income taxes	4,587	4,674
Accumulated deferred ITCs	2,003	2,067
Employee benefit obligations	1,064	1,115
Operating lease obligations, deferred	1,267	1,307
Asset retirement obligations, deferred	9,178	9,573
Other regulatory liabilities, deferred	725	715
Other deferred credits and liabilities	1,075	1,031
Total deferred credits and other liabilities	33,632	33,429
Total Liabilities	107,051	104,106
Total Stockholders' Equity	36,905	35,225
Total Liabilities and Stockholders' Equity	143,956	139,331
Alabama Power
Current Assets:
Cash and cash equivalents	476	324
Receivables —
Unbilled revenues	184	191
Other accounts and notes	207	109
Accumulated provision for uncollectible accounts	(22)	(16)
Fossil fuel stock	348	394
Materials and supplies	699	655
Prepaid expenses	100	62
Regulatory assets – under recovered retail fuel clause revenues	10	246
Other regulatory assets	351	385
Other current assets	77	142
Total current assets	3,142	3,077
Property, Plant, and Equipment:
In service	36,112	35,429
Less: Accumulated depreciation	11,522	11,131
Plant in service, net of depreciation	24,590	24,298
Other utility plant, net	426	499
Nuclear fuel, at amortized cost	250	253
Construction work in progress	1,210	1,095
Total property, plant, and equipment	26,476	26,145
Other Property and Investments:
Nuclear decommissioning trusts, at fair value	1,399	1,261
Equity investments in unconsolidated subsidiaries	49	52
Miscellaneous property and investments	127	155
Total other property and investments	1,575	1,468
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	87	87
Deferred charges related to income taxes	261	262
Prepaid pension and other postretirement benefit costs	757	659
Regulatory assets – asset retirement obligations	1,742	1,810
Other regulatory assets, deferred	1,834	1,858
Other deferred charges and assets	466	414
Total deferred charges and other assets	5,147	5,090
Total Assets	36,340	35,780
Current Liabilities:
Securities due within one year	655	223
Notes payable	0	40
Accounts payable —
Customer deposits	111	105
Accrued taxes	279	51
Accrued interest	88	122
Accrued compensation	210	222
Asset retirement obligations	360	346
Other regulatory liabilities	131	44
Other current liabilities	192	191
Total current liabilities	2,666	2,304
Long-term Debt	10,517	10,960
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	4,183	4,170
Deferred credits related to income taxes	1,413	1,506
Accumulated deferred ITCs	70	74
Employee benefit obligations	152	155
Operating lease obligations, deferred	79	81
Asset retirement obligations, deferred	3,730	3,812
Other regulatory liabilities, deferred	267	291
Other deferred credits and liabilities	128	94
Total deferred credits and other liabilities	10,022	10,183
Total Liabilities	23,205	23,447
Total Stockholders' Equity	13,135	12,333
Total Liabilities and Stockholders' Equity	36,340	35,780
Alabama Power | Nonrelated Party
Receivables —
Customer accounts and affiliated	627	513
Accounts payable —
Affiliated and Other	373	630
Alabama Power | Related Party
Receivables —
Customer accounts and affiliated	85	72
Accounts payable —
Affiliated and Other	$ 267	$ 330

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, 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						255			255
Capital contributions from parent company						330		330
Other comprehensive income	(44)				(44)
Cash dividends on common stock	(742)			(742)		(285)			(285)
Other	0		2
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)
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	3,121
Ending balance (in shares) at Sep. 30, 2023							31
Ending balance at Sep. 30, 2023	35,304	5,422	13,751	12,391	(130)	12,351	$ 1,222	7,097	4,040	(8)
Beginning balance (in shares) at Mar. 31, 2023							31
Beginning balance at Mar. 31, 2023	34,562	5,421	13,715	11,658	(211)	11,987	$ 1,222	7,040	3,734	(9)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						312			312
Capital contributions from parent company						29		29
Other comprehensive income	43				43
Cash dividends on common stock	(764)			(764)		(286)			(286)
Other	0		2
Ending balance (in shares) at Jun. 30, 2023							31
Ending balance at Jun. 30, 2023	34,648	5,422	13,742	11,732	(168)	12,042	$ 1,222	7,069	3,760	(9)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,422					565			565
Capital contributions from parent company						28		28
Other comprehensive income	38				38	1				1
Cash dividends on common stock	(765)			(765)		(285)			(285)
Other	(1)		(2)	2	0
Ending balance (in shares) at Sep. 30, 2023							31
Ending balance at Sep. 30, 2023	35,304	5,422	13,751	12,391	(130)	12,351	$ 1,222	7,097	4,040	(8)
Beginning balance (in shares) at Dec. 31, 2023							31
Beginning balance at Dec. 31, 2023	35,225	5,423	13,775	12,482	(177)	12,333	$ 1,222	7,125	3,993	(7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						333			333
Capital contributions from parent company						427		427
Other comprehensive income	37				37
Cash dividends on common stock	(766)			(766)		(295)			(295)
Other	7		10	(1)		(1)			(1)
Ending balance (in shares) at Mar. 31, 2024							31
Ending balance at Mar. 31, 2024	35,614	5,431	13,846	12,844	(140)	12,797	$ 1,222	7,552	4,030	(7)
Beginning balance (in shares) at Dec. 31, 2023							31
Beginning balance at Dec. 31, 2023	35,225	5,423	13,775	12,482	(177)	12,333	$ 1,222	7,125	3,993	(7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	3,867
Ending balance (in shares) at Sep. 30, 2024							31
Ending balance at Sep. 30, 2024	36,905	5,441	14,048	14,005	(139)	13,135	$ 1,222	7,618	4,301	(6)
Beginning balance (in shares) at Mar. 31, 2024							31
Beginning balance at Mar. 31, 2024	35,614	$ 5,431	13,846	12,844	(140)	12,797	$ 1,222	7,552	4,030	(7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						369			369
Capital contributions from parent company						50		50
Other comprehensive income	10				10	1				1
Cash dividends on common stock	(788)			(788)		(296)			(296)
Other (in shares)		0
Other	1	$ 0	3	0	0
Ending balance (in shares) at Jun. 30, 2024							31
Ending balance at Jun. 30, 2024	36,111	$ 5,436	13,947	13,259	(130)	12,921	$ 1,222	7,602	4,103	(6)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,535					493			493
Capital contributions from parent company						16		16
Other comprehensive income	(9)				(9)
Cash dividends on common stock	(789)			(789)		(295)			(295)
Other (in shares)		0
Other	4	$ 0	(2)	0	0
Ending balance (in shares) at Sep. 30, 2024							31
Ending balance at Sep. 30, 2024	$ 36,905	$ 5,441	$ 14,048	$ 14,005	$ (139)	$ 13,135	$ 1,222	$ 7,618	$ 4,301	$ (6)

Condensed Statements of Incom_2

Condensed Statements of Income (Unaudited) - GPC - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Operating Revenues:
Total operating revenues	$ 7,274	$ 6,980	$ 20,383	$ 19,208
Operating Expenses:
Other operations and maintenance	1,662	1,424	4,543	4,352
Depreciation and amortization	1,210	1,143	3,537	3,365
Taxes other than income taxes	375	341	1,155	1,076
Estimated loss on Plant Vogtle Units 3 and 4	0	160	(21)	160
Total operating expenses	4,906	4,870	14,373	14,589
Operating Income	2,368	2,110	6,010	4,619
Other Income and (Expense):
Allowance for equity funds used during construction	58	66	167	200
Interest expense, net of amounts capitalized	(692)	(620)	(2,050)	(1,812)
Other income (expense), net	147	141	450	428
Total other income and (expense)	(456)	(381)	(1,326)	(1,074)
Earnings Before Income Taxes	1,912	1,729	4,684	3,545
Income taxes	377	297	890	492
Consolidated Net Income	1,535	1,432	3,794	3,053
Retail revenues
Operating Revenues:
Total operating revenues	5,366	5,139	13,793	12,597
Wholesale revenues
Operating Revenues:
Total operating revenues	721	727	1,919	1,930
Other revenues
Operating Revenues:
Total operating revenues	283	222	820	662
Operating Expenses:
Total cost of sales	166	126	464	381
Fuel
Operating Expenses:
Total cost of sales	1,146	1,367	3,174	3,376
Purchased power, non-affiliates
Operating Expenses:
Total cost of sales	249	207	669	680
GEORGIA POWER CO
Operating Revenues:
Total operating revenues	3,472	3,237	8,745	7,805
Operating Expenses:
Other operations and maintenance	613	512	1,586	1,505
Depreciation and amortization	462	429	1,334	1,248
Taxes other than income taxes	177	144	488	406
Estimated loss on Plant Vogtle Units 3 and 4	0	160	(21)	160
Total operating expenses	2,081	2,173	5,701	5,687
Operating Income	1,391	1,064	3,044	2,118
Other Income and (Expense):
Allowance for equity funds used during construction	37	37	108	121
Interest expense, net of amounts capitalized	(184)	(166)	(543)	(472)
Other income (expense), net	52	45	156	125
Total other income and (expense)	(95)	(84)	(279)	(226)
Earnings Before Income Taxes	1,296	980	2,765	1,892
Income taxes	246	200	516	345
Consolidated Net Income	1,050	780	2,249	1,547
GEORGIA POWER CO | Retail revenues
Operating Revenues:
Total operating revenues	3,185	2,996	7,937	7,142
GEORGIA POWER CO | Wholesale revenues
Operating Revenues:
Total operating revenues	78	69	198	147
GEORGIA POWER CO | Other revenues
Operating Revenues:
Total operating revenues	209	172	610	516
GEORGIA POWER CO | Fuel
Operating Expenses:
Total cost of sales	451	576	1,281	1,392
GEORGIA POWER CO | Purchased power, non-affiliates
Operating Expenses:
Total cost of sales	174	131	466	397
GEORGIA POWER CO | Purchased power, affiliates
Operating Expenses:
Total cost of sales	$ 204	$ 221	$ 567	$ 579

Condensed Statements of Compr_3

Condensed Statements of Comprehensive Income (Unaudited) - GPC - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Net income	$ 1,535	$ 1,432	$ 3,794	$ 3,053
Qualifying hedges:
Changes in fair value, net of tax	(2)	2	(5)	(34)
Reclassification adjustment for amounts included in net income, net of tax	(8)	36	39	70
Total other comprehensive income (loss)	(9)	38	38	37
Comprehensive Income	1,526	1,470	3,832	3,090
GEORGIA POWER CO
Net income	1,050	780	2,249	1,547
Qualifying hedges:
Changes in fair value, net of tax	0	0	13	(1)
Reclassification adjustment for amounts included in net income, net of tax	1	1	3	3
Total other comprehensive income (loss)	1	1	16	2
Comprehensive Income	$ 1,051	$ 781	$ 2,265	$ 1,549

Condensed Statements of Compr_4

Condensed Statements of Comprehensive Income (Unaudited) - GPC (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Changes in fair value, tax	$ (1)	$ 3	$ (2)	$ (11)
Qualifying hedges, reclassification adjustment, tax	(2)	12	14	25
GEORGIA POWER CO
Changes in fair value, tax	0	0	4	(1)
Qualifying hedges, reclassification adjustment, tax	$ 0	$ 0	$ 1	$ 1

Condensed Statements of Cash _3

Condensed Statements of Cash Flows (Unaudited) - GPC - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Operating Activities:
Net income	$ 3,794	$ 3,053
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	3,916	3,699
Deferred income taxes	520	(52)
Allowance for equity funds used during construction	(167)	(200)
Pension, postretirement, and other employee benefits	(391)	(397)
Settlement of asset retirement obligations	(405)	(444)
Retail fuel cost under recovery – long-term	0	(157)
Estimated loss on Plant Vogtle Units 3 and 4	(21)	160
Other, net	(100)	(26)
Changes in certain current assets and liabilities —
Receivables	(233)	524
Retail fuel cost under recovery	843	513
Fossil fuel stock	143	(254)
Materials and supplies	(195)	(271)
Other current assets	(181)	(32)
Accounts payable	(161)	(1,031)
Accrued taxes	179	376
Customer refunds	(28)	(177)
Other current liabilities	(27)	66
Net cash provided from operating activities	7,615	5,740
Investing Activities:
Property additions	(6,206)	(6,561)
Nuclear decommissioning trust fund purchases	(1,070)	(885)
Nuclear decommissioning trust fund sales	1,070	879
Cost of removal, net of salvage	(444)	(421)
Proceeds from dispositions	370	165
Other investing activities	(279)	(139)
Net cash used for investing activities	(6,678)	(6,721)
Financing Activities:
Increase (decrease) in notes payable, net	(1,264)	(298)
Proceeds —
Short-term borrowings	700	250
Redemptions and repurchases —
Short-term borrowings	(1,020)	(850)
Payment of common stock dividends	(2,220)	(2,271)
Other financing activities	(157)	(120)
Net cash provided from (used for) financing activities	(803)	834
Net Change in Cash, Cash Equivalents, and Restricted Cash	134	(147)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	921	2,037
Cash, Cash Equivalents, and Restricted Cash at End of Period	1,055	1,890
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	2,015	1,694
Income taxes, net	131	11
Noncash transactions —
Accrued property additions at end of period	937	1,224
Right-of-use assets obtained under operating leases	126	76
Right-of-use assets obtained under finance leases	1	3
GEORGIA POWER CO
Operating Activities:
Net income	2,249	1,547
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	1,566	1,411
Deferred income taxes	396	102
Allowance for equity funds used during construction	(108)	(121)
Pension, postretirement, and other employee benefits	(197)	(207)
Settlement of asset retirement obligations	(191)	(228)
Retail fuel cost under recovery – long-term	0	(157)
Estimated loss on Plant Vogtle Units 3 and 4	(21)	160
Other, net	(141)	12
Changes in certain current assets and liabilities —
Receivables	(499)	(311)
Retail fuel cost under recovery	590	204
Fossil fuel stock	110	(138)
Materials and supplies	(83)	(135)
Other current assets	(163)	(41)
Accounts payable	113	(142)
Accrued taxes	24	118
Customer refunds	(5)	(121)
Other current liabilities	41	16
Net cash provided from operating activities	3,681	1,969
Investing Activities:
Property additions	(3,403)	(3,501)
Nuclear decommissioning trust fund purchases	(623)	(659)
Nuclear decommissioning trust fund sales	622	654
Cost of removal, net of salvage	(225)	(191)
Change in construction payables, net of joint owner portion	(92)	338
Proceeds from dispositions	356	59
Other investing activities	(122)	(76)
Net cash used for investing activities	(3,487)	(3,376)
Financing Activities:
Increase (decrease) in notes payable, net	(776)
Increase (decrease) in notes payable, net		50
Proceeds —
Proceeds — Senior notes	1,400	1,750
Short-term borrowings	350	250
Revenue bonds	0	229
Redemptions and repurchases —
Senior notes	(400)	(800)
Short-term borrowings	(670)	(650)
FFB loan	(64)	(64)
Capital contributions from parent company	1,560	1,837
Payment of common stock dividends	(1,538)	(1,392)
Other financing activities	(67)	(27)
Net cash provided from (used for) financing activities	(205)	1,183
Net Change in Cash, Cash Equivalents, and Restricted Cash	(11)	(224)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	75	480
Cash, Cash Equivalents, and Restricted Cash at End of Period	64	256
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	530	439
Income taxes, net	80	74
Noncash transactions —
Accrued property additions at end of period	590	942
Right-of-use assets obtained under operating leases	121	17
Right-of-use assets obtained under finance leases	$ 44	$ 18

Condensed Statements of Cash _4

Condensed Statements of Cash Flows (Unaudited) - GPC (Parenthetical) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Net cash paid for capitalized interest	$ 76	$ 97
GEORGIA POWER CO
Net cash paid for capitalized interest	$ 43	$ 63

Condensed Balance Sheets (Una_2

Condensed Balance Sheets (Unaudited) - GPC - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Current Assets:
Cash and cash equivalents	$ 1,018	$ 748
Receivables —
Customer accounts, net and Affiliated	2,327	2,030
Unbilled revenues	556	786
Other accounts and notes	909	519
Fossil fuel stock	799	943
Materials and supplies	2,169	1,989
Regulatory assets – asset retirement obligations	390	274
Other regulatory assets	877	1,120
Other current assets	562	569
Total current assets	11,040	10,432
Property, Plant, and Equipment:
In service	134,889	128,428
Less: Accumulated depreciation	39,536	37,725
Plant in service, net of depreciation	95,353	90,703
Nuclear fuel, at amortized cost	886	858
Construction work in progress	6,232	7,784
Total property, plant, and equipment	102,897	99,844
Other Property and Investments:
Nuclear decommissioning trusts, at fair value	2,650	2,424
Equity investments in unconsolidated subsidiaries	1,414	1,368
Miscellaneous property and investments	657	665
Total other property and investments	10,223	9,986
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	1,415	1,432
Deferred charges related to income taxes	874	886
Prepaid pension costs	2,375	2,079
Deferred under recovered fuel clause revenues	632	1,261
Regulatory assets – asset retirement obligations, deferred	5,277	5,459
Other regulatory assets, deferred	7,531	6,264
Other deferred charges and assets	1,484	1,468
Total deferred charges and other assets	19,796	19,069
Total Assets	143,956	139,331
Current Liabilities:
Securities due within one year	1,642	2,476
Notes payable	722	2,314
Accounts payable —
Customer deposits	491	503
Accrued interest	570	652
Accrued compensation	1,065	1,151
Operating lease obligations	197	183
Asset retirement obligations	763	744
Other regulatory liabilities	214	141
Other current liabilities	1,104	1,029
Total current liabilities	12,165	13,467
Long-term Debt	61,254	57,210
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	11,727	10,990
Deferred credits related to income taxes	4,587	4,674
Accumulated deferred ITCs	2,003	2,067
Employee benefit obligations	1,064	1,115
Operating lease obligations, deferred	1,267	1,307
Asset retirement obligations, deferred	9,178	9,573
Other deferred credits and liabilities	1,075	1,031
Total deferred credits and other liabilities	33,632	33,429
Total Liabilities	107,051	104,106
Total Stockholders' Equity	36,905	35,225
Total Liabilities and Stockholders' Equity	143,956	139,331
GEORGIA POWER CO
Current Assets:
Cash and cash equivalents	43	9
Receivables —
Unbilled revenues	251	275
Under recovered retail fuel clause revenues	683	694
Joint owner accounts	116	119
Other accounts and notes	362	81
Fossil fuel stock	370	480
Materials and supplies	955	883
Regulatory assets – asset retirement obligations	215	98
Other regulatory assets	377	423
Other current assets	420	305
Total current assets	5,053	4,261
Property, Plant, and Equipment:
In service	53,861	49,370
Less: Accumulated depreciation	14,635	13,955
Plant in service, net of depreciation	39,226	35,415
Nuclear fuel, at amortized cost	636	605
Construction work in progress	3,188	4,975
Total property, plant, and equipment	43,050	40,995
Other Property and Investments:
Nuclear decommissioning trusts, at fair value	1,251	1,163
Equity investments in unconsolidated subsidiaries	44	47
Miscellaneous property and investments	181	151
Total other property and investments	1,476	1,361
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	879	884
Deferred charges related to income taxes	584	594
Prepaid pension costs	795	706
Deferred under recovered fuel clause revenues	632	1,211
Regulatory assets – asset retirement obligations, deferred	3,292	3,407
Other regulatory assets, deferred	4,217	2,890
Other deferred charges and assets	520	508
Total deferred charges and other assets	10,919	10,200
Total Assets	60,498	56,817
Current Liabilities:
Securities due within one year	850	502
Notes payable	235	1,329
Accounts payable —
Customer deposits	254	250
Accrued taxes	606	582
Accrued interest	174	175
Accrued compensation	229	250
Operating lease obligations	131	135
Asset retirement obligations	345	338
Other regulatory liabilities	34	22
Other current liabilities	404	365
Total current liabilities	6,593	5,935
Long-term Debt	16,813	16,198
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	4,414	4,018
Deferred credits related to income taxes	2,172	2,161
Accumulated deferred ITCs	317	326
Employee benefit obligations	236	248
Operating lease obligations, deferred	725	740
Asset retirement obligations, deferred	5,036	5,327
Other deferred credits and liabilities	521	481
Total deferred credits and other liabilities	13,421	13,301
Total Liabilities	36,827	35,434
Total Stockholders' Equity	23,671	21,383
Total Liabilities and Stockholders' Equity	60,498	56,817
GEORGIA POWER CO | Nonrelated Party
Receivables —
Customer accounts, net and Affiliated	1,187	843
Accounts payable —
Affiliated and Other	2,529	1,147
GEORGIA POWER CO | Related Party
Receivables —
Customer accounts, net and Affiliated	74	51
Accounts payable —
Affiliated and Other	$ 802	$ 840

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 Other Comprehensive Income (Loss)	GEORGIA POWER CO	GEORGIA POWER CO Common Stock	GEORGIA POWER CO Paid-In Capital	GEORGIA POWER CO Retained Earnings	GEORGIA POWER CO Accumulated Other Comprehensive Income (Loss)
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						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)
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	3,053					1,547
Ending balance (in shares) at Sep. 30, 2023							9
Ending balance at Sep. 30, 2023	35,304	5,422	13,751	12,391	(130)	20,857	$ 398	17,467	3,002	(10)
Beginning balance (in shares) at Mar. 31, 2023							9
Beginning balance at Mar. 31, 2023	34,562	5,421	13,715	11,658	(211)	19,443	$ 398	16,378	2,679	(12)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						471			471
Capital contributions from parent company						33		33
Other comprehensive income (loss)	43				43	1				1
Cash dividends on common stock	(764)			(764)		(464)			(464)
Other	0		2
Ending balance (in shares) at Jun. 30, 2023							9
Ending balance at Jun. 30, 2023	34,648	5,422	13,742	11,732	(168)	19,484	$ 398	16,411	2,686	(11)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,432					780			780
Capital contributions from parent company						1,056		1,056
Other comprehensive income (loss)	38				38	1				1
Cash dividends on common stock	(765)			(765)		(464)			(464)
Other	(1)		(2)	2	0
Ending balance (in shares) at Sep. 30, 2023							9
Ending balance at Sep. 30, 2023	35,304	5,422	13,751	12,391	(130)	20,857	$ 398	17,467	3,002	(10)
Beginning balance (in shares) at Dec. 31, 2023							9
Beginning balance at Dec. 31, 2023	35,225	5,423	13,775	12,482	(177)	21,383	$ 398	17,923	3,071	(9)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						437			437
Capital contributions from parent company						750		750
Other comprehensive income (loss)	37				37	13				13
Cash dividends on common stock	(766)			(766)		(513)			(513)
Other	7		10	(1)
Ending balance (in shares) at Mar. 31, 2024							9
Ending balance at Mar. 31, 2024	35,614	5,431	13,846	12,844	(140)	22,070	$ 398	18,673	2,995	4
Beginning balance (in shares) at Dec. 31, 2023							9
Beginning balance at Dec. 31, 2023	35,225	5,423	13,775	12,482	(177)	21,383	$ 398	17,923	3,071	(9)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	3,794					2,249
Ending balance (in shares) at Sep. 30, 2024							9
Ending balance at Sep. 30, 2024	36,905	5,441	14,048	14,005	(139)	23,671	$ 398	19,486	3,781	6
Beginning balance (in shares) at Mar. 31, 2024							9
Beginning balance at Mar. 31, 2024	35,614	5,431	13,846	12,844	(140)	22,070	$ 398	18,673	2,995	4
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						762			762
Capital contributions from parent company						113		113
Other comprehensive income (loss)	10				10	1				1
Cash dividends on common stock	(788)			(788)		(513)			(513)
Other	1	0	3	0	0
Ending balance (in shares) at Jun. 30, 2024							9
Ending balance at Jun. 30, 2024	36,111	5,436	13,947	13,259	(130)	22,433	$ 398	18,786	3,244	5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,535					1,050			1,050
Capital contributions from parent company						700		700
Other comprehensive income (loss)	(9)				(9)	1				1
Cash dividends on common stock	(789)			(789)		(512)			(512)
Other	4	0	(2)	0	0	(1)			(1)
Ending balance (in shares) at Sep. 30, 2024							9
Ending balance at Sep. 30, 2024	$ 36,905	$ 5,441	$ 14,048	$ 14,005	$ (139)	$ 23,671	$ 398	$ 19,486	$ 3,781	$ 6

Condensed Statements of Incom_3

Condensed Statements of Income (Unaudited) - MPC - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Operating Revenues:
Total operating revenues	$ 7,274	$ 6,980	$ 20,383	$ 19,208
Operating Expenses:
Other operations and maintenance	1,662	1,424	4,543	4,352
Depreciation and amortization	1,210	1,143	3,537	3,365
Taxes other than income taxes	375	341	1,155	1,076
Total operating expenses	4,906	4,870	14,373	14,589
Operating Income	2,368	2,110	6,010	4,619
Other Income and (Expense):
Interest expense, net of amounts capitalized	(692)	(620)	(2,050)	(1,812)
Other income (expense), net	147	141	450	428
Total other income and (expense)	(456)	(381)	(1,326)	(1,074)
Earnings Before Income Taxes	1,912	1,729	4,684	3,545
Income taxes	377	297	890	492
Consolidated Net Income	1,535	1,432	3,794	3,053
Retail revenues
Operating Revenues:
Total operating revenues	5,366	5,139	13,793	12,597
Other revenues
Operating Revenues:
Total operating revenues	283	222	820	662
Operating Expenses:
Fuel and purchased power	166	126	464	381
Mississippi Power
Operating Revenues:
Total operating revenues	412	436	1,118	1,137
Operating Expenses:
Other operations and maintenance	90	84	261	258
Depreciation and amortization	48	48	141	139
Taxes other than income taxes	33	32	95	92
Total operating expenses	305	333	860	905
Operating Income	107	103	258	232
Other Income and (Expense):
Interest expense, net of amounts capitalized	(19)	(19)	(58)	(53)
Other income (expense), net	9	9	33	29
Total other income and (expense)	(10)	(10)	(25)	(24)
Earnings Before Income Taxes	97	93	233	208
Income taxes	22	18	47	35
Consolidated Net Income	75	75	186	173
Mississippi Power | Retail revenues
Operating Revenues:
Total operating revenues	276	284	739	747
Mississippi Power | Wholesale revenues, non-affiliates
Operating Revenues:
Total operating revenues	66	77	179	201
Mississippi Power | Wholesale revenues, affiliates
Operating Revenues:
Total operating revenues	57	65	166	158
Mississippi Power | Other revenues
Operating Revenues:
Total operating revenues	13	10	34	31
Mississippi Power | Fuel and purchased power
Operating Expenses:
Fuel and purchased power	$ 134	$ 169	$ 363	$ 416

Condensed Statements of Compr_5

Condensed Statements of Comprehensive Income - MPC - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Net income	$ 1,535	$ 1,432	$ 3,794	$ 3,053
Qualifying hedges:
Changes in fair value, net of tax	(2)	2	(5)	(34)
Total other comprehensive income (loss)	(9)	38	38	37
Comprehensive Income	1,526	1,470	3,832	3,090
Mississippi Power
Net income	75	75	186	173
Qualifying hedges:
Changes in fair value, net of tax	0	0	5	0
Total other comprehensive income (loss)	0	0	5	0
Comprehensive Income	$ 75	$ 75	$ 191	$ 173

Condensed Statements of Compr_6

Condensed Statements of Comprehensive Income - MPC (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Changes in fair value, tax	$ (1)	$ 3	$ (2)	$ (11)
Mississippi Power
Changes in fair value, tax	$ 0	$ 0	$ 2	$ 0

Condensed Statements of Cash _5

Condensed Statements of Cash Flows (Unaudited) - MPC - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Operating Activities:
Net income	$ 3,794	$ 3,053
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	3,916	3,699
Deferred income taxes	520	(52)
Pension, postretirement, and other employee benefits	(391)	(397)
Settlement of asset retirement obligations	(405)	(444)
Other, net	(100)	(26)
Changes in certain current assets and liabilities —
Receivables	(233)	524
Retail fuel cost under recovery	843	513
Fossil fuel stock	143	(254)
Other current assets	(181)	(32)
Accounts payable	(161)	(1,031)
Accrued taxes	179	376
Accrued compensation	(90)	(197)
Other current liabilities	(27)	66
Net cash provided from operating activities	7,615	5,740
Investing Activities:
Property additions	(6,206)	(6,561)
Cost of removal, net of salvage	(444)	(421)
Change in construction payables, net of joint owner portion	(119)	241
Other investing activities	(279)	(139)
Net cash used for investing activities	(6,678)	(6,721)
Financing Activities:
Payment of common stock dividends	(2,220)	(2,271)
Other financing activities	(157)	(120)
Net cash provided from (used for) financing activities	(803)	834
Net Change in Cash, Cash Equivalents, and Restricted Cash	134	(147)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	921	2,037
Cash, Cash Equivalents, and Restricted Cash at End of Period	1,055	1,890
Supplemental Cash Flow Information:
Interest	2,015	1,694
Income taxes, net	131	11
Noncash transactions —
Accrued property additions at end of period	937	1,224
Right-of-use assets obtained under operating leases	126	76
Mississippi Power
Operating Activities:
Net income	186	173
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	153	171
Deferred income taxes	4	(10)
Pension, postretirement, and other employee benefits	(13)	(15)
Settlement of asset retirement obligations	(13)	(12)
Other, net	21	12
Changes in certain current assets and liabilities —
Receivables	(22)	55
Retail fuel cost under recovery	17	(24)
Fossil fuel stock	(10)	7
Other current assets	(13)	7
Accounts payable	(29)	(83)
Accrued taxes	(11)	(16)
Accrued compensation	(4)	(5)
Other current liabilities	(1)	0
Net cash provided from operating activities	265	260
Investing Activities:
Property additions	(220)	(231)
Cost of removal, net of salvage	(32)	(21)
Change in construction payables, net of joint owner portion	(3)	(5)
Payments pursuant to LTSAs	(15)	(21)
Other investing activities	(2)	(2)
Net cash used for investing activities	(272)	(280)
Financing Activities:
Increase in notes payable, net	50	20
Proceeds — Senior notes	250	100
Redemptions — Senior notes	(200)	0
Capital contributions from parent company	60	8
Payment of common stock dividends	(141)	(139)
Other financing activities	(2)	(1)
Net cash provided from (used for) financing activities	17	(12)
Net Change in Cash, Cash Equivalents, and Restricted Cash	10	(32)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	38	59
Cash, Cash Equivalents, and Restricted Cash at End of Period	48	27
Supplemental Cash Flow Information:
Interest	67	53
Income taxes, net	35	33
Noncash transactions —
Accrued property additions at end of period	33	20
Right-of-use assets obtained under operating leases	$ 0	$ 1

Condensed Balance Sheets (Una_3

Condensed Balance Sheets (Unaudited) - MPC - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Current Assets:
Cash and cash equivalents	$ 1,018	$ 748
Receivables —
Customer accounts, net and Affiliated	2,327	2,030
Unbilled revenues	556	786
Other accounts and notes	909	519
Fossil fuel stock	799	943
Materials and supplies	2,169	1,989
Other regulatory assets	877	1,120
Other current assets	562	569
Total current assets	11,040	10,432
Property, Plant, and Equipment:
In service	134,889	128,428
Less: Accumulated depreciation	39,536	37,725
Plant in service, net of depreciation	95,353	90,703
Construction work in progress	6,232	7,784
Total property, plant, and equipment	102,897	99,844
Other Property and Investments:
Total other property and investments	10,223	9,986
Deferred Charges and Other Assets:
Deferred charges related to income taxes	874	886
Prepaid pension costs	2,375	2,079
Deferred under recovered fuel clause revenues	632	1,261
Regulatory assets – asset retirement obligations	5,277	5,459
Other regulatory assets, deferred	7,531	6,264
Other deferred charges and assets	1,484	1,468
Total deferred charges and other assets	19,796	19,069
Total Assets	143,956	139,331
Current Liabilities:
Securities due within one year	1,642	2,476
Notes payable	722	2,314
Accounts payable —
Accrued compensation	1,065	1,151
Asset retirement obligations	763	744
Other regulatory liabilities	214	141
Other current liabilities	1,104	1,029
Total current liabilities	12,165	13,467
Long-term Debt	61,254	57,210
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	11,727	10,990
Deferred credits related to income taxes	4,587	4,674
Employee benefit obligations	1,064	1,115
Asset retirement obligations, deferred	9,178	9,573
Other cost of removal obligations	2,006	1,957
Other regulatory liabilities, deferred	725	715
Other deferred credits and liabilities	1,075	1,031
Total deferred credits and other liabilities	33,632	33,429
Total Liabilities	107,051	104,106
Total Liabilities and Stockholders' Equity	143,956	139,331
Mississippi Power
Current Assets:
Cash and cash equivalents	48	38
Receivables —
Unbilled revenues	43	40
Other accounts and notes	21	20
Fossil fuel stock	57	47
Materials and supplies	98	89
Other regulatory assets	49	56
Other current assets	15	10
Total current assets	421	365
Property, Plant, and Equipment:
In service	5,627	5,523
Less: Accumulated depreciation	1,856	1,792
Plant in service, net of depreciation	3,771	3,731
Construction work in progress	291	203
Total property, plant, and equipment	4,062	3,934
Other Property and Investments:
Total other property and investments	153	158
Deferred Charges and Other Assets:
Deferred charges related to income taxes	27	28
Prepaid pension costs	111	99
Deferred under recovered fuel clause revenues	0	50
Regulatory assets – asset retirement obligations	247	244
Other regulatory assets, deferred	279	285
Accumulated deferred income taxes	83	96
Other deferred charges and assets	64	85
Total deferred charges and other assets	811	887
Total Assets	5,447	5,344
Current Liabilities:
Securities due within one year	12	201
Notes payable	50	0
Accounts payable —
Accrued taxes	105	117
Accrued compensation	39	43
Asset retirement obligations	32	29
Over recovered fuel clause revenues	0	27
Other regulatory liabilities	3	17
Other current liabilities	89	90
Total current liabilities	453	679
Long-term Debt	1,681	1,443
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	476	469
Deferred credits related to income taxes	224	229
Employee benefit obligations	67	67
Asset retirement obligations, deferred	121	139
Other cost of removal obligations	173	186
Other regulatory liabilities, deferred	97	92
Other deferred credits and liabilities	40	37
Total deferred credits and other liabilities	1,198	1,219
Total Liabilities	3,332	3,341
Total common stockholders' equity	2,115	2,003
Total Liabilities and Stockholders' Equity	5,447	5,344
Mississippi Power | Nonrelated Party
Receivables —
Customer accounts, net and Affiliated	64	36
Accounts payable —
Affiliated and Other	70	73
Mississippi Power | Related Party
Receivables —
Customer accounts, net and Affiliated	26	29
Accounts payable —
Affiliated and Other	$ 53	$ 82

Condensed Statements of Commo_3

Condensed Statements of Common Stockholders' Equity (Unaudited) - MPC - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Paid-In Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Income (Loss)	Mississippi Power	Mississippi Power Common Stock	Mississippi Power Paid-In Capital	Mississippi Power Retained Earnings (Accumulated Deficit)	Mississippi Power Accumulated Other Comprehensive Income (Loss)
Beginning balance (in shares) at Dec. 31, 2022							1
Beginning balance at Dec. 31, 2022	$ 34,532	$ 5,417	$ 13,673	$ 11,538	$ (167)	$ 1,931	$ 38	$ 4,652	$ (2,759)	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						58			58
Other comprehensive income (loss)	(44)				(44)
Cash dividends on common stock	(742)			(742)		(46)			(46)
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)	0
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)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	3,053					173
Ending balance (in shares) at Sep. 30, 2023							1
Ending balance at Sep. 30, 2023	35,304	5,422	13,751	12,391	(130)	1,974	$ 38	4,661	(2,725)	0
Beginning balance (in shares) at Mar. 31, 2023							1
Beginning balance at Mar. 31, 2023	34,562	5,421	13,715	11,658	(211)	1,943	$ 38	4,652	(2,747)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						40			40
Capital contributions from parent company						12		12
Other comprehensive income (loss)	43				43
Cash dividends on common stock	(764)			(764)		(47)			(47)
Ending balance (in shares) at Jun. 30, 2023							1
Ending balance at Jun. 30, 2023	34,648	5,422	13,742	11,732	(168)	1,948	$ 38	4,664	(2,754)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,432					75			75
Return of capital to parent company						(3)		(3)
Other comprehensive income (loss)	38				38
Cash dividends on common stock	(765)			(765)		(46)			(46)
Ending balance (in shares) at Sep. 30, 2023							1
Ending balance at Sep. 30, 2023	35,304	5,422	13,751	12,391	(130)	1,974	$ 38	4,661	(2,725)	0
Beginning balance (in shares) at Dec. 31, 2023							1
Beginning balance at Dec. 31, 2023	35,225	5,423	13,775	12,482	(177)	2,003	$ 38	4,721	(2,756)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						50			50
Capital contributions from parent company						1		1
Other comprehensive income (loss)	37				37	5				5
Cash dividends on common stock	(766)			(766)		(47)			(47)
Ending balance (in shares) at Mar. 31, 2024							1
Ending balance at Mar. 31, 2024	35,614	5,431	13,846	12,844	(140)	2,012	$ 38	4,722	(2,753)	5
Beginning balance (in shares) at Dec. 31, 2023							1
Beginning balance at Dec. 31, 2023	35,225	5,423	13,775	12,482	(177)	2,003	$ 38	4,721	(2,756)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	3,794					186
Ending balance (in shares) at Sep. 30, 2024							1
Ending balance at Sep. 30, 2024	36,905	5,441	14,048	14,005	(139)	2,115	$ 38	4,783	(2,711)	5
Beginning balance (in shares) at Mar. 31, 2024							1
Beginning balance at Mar. 31, 2024	35,614	5,431	13,846	12,844	(140)	2,012	$ 38	4,722	(2,753)	5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						61			61
Capital contributions from parent company						58		58
Other comprehensive income (loss)	10				10
Cash dividends on common stock	(788)			(788)		(47)			(47)
Ending balance (in shares) at Jun. 30, 2024							1
Ending balance at Jun. 30, 2024	36,111	5,436	13,947	13,259	(130)	2,084	$ 38	4,780	(2,739)	5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,535					75			75
Capital contributions from parent company						3		3
Other comprehensive income (loss)	(9)				(9)
Cash dividends on common stock	(789)			(789)		(47)			(47)
Ending balance (in shares) at Sep. 30, 2024							1
Ending balance at Sep. 30, 2024	$ 36,905	$ 5,441	$ 14,048	$ 14,005	$ (139)	$ 2,115	$ 38	$ 4,783	$ (2,711)	$ 5

Condensed Consolidated Statem_9

Condensed Consolidated Statements of Income (Unaudited) - SPC - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Operating Revenues:
Total operating revenues	$ 7,274	$ 6,980	$ 20,383	$ 19,208
Operating Expenses:
Other operations and maintenance	1,662	1,424	4,543	4,352
Depreciation and amortization	1,210	1,143	3,537	3,365
Taxes other than income taxes	375	341	1,155	1,076
Total operating expenses	4,906	4,870	14,373	14,589
Operating Income	2,368	2,110	6,010	4,619
Other Income and (Expense):
Interest expense, net of amounts capitalized	(692)	(620)	(2,050)	(1,812)
Other income (expense), net	147	141	450	428
Total other income and (expense)	(456)	(381)	(1,326)	(1,074)
Earnings Before Income Taxes	1,912	1,729	4,684	3,545
Income taxes	377	297	890	492
Consolidated Net Income	1,535	1,432	3,794	3,053
Net income (loss) attributable to noncontrolling interests	0	10	(73)	(68)
Consolidated net income attributable to company	1,535	1,422	3,867	3,121
Other revenues
Operating Revenues:
Total operating revenues	283	222	820	662
Operating Expenses:
Total cost of sales	166	126	464	381
Fuel
Operating Expenses:
Total cost of sales	1,146	1,367	3,174	3,376
Purchased power
Operating Expenses:
Total cost of sales	249	207	669	680
SOUTHERN POWER CO
Operating Revenues:
Total operating revenues	600	653	1,597	1,686
Operating Expenses:
Other operations and maintenance	126	104	367	327
Depreciation and amortization	133	130	378	380
Taxes other than income taxes	12	13	34	38
Gain on dispositions, net	0	0	0	(20)
Total operating expenses	457	476	1,293	1,338
Operating Income	143	177	304	348
Other Income and (Expense):
Interest expense, net of amounts capitalized	(30)	(32)	(89)	(98)
Other income (expense), net	2	4	8	8
Total other income and (expense)	(28)	(28)	(81)	(90)
Earnings Before Income Taxes	115	149	223	258
Income taxes	33	39	32	38
Consolidated Net Income	82	110	191	220
Net income (loss) attributable to noncontrolling interests	0	10	(73)	(68)
Consolidated net income attributable to company	82	100	264	288
SOUTHERN POWER CO | Wholesale revenues, non-affiliates
Operating Revenues:
Total operating revenues	489	479	1,286	1,234
SOUTHERN POWER CO | Wholesale revenues, affiliates
Operating Revenues:
Total operating revenues	102	156	280	406
SOUTHERN POWER CO | Other revenues
Operating Revenues:
Total operating revenues	9	18	31	46
SOUTHERN POWER CO | Fuel
Operating Expenses:
Total cost of sales	166	196	454	526
SOUTHERN POWER CO | Purchased power
Operating Expenses:
Total cost of sales	$ 20	$ 33	$ 60	$ 87

Condensed Consolidated State_10

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - SPC - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Net income	$ 1,535	$ 1,432	$ 3,794	$ 3,053
Qualifying hedges:
Changes in fair value, net of tax	(2)	2	(5)	(34)
Reclassification adjustment for amounts included in net income, net of tax	(8)	36	39	70
Pension and other postretirement benefit plans:
Benefit plan net gain (loss), net of tax	0	0	3	0
Total other comprehensive income (loss)	(9)	38	38	37
Comprehensive Income	1,526	1,470	3,832	3,090
Comprehensive income (loss) attributable to noncontrolling interests	0	10	(73)	(68)
Consolidated Comprehensive Income Attributable to Company	1,526	1,460	3,905	3,158
SOUTHERN POWER CO
Net income	82	110	191	220
Qualifying hedges:
Changes in fair value, net of tax	10	(13)	(5)	(17)
Reclassification adjustment for amounts included in net income, net of tax	(14)	17	5	24
Pension and other postretirement benefit plans:
Benefit plan net gain (loss), net of tax	0	0	1	0
Total other comprehensive income (loss)	(4)	4	1	7
Comprehensive Income	78	114	192	227
Comprehensive income (loss) attributable to noncontrolling interests	0	10	(73)	(68)
Consolidated Comprehensive Income Attributable to Company	$ 78	$ 104	$ 265	$ 295

Condensed Consolidated State_11

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - SPC (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Changes in fair value, tax	$ (1)	$ 3	$ (2)	$ (11)
Reclassification adjustment for amounts included in net income, tax	(2)	12	14	25
Benefit plan net gain (loss), tax	0	0	1	0
SOUTHERN POWER CO
Changes in fair value, tax	3	(2)	(2)	(3)
Reclassification adjustment for amounts included in net income, tax	(4)	4	2	6
Benefit plan net gain (loss), tax	$ 0	$ 0	$ 0	$ 0

Condensed Consolidated State_12

Condensed Consolidated Statements of Cash Flows (Unaudited) - SPC - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Operating Activities:
Net income	$ 3,794	$ 3,053
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	3,916	3,699
Utilization of federal tax credit carryforward	87	195
Other, net	(100)	(26)
Changes in certain current assets and liabilities —
Receivables	(233)	524
Other current assets	(181)	(32)
Accounts payable	(161)	(1,031)
Accrued taxes	179	376
Accrued compensation	(90)	(197)
Other current liabilities	(27)	66
Net cash provided from operating activities	7,615	5,740
Investing Activities:
Property additions	(6,206)	(6,561)
Other investing activities	(279)	(139)
Net cash used for investing activities	(6,678)	(6,721)
Financing Activities:
Increase (decrease) in notes payable, net	(1,264)	(298)
Distributions to noncontrolling interests	(108)	(148)
Payment of common stock dividends	(2,220)	(2,271)
Other financing activities	(157)	(120)
Net cash provided from (used for) financing activities	(803)	834
Net Change in Cash, Cash Equivalents, and Restricted Cash	134	(147)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	921	2,037
Cash, Cash Equivalents, and Restricted Cash at End of Period	1,055	1,890
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	2,015	1,694
Income taxes, net	131	11
Noncash transactions —
Accrued property additions at end of period	937	1,224
Right-of-use assets obtained under operating leases	126	76
Reassessment of right-of-use assets under operating leases	(7)	0
SOUTHERN POWER CO
Operating Activities:
Net income	191	220
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	388	395
Utilization of federal tax credit carryforward	63	179
Amortization of ITCs	(44)	(44)
Gain on dispositions, net	0	(20)
Other, net	18	5
Changes in certain current assets and liabilities —
Receivables	(24)	100
Prepaid income taxes	0	31
Other current assets	(9)	(14)
Accounts payable	(19)	(70)
Accrued taxes	56	9
Accrued compensation	(4)	(7)
Other current liabilities	(9)	15
Net cash provided from operating activities	607	799
Investing Activities:
Acquisitions, net of cash acquired	0	(181)
Property additions	(179)	(40)
Proceeds from dispositions	0	59
Change in construction payables	1	(18)
Payments pursuant to LTSAs	(34)	(49)
Other investing activities	13	5
Net cash used for investing activities	(199)	(224)
Financing Activities:
Increase (decrease) in notes payable, net	(68)
Increase (decrease) in notes payable, net		136
Redemptions — Senior notes	0	(290)
Capital contributions from parent company	8	16
Capital contributions from noncontrolling interests	11	21
Distributions to noncontrolling interests	(108)	(148)
Payment of common stock dividends	(196)	(189)
Other financing activities	(4)	3
Net cash provided from (used for) financing activities	(357)	(451)
Net Change in Cash, Cash Equivalents, and Restricted Cash	51	124
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	144	133
Cash, Cash Equivalents, and Restricted Cash at End of Period	195	257
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	88	103
Income taxes, net	(30)	(124)
Noncash transactions —
Accrued property additions at end of period	52	23
Right-of-use assets obtained under operating leases	10	7
Reassessment of right-of-use assets under operating leases	$ (7)	$ 0

Condensed Consolidated State_13

Condensed Consolidated Statements of Cash Flows (Unaudited) - SPC (Parenthetical) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Net cash paid for capitalized interest	$ 76	$ 97
SOUTHERN POWER CO
Net cash paid for capitalized interest	$ 5	$ 1

Condensed Consolidated Balanc_3

Condensed Consolidated Balance Sheets (Unaudited) - SPC - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Current Assets:
Cash and cash equivalents	$ 1,018	$ 748
Receivables —
Customer accounts, net and Affiliated	2,327	2,030
Other	909	519
Materials and supplies	2,169	1,989
Other current assets	562	569
Total current assets	11,040	10,432
Property, Plant, and Equipment:
In service	134,889	128,428
Less: Accumulated depreciation	39,536	37,725
Plant in service, net of depreciation	95,353	90,703
Construction work in progress	6,232	7,784
Total property, plant, and equipment	102,897	99,844
Other Property and Investments:
Total other property and investments	10,223	9,986
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	1,415	1,432
Other deferred charges and assets	1,484	1,468
Total deferred charges and other assets	19,796	19,069
Total Assets	143,956	139,331
Current Liabilities:
Notes payable	722	2,314
Accounts payable —
Accrued interest	570	652
Operating lease obligations	197	183
Other current liabilities	1,104	1,029
Total current liabilities	12,165	13,467
Long-term Debt	61,254	57,210
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	11,727	10,990
Accumulated deferred ITCs	2,003	2,067
Operating lease obligations, deferred	1,267	1,307
Other deferred credits and liabilities	1,075	1,031
Total deferred credits and other liabilities	33,632	33,429
Total Liabilities	107,051	104,106
Total Stockholders' Equity (See accompanying statements)	36,905	35,225
Total Liabilities and Stockholders' Equity	143,956	139,331
SOUTHERN POWER CO
Current Assets:
Cash and cash equivalents	179	124
Receivables —
Other	39	54
Materials and supplies	96	80
Other current assets	86	92
Total current assets	607	523
Property, Plant, and Equipment:
In service	14,946	14,690
Less: Accumulated depreciation	4,444	4,119
Plant in service, net of depreciation	10,502	10,571
Construction work in progress	187	278
Total property, plant, and equipment	10,689	10,849
Other Property and Investments:
Intangible assets, net of amortization	228	243
Net investment in sales-type leases	144	148
Total other property and investments	372	391
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	486	488
Prepaid LTSAs	247	248
Other deferred charges and assets	245	262
Total deferred charges and other assets	978	998
Total Assets	12,646	12,761
Current Liabilities:
Notes payable	62	138
Accounts payable —
Accrued taxes	45	26
Accrued interest	22	27
Operating lease obligations	28	29
Other current liabilities	90	97
Total current liabilities	390	490
Long-term Debt	2,720	2,711
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	719	614
Accumulated deferred ITCs	1,454	1,498
Operating lease obligations, deferred	510	517
Other deferred credits and liabilities	251	233
Total deferred credits and other liabilities	2,934	2,862
Total Liabilities	6,044	6,063
Total Stockholders' Equity (See accompanying statements)	6,602	6,698
Total Liabilities and Stockholders' Equity	12,646	12,761
SOUTHERN POWER CO | Nonrelated Party
Receivables —
Customer accounts, net and Affiliated	164	136
Accounts payable —
Affiliated and Other	73	91
SOUTHERN POWER CO | Related Party
Receivables —
Customer accounts, net and Affiliated	43	37
Accounts payable —
Affiliated and Other	$ 70	$ 82

Condensed Consolidated Balanc_4

Condensed Consolidated Balance Sheets (Unaudited) - SPC (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Other intangible assets, amortization	$ 403	$ 376
SOUTHERN POWER CO
Other intangible assets, amortization	$ 163	$ 148

Condensed Consolidated State_14

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - SPC - USD ($) $ in Millions	Total	Paid-In Capital	Retained Earnings	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	SOUTHERN POWER CO Accumulated Other Comprehensive Income (Loss)	SOUTHERN POWER CO Noncontrolling Interests
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 (loss)						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)
Other	0	2
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
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 (loss)	3,053					220
Ending balance at Sep. 30, 2023	35,304	13,751	12,391	(130)	3,927	6,843	2,916	1,087	1,839	(10)	3,927
Beginning 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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)						70	85		85		(15)
Capital contributions from parent company						14	14	14
Other comprehensive income (loss)	43			43		10	10			10
Cash dividends on common stock	(764)		(764)			(63)	(63)		(63)
Distributions to noncontrolling interests	(42)				(42)	(42)					(42)
Other	0	2			(1)	0	1			1	(1)
Ending balance at Jun. 30, 2023	34,648	13,742	11,732	(168)	3,976	6,847	2,871	1,083	1,802	(14)	3,976
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	1,432					110	100		100		10
Capital contributions from parent company						3	3	3
Other comprehensive income (loss)	38			38		4	4			4
Cash dividends on common stock	(765)		(765)			(63)	(63)		(63)
Distributions to noncontrolling interests	(59)				(59)	(59)					(59)
Other	(1)	(2)	2	0		1	1	1
Ending balance at Sep. 30, 2023	35,304	13,751	12,391	(130)	3,927	6,843	2,916	1,087	1,839	(10)	3,927
Beginning balance at Dec. 31, 2023	35,225	13,775	12,482	(177)	3,781	6,698	2,917	1,088	1,846	(17)	3,781
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)						38	96		96		(58)
Other comprehensive income (loss)	37			37		2	2			2
Cash dividends on common stock	(766)		(766)			(65)	(65)		(65)
Capital contributions from noncontrolling interests	9				9	9					9
Distributions to noncontrolling interests	(38)				(38)	(38)					(38)
Other	7	10	(1)			(1)	(1)		(1)
Ending balance at Mar. 31, 2024	35,614	13,846	12,844	(140)	3,694	6,643	2,949	1,088	1,876	(15)	3,694
Beginning balance at Dec. 31, 2023	35,225	13,775	12,482	(177)	3,781	6,698	2,917	1,088	1,846	(17)	3,781
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	3,794					191
Ending balance at Sep. 30, 2024	36,905	14,048	14,005	(139)	3,607	6,602	2,995	1,098	1,913	(16)	3,607
Beginning balance at Mar. 31, 2024	35,614	13,846	12,844	(140)	3,694	6,643	2,949	1,088	1,876	(15)	3,694
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)						71	86		86		(15)
Capital contributions from parent company						8	8	8
Other comprehensive income (loss)	10			10		3	3			3
Cash dividends on common stock	(788)		(788)			(66)	(66)		(66)
Capital contributions from noncontrolling interests	2				2	2					2
Distributions to noncontrolling interests	(19)				(19)	(19)					(19)
Other	1	3	0	0	0	1	1	1
Ending balance at Jun. 30, 2024	36,111	13,947	13,259	(130)	3,662	6,643	2,981	1,097	1,896	(12)	3,662
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	1,535					82	82		82		0
Capital contributions from parent company						1	1	1
Other comprehensive income (loss)	(9)			(9)		(4)	(4)			(4)
Cash dividends on common stock	(789)		(789)			(65)	(65)		(65)
Distributions to noncontrolling interests	(55)				(55)	(55)					(55)
Other	4	(2)	0	0	0
Ending balance at Sep. 30, 2024	$ 36,905	$ 14,048	$ 14,005	$ (139)	$ 3,607	$ 6,602	$ 2,995	$ 1,098	$ 1,913	$ (16)	$ 3,607

Condensed Consolidated State_15

Condensed Consolidated Statements of Income (Unaudited) - GAS - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Operating Revenues:
Total operating revenues	$ 7,274	$ 6,980	$ 20,383	$ 19,208
Operating Expenses:
Other operations and maintenance	1,662	1,424	4,543	4,352
Depreciation and amortization	1,210	1,143	3,537	3,365
Taxes other than income taxes	375	341	1,155	1,076
Total operating expenses	4,906	4,870	14,373	14,589
Operating Income	2,368	2,110	6,010	4,619
Other Income and (Expense):
Earnings from equity method investments	31	32	107	110
Interest expense, net of amounts capitalized	(692)	(620)	(2,050)	(1,812)
Other income (expense), net	147	141	450	428
Total other income and (expense)	(456)	(381)	(1,326)	(1,074)
Earnings Before Income Taxes	1,912	1,729	4,684	3,545
Income taxes	377	297	890	492
Consolidated Net Income	1,535	1,432	3,794	3,053
SOUTHERN Co GAS
Operating Revenues:
Total operating revenues	$ 682	$ 689	$ 3,220	$ 3,417
Revenue, Product and Service [Extensible Enumeration]	Natural gas	Natural gas	Natural gas	Natural gas
Operating Expenses:
Cost, Product and Service [Extensible Enumeration]	Natural gas	Natural gas	Natural gas	Natural gas
Total cost of sales	$ 98	$ 102	$ 852	$ 1,199
Other operations and maintenance	295	264	877	879
Depreciation and amortization	162	145	475	429
Taxes other than income taxes	44	42	186	203
Total operating expenses	599	553	2,390	2,710
Operating Income	83	136	830	707
Other Income and (Expense):
Earnings from equity method investments	34	32	110	104
Interest expense, net of amounts capitalized	(84)	(77)	(250)	(226)
Other income (expense), net	16	19	49	50
Total other income and (expense)	(34)	(26)	(91)	(72)
Earnings Before Income Taxes	49	110	739	635
Income taxes	11	28	184	160
Consolidated Net Income	$ 38	$ 82	$ 555	$ 475

Condensed Consolidated State_16

Condensed Consolidated Statements of Income (Unaudited) - GAS (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
SOUTHERN Co GAS
Revenue taxes collected	$ 11	$ 11	$ 87	$ 103

Condensed Consolidated State_17

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - GAS - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Net income	$ 1,535	$ 1,432	$ 3,794	$ 3,053
Qualifying hedges:
Changes in fair value, net of tax	(2)	2	(5)	(34)
Reclassification adjustment for amounts included in net income, net of tax	(8)	36	39	70
Total other comprehensive income (loss)	(9)	38	38	37
Comprehensive Income	1,526	1,470	3,832	3,090
SOUTHERN Co GAS
Net income	38	82	555	475
Qualifying hedges:
Changes in fair value, net of tax	(7)	(6)	(10)	(30)
Reclassification adjustment for amounts included in net income, net of tax	3	16	25	37
Total other comprehensive income (loss)	(4)	10	15	7
Comprehensive Income	$ 34	$ 92	$ 570	$ 482

Condensed Consolidated State_18

Condensed Consolidated Statements of Comprehensive Income (Unaudited) - GAS (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Changes in fair value, tax	$ (1)	$ 3	$ (2)	$ (11)
Qualifying hedges, reclassification adjustment, tax	(2)	12	14	25
SOUTHERN Co GAS
Changes in fair value, tax	(3)	(2)	(4)	(11)
Qualifying hedges, reclassification adjustment, tax	$ 1	$ 7	$ 10	$ 15

Condensed Consolidated State_19

Condensed Consolidated Statements of Cash Flows (Unaudited) - GAS - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Operating Activities:
Net income	$ 3,794	$ 3,053
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	3,916	3,699
Deferred income taxes	520	(52)
Other, net	(100)	(26)
Changes in certain current assets and liabilities —
Receivables	(233)	524
Natural gas cost under recovery	0	108
Other current assets	(181)	(32)
Accounts payable	(161)	(1,031)
Other current liabilities	(27)	66
Net cash provided from operating activities	7,615	5,740
Investing Activities:
Property additions	(6,206)	(6,561)
Cost of removal, net of salvage	(444)	(421)
Change in construction payables, net	(119)	241
Other investing activities	(279)	(139)
Net cash used for investing activities	(6,678)	(6,721)
Financing Activities:
Decrease in notes payable, net	(1,264)	(298)
Proceeds —
Redemptions — Short-term borrowings	(1,020)	(850)
Payment of common stock dividends	(2,220)	(2,271)
Other financing activities	(157)	(120)
Net cash provided from (used for) financing activities	(803)	834
Net Change in Cash, Cash Equivalents, and Restricted Cash	134	(147)
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	921	2,037
Cash, Cash Equivalents, and Restricted Cash at End of Period	1,055	1,890
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	2,015	1,694
Income taxes, net	131	11
Noncash transactions —
Accrued property additions at end of period	937	1,224
Right-of-use assets obtained under operating leases	126	76
SOUTHERN Co GAS
Operating Activities:
Net income	555	475
Adjustments to reconcile net income to net cash provided from operating activities —
Depreciation and amortization, total	466	429
Deferred income taxes	206	75
Other, net	7	(15)
Changes in certain current assets and liabilities —
Receivables	386	776
Natural gas for sale, net of temporary LIFO liquidation	3	31
Natural gas cost under recovery	0	108
Other current assets	(57)	(20)
Accounts payable	(105)	(346)
Natural gas cost over recovery	12	165
Other current liabilities	(66)	(34)
Net cash provided from operating activities	1,407	1,644
Investing Activities:
Property additions	(1,064)	(1,151)
Cost of removal, net of salvage	(63)	(82)
Change in construction payables, net	(13)	(38)
Other investing activities	(56)	45
Net cash used for investing activities	(1,196)	(1,226)
Financing Activities:
Decrease in notes payable, net	(352)	(493)
Proceeds —
Senior notes	450	500
First mortgage bonds	156	125
Other long-term debt	9	29
Redemptions — Short-term borrowings	0	(200)
Capital contributions from parent company	0	377
Payment of common stock dividends	(454)	(439)
Other financing activities	(10)	(1)
Net cash provided from (used for) financing activities	(201)	(102)
Net Change in Cash, Cash Equivalents, and Restricted Cash	10	316
Cash, Cash Equivalents, and Restricted Cash at Beginning of Period	35	83
Cash, Cash Equivalents, and Restricted Cash at End of Period	45	399
Supplemental Cash Flow Information:
Interest, net of amounts capitalized	258	214
Income taxes, net	(54)	70
Noncash transactions —
Accrued property additions at end of period	126	139
Right-of-use assets obtained under operating leases	$ 1	$ 3

Condensed Consolidated State_20

Condensed Consolidated Statements of Cash Flows (Unaudited) - GAS (Parenthetical) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Net cash paid for capitalized interest	$ 76	$ 97
SOUTHERN Co GAS
Net cash paid for capitalized interest	$ 16	$ 12

Condensed Consolidated Balanc_5

Condensed Consolidated Balance Sheets (Unaudited) - GAS - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Current Assets:
Cash and cash equivalents	$ 1,018	$ 748
Receivables —
Customer accounts	2,327	2,030
Unbilled revenues	556	786
Other accounts and notes	909	519
Accumulated provision for uncollectible accounts	(64)	(68)
Materials and supplies	2,169	1,989
Natural gas for sale	417	420
Prepaid expenses	391	406
Other regulatory assets	877	1,120
Other current assets	562	569
Total current assets	11,040	10,432
Property, Plant, and Equipment:
In service	134,889	128,428
Less: Accumulated depreciation	39,536	37,725
Plant in service, net of depreciation	95,353	90,703
Construction work in progress	6,232	7,784
Total property, plant, and equipment	102,897	99,844
Other Property and Investments:
Goodwill	5,161	5,161
Equity investments in unconsolidated subsidiaries	1,414	1,368
Other intangible assets, net of amortization	341	368
Miscellaneous property and investments	657	665
Total other property and investments	10,223	9,986
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	1,415	1,432
Prepaid pension costs	2,375	2,079
Other regulatory assets, deferred	7,531	6,264
Other deferred charges and assets	1,484	1,468
Total deferred charges and other assets	19,796	19,069
Total Assets	143,956	139,331
Current Liabilities:
Securities due within one year	1,642	2,476
Notes payable	722	2,314
Accounts payable —
Customer deposits	491	503
Accrued interest	570	652
Accrued compensation	1,065	1,151
Natural gas cost over recovery	226	214
Other regulatory liabilities	214	141
Other current liabilities	1,104	1,029
Total current liabilities	12,165	13,467
Long-term Debt	61,254	57,210
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	11,727	10,990
Deferred credits related to income taxes	4,587	4,674
Employee benefit obligations	1,064	1,115
Operating lease obligations, deferred	1,267	1,307
Other cost of removal obligations	2,006	1,957
Other deferred credits and liabilities	1,075	1,031
Total deferred credits and other liabilities	33,632	33,429
Total Liabilities	107,051	104,106
Total Stockholders' Equity	36,905	35,225
Total Liabilities and Stockholders' Equity	143,956	139,331
SOUTHERN Co GAS
Current Assets:
Cash and cash equivalents	44	33
Receivables —
Customer accounts	215	405
Unbilled revenues	63	261
Other accounts and notes	54	47
Accumulated provision for uncollectible accounts	(31)	(44)
Materials and supplies	68	66
Natural gas for sale	417	420
Prepaid expenses	74	107
Other regulatory assets	220	141
Other current assets	43	50
Total current assets	1,167	1,486
Property, Plant, and Equipment:
In service	21,753	20,840
Less: Accumulated depreciation	5,790	5,534
Plant in service, net of depreciation	15,963	15,306
Construction work in progress	1,194	1,110
Total property, plant, and equipment	17,157	16,416
Other Property and Investments:
Goodwill	5,015	5,015
Equity investments in unconsolidated subsidiaries	1,279	1,235
Other intangible assets, net of amortization	11	16
Miscellaneous property and investments	25	25
Total other property and investments	6,330	6,291
Deferred Charges and Other Assets:
Operating lease right-of-use assets, net of amortization	41	47
Prepaid pension costs	175	158
Other regulatory assets, deferred	486	504
Other deferred charges and assets	189	181
Total deferred charges and other assets	891	890
Total Assets	25,545	25,083
Current Liabilities:
Securities due within one year	50	0
Notes payable	63	415
Accounts payable —
Customer deposits	105	126
Accrued taxes	68	77
Accrued interest	72	77
Accrued compensation	106	112
Natural gas cost over recovery	226	214
Other regulatory liabilities	6	19
Other current liabilities	136	155
Total current liabilities	1,247	1,708
Long-term Debt	8,387	7,833
Deferred Credits and Other Liabilities:
Accumulated deferred income taxes	1,861	1,671
Deferred credits related to income taxes	764	759
Employee benefit obligations	106	110
Operating lease obligations, deferred	33	40
Other cost of removal obligations	1,833	1,771
Accrued environmental remediation	204	192
Other deferred credits and liabilities	182	196
Total deferred credits and other liabilities	4,983	4,739
Total Liabilities	14,617	14,280
Total Stockholders' Equity	10,928	10,803
Total Liabilities and Stockholders' Equity	25,545	25,083
SOUTHERN Co GAS | Related Party
Accounts payable —
Affiliated and Other	48	89
SOUTHERN Co GAS | Nonrelated Party
Accounts payable —
Affiliated and Other	$ 367	$ 424

Condensed Consolidated Balanc_6

Condensed Consolidated Balance Sheets (Unaudited) - GAS (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Other intangible assets, amortization	$ 403	$ 376
SOUTHERN Co GAS
Other intangible assets, amortization	$ 171	$ 166

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, 2022	$ 34,532	$ 13,673	$ 11,538	$ (167)	$ 10,397	$ 10,445	$ (79)	$ 31
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income					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
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	3,053				475
Ending balance at Sep. 30, 2023	35,304	13,751	12,391	(130)	10,833	10,838	(43)	38
Beginning balance at Mar. 31, 2023	34,562	13,715	11,658	(211)	10,753	10,649	83	21
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income					85		85
Capital contributions from parent company					40	40
Other comprehensive income (loss)	43			43	7			7
Cash dividends on common stock	(764)		(764)		(147)		(147)
Other	0	2
Ending balance at Jun. 30, 2023	34,648	13,742	11,732	(168)	10,738	10,689	21	28
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,432				82		82
Capital contributions from parent company					149	149
Other comprehensive income (loss)	38			38	10			10
Cash dividends on common stock	(765)		(765)		(146)		(146)
Other	(1)	(2)	2	0
Ending balance at Sep. 30, 2023	35,304	13,751	12,391	(130)	10,833	10,838	(43)	38
Beginning balance at Dec. 31, 2023	35,225	13,775	12,482	(177)	10,803	10,836	(49)	16
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income					409		409
Capital contributions from parent company					2	2
Other comprehensive income (loss)	37			37	12			12
Cash dividends on common stock	(766)		(766)		(151)		(151)
Other	7	10	(1)		(1)		(1)
Ending balance at Mar. 31, 2024	35,614	13,846	12,844	(140)	11,074	10,838	208	28
Beginning balance at Dec. 31, 2023	35,225	13,775	12,482	(177)	10,803	10,836	(49)	16
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	3,794				555
Ending balance at Sep. 30, 2024	36,905	14,048	14,005	(139)	10,928	10,845	52	31
Beginning balance at Mar. 31, 2024	35,614	13,846	12,844	(140)	11,074	10,838	208	28
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income					108		108
Capital contributions from parent company					6	6
Other comprehensive income (loss)	10			10	7			7
Cash dividends on common stock	(788)		(788)		(151)		(151)
Other	1	3	0	0
Ending balance at Jun. 30, 2024	36,111	13,947	13,259	(130)	11,044	10,844	165	35
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,535				38		38
Capital contributions from parent company					1	1
Other comprehensive income (loss)	(9)			(9)	(4)			(4)
Cash dividends on common stock	(789)		(789)		(152)		(152)
Other	4	(2)	0	0	1		1	0
Ending balance at Sep. 30, 2024	$ 36,905	$ 14,048	$ 14,005	$ (139)	$ 10,928	$ 10,845	$ 52	$ 31

Introduction

Introduction	9 Months Ended
	Sep. 30, 2024
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, 2023 have been derived from the audited financial statements of each Registrant. In the opinion of each Registrant's management, the information regarding such Registrant furnished herein reflects all adjustments, which, except as otherwise disclosed, are of a normal recurring nature, necessary to present fairly the results of operations for the periods ended September 30, 2024 and 2023. Certain information and 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. Impairment of Long-Lived Assets See Note 1 to the financial statements under "Impairment of Long-Lived Assets" in Item 8 of the Form 10-K for additional information. In the third quarter 2024, Alabama Power discontinued the development of a multi-use commercial facility. Given the decision to discontinue commercial development, Alabama Power performed an impairment test using a comparative market analysis and determined the carrying amount of the asset exceeded its fair value, net of selling costs. This resulted in a pre-tax impairment loss of $36 million ($27 million after tax) reflected in other operations and maintenance on the statements of income. Goodwill and Other Intangible Assets Goodwill at both September 30, 2024 and December 31, 2023 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 goodwill impairment indicators exist. Other intangible assets were as follows: At September 30, 2024 At December 31, 2023 Gross Carrying Amount Accumulated Amortization Other Gross Carrying Amount Accumulated Amortization Other (in millions) (in millions) Southern Company Subject to amortization: Customer relationships $ 212 $ (179) $ 33 $ 212 $ (172) $ 40 Trade names 64 (58) 6 64 (53) 11 PPA fair value adjustments 390 (163) 227 390 (148) 242 Other 3 (3) — 3 (3) — Total subject to amortization $ 669 $ (403) $ 266 $ 669 $ (376) $ 293 Not subject to amortization: FCC licenses 75 — 75 75 — 75 Total other intangible assets $ 744 $ (403) $ 341 $ 744 $ (376) $ 368 Southern Power (*) PPA fair value adjustments $ 390 $ (163) $ 227 $ 390 $ (148) $ 242 Southern Company Gas (*) Gas marketing services Customer relationships $ 156 $ (149) $ 7 $ 156 $ (145) $ 11 Trade names 26 (22) 4 26 (21) 5 Total other intangible assets $ 182 $ (171) $ 11 $ 182 $ (166) $ 16 (*) All subject to amortization. Amortization associated with other intangible assets was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 (in millions) Southern Company (a) $ 9 $ 10 $ 27 $ 27 Southern Power (b) 5 5 15 14 Southern Company Gas 2 3 5 7 (a) Includes $5 million for the three months ended September 30, 2024 and 2023 and $15 million and $14 million for the nine months ended September 30, 2024 and 2023, respectively, recorded as a reduction to operating revenues. (b) Recorded as a reduction to operating revenues. Cash, Cash Equivalents, and Restricted Cash The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the condensed balance sheets that total to the amount shown in the condensed statements of cash flows for the applicable Registrants: Southern Company Alabama Power Georgia Power Southern Power Southern (in millions) At September 30, 2024 Cash and cash equivalents $ 1,018 $ 476 $ 43 $ 179 $ 44 Restricted cash (a) : Other current assets 31 — 14 16 1 Other deferred charges and assets 7 — 7 — — Total cash, cash equivalents, and restricted cash (b) $ 1,055 $ 476 $ 64 $ 195 $ 45 At December 31, 2023 Cash and cash equivalents $ 748 $ 324 $ 9 $ 124 $ 33 Restricted cash (a) : Other current assets 141 85 37 17 2 Other deferred charges and assets 31 — 29 3 — Total cash, cash equivalents, and restricted cash (b) $ 921 $ 409 $ 75 $ 144 $ 35 (a) For Alabama Power and Georgia Power, reflects proceeds from the issuance of solid waste disposal facility revenue bonds in 2023 and 2022, respectively. For Southern Power, reflects $16 million and $17 million at September 30, 2024 and December 31, 2023, respectively, resulting from an arbitration award held to fund future replacement costs and $3 million at December 31, 2023 held to fund estimated construction completion costs at the Deuel Harvest wind facility. See Note (C) under "General Litigation Matters – Southern Power" for additional information related to the arbitration award. 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 September 30, 2024 is expected to be restored prior to year-end. Storm Damage Reserves See Note 1 to the financial statements under "Storm Damage and Reliability Reserves" in Item 8 of the Form 10-K for additional information. Storm damage reserve activity for the traditional electric operating companies during the nine months ended September 30, 2024 was as follows: Southern Company (*) Alabama Power Georgia Power (*) Mississippi (in millions) Balance at December 31, 2023 $ 66 $ 76 $ (54) $ 44 Accrual 45 10 24 11 Weather-related damages (1,239) (33) (1,201) (5) Balance at September 30, 2024 $ (1,128) $ 53 $ (1,231) $ 50 (*) See Note (B) under "Georgia Power – Storm Damage Recovery" for additional information. Depreciation and Amortization See Note 5 to the financial statements under "Depreciation and Amortization" in Item 8 of the Form 10-K for additional information. On October 25, 2024, Mississippi Power filed an updated depreciation study with the Mississippi PSC requesting an $11 million increase in total annual depreciation. The ultimate outcome of this matter cannot be determined at this time. Asset Retirement Obligations See Note 6 to the financial statements in Item 8 of the Form 10-K for additional information. Following initial criticality for Plant Vogtle Unit 4 on February 14, 2024, Georgia Power recorded AROs of approximately $118 million. See Note (B) under "Georgia Power – Nuclear Construction" for additional information on Plant Vogtle Units 3 and 4. In September 2024, Georgia Power completed updated decommissioning cost site studies for Plants Hatch and Vogtle Units 1 through 4. The estimated cost of decommissioning based on the studies resulted in a decrease in Georgia Power's ARO liability of $389 million. See "Nuclear Decommissioning" herein for additional information. Nuclear Decommissioning See Note 6 to the financial statements in Item 8 of the Form 10-K under "Nuclear Decommissioning" for additional information. Site study cost is the estimate to decommission a specific facility as of the site study year. The decommissioning cost estimates are based on removal of the plant from service and prompt dismantlement. The actual decommissioning costs may vary from these estimates because of changes in the assumed date of decommissioning, changes in NRC requirements, or changes in the assumptions used in making these estimates. The estimated costs of decommissioning Plant Hatch and Plant Vogtle based on Georgia Power's September 2024 site studies are as follows: Plant Hatch (*) Plant Vogtle Units 1 and 2 (*) Plant Vogtle Unit 3 and 4 (*) Decommissioning periods: Beginning year 2034 2047 2062 Completion year 2088 2092 2074 (in millions) Site study costs: Radiated structures $ 696 $ 545 $ 542 Spent fuel management 306 255 88 Non-radiated structures 77 107 89 Total site study costs $ 1,079 $ 907 $ 719 (*) Based on Georgia Power's ownership interests. For ratemaking purposes, Georgia Power's decommissioning costs are based on the NRC generic estimate to decommission the radioactive portion of the facilities and the site study estimate for spent fuel management. Significant assumptions used to determine these costs for ratemaking were an estimated inflation rate of 2.5% for Plants Hatch and Vogtle Units 1 and 2 and 2.3% for Plant Vogtle Units 3 and 4 and an estimated trust earnings rate of 4.5% for Plants Hatch and Vogtle Units 1 and 2 and 4.3% for Plant Vogtle Units 3 and 4. Effective May 1, 2024, as approved under the Prudency Stipulation, Georgia Power's annual decommissioning cost for ratemaking is $8 million for Plant Vogtle Unit 4.

Regulatory Matters

Regulatory Matters	9 Months Ended
	Sep. 30, 2024
Regulated Operations [Abstract]
Regulatory Matters	REGULATORY MATTERS See Note 2 to the financial statements in Item 8 of the Form 10-K for additional information relating to regulatory matters. The recovery balances for certain retail regulatory clauses of the traditional electric operating companies and Southern Company Gas at September 30, 2024 and December 31, 2023 were as follows: Regulatory Clause Balance Sheet Line Item September 30, December 31, 2023 (in millions) Alabama Power Rate CNP Compliance Other regulatory assets, current $ — $ 8 Other regulatory assets, deferred — 25 Other regulatory liabilities, current 4 — Other regulatory liabilities, deferred 2 — Rate CNP PPA Other regulatory assets, current 18 18 Other regulatory assets, deferred 70 85 Rate ECR Regulatory assets – under recovered retail fuel clause revenues 10 246 Georgia Power Fuel Cost Recovery Receivables – under recovered retail fuel clause revenues $ 683 $ 694 Deferred under recovered retail fuel clause revenues 632 1,211 Mississippi Power Fuel Cost Recovery (*) Receivables – customer accounts, net $ 6 $ — Deferred under recovered retail fuel clause revenues — 50 Over recovered retail fuel clause revenues — 27 Ad Valorem Tax Other regulatory assets, deferred 14 12 Southern Company Gas Natural Gas Cost Recovery Natural gas cost over recovery $ 226 $ 214 (*) Mississippi Power also has wholesale MRA and Market Based (MB) fuel cost recovery factors. At September 30, 2024 and December 31, 2023, wholesale MRA fuel costs were over recovered $16 million and $5 million, respectively, and were included in other current liabilities on Mississippi Power's balance sheets. The wholesale MB fuel cost recovery was immaterial for both periods presented. Alabama Power Rate ECR On May 8, 2024, the Alabama PSC issued a consent order to lower Rate ECR from 3.270 cents per KWH to 3.015 cents per KWH, or approximately $135 million annually, effective with July 2024 billings. The approved decrease in the Rate ECR factor will have no significant effect on Alabama Power's net income but will decrease operating cash flows. The rate will adjust to 5.910 cents per KWH in January 2026 absent a further order from the Alabama PSC. Reliability Reserve Accounting Order On September 18, 2024, Alabama Power notified the Alabama PSC of its intent to use a portion of its $143 million reliability reserve balance during 2024. The ultimate outcome of this matter cannot be determined at this time. Petition for Certificate of Convenience and Necessity On October 24, 2024, Alabama Power entered into an agreement to acquire all of the equity interests in Tenaska Alabama Partners, L.P. for a total purchase price of approximately $622 million, subject to working capital adjustments. Tenaska Alabama Partners, L.P. owns and operates Lindsay Hill Generating Station, an approximately 855-MW combined cycle generation facility in Autauga County, Alabama. On October 30, 2024, Alabama Power filed a petition for a CCN with the Alabama PSC for authorization to procure additional generating capacity through the acquisition of the Lindsay Hill Generating Station. As part of the acquisition, Alabama Power will assume an existing power sales agreement under which the full output of the generating facility remains committed to a third party through April 2027. Upon expiration of the power sales agreement, Alabama Power expects to recover costs associated with the Lindsay Hill Generating Station acquisition through Rate CNP New Plant, Rate CNP Compliance, Rate ECR, and Rate RSE. The completion of the acquisition is subject to the satisfaction or waiver of certain conditions, including, among other customary conditions, approval by the Alabama PSC and the FERC, as well as the expiration or termination of the waiting period under the Hart-Scott-Rodino Antitrust Improvements Act. Alabama Power expects to complete the acquisition by the end of the third quarter 2025. The ultimate outcome of this matter cannot be determined at this time. Plant Greene County Alabama Power jointly owns Plant Greene County Units 1 and 2 with an affiliate, Mississippi Power. See Note 5 to the financial statements under "Joint Ownership Agreements" in Item 8 of the Form 10-K for additional information. Mississippi Power's 2024 IRP includes a schedule to retire Mississippi Power's 40% ownership interest in Plant Greene County Units 1 and 2 by the end of 2028. Alabama Power currently expects to retire Plant Greene County Units 1 and 2 (300 MWs based on 60% ownership) by the end of 2028. Alabama Power and Mississippi Power continue to evaluate operating conditions and business needs relevant to the anticipated retirement of Plant Greene County Units 1 and 2. The ultimate outcome of this matter cannot be determined at this time. See "Mississippi Power – Integrated Resource Plan" herein for additional information. Georgia Power Rate Plans In accordance with the terms of the 2022 ARP, on October 1, 2024, Georgia Power filed the following tariff adjustments to become effective January 1, 2025 pending approval by the Georgia PSC: • increase traditional base tariffs by approximately $194 million, which is net of $122 million related to the Georgia state tax rate reduction; • increase the Environmental Compliance Cost Recovery tariff by approximately $126 million; • decrease the Demand-Side Management tariffs by approximately $22 million; and • increase the Municipal Franchise Fee tariffs by approximately $9 million. The ultimate outcome of this matter cannot be determined at this time. Integrated Resource Plans On June 27, 2024, the FERC approved five affiliate PPAs with Southern Power with capacities of 1,258 MWs beginning in 2024, 380 MWs beginning in 2025, and 228 MWs beginning in 2028, procured through requests for proposals authorized in the 2019 IRP. See Note (F) under "Georgia Power Lease Modification" for additional information. On April 16, 2024, the Georgia PSC approved Georgia Power's updated IRP (2023 IRP Update) as modified by a stipulation among Georgia Power, the staff of the Georgia PSC, and certain intervenors. In the 2023 IRP Update decision, the Georgia PSC approved the following requests: • Authority to develop, own, and operate up to 1,400 MWs from three simple cycle combustion turbines at Plant Yates with the recoverable costs not to exceed the certified amount, which was approved by the Georgia PSC on August 20, 2024. In doing so, the Georgia PSC recognized the potential for circumstances beyond Georgia Power's control that could cause the project costs to exceed the certified amount, in which case Georgia Power would provide documentation to the Georgia PSC to explain and justify potential recovery of the additional costs. Georgia Power is required to file semi-annual construction monitoring reports with the Georgia PSC through commercial operation. • Certification of an affiliate PPA with Mississippi Power for 750 MWs, which began January 1, 2024 and will continue through December 2028. • Certification of a non-affiliate PPA for 230 MWs, which began May 1, 2024 and will continue through December 2028. • Authority to develop, own, and operate up to 500 MWs of battery energy storage facilities, including storage systems collocated with existing Georgia Power-owned solar facilities, on which the Georgia PSC is expected to render a decision establishing certified amounts in the fourth quarter 2024, as well as the issuance of a request for proposals for an additional 500 MWs of battery energy storage facilities. • Approval of transmission projects necessary to support the generation resources approved in the 2023 IRP Update. On January 12, 2024, Georgia Power entered into an agreement for engineering, procurement, and construction with Mitsubishi Power Americas, Inc. and Black & Veatch Construction, Inc. to construct three 442-MW simple cycle combustion turbine units at Plant Yates (Plant Yates Units 8, 9, and 10), which are projected to be placed in service in the fourth quarter 2026, the second quarter 2027, and the third quarter 2027, respectively. In the third quarter 2024, Georgia Power entered into agreements for engineering, procurement, and construction of four battery energy storage facilities totaling 500 MWs and a 265-MW battery energy storage facility, which are projected to be placed in service in 2026, as authorized in the 2023 IRP Update and 2022 IRP, respectively. The ultimate outcome of these matters cannot be determined at this time. Transmission Asset Sales On March 7, 2024, the FERC approved the sale of transmission line assets under the integrated transmission system agreement, with a net book value of $236 million. On April 24, 2024, the sale, with a purchase price of $351 million, was completed resulting in a pre-tax gain of approximately $114 million ($84 million after tax) recorded in the second quarter 2024. Storm Damage Recovery Georgia Power is recovering $31 million annually under the 2022 ARP for incremental operating and maintenance costs of damage from major storms to its transmission and distribution facilities. During September 2024, Hurricane Helene caused significant damage to Georgia Power's transmission and distribution facilities. The initial estimated incremental restoration costs related to this hurricane deferred in the regulatory asset for storm damage totaled approximately $1.1 billion. A portion of the amounts included in the storm damage reserve will be capitalized to property, plant, and equipment once the nature of storm restoration costs is fully assessed. At September 30, 2024, Georgia Power's regulatory asset balance related to storm damage was $1.2 billion. The rate of storm damage cost recovery is expected to be adjusted as part of the next base rate case and in future regulatory proceedings as necessary. As a result of this regulatory treatment, costs related to storms are not expected to have a material impact on Southern Company's or Georgia Power's net income but do impact the related operating cash flows. Nuclear Construction Cost and Schedule Georgia Power placed Unit 3 and Unit 4 in service on July 31, 2023 and April 29, 2024, respectively. During the second quarter 2024, following Unit 4's in-service date, Southern Nuclear evaluated the remaining expected site demobilization costs and other contractor obligations and reduced the remaining estimate to complete forecast by approximately $21 million. Accordingly, Georgia Power recorded a pre-tax credit to income of approximately $21 million ($16 million after tax) in the second quarter 2024 to recognize capital costs previously charged to income. Georgia Power's net capital costs incurred through September 30, 2024 in connection with Plant Vogtle Units 3 and 4, and its approximate proportionate share of additional capital costs to be incurred after September 30, 2024, including completion of site demobilization and remaining contractor obligations, is as follows: (in millions) Total project capital cost forecast (a)(b) $ 10,732 Net investment at September 30, 2024 (b) (10,649) Remaining estimate to complete $ 83 (a) Includes approximately $1.2 billion of costs that are not shared with the other Vogtle Owners. Excludes financing costs capitalized through AFUDC of approximately $440 million accrued through Unit 4's in-service date. (b) Net of $1.7 billion received from Toshiba under the Guarantee Settlement Agreement and approximately $188 million in related customer refunds. Georgia Power's financing costs for construction of Plant Vogtle Units 3 and 4 totaled approximately $3.53 billion, of which $3.08 billion had been recovered through Unit 4's in-service date. Regulatory Matters Georgia Power increased annual retail base rates by $318 million effective August 1, 2023 based on the in-service date of July 31, 2023 for Unit 3. Financing costs (debt and equity) on the remaining portion of the total Unit 3 and the common facilities construction costs continued to be recovered through the NCCR tariff or deferred. Georgia Power deferred as a regulatory asset the debt component of financing costs as well as the remaining depreciation expense until Unit 4 costs were placed in retail base rates as described below. The regulatory assets for the debt component of financing costs and depreciation expense are being recovered over 10 years beginning May 2024, as approved by the Georgia PSC, with a remaining balance of $24 million and $30 million, respectively, at September 30, 2024. The equity component of financing costs ($40 million at September 30, 2024) represents an unrecognized ratemaking amount that is not reflected on Georgia Power's balance sheets. This amount will be recognized in Georgia Power's statements of income in the periods it is billable to customers. After considering construction and capital costs already in retail base rates of $2.1 billion and $362 million of associated retail rate base items for Unit 3 and common facilities, Georgia Power included in retail rate base the remaining $5.462 billion of construction and capital costs as well as $647 million of associated retail rate base items effective with the April 29, 2024 in-service date for Unit 4, pursuant to the approved Prudency Stipulation. Annual retail base revenues increased approximately $730 million and the average retail base rates were adjusted by approximately 5% (net of the elimination of the NCCR tariff described below) effective May 1, 2024. Reductions to the ROE used to calculate the NCCR tariff (pursuant to prior Georgia PSC orders) negatively impacted earnings by approximately $310 million in 2023 and $80 million through the second quarter 2024. Further, as included in the approved Prudency Stipulation, since commercial operation for Unit 4 was not achieved by March 31, 2024, Georgia Power's ROE used to determine the NCCR tariff and calculate AFUDC was reduced to zero effective April 1, 2024, which resulted in a negative impact to earnings of approximately $10 million (for one month) in the second quarter 2024 based on the April 29, 2024 in-service date. Effective May 1, 2024, following commercial operation of Unit 4, Georgia Power's NCCR tariff was eliminated and related financing costs are included in Georgia Power's general retail revenue requirements. Financing costs of $10 million that were not Mississippi Power Performance Evaluation Plan On June 13, 2024, the Mississippi PSC approved Mississippi Power's annual retail PEP filing for 2024 with no change in retail rates. Environmental Compliance Overview Plan On May 7, 2024, the Mississippi PSC approved Mississippi Power's annual ECO Plan filing for 2024, resulting in an $8 million annual increase in revenues effective with the first billing cycle of June 2024. Ad Valorem Tax Adjustment On June 13, 2024, the Mississippi PSC approved Mississippi Power's annual ad valorem tax adjustment filing for 2024, resulting in a $5 million annual decrease in revenues effective with the first billing cycle of July 2024. This decrease is not expected to have a significant effect on Mississippi Power's net income but will affect operating cash flows. System Restoration Rider On April 11, 2024, the Mississippi PSC approved Mississippi Power's annual SRR filing, which indicated no change in retail rates. Mississippi Power's minimum annual SRR accrual was increased from $12 million to $13 million. Integrated Resource Plan On April 26, 2024, Mississippi Power filed its 2024 IRP with the Mississippi PSC. The Mississippi PSC did not note any deficiencies within the review period; therefore, the filing is concluded. The 2024 IRP included a schedule to retire Plant Watson Unit 4 (268 MWs) and Plant Greene County Units 1 and 2 (206 MWs based on 40% ownership) and to retire early Plant Daniel Units 1 and 2 (502 MWs based on 50% ownership), all by the end of 2028, which is consistent with the completion of Mississippi Power's affiliate PPA with Georgia Power. The remaining net book value of Plant Daniel Units 1 and 2 was approximately $476 million at September 30, 2024, and Mississippi Power is continuing to depreciate these units using the current approved rates. Mississippi Power expects to reclassify the net book value remaining at retirement to a regulatory asset to be amortized over a period to be determined by the Mississippi PSC in future proceedings, consistent with a 2020 Mississippi PSC order. The Plant Watson and Plant Greene County units are expected to be fully depreciated upon retirement. The ultimate outcome of this matter cannot be determined at this time. Municipal and Rural Associations Tariff On March 29, 2024, Mississippi Power filed a request with the FERC for an $8 million increase in annual wholesale base revenues under the MRA tariff and requested an effective date of May 29, 2024. On April 19, 2024, Cooperative Energy challenged the new rates in a filing with the FERC. On May 28, 2024, the FERC issued an order accepting Mississippi Power's request effective May 29, 2024, subject to refund, and establishing hearing and settlement judge procedures. The ultimate outcome of this matter cannot be determined at this time. Southern Company Gas Infrastructure Replacement Programs and Capital Projects On June 7, 2024, the Virginia Commission approved the extension of Virginia Natural Gas' SAVE program through 2029. The extension of the program includes investments of $70 million in each year from 2025 through 2029, with a potential variance of up to $5 million allowed for the program, for a maximum total investment over the five-year extension of $355 million. Rate Proceedings Atlanta Gas Light On July 2, 2024, the Georgia PSC approved a stipulation related to Atlanta Gas Light's triennial Integrated Capacity and Delivery Plan filing, filed on February 1, 2024, which allows capital investments totaling approximately $0.6 billion annually for the years 2025 through 2027 with related revenue requirement recovery through either the annual GRAM filing or the System Reinforcement Rider surcharge adjustment. Additionally, the Georgia PSC approved a surcharge recovery mechanism for capital projects related to municipal, county, and Georgia Department of Transportation (GDOT) infrastructure work. Rate changes associated with the new surcharge, if approved, will be based on requests filed annually on September 1, with new rates to become effective January 1 of the following year. Finally, the stipulation requires Atlanta Gas Light to include an alternate rate plan for the three-year period of 2025 through 2027 with its 2025 GRAM filing. On July 31, 2024, Atlanta Gas Light submitted its annual GRAM filing with the Georgia PSC, which includes projections for portions of the System Reinforcement Rider and municipal, county, and GDOT projects. The filing requests a traditional annual base rate increase of $120 million based on the projected 12-month period beginning January 1, 2025. In accordance with the approved Integrated Capacity and Delivery Plan filing, Atlanta Gas Light also included two alternative annual base rate increases for 2025 that provide for lower increases in 2025 with subsequent increases in 2026 and 2027. Resolution of the GRAM filing is expected by December 31, 2024, with new rates effective January 1, 2025. The ultimate outcome of this matter cannot be determined at this time. Virginia Natural Gas On August 1, 2024, Virginia Natural Gas filed a base rate case with the Virginia Commission seeking an increase in annual base revenues of $63 million, including $17 million related to the recovery of investments under the SAVE program, primarily to recover investments and increased costs associated with infrastructure and technology. The requested increase is based on a projected 12-month period beginning January 1, 2025, an ROE of 10.45%, and an equity ratio of 54.92%. Rate adjustments will be effective January 1, 2025, subject to refund. The Virginia Commission is expected to issue an order on the requested increase in the third quarter 2025. The ultimate outcome of this matter cannot be determined at this time.

Contingencies

Contingencies	9 Months Ended
	Sep. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Contingencies	CONTINGENCIES See 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 intend to dispute the allegations raised in and vigorously defend against the pending legal challenges discussed below; however, the ultimate outcome of each of these matters cannot be determined at this time. Southern Company and Mississippi Power In 2010, the DOE, through a cooperative agreement with SCS, agreed to fund $270 million of the Kemper County energy facility through the grants awarded to the project by the DOE under the Clean Coal Power Initiative Round 2. In 2016, additional DOE grants in the amount of $137 million were awarded to the Kemper County energy facility. In 2018, Mississippi Power filed with the DOE its request for property closeout certification under the contract related to the $387 million of total grants received. In 2020, Mississippi Power and Southern Company executed an agreement with the DOE completing Mississippi Power's request, which enabled Mississippi Power to proceed with full dismantlement of the abandoned gasifier-related assets and site restoration activities. In connection with the DOE closeout discussions, in 2019, the Civil Division of the Department of Justice informed Southern Company and Mississippi Power of a civil investigation related to the DOE grants. In August 2023, the U.S. District Court for the Northern District of Georgia unsealed a civil action in which defendants Southern Company, SCS, and Mississippi Power are alleged to have violated certain provisions of the False Claims Act by fraudulently inducing the DOE to disburse funds pursuant to the grants. The federal government declined to intervene in the action. In October 2023, the plaintiff, a former SCS employee, filed an amended complaint, again alleging certain violations of the False Claims Act. The plaintiff seeks to recover all damages incurred personally and on behalf of the federal government caused by the defendants' alleged violations, as well as treble damages and attorneys' fees, among other relief. On February 2, 2024, the defendants moved to dismiss the amended complaint. On August 28, 2024, the court granted the defendants' motion in part and denied it in part, dismissing the plaintiff's False Claims Act count along with its accompanying treble damages and attorneys' fees but allowing the employment retaliation claim to proceed. The plaintiff requested interlocutory appeal of the court's decision on October 4, 2024. On October 14, 2024, the defendants asserted counterclaims for conversion and misappropriation of trade secrets. An adverse outcome could have a material impact on Southern Company's and Mississippi Power's financial statements. 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 surface impoundment utilizing a closure-in-place methodology violates the Resource Conservation and Recovery Act (RCRA) and regulations governing CCR. Among other relief requested, Mobile Baykeeper sought a declaratory judgment that the RCRA and regulations governing CCR were 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. In December 2022, Alabama Power filed a motion to dismiss the case. On January 4, 2024, the lawsuit was dismissed without prejudice by the U.S. District Court judge. On February 1, 2024, the plaintiff filed a motion to reconsider, which was denied by the U.S. District Court judge on July 22, 2024. On August 20, 2024, the plaintiff filed a notice of appeal in the U.S. Court of Appeals for the Eleventh Circuit challenging the denial of the motion to reconsider the order of dismissal. In January 2023, the EPA issued a Notice of Potential Violations (NOPV) associated with Alabama Power's plan to close the Plant Barry surface impoundment. On September 26, 2024, Alabama Power reached a settlement with the EPA resolving two of the three allegations in the NOPV related to the groundwater monitoring system and the emergency action plan at the Plant Barry surface impoundment. Alabama Power has affirmed to the EPA its position that it is in compliance with CCR requirements. These matters could have a material impact on Alabama Power's financial statements, including ARO estimates and cash flows. 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 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. 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 May 2023, the Superior Court of Monroe County, Georgia denied Georgia Power's motion to dismiss the case for lack of subject matter jurisdiction. In July 2023, the Superior Court of Monroe County, Georgia denied the remaining motions to dismiss certain claims and plaintiffs that Georgia Power filed at the outset of the case. On March 11, 2024, Georgia Power filed a motion to dismiss certain claims. On March 14, 2024, Georgia Power filed motions for summary judgment. In May 2024, Georgia Power filed additional motions for summary judgment. In August 2024, the court denied certain motions for summary judgment, while granting other motions for summary judgment, eliminating some claims from the first one-plaintiff trial. In October 2021, February 2022, and January 2023, a total of eight 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. After Georgia Power removed these cases to the U.S. District Court for the Middle District of Georgia, the plaintiffs voluntarily dismissed their complaints without prejudice in November 2022 and January 2023. In May 2023, the plaintiffs in the cases originally filed in October 2021, February 2022, and January 2023 refiled their eight complaints in the Superior Court of Monroe County, Georgia. Also in May 2023, a new 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 seeks an unspecified amount of monetary damages, including punitive damages. Also in May 2023, Georgia Power removed all of these cases to the U.S. District Court for the Middle District of Georgia. The plaintiffs are requesting the court remand the cases back to the Superior Court of Monroe County, Georgia. The amount of possible loss, if any, 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 County energy facility prior to placing the Kemper County energy facility into service. The Mississippi Supreme Court reversed that approval and ordered Mississippi Power to refund the amounts paid by customers under the previously-approved mirror CWIP rate. The plaintiffs allege that the initial approval process, and the amount approved, were improper and make claims for gross negligence, reckless conduct, and intentional wrongdoing. They also allege that Mississippi Power underpaid customers by up to $23.5 million in the refund process by applying an incorrect interest rate. The plaintiffs seek to recover, on behalf of themselves and their putative class, actual damages, punitive damages, pre-judgment interest, post-judgment interest, attorney's fees, and costs. The district court dismissed the amended complaint; however, in March 2020, the plaintiffs filed a motion seeking to name the new members of the Mississippi PSC, the Mississippi Development Authority, and Southern Company as additional defendants and add a cause of action against all defendants based on a dormant commerce clause theory under the U.S. Constitution. In July 2020, the plaintiffs filed a motion for leave to file a third amended complaint, which included the same federal claims as the proposed second amended complaint, as well as several additional state law claims based on the allegation that Mississippi Power failed to disclose the annual percentage rate of interest applicable to refunds. In November 2020, the district court denied each of the plaintiffs' pending motions and entered final judgment in favor of Mississippi Power. In January 2021, the district court denied further motions by the plaintiffs to vacate the judgment and to file a revised second amended complaint. In February 2021, the plaintiffs filed a notice of appeal with the U.S. Court of Appeals for the Fifth Circuit. In March 2022, the U.S. Court of Appeals for the Fifth Circuit issued an opinion affirming the dismissal of the claims against the Mississippi PSC defendants but reversing the dismissal of the claims against Mississippi Power. In May 2022, the U.S. Court of Appeals for the Fifth Circuit denied a petition by Mississippi Power for a rehearing en banc and remanded the case to the U.S. District Court for the Southern District of Mississippi for further proceedings. In June 2022, Mississippi Power filed with the trial court a motion to dismiss the complaint with prejudice, which was granted on March 15, 2023. On March 28, 2023, the plaintiffs filed a notice of appeal with the U.S. Court of Appeals for the Fifth Circuit. In December 2023, the U.S Court of Appeals for the Fifth Circuit affirmed the district court's order dismissing the plaintiffs' complaint against Mississippi Power, and the plaintiffs filed a petition for panel rehearing, which was denied on January 10, 2024. The plaintiffs did not file a petition for writ of certiorari with the U.S. Supreme Court. This matter is now concluded. Southern Power In 2021, Southern Power and certain of its subsidiaries filed an arbitration demand with the American Arbitration Association against First Solar for defective design of actuators on trackers and inverters installed by First Solar under the engineering, procurement, and construction agreements associated with five solar projects owned by Southern Power and partners and managed by Southern Power. In 2023, Southern Power received an award of approximately $36 million and filed for confirmation in the Delaware Court of Chancery. Subsequently in 2023, First Solar filed a motion to dismiss the confirmation and, in February 2024, filed a petition to vacate the arbitration award in the Supreme Court of New York County, New York. In March 2024, Southern Power dismissed the proceeding in Delaware without prejudice and filed an opposition to First Solar's petition in the New York matter. On May 6, 2024, the Supreme Court of New York County, New York denied First Solar's petition to vacate and confirmed the arbitration award. This matter is now concluded. At September 30, 2024, $16 million of the award remains on the balance sheet as restricted cash and as a liability to fund future replacement costs. See Note (A) under "Cash, Cash Equivalents, and Restricted Cash" for additional information. 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 $13 million and $14 million at September 30, 2024 and December 31, 2023, respectively. Georgia Power has been designated or identified as a potentially responsible party at sites governed by the Georgia Hazardous Site Response Act and/or by the federal Comprehensive Environmental Response, Compensation, and Liability Act, and assessment and potential cleanup of such sites is expected. Southern Company Gas' environmental remediation liability was $230 million and $222 million at September 30, 2024 and December 31, 2023, respectively, based on the estimated cost of environmental investigation and remediation associated with known former manufactured gas plant operating sites. Southern Company Gas has identified one former manufactured gas plant site in North Carolina where environmental investigation and remediation are possible. Costs associated with this site cannot be reasonably estimated at this time. 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. Nuclear Fuel Disposal Costs On June 7, 2024 and August 15, 2024, the Court of Federal Claims entered final judgments on damages in the third and fourth round of lawsuits, respectively, against the U.S. government awarding Alabama Power a total of $100 million and Georgia Power a total of $121 million (based on its ownership interests), which represent claims for the period from January 1, 2011 through December 31, 2019. This represents all outstanding claims. At September 30, 2024, Alabama Power recognized both a receivable and a regulatory liability of $100 million. Alabama Power expects to credit recovery for the benefit of customers in accordance with direction from the Alabama PSC. At September 30, 2024, Georgia Power recognized a receivable of $259 million and a payable to the joint owners of Plants Hatch and Vogtle of $138 million (based on their ownership interests) and credited the award to accounts where the original costs were charged, which reduced rate base, fuel, and cost of service for the benefit of customers, as previously authorized by the Georgia PSC. As a result of this regulatory treatment, there will be no material impact on Southern Company's, Alabama Power's, or Georgia Power's net income. 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 joint use agreement remains in effect. 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	9 Months Ended
	Sep. 30, 2024
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. Included in the wholesale electric revenues of the traditional electric operating companies and Southern Power are revenues associated with affiliate transactions. These revenues are generated through long-term PPAs or short-term energy sales made in accordance with the IIC, as approved by the FERC. Amounts related to these affiliate revenues are eliminated in consolidation for Southern Company. See Note 1 to the financial statements under "Revenues" and "Affiliate Transactions" in Item 8 of the Form 10-K for additional information. See "Lease Income" herein and Note (J) for additional information on revenue accounted for under lease and derivative accounting guidance, respectively. The following table disaggregates revenue from contracts with customers for the three and nine months ended September 30, 2024 and 2023: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Three Months Ended September 30, 2024 Operating revenues Retail electric revenues Residential $ 2,651 $ 975 $ 1,580 $ 96 $ — $ — Commercial 1,991 607 1,288 96 — — Industrial 1,184 483 606 95 — — Other 33 3 28 2 — — Total retail electric revenues 5,859 2,068 3,502 289 — — Natural gas distribution revenues Residential 212 — — — — 212 Commercial 55 — — — — 55 Transportation 294 — — — — 294 Industrial 4 — — — — 4 Other 45 — — — — 45 Total natural gas distribution revenues 610 — — — — 610 Wholesale electric revenues PPA energy revenues 300 58 26 1 222 — PPA capacity revenues 190 24 42 15 125 — Non-PPA revenues 67 34 — 106 67 — Total wholesale electric revenues 557 116 68 122 414 — Other natural gas revenues Gas marketing services 51 — — — — 51 Other 6 — — — — 6 Total other natural gas revenues 57 — — — — 57 Other revenues 398 60 170 13 9 — Total revenue from contracts with customers 7,481 2,244 3,740 424 423 667 Other revenue sources (*) (207) (106) (268) (12) 177 15 Total operating revenues $ 7,274 $ 2,138 $ 3,472 $ 412 $ 600 $ 682 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Nine Months Ended September 30, 2024 Operating revenues Retail electric revenues Residential $ 6,551 $ 2,477 $ 3,832 $ 242 $ — $ — Commercial 5,075 1,583 3,243 249 — — Industrial 3,019 1,338 1,424 257 — — Other 94 9 78 7 — — Total retail electric revenues 14,739 5,407 8,577 755 — — Natural gas distribution revenues Residential 1,244 — — — — 1,244 Commercial 300 — — — — 300 Transportation 959 — — — — 959 Industrial 25 — — — — 25 Other 221 — — — — 221 Total natural gas distribution revenues 2,749 — — — — 2,749 Wholesale electric revenues PPA energy revenues 838 171 66 3 616 — PPA capacity revenues 495 71 106 47 320 — Non-PPA revenues 179 103 3 292 176 — Total wholesale electric revenues 1,512 345 175 342 1,112 — Other natural gas revenues Gas marketing services 352 — — — — 352 Other 16 — — — — 16 Total other natural gas revenues 368 — — — — 368 Other revenues 1,145 174 507 34 31 — Total revenue from contracts with customers 20,513 5,926 9,259 1,131 1,143 3,117 Other revenue sources (*) (130) (123) (514) (13) 454 103 Total operating revenues $ 20,383 $ 5,803 $ 8,745 $ 1,118 $ 1,597 $ 3,220 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Three Months Ended September 30, 2023 Operating revenues Retail electric revenues Residential $ 2,543 $ 969 $ 1,473 $ 101 $ — $ — Commercial 1,845 599 1,151 95 — — Industrial 1,116 498 528 90 — — Other 30 3 25 2 — — Total retail electric revenues 5,534 2,069 3,177 288 — — Natural gas distribution revenues Residential 217 — — — — 217 Commercial 56 — — — — 56 Transportation 275 — — — — 275 Industrial 4 — — — — 4 Other 60 — — — — 60 Total natural gas distribution revenues 612 — — — — 612 Wholesale electric revenues PPA energy revenues 317 66 31 2 226 — PPA capacity revenues 151 26 13 3 110 — Non-PPA revenues 101 15 21 137 126 — Total wholesale electric revenues 569 107 65 142 462 — Other natural gas revenues Gas marketing services 54 — — — — 54 Other 8 — — — — 8 Total other natural gas revenues 62 — — — — 62 Other revenues 330 54 146 10 18 — Total revenue from contracts with customers 7,107 2,230 3,388 440 480 674 Other revenue sources (*) (127) (147) (151) (4) 173 15 Total operating revenues $ 6,980 $ 2,083 $ 3,237 $ 436 $ 653 $ 689 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Nine Months Ended September 30, 2023 Operating revenues Retail electric revenues Residential $ 5,717 $ 2,277 $ 3,202 $ 238 $ — $ — Commercial 4,464 1,493 2,733 238 — — Industrial 2,770 1,324 1,195 251 — — Other 84 10 68 6 — — Total retail electric revenues 13,035 5,104 7,198 733 — — Natural gas distribution revenues Residential 1,443 — — — — 1,443 Commercial 370 — — — — 370 Transportation 878 — — — — 878 Industrial 33 — — — — 33 Other 228 — — — — 228 Total natural gas distribution revenues 2,952 — — — — 2,952 Wholesale electric revenues PPA energy revenues 853 196 66 8 601 — PPA capacity revenues 490 130 38 36 289 — Non-PPA revenues 199 49 30 315 312 — Total wholesale electric revenues 1,542 375 134 359 1,202 — Other natural gas revenues Gas marketing services 358 — — — — 358 Other 28 — — — — 28 Total other natural gas revenues 386 — — — — 386 Other revenues 971 159 422 31 46 — Total revenue from contracts with customers 18,886 5,638 7,754 1,123 1,248 3,338 Other revenue sources (*) 322 (218) 51 14 438 79 Total operating revenues $ 19,208 $ 5,420 $ 7,805 $ 1,137 $ 1,686 $ 3,417 (*) 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 (including those related to fuel costs) 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 September 30, 2024 and December 31, 2023: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Accounts Receivable At September 30, 2024 $ 2,946 $ 978 $ 1,347 $ 111 $ 125 $ 306 At December 31, 2023 2,820 821 1,011 90 122 684 Contract Assets At September 30, 2024 $ 379 $ 7 $ 202 $ — $ — $ 71 At December 31, 2023 271 2 121 — — 56 Contract Liabilities At September 30, 2024 $ 181 $ — $ 49 $ — $ 2 $ 3 At December 31, 2023 116 — 1 — 4 — 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. 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 $68 million had been received at September 30, 2024. 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 September 30, 2024 and December 31, 2023, Southern Company's unregulated distributed generation business had contract assets of $102 million and $91 million, respectively, and contract liabilities of $132 million and $115 million, respectively, for outstanding performance obligations, all of which are expected to be satisfied within one year. Revenues recognized in the three and nine months ended September 30, 2024, which were included in contract liabilities at December 31, 2023, were $20 million and $97 million, respectively, for Southern Company and immaterial for the other Registrants. Contract liabilities are primarily classified as current on the balance sheets as the corresponding revenues are generally expected to be recognized within one year. Remaining Performance Obligations Southern Company's subsidiaries may enter into long-term contracts with customers in which revenues are recognized as performance obligations are satisfied over the contract term. For the traditional electric operating companies and Southern Power, these contracts primarily relate to PPAs whereby electricity and generation capacity are provided to a customer. The revenue recognized for the delivery of electricity is variable; however, certain PPAs include a fixed payment for fixed generation capacity over the term of the contract. For Southern Company Gas, these contracts 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 September 30, 2024 are expected to be recognized as follows: 2024 (remaining) 2025 2026 2027 2028 Thereafter (in millions) Southern Company $ 303 $ 884 $ 375 $ 336 $ 325 $ 2,180 Alabama Power 11 11 — — — — Georgia Power 21 64 26 17 17 17 Mississippi Power (*) 15 63 66 69 73 — Southern Power (*) 73 312 299 306 297 2,169 Southern Company Gas 3 2 — — — — (*) Includes performance obligations related to affiliate PPAs with Georgia Power. See Note 1 to the financial statements under "Affiliate Transactions" in Item 8 of the Form 10-K for additional information. Lease Income Lease income for the three and nine months ended September 30, 2024 and 2023 is as follows: Southern Alabama Power Georgia Power Mississippi Southern Power Southern Company Gas (in millions) For the Three Months Ended September 30, 2024 Lease income - interest income on sales-type leases $ 5 $ — $ — $ 3 $ 2 $ — Lease income - operating leases 38 2 13 — 20 9 Variable lease income 142 — — — 152 — Total lease income $ 185 $ 2 $ 13 $ 3 $ 174 $ 9 For the Nine Months Ended September 30, 2024 Lease income - interest income on sales-type leases $ 18 $ — $ — $ 11 $ 7 $ — Lease income - operating leases 108 6 28 2 63 27 Variable lease income 343 — — — 370 — Total lease income $ 469 $ 6 $ 28 $ 13 $ 440 $ 27 For the Three Months Ended September 30, 2023 Lease income - interest income on sales-type leases $ 6 $ — $ — $ 4 $ 2 $ — Lease income - operating leases 36 3 7 — 21 9 Variable lease income 134 — — — 144 — Total lease income $ 176 $ 3 $ 7 $ 4 $ 167 $ 9 For the Nine Months Ended September 30, 2023 Lease income - interest income on sales-type leases $ 18 $ — $ — $ 11 $ 7 $ — Lease income - operating leases 129 32 22 2 64 27 Variable lease income 327 1 — — 351 — Total lease income $ 474 $ 33 $ 22 $ 13 $ 422 $ 27

Consolidated Entities and Equit

Consolidated Entities and Equity Method Investments	9 Months Ended
	Sep. 30, 2024
Regulated Operations [Abstract]
Consolidated Entities and Equity Method Investments	CONSOLIDATED ENTITIES AND EQUITY METHOD INVESTMENTS See Note 7 to the financial statements in Item 8 of the Form 10-K for additional information. Southern Company At September 30, 2024 and December 31, 2023, Southern Holdings had equity method investments totaling $127 million and $126 million, respectively, primarily related to investments in venture capital funds focused on energy and utility investments. Earnings from these investments were immaterial for all periods presented. Southern Power Variable Interest Entities Southern Power has certain subsidiaries that are determined to be VIEs. Southern Power is considered the primary beneficiary of these VIEs because it controls the most significant activities of the VIEs, including operating and maintaining the respective assets, and has the obligation to absorb expected losses of these VIEs to the extent of its equity interests. SP Solar and SP Wind At September 30, 2024 and December 31, 2023, SP Solar had total assets of $5.6 billion, total liabilities of $378 million and $399 million, respectively, and noncontrolling interests of $1.0 billion. Cash distributions from SP Solar are allocated 67% to Southern Power and 33% to the limited partner in accordance with their partnership interest percentage. Under the terms of the limited partnership agreement, distributions without limited partner consent are limited to available cash and SP Solar is obligated to distribute all such available cash to its partners each quarter. Available cash includes all cash generated in the quarter subject to the maintenance of appropriate operating reserves. At September 30, 2024 and December 31, 2023, SP Wind had total assets of $2.1 billion, total liabilities of $184 million and $187 million, respectively, and noncontrolling interests of $36 million and $38 million, respectively. Under the terms of the limited liability agreement, distributions without Class A member consent are limited to available cash and SP Wind is obligated to distribute all such available cash to its members each quarter. Available cash includes all cash generated in the quarter subject to the maintenance of appropriate operating reserves. Cash distributions from SP Wind are generally allocated 60% to Southern Power and 40% to the three financial investors in accordance with the limited liability agreement. Southern Power consolidates both SP Solar and SP Wind, as the primary beneficiary, since it controls the most significant activities of each entity, including operating and maintaining their assets. Certain transfers and sales of the assets in the VIEs are subject to partner consent and the liabilities are non-recourse to the general credit of Southern Power. Liabilities consist of customary working capital items and do not include any long-term debt. Other Variable Interest Entities Southern Power has other consolidated VIEs that relate to certain subsidiaries that have either sold noncontrolling interests to tax equity investors or acquired less than a 100% interest from facility developers. These entities are considered VIEs because the arrangements are structured similar to a limited partnership and the noncontrolling members do not have substantive kick-out rights. At September 30, 2024 and December 31, 2023, the other VIEs had total assets of $1.7 billion, total liabilities of $240 million and $230 million, respectively, and noncontrolling interests of $710 million and $761 million, respectively. Under the terms of the partnership agreements, distributions of all available cash are required each month or quarter and additional distributions require partner consent. Southern Company Gas Equity Method Investments The carrying amounts of Southern Company Gas' equity method investments at September 30, 2024 and December 31, 2023 were as follows: Investment Balance September 30, 2024 December 31, 2023 (in millions) SNG $ 1,246 $ 1,202 Other 33 33 Total $ 1,279 $ 1,235 The earnings from Southern Company Gas' equity method investment related to SNG were $34 million and $32 million for the three months ended September 30, 2024 and 2023, respectively, and $110 million and $104 million for the nine months ended September 30, 2024 and 2023, respectively. The earnings from Southern Company Gas' other equity method investments were immaterial for all periods presented.

Financing and Leases

Financing and Leases	9 Months Ended
	Sep. 30, 2024
Debt Disclosure [Abstract]
Financing and Leases	FINANCING AND LEASES Bank Credit Arrangements See Note 8 to the financial statements under "Bank Credit Arrangements" in Item 8 of the Form 10-K for additional information. At September 30, 2024, committed credit arrangements with banks were as follows: Expires Company 2025 2026 2027 2029 Total Unused Expires within (in millions) Southern Company parent (a) $ 150 $ — $ — $ 1,850 $ 2,000 $ 1,998 $ 150 Alabama Power — 650 — 700 1,350 1,350 — Georgia Power 300 — — 1,750 2,050 2,026 300 Mississippi Power — — 275 — 275 275 — Southern Power (a)(b) — — — 600 600 600 — Southern Company Gas (c) 100 — — 1,500 1,600 1,598 100 SEGCO 30 — — — 30 30 30 Southern Company $ 580 $ 650 $ 275 $ 6,400 $ 7,905 $ 7,877 $ 580 (a) Arrangement expiring in 2029 represents a $2.45 billion combined arrangement for Southern Company and Southern Power as borrowers. Pursuant to the combined facility, the allocations between Southern Company and Southern Power may be adjusted. (b) 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 $10 million and $11 million, respectively, was unused at September 30, 2024. Southern Power's subsidiaries are not parties to its bank credit arrangements or letter of credit facilities. (c) 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 2029. Southern Company Gas' committed credit arrangement expiring in 2029 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 2029, the allocations between Southern Company Gas Capital and Nicor Gas may be adjusted. Nicor Gas is also the borrower under a $100 million credit arrangement expiring in 2025. As reflected in the table above, in March 2024, Mississippi Power amended and restated a $125 million multi-year credit arrangement, which, among other things, extended the maturity date from 2025 to 2027. In May 2024, (i) Alabama Power, Georgia Power, and Southern Company Gas Capital, along with Nicor Gas, extended the maturity dates of certain of their multi-year credit arrangements from 2028 to 2029; (ii) Southern Company and Southern Power extended the maturity date of their combined multi-year credit arrangement from 2028 to 2029; (iii) Southern Company, Nicor Gas, and SEGCO amended their credit arrangements aggregating $150 million, $100 million, and $30 million, respectively, which extended the maturity dates from 2024 to 2025; and (iv) Georgia Power entered into two new credit arrangements aggregating $300 million, which mature in 2025. In June 2024, Mississippi Power amended certain of its multi-year credit arrangements aggregating $150 million, which extended the maturity dates from 2026 to 2027. 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 provisions to other indebtedness (including guarantee obligations) that are restricted only to the indebtedness of the individual company. The cross-acceleration provisions to other indebtedness would trigger an event of default if the applicable borrower defaulted on indebtedness, the payment of which was then accelerated. At September 30, 2024, 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 certain revenue bonds of the traditional electric operating companies and the commercial paper programs of the Registrants, Nicor Gas, and SEGCO. At September 30, 2024, outstanding variable rate demand revenue bonds of the traditional electric operating companies with allocated liquidity support totaled approximately $1.7 billion (comprised of approximately $796 million at Alabama Power, $819 million at Georgia Power, and $69 million at Mississippi Power). In addition, at September 30, 2024, Alabama Power and Georgia Power had approximately $207 million and $157 million, respectively, of fixed rate revenue bonds outstanding that are required to be remarketed within the next 12 months. Alabama Power's $207 million of fixed rate revenue bonds are classified as securities due within one year on its balance sheets as they are not covered by long-term committed credit. All other variable rate demand revenue bonds and fixed rate revenue bonds required to be remarketed within the next 12 months are classified as long-term debt on the balance sheets as a result of available long-term committed credit. Convertible Senior Notes In May 2024, Southern Company issued $1.5 billion aggregate principal amount of Series 2024A 4.50% Convertible Senior Notes due June 15, 2027 (Series 2024A Convertible Senior Notes). Interest on the Series 2024A Convertible Senior Notes is payable semiannually, beginning December 15, 2024. The Series 2024A Convertible Senior Notes will mature on June 15, 2027, unless earlier converted or repurchased, but are not redeemable at the option of Southern Company. The Series 2024A 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 2024A Convertible Senior Notes at their option prior to the close of business on the business day preceding March 15, 2027, 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 2024A 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 2024A Convertible Senior Notes. On or after March 15, 2027, a holder may convert all or any portion of its Series 2024A 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 2024A Convertible Senior Notes by paying cash up to the aggregate principal amount of the Series 2024A 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 2024A Convertible Senior Notes being converted. The Series 2024A Convertible Senior Notes are initially convertible at a rate of 10.8166 shares of common stock per $1,000 principal amount converted, which is approximately equal to $92.45 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 2024A 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 2024A Convertible Senior Notes), holders of the Series 2024A Convertible Senior Notes may require Southern Company to purchase all or a portion of their Series 2024A 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 2024A 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 and Series 2024A 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 and Series 2024A Convertible Senior Notes is determined using the net share settlement method. See "Convertible Senior Notes" herein and Note 8 to the financial statements under "Convertible Senior Notes" and Note 12 to the financial statements in Item 8 of the Form 10-K for additional information. Shares used to compute diluted EPS were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 (in millions) As reported shares 1,097 1,092 1,096 1,092 Effect of stock-based compensation 6 7 6 6 Diluted shares 1,103 1,099 1,102 1,098 For all periods presented, an immaterial number of stock-based compensation awards was excluded from the diluted EPS calculation because the awards were anti-dilutive. For the three and nine months ended September 30, 2024, there was no dilution resulting from the Series 2024A Convertible Senior Notes, and the dilution resulting from the Series 2023A convertible senior notes was immaterial. Georgia Power Lease Modification See Note 9 to the financial statements in Item 8 of the Form 10-K for information on Georgia Power's leases. In June 2024, Georgia Power recognized a lease modification related to an existing affiliate PPA with Southern Power which converted from an operating lease to a finance lease upon its approval by the FERC. As a result, Georgia Power removed from its balance sheet operating lease right-of-use assets, net of amortization of $8 million and lease obligations of $10 million maturing through 2025 and recorded finance lease right-of-use assets of $44 million and lease obligations of $45 million maturing through 2035. See Note (B) under "Georgia Power – Integrated Resource Plans" for additional information.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2024
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. 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. 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 19.0% for the nine months ended September 30, 2024 compared to 13.9% for the corresponding period in 2023. The effective tax rate increase was primarily due to a decrease in the flowback of certain excess deferred income taxes at Alabama Power, higher pre-tax earnings, and an increase in the valuation allowance on certain state tax credit carryforwards at Georgia Power, partially offset by an increase in PTCs and the recognition of certain state tax positions from amended returns primarily at Georgia Power. See "Unrecognized Tax Benefits" herein for additional information. Alabama Power Alabama Power's effective tax rate was 21.2% for the nine months ended September 30, 2024 compared to 8.3% for the corresponding period in 2023. The effective tax rate increase was primarily due to a decrease in the flowback of certain excess deferred income taxes. Georgia Power Georgia Power's effective tax rate was 18.7% for the nine months ended September 30, 2024 compared to 18.2% for the corresponding period in 2023. The effective tax rate increase was primarily due to higher pre-tax earnings and an increase in the valuation allowance on certain state tax credit carryforwards, partially offset by an increase in PTCs and the recognition of certain state tax positions from amended returns. See "Unrecognized Tax Benefits" herein for additional information. Mississippi Power Mississippi Power's effective tax rate was 20.0% for the nine months ended September 30, 2024 compared to 16.9% for the corresponding period in 2023. The effective tax rate increase was primarily due to a decrease in the flowback of certain excess deferred income taxes. Unrecognized Tax Benefits Southern Company's and Georgia Power's unrecognized tax position balances at September 30, 2024 were $73 million and $34 million, respectively, compared to $116 million and $77 million, respectively, at December 31, 2023. The decreases from prior periods are primarily related to the 2019 and 2020 amended state filing positions related to tax credit utilization and decreased Southern Company's and Georgia Power's effective tax rates.

Retirement Benefits

Retirement Benefits	9 Months Ended
	Sep. 30, 2024
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, 2024. 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 and nine months ended September 30, 2024 and 2023 are presented in the following tables. Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) Three Months Ended September 30, 2024 Pension Plans Service cost $ 73 $ 17 $ 18 $ 3 $ 2 $ 7 Interest cost 159 37 47 7 2 11 Expected return on plan assets (316) (77) (99) (14) (4) (21) Amortization: Prior service costs — — — — — (1) Regulatory asset — — — — — 4 Net (gain) loss 14 4 6 — (1) — Net periodic pension income $ (70) $ (19) $ (28) $ (4) $ (1) $ — Postretirement Benefits Service cost $ 4 $ 1 $ 1 $ — $ — $ — Interest cost 16 4 6 1 — 2 Expected return on plan assets (22) (9) (8) (1) — (2) Amortization: Prior service costs 1 — 1 — — — Regulatory asset — — — — — 2 Net (gain) loss (4) — (3) 1 — (1) Net periodic postretirement benefit cost (income) $ (5) $ (4) $ (3) $ 1 $ — $ 1 Nine Months Ended September 30, 2024 Pension Plans Service cost $ 219 $ 51 $ 53 $ 9 $ 5 $ 21 Interest cost 476 111 143 21 6 32 Expected return on plan assets (947) (230) (296) (43) (12) (64) Amortization: Prior service costs — — 1 — — (2) Regulatory asset — — — — — 11 Net loss 41 12 15 2 — — Net periodic pension income $ (211) $ (56) $ (84) $ (11) $ (1) $ (2) Postretirement Benefits Service cost $ 11 $ 3 $ 3 $ — $ — $ 1 Interest cost 49 12 17 2 — 6 Expected return on plan assets (66) (26) (24) (1) — (6) Amortization: Prior service costs 2 — 1 — — — Regulatory asset — — — — — 5 Net gain (12) (2) (4) — — (4) Net periodic postretirement benefit cost (income) $ (16) $ (13) $ (7) $ 1 $ — $ 2 Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) Three Months Ended September 30, 2023 Pension Plans Service cost $ 69 $ 16 $ 17 $ 2 $ 2 $ 6 Interest cost 156 37 48 7 2 11 Expected return on plan assets (307) (75) (97) (13) (4) (22) Amortization: Prior service costs — — — — — (1) Regulatory asset — — — — — 4 Net (gain) loss 8 2 4 1 — (1) Net periodic pension income $ (74) $ (20) $ (28) $ (3) $ — $ (3) Postretirement Benefits Service cost $ 4 $ 1 $ 1 $ — $ — $ — Interest cost 18 5 6 1 — 2 Expected return on plan assets (21) (9) (7) (1) — (2) Amortization: Prior service costs — — 1 — — — Regulatory asset — — — — — 2 Net gain (4) (1) (1) — — (1) Net periodic postretirement benefit cost (income) $ (3) $ (4) $ — $ — $ — $ 1 Nine Months Ended September 30, 2023 Pension Plans Service cost $ 207 $ 48 $ 51 $ 8 $ 5 $ 18 Interest cost 469 109 143 21 6 32 Expected return on plan assets (922) (223) (289) (41) (12) (65) Amortization: Prior service costs — — 1 — — (2) Regulatory asset — — — — — 11 Net (gain) loss 24 7 10 1 — (3) Net periodic pension income $ (222) $ (59) $ (84) $ (11) $ (1) $ (9) Postretirement Benefits Service cost $ 11 $ 3 $ 3 $ — $ — $ 1 Interest cost 53 13 19 2 — 6 Expected return on plan assets (62) (26) (22) (1) — (5) Amortization: Prior service costs 1 — 1 — — — Regulatory asset — — — — — 5 Net gain (10) (2) (3) — — (3) Net periodic postretirement benefit cost (income) $ (7) $ (12) $ (2) $ 1 $ — $ 4

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2024
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS At September 30, 2024, assets and liabilities measured at fair value on a recurring basis during the period, together with their associated level of the fair value hierarchy, were as follows: Fair Value Measurements Using: At September 30, 2024 Quoted Prices Significant Significant Net Asset Value as a Practical Expedient (NAV) Total (in millions) Southern Company Assets: Energy-related derivatives (a) $ 8 $ 59 $ — $ — $ 67 Interest rate derivatives — 1 — — 1 Investments in trusts: (b) Domestic equity 843 255 — — 1,098 Foreign equity 163 189 — — 352 U.S. Treasury and government agency securities — 368 — — 368 Municipal bonds — 50 — — 50 Pooled funds – fixed income — 7 — — 7 Corporate bonds — 464 — — 464 Mortgage and asset backed securities — 106 — — 106 Private equity — — — 179 179 Cash and cash equivalents 1 — — — 1 Other 28 3 — 9 40 Cash equivalents and restricted cash 336 16 — — 352 Other investments 9 28 8 — 45 Total $ 1,388 $ 1,546 $ 8 $ 188 $ 3,130 Liabilities: Energy-related derivatives (a) $ 13 $ 189 $ — $ — $ 202 Interest rate derivatives — 218 — — 218 Foreign currency derivatives — 105 — — 105 Contingent consideration 3 — 17 — 20 Other — 13 9 — 22 Total $ 16 $ 525 $ 26 $ — $ 567 Fair Value Measurements Using: At September 30, 2024 Quoted Prices Significant Significant Net Asset Value as a Practical Expedient (NAV) Total (in millions) Alabama Power Assets: Energy-related derivatives $ — $ 21 $ — $ — $ 21 Nuclear decommissioning trusts: (b) Domestic equity 460 246 — — 706 Foreign equity 163 — — — 163 U.S. Treasury and government agency securities — 18 — — 18 Municipal bonds — 1 — — 1 Corporate bonds — 286 — — 286 Mortgage and asset backed securities — 29 — — 29 Private equity — — — 179 179 Other 5 1 — 9 15 Cash equivalents and restricted cash 197 16 — — 213 Other investments — 28 — — 28 Total $ 825 $ 646 $ — $ 188 $ 1,659 Liabilities: Energy-related derivatives $ — $ 65 $ — $ — $ 65 Georgia Power Assets: Energy-related derivatives $ — $ 13 $ — $ — $ 13 Interest rate derivatives — 1 — — 1 Nuclear decommissioning trusts: (b) Domestic equity 383 1 — — 384 Foreign equity — 188 — — 188 U.S. Treasury and government agency securities — 350 — — 350 Municipal bonds — 49 — — 49 Corporate bonds — 178 — — 178 Mortgage and asset backed securities — 77 — — 77 Other 23 2 — — 25 Total $ 406 $ 859 $ — $ — $ 1,265 Liabilities: Energy-related derivatives $ — $ 65 $ — $ — $ 65 Fair Value Measurements Using: At September 30, 2024 Quoted Prices Significant Significant Net Asset Value as a Practical Expedient (NAV) Total (in millions) Mississippi Power Assets: Energy-related derivatives $ — $ 14 $ — $ — $ 14 Liabilities: Energy-related derivatives $ — $ 51 $ — $ — $ 51 Southern Power Assets: Energy-related derivatives $ — $ 4 $ — $ — $ 4 Liabilities: Energy-related derivatives $ — $ 2 $ — $ — $ 2 Foreign currency derivatives — 15 — — 15 Contingent consideration 3 — 17 — 20 Other — 13 9 — 22 Total $ 3 $ 30 $ 26 $ — $ 59 Southern Company Gas Assets: Energy-related derivatives (a) $ 8 $ 7 $ — $ — $ 15 Non-qualified deferred compensation trusts: Domestic equity — 8 — — 8 Foreign equity — 1 — — 1 Pooled funds – fixed income — 7 — — 7 Cash and cash equivalents 1 — — — 1 Cash equivalents 10 — — — 10 Total $ 19 $ 23 $ — $ — $ 42 Liabilities: Energy-related derivatives (a) $ 13 $ 6 $ — $ — $ 19 Interest rate derivatives — 62 — — 62 Total $ 13 $ 68 $ — $ — $ 81 (a) Excludes cash collateral of $22 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. Southern Company, Alabama Power, and Georgia Power continue to elect the option to fair value investment securities held in the nuclear decommissioning trust funds. The fair value of the funds, including reinvested interest and dividends and excluding the funds' expenses, increased (decreased) by the amounts shown in the table below for the three and nine months ended September 30, 2024 and 2023. 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 September 30, Nine Months Ended September 30, Fair value increases (decreases) 2024 2023 2024 2023 (in millions) Southern Company $ 97 $ (4) $ 230 $ 211 Alabama Power 67 (36) 153 54 Georgia Power 30 32 77 157 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 two of its acquisitions whereby it is primarily obligated to make generation-based payments to the seller, commencing at the commercial operation of each facility and continuing through 2026 and 2036, respectively. The obligations are primarily categorized as Level 3 under Fair Value Measurements as the fair value is determined using significant unobservable inputs for the forecasted facility's 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 the obligations 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 September 30, 2024, 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 $188 million and unfunded commitments related to the private market investments totaled $89 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 September 30, 2024, other financial instruments for which the carrying amount did not equal fair value were as follows: Southern Company (*) Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (*) (in billions) Long-term debt, including securities due within one year: Carrying amount $ 62.6 $ 11.2 $ 17.4 $ 1.7 $ 2.7 $ 8.4 Fair value 59.8 10.3 16.3 1.5 2.7 7.7 (*) The carrying amount of Southern Company Gas' long-term debt includes fair value adjustments from the effective date of the 2016 merger with Southern Company. Southern Company Gas amortizes the fair value adjustments over the remaining lives of the respective bonds, the latest being through 2043. The fair values are determined using Level 2 measurements and are based on quoted market prices for the same or similar issues or on the current rates available to the Registrants.

Derivatives

Derivatives	9 Months Ended
	Sep. 30, 2024
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. 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 natural gas 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 natural gas revenues. Energy-related derivative contracts are accounted for under one of three methods: • Regulatory Hedges – Energy-related derivative contracts designated as regulatory hedges relate primarily to the traditional electric operating companies' and the natural gas distribution utilities' fuel-hedging programs, where gains and losses are initially recorded as regulatory liabilities and assets, respectively, and then are included in fuel expense as the underlying fuel is used in operations and ultimately recovered through an approved cost recovery mechanism. • Cash Flow Hedges – Gains and losses on energy-related derivatives designated as cash flow hedges (which are mainly used to hedge anticipated purchases and sales) are initially deferred in accumulated OCI before being recognized in the statements of income in the same period and in the same income statement line item as the earnings effect of the hedged transactions. • Not Designated – Gains and losses on energy-related derivative contracts that are not designated or fail to qualify as hedges are recognized in the statements of income as incurred. Some energy-related derivative contracts require physical delivery as opposed to financial settlement, and this type of derivative is both common and prevalent within the electric and natural gas industries. When an energy-related derivative contract is settled physically, any cumulative unrealized gain or loss is reversed and the contract price is recognized in the respective line item representing the actual price of the underlying goods being delivered. At September 30, 2024, 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 (*) 479 2030 2028 Alabama Power 130 2027 — Georgia Power 127 2027 — Mississippi Power 109 2028 — Southern Power 6 2030 2024 Southern Company Gas (*) 107 2027 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 118 million mmBtu long natural gas positions and 11 million mmBtu short natural gas positions at September 30, 2024, 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 13 million mmBtu for Southern Company, which includes 3 million mmBtu for Alabama Power, 5 million mmBtu for Georgia Power, 2 million mmBtu for Mississippi Power, and 3 million mmBtu for Southern Power. For cash flow hedges of energy-related derivatives, the estimated pre-tax losses expected to be reclassified from accumulated OCI to earnings for the 12-month period ending September 30, 2025 are immaterial for Southern Company, Southern Power, and Southern Company Gas. Interest Rate Derivatives Southern Company and certain subsidiaries may enter into interest rate derivatives to hedge exposure to changes in interest rates. Derivatives related to existing variable rate securities or forecasted transactions are accounted for as cash flow hedges where the derivatives' fair value gains or losses are recorded in OCI and are reclassified into earnings at the same time and presented on the same income statement line item as the earnings effect of the hedged transactions. Derivatives related to existing fixed rate securities are accounted for as fair value hedges, where the derivatives' fair value gains or losses and hedged items' fair value gains or losses are both recorded directly to earnings on the same income statement line item. Fair value gains or losses on derivatives that are not designated or fail to qualify as hedges are recognized in the statements of income as incurred. At September 30, 2024, the following interest rate derivatives were outstanding: Notional Weighted Interest Hedge Fair Value Gain (Loss) at September 30, 2024 (in millions) (in millions) Cash Flow Hedges of Forecasted Debt Georgia Power $ 350 3.53% N/A December $ 1 Fair Value Hedges of Existing Debt Southern Company parent 400 1-month SOFR + 0.80% 1.75% March 2028 (32) Southern Company parent 1,000 1-month SOFR + 2.48% 3.70% April 2030 (124) Southern Company Gas 500 1-month SOFR + 0.49% 1.75% January 2031 (62) Southern Company $ 2,250 $ (217) For cash flow hedges of interest rate derivatives, the estimated pre-tax gains and (losses) expected to be reclassified from accumulated OCI to interest expense for the 12-month period ending September 30, 2025 are $(14) million for Southern Company and immaterial for the traditional electric operating companies and Southern Company Gas. Deferred gains and losses related to interest rate derivatives are expected to be amortized into earnings through 2054 for Southern Company, Georgia Power, and Mississippi Power, 2052 for Alabama Power, and 2046 for Southern Company Gas. Foreign Currency Derivatives Southern Company and certain subsidiaries, including Southern Power, may enter into foreign currency derivatives to hedge exposure to changes in foreign currency exchange rates, such as that arising from the issuance of debt denominated in a currency other than U.S. dollars. Derivatives related to forecasted transactions are accounted for as cash flow hedges where the derivatives' fair value gains or losses are recorded in OCI and are reclassified into earnings at the same time and on the same income statement line as the earnings effect of the hedged transactions, including foreign currency gains or losses arising from changes in the U.S. currency exchange rates. Derivatives related to existing fixed rate securities are accounted for as fair value hedges, where the derivatives' fair value gains or losses and hedged items' fair value gains or losses are both recorded directly to earnings on the same income statement line item, including foreign currency gains or losses arising from changes in the U.S. currency exchange rates. Southern Company has elected to exclude the cross-currency basis spread from the assessment of effectiveness in the fair value hedges of its foreign currency risk and record any difference between the change in the fair value of the excluded components and the amounts recognized in earnings as a component of OCI. At September 30, 2024, the following foreign currency derivatives were outstanding: Pay Notional Pay Receive Notional Receive Hedge Fair Value Gain (Loss) at September 30, 2024 (in millions) (in millions) (in millions) Cash Flow Hedges of Existing Debt Southern Power $ 564 3.78% € 500 1.85% June 2026 $ (15) Fair Value Hedges of Existing Debt Southern Company parent 1,476 3.39% 1,250 1.88% September 2027 (90) Southern Company $ 2,040 € 1,750 $ (105) For cash flow hedges of foreign currency derivatives, the estimated pre-tax losses expected to be reclassified from accumulated OCI to earnings for the 12-month period ending September 30, 2025 are immaterial for Southern Power. Derivative Financial Statement Presentation and Amounts The Registrants enter into derivative contracts that may contain certain provisions that permit intra-contract netting of derivative receivables and payables for routine billing and offsets related to events of default and settlements. Southern Company and certain subsidiaries also utilize master netting agreements to mitigate exposure to counterparty credit risk. These agreements may contain provisions that permit netting across product lines and against cash collateral. The fair value amounts of derivative assets and liabilities on the balance sheets are presented net to the extent that there are netting arrangements or similar agreements with the counterparties. The fair value of energy-related derivatives, interest rate derivatives, and foreign currency derivatives was reflected in the balance sheets as follows: At September 30, 2024 At December 31, 2023 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 Other current assets/Liabilities from risk management activities, net of collateral $ 26 $ 114 $ 12 $ 198 Other current assets/Other deferred credits and liabilities 33 73 31 117 Total derivatives designated as hedging instruments for regulatory purposes 59 187 43 315 Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Other current assets/Liabilities from risk management activities, net of collateral 1 10 — 29 Other deferred charges and assets/Other deferred credits and liabilities 3 1 3 4 Interest rate derivatives: Other current assets/Liabilities from risk management activities, net of collateral 1 63 — 74 Other deferred charges and assets/Other deferred credits and liabilities — 155 — 190 Foreign currency derivatives: Other current assets/Liabilities from risk management activities, net of collateral — 34 — 34 Other deferred charges and assets/Other deferred credits and liabilities — 71 — 88 Total derivatives designated as hedging instruments in cash flow and fair value hedges 5 334 3 419 Energy-related derivatives not designated as hedging instruments Other current assets/Liabilities from risk management activities, net of collateral 3 4 8 8 Other deferred charges and assets/Other deferred credits and liabilities 1 — 1 2 Total derivatives not designated as hedging instruments 4 4 9 10 Gross amounts recognized 68 525 55 744 Gross amounts offset (a) (34) (56) (23) (85) Net amounts recognized in the Balance Sheets (b) $ 34 $ 469 $ 32 $ 659 At September 30, 2024 At December 31, 2023 Derivative Category and Balance Sheet Location Assets Liabilities Assets Liabilities (in millions) (in millions) Alabama Power Energy-related derivatives designated as hedging instruments for regulatory purposes Other current assets/Other current liabilities $ 9 $ 40 $ 6 $ 69 Other deferred charges and assets/Other deferred credits and liabilities 12 25 9 41 Total derivatives designated as hedging instruments for regulatory purposes 21 65 15 110 Gross amounts offset (13) (13) (10) (10) Net amounts recognized in the Balance Sheets $ 8 $ 52 $ 5 $ 100 Georgia Power Energy-related derivatives designated as hedging instruments for regulatory purposes Other current assets/Other current liabilities $ 2 $ 46 $ 2 $ 82 Other deferred charges and assets/Other deferred credits and liabilities 10 19 10 42 Total derivatives designated as hedging instruments for regulatory purposes 12 65 12 124 Interest rate derivatives designated as hedging instruments in cash flow and fair value hedges Interest rate derivatives: 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 — Gross amounts recognized 14 65 13 124 Gross amounts offset (11) (11) (11) (11) Net amounts recognized in the Balance Sheets $ 3 $ 54 $ 2 $ 113 Mississippi Power Energy-related derivatives designated as hedging instruments for regulatory purposes Other current assets/Other current liabilities $ 3 $ 22 $ 3 $ 27 Other deferred charges and assets/Other deferred credits and liabilities 11 29 12 34 Total derivatives designated as hedging instruments for regulatory purposes 14 51 15 61 Gross amounts offset (13) (13) (14) (14) Net amounts recognized in the Balance Sheets $ 1 $ 38 $ 1 $ 47 At September 30, 2024 At December 31, 2023 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 $ — $ 1 $ — $ 5 Other deferred charges and assets/Other deferred credits and liabilities 3 — 3 — Foreign currency derivatives: Other current assets/Other current liabilities — 11 — 11 Other deferred charges and assets/Other deferred credits and liabilities — 4 — 11 Total derivatives designated as hedging instruments in cash flow and fair value hedges 3 16 3 27 Energy-related derivatives not designated as hedging instruments Energy-related derivatives: Other current assets/Other current liabilities — 1 — — Other deferred charges and assets/Other deferred credits and liabilities 1 — — — Total derivatives not designated as hedging instruments 1 1 — — Gross amounts recognized 4 17 3 27 Gross amounts offset (1) (1) — — Net amounts recognized in the Balance Sheets $ 3 $ 16 $ 3 $ 27 Southern Company Gas Energy-related derivatives designated as hedging instruments for regulatory purposes Other current assets/Other current liabilities $ 12 $ 6 $ 1 $ 20 Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Other current assets/Other current liabilities 1 9 — 24 Other deferred charges and assets/Other deferred credits and liabilities — 1 — 4 Interest rate derivatives: Other current assets/Other current liabilities — 15 — 20 Other deferred charges and assets/Other deferred credits and liabilities — 47 — 59 Total derivatives designated as hedging instruments in cash flow and fair value hedges 1 72 — 107 Energy-related derivatives not designated as hedging instruments Other current assets/Other current liabilities 2 3 7 8 Other deferred charges and assets/Other deferred credits and liabilities — — 1 2 Total derivatives not designated as hedging instruments 2 3 8 10 Gross amounts recognized 15 81 9 137 Gross amounts offset (a) 4 (18) 12 (50) Net amounts recognized in the Balance Sheets (b) $ 19 $ 63 $ 21 $ 87 (a) Gross amounts offset includes cash collateral held on deposit in broker margin accounts of $22 million and $62 million at September 30, 2024 and December 31, 2023, respectively. (b) Net amounts of derivative instruments outstanding exclude immaterial premium and intrinsic value associated with weather derivatives at September 30, 2024 and December 31, 2023. At September 30, 2024 and December 31, 2023, the pre-tax effects of unrealized derivative gains (losses) arising from energy-related derivative instruments designated as regulatory hedging instruments and deferred were as follows: Regulatory Hedge Unrealized Gain (Loss) Recognized in the Balance Sheet Derivative Category and Balance Sheet Southern Alabama Georgia Mississippi Southern Company Gas (in millions) At September 30, 2024: Energy-related derivatives: Other regulatory assets, current $ (102) $ (37) $ (44) $ (19) $ (2) Other regulatory assets, deferred (43) (14) (10) (19) — Other regulatory liabilities, current 12 6 — — 6 Other regulatory liabilities, deferred 3 1 1 1 — Total energy-related derivative gains (losses) $ (130) $ (44) $ (53) $ (37) $ 4 At December 31, 2023: Energy-related derivatives: Other regulatory assets, current $ (180) $ (67) $ (80) $ (25) $ (8) Other regulatory assets, deferred (87) (32) (33) (22) — Other regulatory liabilities, current 9 4 — 1 4 Other regulatory liabilities, deferred 1 — 1 — — Total energy-related derivative gains (losses) $ (257) $ (95) $ (112) $ (46) $ (4) For the three and nine months ended September 30, 2024 and 2023, 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 September 30, For the Nine Months Ended September 30, 2024 2023 2024 2023 (in millions) Southern Company Cash flow hedges: Energy-related derivatives $ (7) $ (4) $ (11) $ (55) Interest rate derivatives (8) (3) 16 (12) Foreign currency derivatives 15 (15) (4) (6) Fair value hedges (*) : Foreign currency derivatives (2) 27 (8) 28 Total $ (2) $ 5 $ (7) $ (45) Georgia Power Cash flow hedges: Interest rate derivatives $ 1 $ — $ 17 $ (3) Mississippi Power Cash flow hedges: Interest rate derivatives $ — $ — $ 7 $ — Southern Power Cash flow hedges: Energy-related derivatives $ (2) $ — $ (2) $ (14) Foreign currency derivatives 15 (15) (4) (6) Total $ 13 $ (15) $ (6) $ (20) Southern Company Gas Cash flow hedges: Energy-related derivatives $ (4) $ (4) $ (9) $ (41) Interest rate derivatives (6) (4) (5) — Total $ (10) $ (8) $ (14) $ (41) (*) Represents amounts excluded from the assessment of effectiveness for which the difference between changes in fair value and periodic amortization is recorded in OCI. For the three and nine months ended September 30, 2024 and 2023, the pre-tax effects of energy-related derivatives designated as cash flow hedging instruments on accumulated OCI were immaterial for Alabama Power. For the three and nine months ended September 30, 2024 and 2023, the pre-tax effects of cash flow and fair value hedge accounting on income were as follows: Location and Amount of Gain (Loss) Recognized in Income on Cash Flow and Fair Value Hedging Relationships For the Three Months Ended September 30, For the Nine Months Ended September 30, 2024 2023 2024 2023 (in millions) (in millions) Southern Company Total cost of natural gas $ 98 $ 102 $ 852 $ 1,199 Gain (loss) on energy-related cash flow hedges (a) (4) (4) (34) (32) Total other operations and maintenance 1,662 1,424 4,543 4,352 Gain (loss) on energy-related cash flow hedges (a) — (1) (1) (2) Total depreciation and amortization 1,210 1,143 3,537 3,365 Gain (loss) on energy-related cash flow hedges (a) (3) (5) (5) (18) Total interest expense, net of amounts capitalized (692) (620) (2,050) (1,812) Gain (loss) on interest rate cash flow hedges (a) (4) (22) (12) (31) Gain (loss) on foreign currency cash flow hedges (a) (3) (3) (9) (8) Gain (loss) on interest rate fair value hedges (b) 78 (47) 47 (50) Total other income (expense), net 147 141 450 428 Gain (loss) on foreign currency cash flow hedges (a)(c) 24 (14) 7 (4) Gain (loss) on foreign currency fair value hedges 58 (7) 79 19 Amount excluded from effectiveness testing recognized in earnings 3 (27) 8 (28) Southern Power Total depreciation and amortization $ 133 $ 130 $ 378 $ 380 Gain (loss) on energy-related cash flow hedges (a) (3) (5) (5) (18) Total interest expense, net of amounts capitalized (30) (32) (89) (98) Gain (loss) on foreign currency cash flow hedges (a) (3) (3) (9) (8) Total other income (expense), net 2 4 8 8 Gain (loss) on foreign currency cash flow hedges (a)(c) 24 (14) 7 (4) Southern Company Gas Total cost of natural gas $ 98 $ 102 $ 852 $ 1,199 Gain (loss) on energy-related cash flow hedges (a) (4) (4) (34) (32) Total other operations and maintenance 295 264 877 879 Gain (loss) on energy-related cash flow hedges (a) — (1) (1) (2) Total interest expense, net of amounts capitalized (84) (77) (250) (226) Gain (loss) on interest rate cash flow hedges (a) — (18) — (18) Gain (loss) on interest rate fair value hedges (b) 28 (11) 18 (14) (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 hedge accounting on income for interest rate derivatives were immaterial for the traditional electric operating companies for all periods presented. At September 30, 2024 and December 31, 2023, the following amounts were recorded on the balance sheets related to cumulative basis adjustments for fair value hedges: Carrying Amount of the Hedged Item Cumulative Amount of Fair Value Hedging Adjustment included in Carrying Amount of the Hedged Item Balance Sheet Location of Hedged Items At September 30, 2024 At December 31, 2023 At September 30, 2024 At December 31, 2023 (in millions) (in millions) Southern Company Long-term debt $ (3,085) $ (3,024) $ 193 $ 235 Southern Company Gas Long-term debt $ (440) $ (427) $ 57 $ 70 Pre-tax gains on energy-related derivatives not designated as hedging instruments were $6 million and $69 million for the three and nine months ended September 30, 2024, respectively, and $7 million and $36 million for the three and nine months ended September 30, 2023, respectively, and reflected in cost of natural gas on the statements of income of Southern Company and Southern Company Gas and were immaterial for the other Registrants for all periods presented. Contingent Features The Registrants do not have any credit arrangements that would require material changes in payment schedules or terminations as a result of a credit rating downgrade. There are certain derivatives that could require collateral, but not accelerated payment, in the event of various credit rating changes of certain Southern Company subsidiaries. Generally, collateral may be provided by a Southern Company guaranty, letter of credit, or cash. At September 30, 2024, the Registrants had no collateral posted with derivative counterparties to satisfy these arrangements. For Southern Company, the fair value of foreign currency derivative liabilities and 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, was $61 million at September 30, 2024. For Southern Power, the fair value of foreign currency 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, was immaterial at September 30, 2024. For the traditional electric operating companies and Southern Power, energy-related derivative liabilities with contingent features and the maximum potential collateral requirements arising from the credit-risk-related contingent features, at a rating below BBB- and/or Baa3, were immaterial at September 30, 2024. 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 September 30, 2024, cash collateral posted in these accounts was immaterial for Alabama Power and Southern 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 September 30, 2024, cash collateral held on deposit in broker margin accounts was $22 million. The Registrants are exposed to losses related to financial instruments in the event of counterparties' nonperformance. The Registrants generally enter into agreements and material transactions with counterparties that have investment grade credit ratings by Moody's and S&P or with counterparties who have posted collateral to cover potential credit exposure. The Registrants have also established risk management policies and controls to determine and monitor the creditworthiness of counterparties in order to mitigate their exposure to counterparty credit risk. Southern Company Gas uses established credit policies to determine and monitor the creditworthiness of counterparties, including requirements to post collateral or other credit security, as well as the quality of pledged collateral. Collateral or credit security is most often in the form of cash or letters of credit from an investment-grade financial institution, but may also include cash or U.S. government securities held by a trustee. Prior to entering a physical transaction, Southern Company Gas assigns its counterparties an internal credit rating and credit limit based on the counterparties' Moody's, S&P, and Fitch ratings, commercially available credit reports, and audited financial statements. Southern Company Gas may require counterparties to pledge additional collateral when deemed necessary. Southern Company Gas utilizes netting agreements whenever possible to mitigate exposure to counterparty credit risk. Netting agreements enable Southern Company Gas to net certain assets and liabilities by counterparty across product lines and against cash collateral, provided the netting and cash collateral agreements include such provisions. While the amounts due from, or owed to, counterparties are settled net, they are recorded on a gross basis on the balance sheet as energy marketing receivables and energy marketing payables. The Registrants do not anticipate a material adverse effect on their respective financial statements as a result of counterparty nonperformance.

Acquisitions and Dispositions

Acquisitions and Dispositions	9 Months Ended
	Sep. 30, 2024
Business Combination, Asset Acquisition, and Joint Venture Formation [Abstract]
Acquisitions and Dispositions	ACQUISITIONS AND DISPOSITIONS See Note 15 to the financial statements in Item 8 of the Form 10-K for additional information. Alabama Power On October 24, 2024, Alabama Power entered into an agreement to acquire all of the equity interests in Tenaska Alabama Partners, L.P., which owns and operates the Lindsay Hill Generating Station. See Note (B) under "Alabama Power – Petition for Certificate of Convenience and Necessity" for additional information. Southern Power Construction Projects During the nine months ended September 30, 2024, Southern Power completed construction of and placed in service the 150-MW South Cheyenne solar facility. In addition, Southern Power continued construction of the 200-MW first phase, the 180-MW second phase, and the 90-MW third phase of the Millers Branch solar facility. At September 30, 2024, the total cost of construction incurred for the Millers Branch project was $159 million, which is primarily included in CWIP. Project Facility Resource Approximate Nameplate Capacity ( MW ) Location Projected/ PPA Contract Period Projects Completed During the Nine Months Ended September 30, 2024 South Cheyenne Solar 150 Laramie County, WY Second quarter 2024 20 years Projects Under Construction at September 30, 2024 Millers Branch Phase I Solar 200 Haskell County, TX Fourth quarter 2025 20 years Phase II Solar 180 Haskell County, TX Second quarter 2026 15 years Phase III (*) Solar 90 Haskell County, TX Fourth quarter 2026 15 years (*) Subsequent to September 30, 2024, Southern Power committed to expand construction of Phase III by 42 MWs of capacity, substantially all of which is contracted under a 15-year PPA, with commercial operation projected to occur in the fourth quarter 2026. With the addition of the 42 MWs of capacity for Phase III, the Millers Branch project has a total of 512 MWs under construction.

Segment and Related Information

Segment and Related Information	9 Months Ended
	Sep. 30, 2024
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 $102 million and $280 million for the three and nine months ended September 30, 2024, respectively and $156 million and $406 million for the three and nine months ended September 30, 2023, respectively. Revenues from sales of natural gas from Southern Company Gas to the traditional electric operating companies and Southern Power were immaterial for all 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. All other inter-segment revenues are not material. Financial data for business segments and products and services for the three and nine months ended September 30, 2024 and 2023 was as follows: Electric Utilities Traditional Southern Eliminations Total Southern Company Gas All Eliminations Consolidated (in millions) Three Months Ended September 30, 2024 Operating revenues $ 5,927 $ 600 $ (105) $ 6,422 $ 682 $ 215 $ (45) $ 7,274 Segment net income (loss) (a)(b) 1,618 82 — 1,700 38 (201) (2) 1,535 Nine Months Ended September 30, 2024 Operating revenues $ 15,389 $ 1,597 $ (293) $ 16,693 $ 3,220 $ 598 $ (128) $ 20,383 Segment net income (loss) (a)(b)(c) 3,630 264 — 3,894 555 (569) (13) 3,867 At September 30, 2024 Goodwill $ — $ 2 $ — $ 2 $ 5,015 $ 144 $ — $ 5,161 Total assets 104,565 12,646 (547) 116,664 25,545 2,347 (600) 143,956 Three Months Ended September 30, 2023 Operating revenues $ 5,674 $ 653 $ (160) $ 6,167 $ 689 $ 154 $ (30) $ 6,980 Segment net income (loss) (a)(c)(d) 1,419 100 — 1,519 82 (179) — 1,422 Nine Months Ended September 30, 2023 Operating revenues $ 14,145 $ 1,686 $ (417) $ 15,414 $ 3,417 $ 499 $ (122) $ 19,208 Segment net income (loss) (a)(c)(d)(e) 2,852 288 — 3,140 475 (490) (4) 3,121 At December 31, 2023 Goodwill $ — $ 2 $ — $ 2 $ 5,015 $ 144 $ — $ 5,161 Total assets 100,429 12,761 (545) 112,645 25,083 2,446 (843) 139,331 (a) Attributable to Southern Company. (b) For the traditional electric operating companies, includes a pre-tax impairment loss at Alabama Power of $36 million ($27 million after tax) related to Alabama Power discontinuing the development of a multi-use commercial facility. See Note (A) under "Impairment of Long-Lived Assets" for additional information. (c) For the traditional electric operating companies, includes pre-tax charges (credits) to income at Georgia Power related to the estimated probable loss associated with the construction and completion of Plant Vogtle Units 3 and 4 of $(21) million ($(16) million after tax) for the nine months ended September 30, 2024 and $160 million ($120 million after tax) for the three and nine months ended September 30, 2023. Also includes a pre-tax gain at Georgia Power of approximately $114 million ($84 million after tax) for the nine months ended September 30, 2024 related to the sale of transmission line assets under the integrated transmission system agreement. See Note (B) under "Georgia Power" and Note 2 to the financial statements under "Georgia Power – Nuclear Construction" in Item 8 of the Form 10-K for additional information. (d) For Southern Power, includes an $18 million pre-tax loss recovery ($9 million after tax and partnership allocations) for the three and nine months ended September 30, 2023 related to an arbitration award and a $16 million pre-tax gain ($12 million after tax) on the sale of spare parts for the nine months ended September 30, 2023. See Note (C) under "General Litigation Matters – Southern Power" for additional information related to the arbitration award. (e) For Southern Company Gas, includes a pre-tax charge of approximately $38 million ($28 million after tax) associated with the disallowance of certain capital expenditures at Nicor Gas. See Note 2 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K for additional information. Products and Services Electric Utilities' Revenues Retail Wholesale Other Total (in millions) Three Months Ended September 30, 2024 $ 5,366 $ 721 $ 335 $ 6,422 Three Months Ended September 30, 2023 5,139 727 301 6,167 Nine Months Ended September 30, 2024 $ 13,793 $ 1,919 $ 981 $ 16,693 Nine Months Ended September 30, 2023 12,597 1,930 887 15,414 Southern Company Gas' Revenues Gas Gas Other Total (in millions) Three Months Ended September 30, 2024 $ 616 $ 53 $ 13 $ 682 Three Months Ended September 30, 2023 617 56 16 689 Nine Months Ended September 30, 2024 $ 2,828 $ 358 $ 34 $ 3,220 Nine Months Ended September 30, 2023 2,989 376 52 3,417 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 consist 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 California through its sale in September 2023. See Note 15 to the financial statements in Item 8 of the Form 10-K for additional information. Business segment financial data for the three and nine months ended September 30, 2024 and 2023 was as follows: Gas Distribution Operations Gas Gas Marketing Services Total All Other Eliminations Consolidated (in millions) Three Months Ended September 30, 2024 Operating revenues $ 616 $ 8 $ 53 $ 677 $ 6 $ (1) $ 682 Segment net income 21 24 (2) 43 (5) — 38 Nine Months Ended September 30, 2024 Operating revenues $ 2,828 $ 24 $ 358 $ 3,210 $ 19 $ (9) $ 3,220 Segment net income 403 77 72 552 3 — 555 Total assets at September 30, 2024 23,543 1,573 1,619 26,735 9,910 (11,100) 25,545 Three Months Ended September 30, 2023 Operating revenues $ 619 $ 8 $ 56 $ 683 $ 8 $ (2) $ 689 Segment net income (loss) 70 24 2 96 (14) — 82 Nine Months Ended September 30, 2023 Operating revenues $ 3,002 $ 24 $ 376 $ 3,402 $ 30 $ (15) $ 3,417 Segment net income (*) 352 73 59 484 (9) — 475 Total assets at December 31, 2023 22,906 1,534 1,615 26,055 9,675 (10,647) 25,083 (*) For gas distribution operations, includes a pre-tax charge of approximately $38 million ($28 million after tax) associated with the disallowance of certain capital expenditures at Nicor Gas. See Note 2 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K for additional information.

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended	9 Months Ended
	Sep. 30, 2024 shares	Sep. 30, 2024 shares
Trading Arrangements, by Individual
Material Terms of Trading Arrangement		The following table reports information regarding the adoption of "Rule 10b5-1 trading arrangements" or "non-Rule 10b5-1 trading arrangements," as defined in Item 408(a) of Regulation S-K, during the three months ended September 30, 2024 for Southern Company's directors and "officers," as defined in Rule 16a-1(f) under the Securities Exchange Act of 1934, as amended. There were no modifications or terminations of such trading arrangements during the three months ended September 30, 2024. Unless otherwise indicated, each trading arrangement listed below is a "Rule 10b5-1 trading arrangement," provides for the sale of shares of Southern Company's common stock, commences no earlier than the expiration of the cooling-off period required by Rule 10b5-1(c)(1)(ii)(B)(1) under the Securities Exchange Act of 1934, as amended, and terminates upon the earlier of the "Expiration Date" listed below or the completion of all sales. The Subsidiary Registrants had no reportable trading arrangements for the three months ended September 30, 2024. Name Title Date of Adoption Expiration Date Aggregate Number of Shares Covered Martin B. Davis Executive Vice President August 6, 2024 December 31, 2025 8,000 (1) J. Jeffrey Peoples Chairman, President, and Chief Executive Officer of Alabama Power September 5, 2024 December 31, 2025 15,625 (2) Christopher C. Womack Chairman, President, and Chief Executive Officer September 5, 2024 December 31, 2025 40,000 (1) The maximum number of shares that may be sold for Mr. Davis is the lesser of 8,000 and the number of shares that generates $400,000 in net proceeds. (2) The maximum number of shares that may be sold for Mr. Peoples is the lesser of 15,625 and the number of shares that generates $1,250,000 in net proceeds.
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false
Martin B. Davis [Member]
Trading Arrangements, by Individual
Name	Martin B. Davis
Title	Executive Vice President
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	August 6, 2024
Expiration Date	December 31, 2025
Arrangement Duration	512 days
Aggregate Available	8,000	8,000
J. Jeffrey Peoples [Member]
Trading Arrangements, by Individual
Name	J. Jeffrey Peoples
Title	Chairman, President, and Chief Executive Officer of Alabama Power
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	September 5, 2024
Expiration Date	December 31, 2025
Arrangement Duration	482 days
Aggregate Available	15,625	15,625
Christopher C. Womack [Member]
Trading Arrangements, by Individual
Name	Christopher C. Womack
Title	Chairman, President, and Chief Executive Officer
Rule 10b5-1 Arrangement Adopted	true
Adoption Date	September 5, 2024
Expiration Date	December 31, 2025
Arrangement Duration	482 days
Aggregate Available	40,000	40,000

Introduction (Policies)

Introduction (Policies)	9 Months Ended
	Sep. 30, 2024
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, 2023 have been derived from the audited financial statements of each Registrant. In the opinion of each Registrant's management, the information regarding such Registrant furnished herein reflects all adjustments, which, except as otherwise disclosed, are of a normal recurring nature, necessary to present fairly the results of operations for the periods ended September 30, 2024 and 2023. Certain information and 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.
Impairment of Long-Lived Assets	In the third quarter 2024, Alabama Power discontinued the development of a multi-use commercial facility. Given the decision to discontinue commercial development, Alabama Power performed an impairment test using a comparative market analysis and determined the carrying amount of the asset exceeded its fair value, net of selling costs. This resulted in a pre-tax impairment loss of $36 million ($27 million after tax) reflected in other operations and maintenance on the statements of income.
Goodwill	Goodwill is not amortized but is subject to an annual impairment test during the fourth quarter of each year, or more frequently if goodwill impairment indicators exist.
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	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 two of its acquisitions whereby it is primarily obligated to make generation-based payments to the seller, commencing at the commercial operation of each facility and continuing through 2026 and 2036, respectively. The obligations are primarily categorized as Level 3 under Fair Value Measurements as the fair value is determined using significant unobservable inputs for the forecasted facility's 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 the obligations 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.
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. 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 natural gas 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 natural gas revenues. Energy-related derivative contracts are accounted for under one of three methods: • Regulatory Hedges – Energy-related derivative contracts designated as regulatory hedges relate primarily to the traditional electric operating companies' and the natural gas distribution utilities' fuel-hedging programs, where gains and losses are initially recorded as regulatory liabilities and assets, respectively, and then are included in fuel expense as the underlying fuel is used in operations and ultimately recovered through an approved cost recovery mechanism. • Cash Flow Hedges – Gains and losses on energy-related derivatives designated as cash flow hedges (which are mainly used to hedge anticipated purchases and sales) are initially deferred in accumulated OCI before being recognized in the statements of income in the same period and in the same income statement line item as the earnings effect of the hedged transactions. • Not Designated – Gains and losses on energy-related derivative contracts that are not designated or fail to qualify as hedges are recognized in the statements of income as incurred. Some energy-related derivative contracts require physical delivery as opposed to financial settlement, and this type of derivative is both common and prevalent within the electric and natural gas industries. When an energy-related derivative contract is settled physically, any cumulative unrealized gain or loss is reversed and the contract price is recognized in the respective line item representing the actual price of the underlying goods being delivered. Interest Rate Derivatives Southern Company and certain subsidiaries may enter into interest rate derivatives to hedge exposure to changes in interest rates. Derivatives related to existing variable rate securities or forecasted transactions are accounted for as cash flow hedges where the derivatives' fair value gains or losses are recorded in OCI and are reclassified into earnings at the same time and presented on the same income statement line item as the earnings effect of the hedged transactions. Derivatives related to existing fixed rate securities are accounted for as fair value hedges, where the derivatives' fair value gains or losses and hedged items' fair value gains or losses are both recorded directly to earnings on the same income statement line item. Fair value gains or losses on derivatives that are not designated or fail to qualify as hedges are recognized in the statements of income as incurred. Foreign Currency Derivatives Southern Company and certain subsidiaries, including Southern Power, may enter into foreign currency derivatives to hedge exposure to changes in foreign currency exchange rates, such as that arising from the issuance of debt denominated in a currency other than U.S. dollars. Derivatives related to forecasted transactions are accounted for as cash flow hedges where the derivatives' fair value gains or losses are recorded in OCI and are reclassified into earnings at the same time and on the same income statement line as the earnings effect of the hedged transactions, including foreign currency gains or losses arising from changes in the U.S. currency exchange rates. Derivatives related to existing fixed rate securities are accounted for as fair value hedges, where the derivatives' fair value gains or losses and hedged items' fair value gains or losses are both recorded directly to earnings on the same income statement line item, including foreign currency gains or losses arising from changes in the U.S. currency exchange rates. Southern Company has elected to exclude the cross-currency basis spread from the assessment of effectiveness in the fair value hedges of its foreign currency risk and record any difference between the change in the fair value of the excluded components and the amounts recognized in earnings as a component of OCI. Derivative Financial Statement Presentation and Amounts The Registrants enter into derivative contracts that may contain certain provisions that permit intra-contract netting of derivative receivables and payables for routine billing and offsets related to events of default and settlements. Southern Company and certain subsidiaries also utilize master netting agreements to mitigate exposure to counterparty credit risk. These agreements may contain provisions that permit netting across product lines and against cash collateral. The fair value amounts of derivative assets and liabilities on the balance sheets are presented net to the extent that there are netting arrangements or similar agreements with the counterparties.

Introduction (Tables)

Introduction (Tables)	9 Months Ended
	Sep. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Goodwill	Goodwill at both September 30, 2024 and December 31, 2023 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 September 30, 2024 At December 31, 2023 Gross Carrying Amount Accumulated Amortization Other Gross Carrying Amount Accumulated Amortization Other (in millions) (in millions) Southern Company Subject to amortization: Customer relationships $ 212 $ (179) $ 33 $ 212 $ (172) $ 40 Trade names 64 (58) 6 64 (53) 11 PPA fair value adjustments 390 (163) 227 390 (148) 242 Other 3 (3) — 3 (3) — Total subject to amortization $ 669 $ (403) $ 266 $ 669 $ (376) $ 293 Not subject to amortization: FCC licenses 75 — 75 75 — 75 Total other intangible assets $ 744 $ (403) $ 341 $ 744 $ (376) $ 368 Southern Power (*) PPA fair value adjustments $ 390 $ (163) $ 227 $ 390 $ (148) $ 242 Southern Company Gas (*) Gas marketing services Customer relationships $ 156 $ (149) $ 7 $ 156 $ (145) $ 11 Trade names 26 (22) 4 26 (21) 5 Total other intangible assets $ 182 $ (171) $ 11 $ 182 $ (166) $ 16 (*) All subject to amortization.
Schedule of Other Intangible Assets, Finite-Lived	Other intangible assets were as follows: At September 30, 2024 At December 31, 2023 Gross Carrying Amount Accumulated Amortization Other Gross Carrying Amount Accumulated Amortization Other (in millions) (in millions) Southern Company Subject to amortization: Customer relationships $ 212 $ (179) $ 33 $ 212 $ (172) $ 40 Trade names 64 (58) 6 64 (53) 11 PPA fair value adjustments 390 (163) 227 390 (148) 242 Other 3 (3) — 3 (3) — Total subject to amortization $ 669 $ (403) $ 266 $ 669 $ (376) $ 293 Not subject to amortization: FCC licenses 75 — 75 75 — 75 Total other intangible assets $ 744 $ (403) $ 341 $ 744 $ (376) $ 368 Southern Power (*) PPA fair value adjustments $ 390 $ (163) $ 227 $ 390 $ (148) $ 242 Southern Company Gas (*) Gas marketing services Customer relationships $ 156 $ (149) $ 7 $ 156 $ (145) $ 11 Trade names 26 (22) 4 26 (21) 5 Total other intangible assets $ 182 $ (171) $ 11 $ 182 $ (166) $ 16 (*) All subject to amortization.
Schedule of Amortization of Other Intangible Assets	Amortization associated with other intangible assets was as follows: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 (in millions) Southern Company (a) $ 9 $ 10 $ 27 $ 27 Southern Power (b) 5 5 15 14 Southern Company Gas 2 3 5 7 (a) Includes $5 million for the three months ended September 30, 2024 and 2023 and $15 million and $14 million for the nine months ended September 30, 2024 and 2023, respectively, recorded as a reduction to operating revenues. (b) Recorded as a reduction to operating revenues.
Schedule of Restrictions on Cash and Cash Equivalents	The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the condensed balance sheets that total to the amount shown in the condensed statements of cash flows for the applicable Registrants: Southern Company Alabama Power Georgia Power Southern Power Southern (in millions) At September 30, 2024 Cash and cash equivalents $ 1,018 $ 476 $ 43 $ 179 $ 44 Restricted cash (a) : Other current assets 31 — 14 16 1 Other deferred charges and assets 7 — 7 — — Total cash, cash equivalents, and restricted cash (b) $ 1,055 $ 476 $ 64 $ 195 $ 45 At December 31, 2023 Cash and cash equivalents $ 748 $ 324 $ 9 $ 124 $ 33 Restricted cash (a) : Other current assets 141 85 37 17 2 Other deferred charges and assets 31 — 29 3 — Total cash, cash equivalents, and restricted cash (b) $ 921 $ 409 $ 75 $ 144 $ 35 (a) For Alabama Power and Georgia Power, reflects proceeds from the issuance of solid waste disposal facility revenue bonds in 2023 and 2022, respectively. For Southern Power, reflects $16 million and $17 million at September 30, 2024 and December 31, 2023, respectively, resulting from an arbitration award held to fund future replacement costs and $3 million at December 31, 2023 held to fund estimated construction completion costs at the Deuel Harvest wind facility. See Note (C) under "General Litigation Matters – Southern Power" for additional information related to the arbitration award. 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 Alabama Power Georgia Power Southern Power Southern (in millions) At September 30, 2024 Cash and cash equivalents $ 1,018 $ 476 $ 43 $ 179 $ 44 Restricted cash (a) : Other current assets 31 — 14 16 1 Other deferred charges and assets 7 — 7 — — Total cash, cash equivalents, and restricted cash (b) $ 1,055 $ 476 $ 64 $ 195 $ 45 At December 31, 2023 Cash and cash equivalents $ 748 $ 324 $ 9 $ 124 $ 33 Restricted cash (a) : Other current assets 141 85 37 17 2 Other deferred charges and assets 31 — 29 3 — Total cash, cash equivalents, and restricted cash (b) $ 921 $ 409 $ 75 $ 144 $ 35 (a) For Alabama Power and Georgia Power, reflects proceeds from the issuance of solid waste disposal facility revenue bonds in 2023 and 2022, respectively. For Southern Power, reflects $16 million and $17 million at September 30, 2024 and December 31, 2023, respectively, resulting from an arbitration award held to fund future replacement costs and $3 million at December 31, 2023 held to fund estimated construction completion costs at the Deuel Harvest wind facility. See Note (C) under "General Litigation Matters – Southern Power" for additional information related to the arbitration award. 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 nine months ended September 30, 2024 was as follows: Southern Company (*) Alabama Power Georgia Power (*) Mississippi (in millions) Balance at December 31, 2023 $ 66 $ 76 $ (54) $ 44 Accrual 45 10 24 11 Weather-related damages (1,239) (33) (1,201) (5) Balance at September 30, 2024 $ (1,128) $ 53 $ (1,231) $ 50 (*) See Note (B) under "Georgia Power – Storm Damage Recovery" for additional information.
Schedule of Estimated Cost of Decommissioning	The estimated costs of decommissioning Plant Hatch and Plant Vogtle based on Georgia Power's September 2024 site studies are as follows: Plant Hatch (*) Plant Vogtle Units 1 and 2 (*) Plant Vogtle Unit 3 and 4 (*) Decommissioning periods: Beginning year 2034 2047 2062 Completion year 2088 2092 2074 (in millions) Site study costs: Radiated structures $ 696 $ 545 $ 542 Spent fuel management 306 255 88 Non-radiated structures 77 107 89 Total site study costs $ 1,079 $ 907 $ 719 (*) Based on Georgia Power's ownership interests.

Regulatory Matters (Tables)

Regulatory Matters (Tables)	9 Months Ended
	Sep. 30, 2024
Regulated Operations [Abstract]
Schedule of Cost Recovery Clauses	The recovery balances for certain retail regulatory clauses of the traditional electric operating companies and Southern Company Gas at September 30, 2024 and December 31, 2023 were as follows: Regulatory Clause Balance Sheet Line Item September 30, December 31, 2023 (in millions) Alabama Power Rate CNP Compliance Other regulatory assets, current $ — $ 8 Other regulatory assets, deferred — 25 Other regulatory liabilities, current 4 — Other regulatory liabilities, deferred 2 — Rate CNP PPA Other regulatory assets, current 18 18 Other regulatory assets, deferred 70 85 Rate ECR Regulatory assets – under recovered retail fuel clause revenues 10 246 Georgia Power Fuel Cost Recovery Receivables – under recovered retail fuel clause revenues $ 683 $ 694 Deferred under recovered retail fuel clause revenues 632 1,211 Mississippi Power Fuel Cost Recovery (*) Receivables – customer accounts, net $ 6 $ — Deferred under recovered retail fuel clause revenues — 50 Over recovered retail fuel clause revenues — 27 Ad Valorem Tax Other regulatory assets, deferred 14 12 Southern Company Gas Natural Gas Cost Recovery Natural gas cost over recovery $ 226 $ 214 (*) Mississippi Power also has wholesale MRA and Market Based (MB) fuel cost recovery factors. At September 30, 2024 and December 31, 2023, wholesale MRA fuel costs were over recovered $16 million and $5 million, respectively, and were included in other current liabilities on Mississippi Power's balance sheets. The wholesale MB fuel cost recovery was immaterial for both periods presented.
Nuclear Construction Cost and Schedule	Georgia Power's net capital costs incurred through September 30, 2024 in connection with Plant Vogtle Units 3 and 4, and its approximate proportionate share of additional capital costs to be incurred after September 30, 2024, including completion of site demobilization and remaining contractor obligations, is as follows: (in millions) Total project capital cost forecast (a)(b) $ 10,732 Net investment at September 30, 2024 (b) (10,649) Remaining estimate to complete $ 83 (a) Includes approximately $1.2 billion of costs that are not shared with the other Vogtle Owners. Excludes financing costs capitalized through AFUDC of approximately $440 million accrued through Unit 4's in-service date. (b) Net of $1.7 billion received from Toshiba under the Guarantee Settlement Agreement and approximately $188 million in related customer refunds.

Revenue from Contracts with C_2

Revenue from Contracts with Customers and Lease Income (Tables)	9 Months Ended
	Sep. 30, 2024
Revenue from Contract with Customer [Abstract]
Schedule of Disaggregation of Revenue	The following table disaggregates revenue from contracts with customers for the three and nine months ended September 30, 2024 and 2023: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Three Months Ended September 30, 2024 Operating revenues Retail electric revenues Residential $ 2,651 $ 975 $ 1,580 $ 96 $ — $ — Commercial 1,991 607 1,288 96 — — Industrial 1,184 483 606 95 — — Other 33 3 28 2 — — Total retail electric revenues 5,859 2,068 3,502 289 — — Natural gas distribution revenues Residential 212 — — — — 212 Commercial 55 — — — — 55 Transportation 294 — — — — 294 Industrial 4 — — — — 4 Other 45 — — — — 45 Total natural gas distribution revenues 610 — — — — 610 Wholesale electric revenues PPA energy revenues 300 58 26 1 222 — PPA capacity revenues 190 24 42 15 125 — Non-PPA revenues 67 34 — 106 67 — Total wholesale electric revenues 557 116 68 122 414 — Other natural gas revenues Gas marketing services 51 — — — — 51 Other 6 — — — — 6 Total other natural gas revenues 57 — — — — 57 Other revenues 398 60 170 13 9 — Total revenue from contracts with customers 7,481 2,244 3,740 424 423 667 Other revenue sources (*) (207) (106) (268) (12) 177 15 Total operating revenues $ 7,274 $ 2,138 $ 3,472 $ 412 $ 600 $ 682 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Nine Months Ended September 30, 2024 Operating revenues Retail electric revenues Residential $ 6,551 $ 2,477 $ 3,832 $ 242 $ — $ — Commercial 5,075 1,583 3,243 249 — — Industrial 3,019 1,338 1,424 257 — — Other 94 9 78 7 — — Total retail electric revenues 14,739 5,407 8,577 755 — — Natural gas distribution revenues Residential 1,244 — — — — 1,244 Commercial 300 — — — — 300 Transportation 959 — — — — 959 Industrial 25 — — — — 25 Other 221 — — — — 221 Total natural gas distribution revenues 2,749 — — — — 2,749 Wholesale electric revenues PPA energy revenues 838 171 66 3 616 — PPA capacity revenues 495 71 106 47 320 — Non-PPA revenues 179 103 3 292 176 — Total wholesale electric revenues 1,512 345 175 342 1,112 — Other natural gas revenues Gas marketing services 352 — — — — 352 Other 16 — — — — 16 Total other natural gas revenues 368 — — — — 368 Other revenues 1,145 174 507 34 31 — Total revenue from contracts with customers 20,513 5,926 9,259 1,131 1,143 3,117 Other revenue sources (*) (130) (123) (514) (13) 454 103 Total operating revenues $ 20,383 $ 5,803 $ 8,745 $ 1,118 $ 1,597 $ 3,220 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Three Months Ended September 30, 2023 Operating revenues Retail electric revenues Residential $ 2,543 $ 969 $ 1,473 $ 101 $ — $ — Commercial 1,845 599 1,151 95 — — Industrial 1,116 498 528 90 — — Other 30 3 25 2 — — Total retail electric revenues 5,534 2,069 3,177 288 — — Natural gas distribution revenues Residential 217 — — — — 217 Commercial 56 — — — — 56 Transportation 275 — — — — 275 Industrial 4 — — — — 4 Other 60 — — — — 60 Total natural gas distribution revenues 612 — — — — 612 Wholesale electric revenues PPA energy revenues 317 66 31 2 226 — PPA capacity revenues 151 26 13 3 110 — Non-PPA revenues 101 15 21 137 126 — Total wholesale electric revenues 569 107 65 142 462 — Other natural gas revenues Gas marketing services 54 — — — — 54 Other 8 — — — — 8 Total other natural gas revenues 62 — — — — 62 Other revenues 330 54 146 10 18 — Total revenue from contracts with customers 7,107 2,230 3,388 440 480 674 Other revenue sources (*) (127) (147) (151) (4) 173 15 Total operating revenues $ 6,980 $ 2,083 $ 3,237 $ 436 $ 653 $ 689 Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Nine Months Ended September 30, 2023 Operating revenues Retail electric revenues Residential $ 5,717 $ 2,277 $ 3,202 $ 238 $ — $ — Commercial 4,464 1,493 2,733 238 — — Industrial 2,770 1,324 1,195 251 — — Other 84 10 68 6 — — Total retail electric revenues 13,035 5,104 7,198 733 — — Natural gas distribution revenues Residential 1,443 — — — — 1,443 Commercial 370 — — — — 370 Transportation 878 — — — — 878 Industrial 33 — — — — 33 Other 228 — — — — 228 Total natural gas distribution revenues 2,952 — — — — 2,952 Wholesale electric revenues PPA energy revenues 853 196 66 8 601 — PPA capacity revenues 490 130 38 36 289 — Non-PPA revenues 199 49 30 315 312 — Total wholesale electric revenues 1,542 375 134 359 1,202 — Other natural gas revenues Gas marketing services 358 — — — — 358 Other 28 — — — — 28 Total other natural gas revenues 386 — — — — 386 Other revenues 971 159 422 31 46 — Total revenue from contracts with customers 18,886 5,638 7,754 1,123 1,248 3,338 Other revenue sources (*) 322 (218) 51 14 438 79 Total operating revenues $ 19,208 $ 5,420 $ 7,805 $ 1,137 $ 1,686 $ 3,417 (*) 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 (including those related to fuel costs) 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 September 30, 2024 and December 31, 2023: Southern Company Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (in millions) Accounts Receivable At September 30, 2024 $ 2,946 $ 978 $ 1,347 $ 111 $ 125 $ 306 At December 31, 2023 2,820 821 1,011 90 122 684 Contract Assets At September 30, 2024 $ 379 $ 7 $ 202 $ — $ — $ 71 At December 31, 2023 271 2 121 — — 56 Contract Liabilities At September 30, 2024 $ 181 $ — $ 49 $ — $ 2 $ 3 At December 31, 2023 116 — 1 — 4 —
Schedule of Remaining Performance Obligations	Revenues from contracts with customers related to these performance obligations remaining at September 30, 2024 are expected to be recognized as follows: 2024 (remaining) 2025 2026 2027 2028 Thereafter (in millions) Southern Company $ 303 $ 884 $ 375 $ 336 $ 325 $ 2,180 Alabama Power 11 11 — — — — Georgia Power 21 64 26 17 17 17 Mississippi Power (*) 15 63 66 69 73 — Southern Power (*) 73 312 299 306 297 2,169 Southern Company Gas 3 2 — — — — (*) Includes performance obligations related to affiliate PPAs with Georgia Power. See Note 1 to the financial statements under "Affiliate Transactions" in Item 8 of the Form 10-K for additional information.
Schedule of Lease Income	Lease income for the three and nine months ended September 30, 2024 and 2023 is as follows: Southern Alabama Power Georgia Power Mississippi Southern Power Southern Company Gas (in millions) For the Three Months Ended September 30, 2024 Lease income - interest income on sales-type leases $ 5 $ — $ — $ 3 $ 2 $ — Lease income - operating leases 38 2 13 — 20 9 Variable lease income 142 — — — 152 — Total lease income $ 185 $ 2 $ 13 $ 3 $ 174 $ 9 For the Nine Months Ended September 30, 2024 Lease income - interest income on sales-type leases $ 18 $ — $ — $ 11 $ 7 $ — Lease income - operating leases 108 6 28 2 63 27 Variable lease income 343 — — — 370 — Total lease income $ 469 $ 6 $ 28 $ 13 $ 440 $ 27 For the Three Months Ended September 30, 2023 Lease income - interest income on sales-type leases $ 6 $ — $ — $ 4 $ 2 $ — Lease income - operating leases 36 3 7 — 21 9 Variable lease income 134 — — — 144 — Total lease income $ 176 $ 3 $ 7 $ 4 $ 167 $ 9 For the Nine Months Ended September 30, 2023 Lease income - interest income on sales-type leases $ 18 $ — $ — $ 11 $ 7 $ — Lease income - operating leases 129 32 22 2 64 27 Variable lease income 327 1 — — 351 — Total lease income $ 474 $ 33 $ 22 $ 13 $ 422 $ 27

Consolidated Entities and Equ_2

Consolidated Entities and Equity Method Investments (Tables)	9 Months Ended
	Sep. 30, 2024
Regulated Operations [Abstract]
Schedule of Equity Method Investments	The carrying amounts of Southern Company Gas' equity method investments at September 30, 2024 and December 31, 2023 were as follows: Investment Balance September 30, 2024 December 31, 2023 (in millions) SNG $ 1,246 $ 1,202 Other 33 33 Total $ 1,279 $ 1,235

Financing and Leases (Tables)

Financing and Leases (Tables)	9 Months Ended
	Sep. 30, 2024
Debt Disclosure [Abstract]
Schedule of Credit Arrangements	At September 30, 2024, committed credit arrangements with banks were as follows: Expires Company 2025 2026 2027 2029 Total Unused Expires within (in millions) Southern Company parent (a) $ 150 $ — $ — $ 1,850 $ 2,000 $ 1,998 $ 150 Alabama Power — 650 — 700 1,350 1,350 — Georgia Power 300 — — 1,750 2,050 2,026 300 Mississippi Power — — 275 — 275 275 — Southern Power (a)(b) — — — 600 600 600 — Southern Company Gas (c) 100 — — 1,500 1,600 1,598 100 SEGCO 30 — — — 30 30 30 Southern Company $ 580 $ 650 $ 275 $ 6,400 $ 7,905 $ 7,877 $ 580 (a) Arrangement expiring in 2029 represents a $2.45 billion combined arrangement for Southern Company and Southern Power as borrowers. Pursuant to the combined facility, the allocations between Southern Company and Southern Power may be adjusted. (b) 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 $10 million and $11 million, respectively, was unused at September 30, 2024. Southern Power's subsidiaries are not parties to its bank credit arrangements or letter of credit facilities. (c) 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 2029. Southern Company Gas' committed credit arrangement expiring in 2029 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 2029, the allocations between Southern Company Gas Capital and Nicor Gas may be adjusted. Nicor Gas is also the borrower under a $100 million credit arrangement expiring in 2025.
Schedule of Shares Used to Compute Diluted Earnings Per Share	Shares used to compute diluted EPS were as follows: Three Months Ended September 30, Nine Months Ended September 30, 2024 2023 2024 2023 (in millions) As reported shares 1,097 1,092 1,096 1,092 Effect of stock-based compensation 6 7 6 6 Diluted shares 1,103 1,099 1,102 1,098

Retirement Benefits (Tables)

Retirement Benefits (Tables)	9 Months Ended
	Sep. 30, 2024
Retirement Benefits [Abstract]
Schedule of Pension Plans and Postretirement Plans	Components of the net periodic benefit costs for the three and nine months ended September 30, 2024 and 2023 are presented in the following tables. Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) Three Months Ended September 30, 2024 Pension Plans Service cost $ 73 $ 17 $ 18 $ 3 $ 2 $ 7 Interest cost 159 37 47 7 2 11 Expected return on plan assets (316) (77) (99) (14) (4) (21) Amortization: Prior service costs — — — — — (1) Regulatory asset — — — — — 4 Net (gain) loss 14 4 6 — (1) — Net periodic pension income $ (70) $ (19) $ (28) $ (4) $ (1) $ — Postretirement Benefits Service cost $ 4 $ 1 $ 1 $ — $ — $ — Interest cost 16 4 6 1 — 2 Expected return on plan assets (22) (9) (8) (1) — (2) Amortization: Prior service costs 1 — 1 — — — Regulatory asset — — — — — 2 Net (gain) loss (4) — (3) 1 — (1) Net periodic postretirement benefit cost (income) $ (5) $ (4) $ (3) $ 1 $ — $ 1 Nine Months Ended September 30, 2024 Pension Plans Service cost $ 219 $ 51 $ 53 $ 9 $ 5 $ 21 Interest cost 476 111 143 21 6 32 Expected return on plan assets (947) (230) (296) (43) (12) (64) Amortization: Prior service costs — — 1 — — (2) Regulatory asset — — — — — 11 Net loss 41 12 15 2 — — Net periodic pension income $ (211) $ (56) $ (84) $ (11) $ (1) $ (2) Postretirement Benefits Service cost $ 11 $ 3 $ 3 $ — $ — $ 1 Interest cost 49 12 17 2 — 6 Expected return on plan assets (66) (26) (24) (1) — (6) Amortization: Prior service costs 2 — 1 — — — Regulatory asset — — — — — 5 Net gain (12) (2) (4) — — (4) Net periodic postretirement benefit cost (income) $ (16) $ (13) $ (7) $ 1 $ — $ 2 Southern Alabama Georgia Mississippi Southern Power Southern Company Gas (in millions) Three Months Ended September 30, 2023 Pension Plans Service cost $ 69 $ 16 $ 17 $ 2 $ 2 $ 6 Interest cost 156 37 48 7 2 11 Expected return on plan assets (307) (75) (97) (13) (4) (22) Amortization: Prior service costs — — — — — (1) Regulatory asset — — — — — 4 Net (gain) loss 8 2 4 1 — (1) Net periodic pension income $ (74) $ (20) $ (28) $ (3) $ — $ (3) Postretirement Benefits Service cost $ 4 $ 1 $ 1 $ — $ — $ — Interest cost 18 5 6 1 — 2 Expected return on plan assets (21) (9) (7) (1) — (2) Amortization: Prior service costs — — 1 — — — Regulatory asset — — — — — 2 Net gain (4) (1) (1) — — (1) Net periodic postretirement benefit cost (income) $ (3) $ (4) $ — $ — $ — $ 1 Nine Months Ended September 30, 2023 Pension Plans Service cost $ 207 $ 48 $ 51 $ 8 $ 5 $ 18 Interest cost 469 109 143 21 6 32 Expected return on plan assets (922) (223) (289) (41) (12) (65) Amortization: Prior service costs — — 1 — — (2) Regulatory asset — — — — — 11 Net (gain) loss 24 7 10 1 — (3) Net periodic pension income $ (222) $ (59) $ (84) $ (11) $ (1) $ (9) Postretirement Benefits Service cost $ 11 $ 3 $ 3 $ — $ — $ 1 Interest cost 53 13 19 2 — 6 Expected return on plan assets (62) (26) (22) (1) — (5) Amortization: Prior service costs 1 — 1 — — — Regulatory asset — — — — — 5 Net gain (10) (2) (3) — — (3) Net periodic postretirement benefit cost (income) $ (7) $ (12) $ (2) $ 1 $ — $ 4

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2024
Fair Value Disclosures [Abstract]
Schedule of Assets and Liabilities Measured at Fair Value	At September 30, 2024, assets and liabilities measured at fair value on a recurring basis during the period, together with their associated level of the fair value hierarchy, were as follows: Fair Value Measurements Using: At September 30, 2024 Quoted Prices Significant Significant Net Asset Value as a Practical Expedient (NAV) Total (in millions) Southern Company Assets: Energy-related derivatives (a) $ 8 $ 59 $ — $ — $ 67 Interest rate derivatives — 1 — — 1 Investments in trusts: (b) Domestic equity 843 255 — — 1,098 Foreign equity 163 189 — — 352 U.S. Treasury and government agency securities — 368 — — 368 Municipal bonds — 50 — — 50 Pooled funds – fixed income — 7 — — 7 Corporate bonds — 464 — — 464 Mortgage and asset backed securities — 106 — — 106 Private equity — — — 179 179 Cash and cash equivalents 1 — — — 1 Other 28 3 — 9 40 Cash equivalents and restricted cash 336 16 — — 352 Other investments 9 28 8 — 45 Total $ 1,388 $ 1,546 $ 8 $ 188 $ 3,130 Liabilities: Energy-related derivatives (a) $ 13 $ 189 $ — $ — $ 202 Interest rate derivatives — 218 — — 218 Foreign currency derivatives — 105 — — 105 Contingent consideration 3 — 17 — 20 Other — 13 9 — 22 Total $ 16 $ 525 $ 26 $ — $ 567 Fair Value Measurements Using: At September 30, 2024 Quoted Prices Significant Significant Net Asset Value as a Practical Expedient (NAV) Total (in millions) Alabama Power Assets: Energy-related derivatives $ — $ 21 $ — $ — $ 21 Nuclear decommissioning trusts: (b) Domestic equity 460 246 — — 706 Foreign equity 163 — — — 163 U.S. Treasury and government agency securities — 18 — — 18 Municipal bonds — 1 — — 1 Corporate bonds — 286 — — 286 Mortgage and asset backed securities — 29 — — 29 Private equity — — — 179 179 Other 5 1 — 9 15 Cash equivalents and restricted cash 197 16 — — 213 Other investments — 28 — — 28 Total $ 825 $ 646 $ — $ 188 $ 1,659 Liabilities: Energy-related derivatives $ — $ 65 $ — $ — $ 65 Georgia Power Assets: Energy-related derivatives $ — $ 13 $ — $ — $ 13 Interest rate derivatives — 1 — — 1 Nuclear decommissioning trusts: (b) Domestic equity 383 1 — — 384 Foreign equity — 188 — — 188 U.S. Treasury and government agency securities — 350 — — 350 Municipal bonds — 49 — — 49 Corporate bonds — 178 — — 178 Mortgage and asset backed securities — 77 — — 77 Other 23 2 — — 25 Total $ 406 $ 859 $ — $ — $ 1,265 Liabilities: Energy-related derivatives $ — $ 65 $ — $ — $ 65 Fair Value Measurements Using: At September 30, 2024 Quoted Prices Significant Significant Net Asset Value as a Practical Expedient (NAV) Total (in millions) Mississippi Power Assets: Energy-related derivatives $ — $ 14 $ — $ — $ 14 Liabilities: Energy-related derivatives $ — $ 51 $ — $ — $ 51 Southern Power Assets: Energy-related derivatives $ — $ 4 $ — $ — $ 4 Liabilities: Energy-related derivatives $ — $ 2 $ — $ — $ 2 Foreign currency derivatives — 15 — — 15 Contingent consideration 3 — 17 — 20 Other — 13 9 — 22 Total $ 3 $ 30 $ 26 $ — $ 59 Southern Company Gas Assets: Energy-related derivatives (a) $ 8 $ 7 $ — $ — $ 15 Non-qualified deferred compensation trusts: Domestic equity — 8 — — 8 Foreign equity — 1 — — 1 Pooled funds – fixed income — 7 — — 7 Cash and cash equivalents 1 — — — 1 Cash equivalents 10 — — — 10 Total $ 19 $ 23 $ — $ — $ 42 Liabilities: Energy-related derivatives (a) $ 13 $ 6 $ — $ — $ 19 Interest rate derivatives — 62 — — 62 Total $ 13 $ 68 $ — $ — $ 81 (a) Excludes cash collateral of $22 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.
Schedule of Increase (Decrease) In Fair Value Of Funds	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 September 30, Nine Months Ended September 30, Fair value increases (decreases) 2024 2023 2024 2023 (in millions) Southern Company $ 97 $ (4) $ 230 $ 211 Alabama Power 67 (36) 153 54 Georgia Power 30 32 77 157
Schedule of Financial Instruments for which Carrying Amount Did Not Equal Fair Value	At September 30, 2024, other financial instruments for which the carrying amount did not equal fair value were as follows: Southern Company (*) Alabama Power Georgia Power Mississippi Power Southern Power Southern Company Gas (*) (in billions) Long-term debt, including securities due within one year: Carrying amount $ 62.6 $ 11.2 $ 17.4 $ 1.7 $ 2.7 $ 8.4 Fair value 59.8 10.3 16.3 1.5 2.7 7.7 (*) The carrying amount of Southern Company Gas' long-term debt includes fair value adjustments from the effective date of the 2016 merger with Southern Company. Southern Company Gas amortizes the fair value adjustments over the remaining lives of the respective bonds, the latest being through 2043.

Derivatives (Tables)

Derivatives (Tables)	9 Months Ended
	Sep. 30, 2024
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Schedule of Energy-Related Derivatives	At September 30, 2024, 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 (*) 479 2030 2028 Alabama Power 130 2027 — Georgia Power 127 2027 — Mississippi Power 109 2028 — Southern Power 6 2030 2024 Southern Company Gas (*) 107 2027 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 118 million mmBtu long natural gas positions and 11 million mmBtu short natural gas positions at September 30, 2024, which is also included in Southern Company's total volume.
Schedule of Interest Rate Derivatives	At September 30, 2024, the following interest rate derivatives were outstanding: Notional Weighted Interest Hedge Fair Value Gain (Loss) at September 30, 2024 (in millions) (in millions) Cash Flow Hedges of Forecasted Debt Georgia Power $ 350 3.53% N/A December $ 1 Fair Value Hedges of Existing Debt Southern Company parent 400 1-month SOFR + 0.80% 1.75% March 2028 (32) Southern Company parent 1,000 1-month SOFR + 2.48% 3.70% April 2030 (124) Southern Company Gas 500 1-month SOFR + 0.49% 1.75% January 2031 (62) Southern Company $ 2,250 $ (217)
Schedule of Foreign Currency Derivatives	At September 30, 2024, the following foreign currency derivatives were outstanding: Pay Notional Pay Receive Notional Receive Hedge Fair Value Gain (Loss) at September 30, 2024 (in millions) (in millions) (in millions) Cash Flow Hedges of Existing Debt Southern Power $ 564 3.78% € 500 1.85% June 2026 $ (15) Fair Value Hedges of Existing Debt Southern Company parent 1,476 3.39% 1,250 1.88% September 2027 (90) Southern Company $ 2,040 € 1,750 $ (105)
Schedule of Derivative Category and Balance Sheet Location	The fair value of energy-related derivatives, interest rate derivatives, and foreign currency derivatives was reflected in the balance sheets as follows: At September 30, 2024 At December 31, 2023 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 Other current assets/Liabilities from risk management activities, net of collateral $ 26 $ 114 $ 12 $ 198 Other current assets/Other deferred credits and liabilities 33 73 31 117 Total derivatives designated as hedging instruments for regulatory purposes 59 187 43 315 Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Other current assets/Liabilities from risk management activities, net of collateral 1 10 — 29 Other deferred charges and assets/Other deferred credits and liabilities 3 1 3 4 Interest rate derivatives: Other current assets/Liabilities from risk management activities, net of collateral 1 63 — 74 Other deferred charges and assets/Other deferred credits and liabilities — 155 — 190 Foreign currency derivatives: Other current assets/Liabilities from risk management activities, net of collateral — 34 — 34 Other deferred charges and assets/Other deferred credits and liabilities — 71 — 88 Total derivatives designated as hedging instruments in cash flow and fair value hedges 5 334 3 419 Energy-related derivatives not designated as hedging instruments Other current assets/Liabilities from risk management activities, net of collateral 3 4 8 8 Other deferred charges and assets/Other deferred credits and liabilities 1 — 1 2 Total derivatives not designated as hedging instruments 4 4 9 10 Gross amounts recognized 68 525 55 744 Gross amounts offset (a) (34) (56) (23) (85) Net amounts recognized in the Balance Sheets (b) $ 34 $ 469 $ 32 $ 659 At September 30, 2024 At December 31, 2023 Derivative Category and Balance Sheet Location Assets Liabilities Assets Liabilities (in millions) (in millions) Alabama Power Energy-related derivatives designated as hedging instruments for regulatory purposes Other current assets/Other current liabilities $ 9 $ 40 $ 6 $ 69 Other deferred charges and assets/Other deferred credits and liabilities 12 25 9 41 Total derivatives designated as hedging instruments for regulatory purposes 21 65 15 110 Gross amounts offset (13) (13) (10) (10) Net amounts recognized in the Balance Sheets $ 8 $ 52 $ 5 $ 100 Georgia Power Energy-related derivatives designated as hedging instruments for regulatory purposes Other current assets/Other current liabilities $ 2 $ 46 $ 2 $ 82 Other deferred charges and assets/Other deferred credits and liabilities 10 19 10 42 Total derivatives designated as hedging instruments for regulatory purposes 12 65 12 124 Interest rate derivatives designated as hedging instruments in cash flow and fair value hedges Interest rate derivatives: 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 — Gross amounts recognized 14 65 13 124 Gross amounts offset (11) (11) (11) (11) Net amounts recognized in the Balance Sheets $ 3 $ 54 $ 2 $ 113 Mississippi Power Energy-related derivatives designated as hedging instruments for regulatory purposes Other current assets/Other current liabilities $ 3 $ 22 $ 3 $ 27 Other deferred charges and assets/Other deferred credits and liabilities 11 29 12 34 Total derivatives designated as hedging instruments for regulatory purposes 14 51 15 61 Gross amounts offset (13) (13) (14) (14) Net amounts recognized in the Balance Sheets $ 1 $ 38 $ 1 $ 47 At September 30, 2024 At December 31, 2023 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 $ — $ 1 $ — $ 5 Other deferred charges and assets/Other deferred credits and liabilities 3 — 3 — Foreign currency derivatives: Other current assets/Other current liabilities — 11 — 11 Other deferred charges and assets/Other deferred credits and liabilities — 4 — 11 Total derivatives designated as hedging instruments in cash flow and fair value hedges 3 16 3 27 Energy-related derivatives not designated as hedging instruments Energy-related derivatives: Other current assets/Other current liabilities — 1 — — Other deferred charges and assets/Other deferred credits and liabilities 1 — — — Total derivatives not designated as hedging instruments 1 1 — — Gross amounts recognized 4 17 3 27 Gross amounts offset (1) (1) — — Net amounts recognized in the Balance Sheets $ 3 $ 16 $ 3 $ 27 Southern Company Gas Energy-related derivatives designated as hedging instruments for regulatory purposes Other current assets/Other current liabilities $ 12 $ 6 $ 1 $ 20 Derivatives designated as hedging instruments in cash flow and fair value hedges Energy-related derivatives: Other current assets/Other current liabilities 1 9 — 24 Other deferred charges and assets/Other deferred credits and liabilities — 1 — 4 Interest rate derivatives: Other current assets/Other current liabilities — 15 — 20 Other deferred charges and assets/Other deferred credits and liabilities — 47 — 59 Total derivatives designated as hedging instruments in cash flow and fair value hedges 1 72 — 107 Energy-related derivatives not designated as hedging instruments Other current assets/Other current liabilities 2 3 7 8 Other deferred charges and assets/Other deferred credits and liabilities — — 1 2 Total derivatives not designated as hedging instruments 2 3 8 10 Gross amounts recognized 15 81 9 137 Gross amounts offset (a) 4 (18) 12 (50) Net amounts recognized in the Balance Sheets (b) $ 19 $ 63 $ 21 $ 87 (a) Gross amounts offset includes cash collateral held on deposit in broker margin accounts of $22 million and $62 million at September 30, 2024 and December 31, 2023, respectively. (b) Net amounts of derivative instruments outstanding exclude immaterial premium and intrinsic value associated with weather derivatives at September 30, 2024 and December 31, 2023.
Schedule of Pre-tax Effects of Unrealized Derivative Gains (Losses)	At September 30, 2024 and December 31, 2023, the pre-tax effects of unrealized derivative gains (losses) arising from energy-related derivative instruments designated as regulatory hedging instruments and deferred were as follows: Regulatory Hedge Unrealized Gain (Loss) Recognized in the Balance Sheet Derivative Category and Balance Sheet Southern Alabama Georgia Mississippi Southern Company Gas (in millions) At September 30, 2024: Energy-related derivatives: Other regulatory assets, current $ (102) $ (37) $ (44) $ (19) $ (2) Other regulatory assets, deferred (43) (14) (10) (19) — Other regulatory liabilities, current 12 6 — — 6 Other regulatory liabilities, deferred 3 1 1 1 — Total energy-related derivative gains (losses) $ (130) $ (44) $ (53) $ (37) $ 4 At December 31, 2023: Energy-related derivatives: Other regulatory assets, current $ (180) $ (67) $ (80) $ (25) $ (8) Other regulatory assets, deferred (87) (32) (33) (22) — Other regulatory liabilities, current 9 4 — 1 4 Other regulatory liabilities, deferred 1 — 1 — — Total energy-related derivative gains (losses) $ (257) $ (95) $ (112) $ (46) $ (4)
Schedule of Pre-Tax Effects of Hedging on AOCI	For the three and nine months ended September 30, 2024 and 2023, 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 September 30, For the Nine Months Ended September 30, 2024 2023 2024 2023 (in millions) Southern Company Cash flow hedges: Energy-related derivatives $ (7) $ (4) $ (11) $ (55) Interest rate derivatives (8) (3) 16 (12) Foreign currency derivatives 15 (15) (4) (6) Fair value hedges (*) : Foreign currency derivatives (2) 27 (8) 28 Total $ (2) $ 5 $ (7) $ (45) Georgia Power Cash flow hedges: Interest rate derivatives $ 1 $ — $ 17 $ (3) Mississippi Power Cash flow hedges: Interest rate derivatives $ — $ — $ 7 $ — Southern Power Cash flow hedges: Energy-related derivatives $ (2) $ — $ (2) $ (14) Foreign currency derivatives 15 (15) (4) (6) Total $ 13 $ (15) $ (6) $ (20) Southern Company Gas Cash flow hedges: Energy-related derivatives $ (4) $ (4) $ (9) $ (41) Interest rate derivatives (6) (4) (5) — Total $ (10) $ (8) $ (14) $ (41) (*) 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 and nine months ended September 30, 2024 and 2023, the pre-tax effects of cash flow and fair value hedge accounting on income were as follows: Location and Amount of Gain (Loss) Recognized in Income on Cash Flow and Fair Value Hedging Relationships For the Three Months Ended September 30, For the Nine Months Ended September 30, 2024 2023 2024 2023 (in millions) (in millions) Southern Company Total cost of natural gas $ 98 $ 102 $ 852 $ 1,199 Gain (loss) on energy-related cash flow hedges (a) (4) (4) (34) (32) Total other operations and maintenance 1,662 1,424 4,543 4,352 Gain (loss) on energy-related cash flow hedges (a) — (1) (1) (2) Total depreciation and amortization 1,210 1,143 3,537 3,365 Gain (loss) on energy-related cash flow hedges (a) (3) (5) (5) (18) Total interest expense, net of amounts capitalized (692) (620) (2,050) (1,812) Gain (loss) on interest rate cash flow hedges (a) (4) (22) (12) (31) Gain (loss) on foreign currency cash flow hedges (a) (3) (3) (9) (8) Gain (loss) on interest rate fair value hedges (b) 78 (47) 47 (50) Total other income (expense), net 147 141 450 428 Gain (loss) on foreign currency cash flow hedges (a)(c) 24 (14) 7 (4) Gain (loss) on foreign currency fair value hedges 58 (7) 79 19 Amount excluded from effectiveness testing recognized in earnings 3 (27) 8 (28) Southern Power Total depreciation and amortization $ 133 $ 130 $ 378 $ 380 Gain (loss) on energy-related cash flow hedges (a) (3) (5) (5) (18) Total interest expense, net of amounts capitalized (30) (32) (89) (98) Gain (loss) on foreign currency cash flow hedges (a) (3) (3) (9) (8) Total other income (expense), net 2 4 8 8 Gain (loss) on foreign currency cash flow hedges (a)(c) 24 (14) 7 (4) Southern Company Gas Total cost of natural gas $ 98 $ 102 $ 852 $ 1,199 Gain (loss) on energy-related cash flow hedges (a) (4) (4) (34) (32) Total other operations and maintenance 295 264 877 879 Gain (loss) on energy-related cash flow hedges (a) — (1) (1) (2) Total interest expense, net of amounts capitalized (84) (77) (250) (226) Gain (loss) on interest rate cash flow hedges (a) — (18) — (18) Gain (loss) on interest rate fair value hedges (b) 28 (11) 18 (14) (a) Reclassified from accumulated OCI into earnings. (b) For fair value hedges, changes in the fair value of the derivative contracts are generally equal to changes in the fair value of the underlying debt and have no material impact on income. (c) The reclassification from accumulated OCI into other income (expense), net completely offsets currency gains and losses arising from changes in the U.S. currency exchange rates used to record the euro-denominated notes.
Schedule of Cumulative Basis Adjustments for Fair Value Hedges	At September 30, 2024 and December 31, 2023, the following amounts were recorded on the balance sheets related to cumulative basis adjustments for fair value hedges: Carrying Amount of the Hedged Item Cumulative Amount of Fair Value Hedging Adjustment included in Carrying Amount of the Hedged Item Balance Sheet Location of Hedged Items At September 30, 2024 At December 31, 2023 At September 30, 2024 At December 31, 2023 (in millions) (in millions) Southern Company Long-term debt $ (3,085) $ (3,024) $ 193 $ 235 Southern Company Gas Long-term debt $ (440) $ (427) $ 57 $ 70

Acquisitions and Dispositions (

Acquisitions and Dispositions (Tables)	9 Months Ended
	Sep. 30, 2024
Business Combination, Asset Acquisition, and Joint Venture Formation [Abstract]
Schedule of Asset Acquisitions	Project Facility Resource Approximate Nameplate Capacity ( MW ) Location Projected/ PPA Contract Period Projects Completed During the Nine Months Ended September 30, 2024 South Cheyenne Solar 150 Laramie County, WY Second quarter 2024 20 years Projects Under Construction at September 30, 2024 Millers Branch Phase I Solar 200 Haskell County, TX Fourth quarter 2025 20 years Phase II Solar 180 Haskell County, TX Second quarter 2026 15 years Phase III (*) Solar 90 Haskell County, TX Fourth quarter 2026 15 years (*) Subsequent to September 30, 2024, Southern Power committed to expand construction of Phase III by 42 MWs of capacity, substantially all of which is contracted under a 15-year PPA, with commercial operation projected to occur in the fourth quarter 2026. With the addition of the 42 MWs of capacity for Phase III, the Millers Branch project has a total of 512 MWs under construction.

Segment and Related Informati_2

Segment and Related Information (Tables)	9 Months Ended
	Sep. 30, 2024
Segment Reporting [Abstract]
Schedule of Financial Data for Business Segments	Financial data for business segments and products and services for the three and nine months ended September 30, 2024 and 2023 was as follows: Electric Utilities Traditional Southern Eliminations Total Southern Company Gas All Eliminations Consolidated (in millions) Three Months Ended September 30, 2024 Operating revenues $ 5,927 $ 600 $ (105) $ 6,422 $ 682 $ 215 $ (45) $ 7,274 Segment net income (loss) (a)(b) 1,618 82 — 1,700 38 (201) (2) 1,535 Nine Months Ended September 30, 2024 Operating revenues $ 15,389 $ 1,597 $ (293) $ 16,693 $ 3,220 $ 598 $ (128) $ 20,383 Segment net income (loss) (a)(b)(c) 3,630 264 — 3,894 555 (569) (13) 3,867 At September 30, 2024 Goodwill $ — $ 2 $ — $ 2 $ 5,015 $ 144 $ — $ 5,161 Total assets 104,565 12,646 (547) 116,664 25,545 2,347 (600) 143,956 Three Months Ended September 30, 2023 Operating revenues $ 5,674 $ 653 $ (160) $ 6,167 $ 689 $ 154 $ (30) $ 6,980 Segment net income (loss) (a)(c)(d) 1,419 100 — 1,519 82 (179) — 1,422 Nine Months Ended September 30, 2023 Operating revenues $ 14,145 $ 1,686 $ (417) $ 15,414 $ 3,417 $ 499 $ (122) $ 19,208 Segment net income (loss) (a)(c)(d)(e) 2,852 288 — 3,140 475 (490) (4) 3,121 At December 31, 2023 Goodwill $ — $ 2 $ — $ 2 $ 5,015 $ 144 $ — $ 5,161 Total assets 100,429 12,761 (545) 112,645 25,083 2,446 (843) 139,331 (a) Attributable to Southern Company. (b) For the traditional electric operating companies, includes a pre-tax impairment loss at Alabama Power of $36 million ($27 million after tax) related to Alabama Power discontinuing the development of a multi-use commercial facility. See Note (A) under "Impairment of Long-Lived Assets" for additional information. (c) For the traditional electric operating companies, includes pre-tax charges (credits) to income at Georgia Power related to the estimated probable loss associated with the construction and completion of Plant Vogtle Units 3 and 4 of $(21) million ($(16) million after tax) for the nine months ended September 30, 2024 and $160 million ($120 million after tax) for the three and nine months ended September 30, 2023. Also includes a pre-tax gain at Georgia Power of approximately $114 million ($84 million after tax) for the nine months ended September 30, 2024 related to the sale of transmission line assets under the integrated transmission system agreement. See Note (B) under "Georgia Power" and Note 2 to the financial statements under "Georgia Power – Nuclear Construction" in Item 8 of the Form 10-K for additional information. (d) For Southern Power, includes an $18 million pre-tax loss recovery ($9 million after tax and partnership allocations) for the three and nine months ended September 30, 2023 related to an arbitration award and a $16 million pre-tax gain ($12 million after tax) on the sale of spare parts for the nine months ended September 30, 2023. See Note (C) under "General Litigation Matters – Southern Power" for additional information related to the arbitration award. (e) For Southern Company Gas, includes a pre-tax charge of approximately $38 million ($28 million after tax) associated with the disallowance of certain capital expenditures at Nicor Gas. See Note 2 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K for additional information. Business segment financial data for the three and nine months ended September 30, 2024 and 2023 was as follows: Gas Distribution Operations Gas Gas Marketing Services Total All Other Eliminations Consolidated (in millions) Three Months Ended September 30, 2024 Operating revenues $ 616 $ 8 $ 53 $ 677 $ 6 $ (1) $ 682 Segment net income 21 24 (2) 43 (5) — 38 Nine Months Ended September 30, 2024 Operating revenues $ 2,828 $ 24 $ 358 $ 3,210 $ 19 $ (9) $ 3,220 Segment net income 403 77 72 552 3 — 555 Total assets at September 30, 2024 23,543 1,573 1,619 26,735 9,910 (11,100) 25,545 Three Months Ended September 30, 2023 Operating revenues $ 619 $ 8 $ 56 $ 683 $ 8 $ (2) $ 689 Segment net income (loss) 70 24 2 96 (14) — 82 Nine Months Ended September 30, 2023 Operating revenues $ 3,002 $ 24 $ 376 $ 3,402 $ 30 $ (15) $ 3,417 Segment net income (*) 352 73 59 484 (9) — 475 Total assets at December 31, 2023 22,906 1,534 1,615 26,055 9,675 (10,647) 25,083 (*) For gas distribution operations, includes a pre-tax charge of approximately $38 million ($28 million after tax) associated with the disallowance of certain capital expenditures at Nicor Gas. See Note 2 to the financial statements under "Southern Company Gas" in Item 8 of the Form 10-K for additional information.
Schedule of Financial Data for Products and Services	Electric Utilities' Revenues Retail Wholesale Other Total (in millions) Three Months Ended September 30, 2024 $ 5,366 $ 721 $ 335 $ 6,422 Three Months Ended September 30, 2023 5,139 727 301 6,167 Nine Months Ended September 30, 2024 $ 13,793 $ 1,919 $ 981 $ 16,693 Nine Months Ended September 30, 2023 12,597 1,930 887 15,414 Southern Company Gas' Revenues Gas Gas Other Total (in millions) Three Months Ended September 30, 2024 $ 616 $ 53 $ 13 $ 682 Three Months Ended September 30, 2023 617 56 16 689 Nine Months Ended September 30, 2024 $ 2,828 $ 358 $ 34 $ 3,220 Nine Months Ended September 30, 2023 2,989 376 52 3,417

Introduction - Schedule of Good

Introduction - Schedule of Goodwill (Details) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Goodwill [Line Items]
Goodwill	$ 5,161	$ 5,161
ALABAMA POWER CO
Goodwill [Line Items]
Pre tax impairment loss	36
After tax impairment loss	27
SOUTHERN Co GAS
Goodwill [Line Items]
Goodwill	5,015	5,015
SOUTHERN Co GAS | Gas distribution operations
Goodwill [Line Items]
Goodwill	4,034	4,034
SOUTHERN Co GAS | Gas marketing services
Goodwill [Line Items]
Goodwill	$ 981	$ 981

Introduction - Schedule of Othe

Introduction - Schedule of Other Intangible Assets (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Subject to amortization:
Gross Carrying Amount	$ 669	$ 669
Accumulated Amortization	(403)	(376)
Other Intangible Assets, Net	266	293
Not subject to amortization:
FCC licenses	75	75
Total other intangible assets
Gross Carrying Amount	744	744
Accumulated Amortization	(403)	(376)
Other Intangible Assets, Net	341	368
Customer relationships
Subject to amortization:
Gross Carrying Amount	212	212
Accumulated Amortization	(179)	(172)
Other Intangible Assets, Net	33	40
Total other intangible assets
Accumulated Amortization	(179)	(172)
Trade names
Subject to amortization:
Gross Carrying Amount	64	64
Accumulated Amortization	(58)	(53)
Other Intangible Assets, Net	6	11
Total other intangible assets
Accumulated Amortization	(58)	(53)
PPA fair value adjustments
Subject to amortization:
Gross Carrying Amount	390	390
Accumulated Amortization	(163)	(148)
Other Intangible Assets, Net	227	242
Total other intangible assets
Accumulated Amortization	(163)	(148)
Other
Subject to amortization:
Gross Carrying Amount	3	3
Accumulated Amortization	(3)	(3)
Other Intangible Assets, Net	0	0
Total other intangible assets
Accumulated Amortization	(3)	(3)
SOUTHERN POWER CO
Subject to amortization:
Accumulated Amortization	(163)	(148)
Total other intangible assets
Accumulated Amortization	(163)	(148)
SOUTHERN POWER CO | PPA fair value adjustments
Subject to amortization:
Gross Carrying Amount	390	390
Accumulated Amortization	(163)	(148)
Other Intangible Assets, Net	227	242
Total other intangible assets
Accumulated Amortization	(163)	(148)
SOUTHERN Co GAS
Subject to amortization:
Gross Carrying Amount	182	182
Accumulated Amortization	(171)	(166)
Other Intangible Assets, Net	11	16
Total other intangible assets
Accumulated Amortization	(171)	(166)
Other Intangible Assets, Net	11	16
SOUTHERN Co GAS | Customer relationships
Subject to amortization:
Gross Carrying Amount	156	156
Accumulated Amortization	(149)	(145)
Other Intangible Assets, Net	7	11
Total other intangible assets
Accumulated Amortization	(149)	(145)
SOUTHERN Co GAS | Trade names
Subject to amortization:
Gross Carrying Amount	26	26
Accumulated Amortization	(22)	(21)
Other Intangible Assets, Net	4	5
Total other intangible assets
Accumulated Amortization	$ (22)	$ (21)

Introduction - Schedule of Amor

Introduction - Schedule of Amortization of Other Intangible Assets (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 9	$ 10	$ 27	$ 27
Decrease in operating revenues	5	5	15	14
SOUTHERN POWER CO
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	5	5	15	14
SOUTHERN Co GAS
Finite-Lived Intangible Assets [Line Items]
Amortization of intangible assets	$ 2	$ 3	$ 5	$ 7

Introduction - Schedule of Cash

Introduction - Schedule of Cash, Cash Equivalents, and Restricted Cash (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023	Sep. 30, 2023	Dec. 31, 2022
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	$ 1,018	$ 748
Restricted cash:
Total cash, cash equivalents, and restricted cash	1,055	921	$ 1,890	$ 2,037
Other current assets
Restricted cash:
Restricted cash	31	141
Other deferred charges and assets
Restricted cash:
Restricted cash	7	31
ALABAMA POWER CO
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	476	324
Restricted cash:
Total cash, cash equivalents, and restricted cash	476	409	729	687
ALABAMA POWER CO | Other current assets
Restricted cash:
Restricted cash	0	85
ALABAMA POWER CO | Other deferred charges and assets
Restricted cash:
Restricted cash	0	0
GEORGIA POWER CO
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	43	9
Restricted cash:
Total cash, cash equivalents, and restricted cash	64	75	256	480
GEORGIA POWER CO | Other current assets
Restricted cash:
Restricted cash	14	37
GEORGIA POWER CO | Other deferred charges and assets
Restricted cash:
Restricted cash	7	29
SOUTHERN POWER CO
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	179	124
Restricted cash:
Total cash, cash equivalents, and restricted cash	195	144	257	133
SOUTHERN POWER CO | Other current assets
Restricted cash:
Restricted cash	16	17
SOUTHERN POWER CO | Other deferred charges and assets
Restricted cash:
Restricted cash	0	3
SOUTHERN POWER CO | Proceeds From Issuance Of Solid Waste Disposal Facility Revenue Bonds
Restricted cash:
Restricted cash	16	17
SOUTHERN POWER CO | Estimated Construction Completion Costs | Deuel Harvest
Restricted cash:
Restricted cash		3
SOUTHERN Co GAS
Restricted Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents	44	33
Restricted cash:
Total cash, cash equivalents, and restricted cash	45	35	$ 399	$ 83
SOUTHERN Co GAS | Other current assets
Restricted cash:
Restricted cash	1	2
SOUTHERN Co GAS | Other deferred charges and assets
Restricted cash:
Restricted cash	$ 0	$ 0

Introduction - Storm Damage Res

Introduction - Storm Damage Reserves (Details) - USD ($) $ in Millions		1 Months Ended	9 Months Ended
	Oct. 25, 2024	Sep. 30, 2024	Sep. 30, 2024
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance at December 31, 2023			$ 66
Balance at September 30, 2024		$ (1,128)	(1,128)
Accrued Storm Reserve
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Accrual			45
Storm Reserve
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Weather-related damages			(1,239)
ALABAMA POWER CO
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance at December 31, 2023			76
Balance at September 30, 2024		53	53
ALABAMA POWER CO | Accrued Storm Reserve
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Accrual			10
ALABAMA POWER CO | Storm Reserve
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Weather-related damages			(33)
GEORGIA POWER CO
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance at December 31, 2023			(54)
Weather-related damages		(1,100)
Balance at September 30, 2024		1,200	1,200
Balance at September 30, 2024		(1,231)	(1,231)
GEORGIA POWER CO | Accrued Storm Reserve
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Accrual			24
GEORGIA POWER CO | Storm Reserve
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Weather-related damages			(1,201)
MISSISSIPPI POWER CO
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Balance at December 31, 2023			44
Balance at September 30, 2024		$ 50	50
MISSISSIPPI POWER CO | Subsequent Event
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Requested rate increase (decrease) amount	$ 11
MISSISSIPPI POWER CO | Accrued Storm Reserve
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Accrual			11
MISSISSIPPI POWER CO | Storm Reserve
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Weather-related damages			$ (5)

Introduction - Asset Retirement

Introduction - Asset Retirement Obligations (Details) - USD ($) $ in Millions	1 Months Ended
	Sep. 30, 2024	Feb. 14, 2024
GEORGIA POWER CO
Schedule of Asset Retirement Obligation [Line Items]
Asset retirement obligation, period decrease	$ 389
Plant Vogtle Unit 3
Schedule of Asset Retirement Obligation [Line Items]
Asset retirement obligations		$ 118

Introduction - Nuclear Decommis

Introduction - Nuclear Decommissioning (Details) - GEORGIA POWER CO $ in Millions	9 Months Ended
	Sep. 30, 2024 USD ($)
Plant Hatch
Liability for Claims and Claims Adjustment Expense [Line Items]
Site study costs:	$ 1,079
Plant Hatch | Site Study Cost Radiated Structures
Liability for Claims and Claims Adjustment Expense [Line Items]
Site study costs:	696
Plant Hatch | Spent fuel management
Liability for Claims and Claims Adjustment Expense [Line Items]
Site study costs:	306
Plant Hatch | Non-radiated structures
Liability for Claims and Claims Adjustment Expense [Line Items]
Site study costs:	77
Plant Vogtle Nuclear Units One and Two
Liability for Claims and Claims Adjustment Expense [Line Items]
Site study costs:	907
Plant Vogtle Nuclear Units One and Two | Site Study Cost Radiated Structures
Liability for Claims and Claims Adjustment Expense [Line Items]
Site study costs:	545
Plant Vogtle Nuclear Units One and Two | Spent fuel management
Liability for Claims and Claims Adjustment Expense [Line Items]
Site study costs:	255
Plant Vogtle Nuclear Units One and Two | Non-radiated structures
Liability for Claims and Claims Adjustment Expense [Line Items]
Site study costs:	107
Plant Vogtle Units 3 And 4
Liability for Claims and Claims Adjustment Expense [Line Items]
Site study costs:	$ 719
Estimated inflation rate	2.30%
Estimated trust earnings rate	4.30%
Plant Vogtle Units 3 And 4 | Site Study Cost Radiated Structures
Liability for Claims and Claims Adjustment Expense [Line Items]
Site study costs:	$ 542
Plant Vogtle Units 3 And 4 | Spent fuel management
Liability for Claims and Claims Adjustment Expense [Line Items]
Site study costs:	88
Plant Vogtle Units 3 And 4 | Non-radiated structures
Liability for Claims and Claims Adjustment Expense [Line Items]
Site study costs:	$ 89
Plant Hatch And Plant Vogtle Units 1 And 2
Liability for Claims and Claims Adjustment Expense [Line Items]
Estimated inflation rate	2.50%
Estimated trust earnings rate	4.50%
Plant Vogtle Unit 4
Liability for Claims and Claims Adjustment Expense [Line Items]
Amount expensed for ratemaking	$ 8

Regulatory Matters - Schedule o

Regulatory Matters - Schedule of Cost Recovery Clauses (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
ALABAMA POWER CO | Other regulatory assets, current
Loss Contingencies [Line Items]
Rate CNP Compliance	$ 0	$ 8
Rate CNP PPA	18	18
ALABAMA POWER CO | Other regulatory assets, deferred
Loss Contingencies [Line Items]
Rate CNP Compliance	0	25
Rate CNP PPA	70	85
ALABAMA POWER CO | Other regulatory liabilities, current
Loss Contingencies [Line Items]
Rate CNP Compliance	4	0
ALABAMA POWER CO | Other regulatory liabilities, deferred
Loss Contingencies [Line Items]
Rate CNP Compliance	2	0
ALABAMA POWER CO | Deferred under recovered retail fuel clause revenues
Loss Contingencies [Line Items]
Rate ECR	10	246
GEORGIA POWER CO | Receivables – under recovered retail fuel clause revenues
Loss Contingencies [Line Items]
Fuel Cost Recovery	683	694
GEORGIA POWER CO | Deferred under recovered retail fuel clause revenues
Loss Contingencies [Line Items]
Fuel Cost Recovery	632	1,211
MISSISSIPPI POWER CO | Wholesale MB
Loss Contingencies [Line Items]
Fuel Cost Recovery	0	0
MISSISSIPPI POWER CO | Other regulatory assets, deferred
Loss Contingencies [Line Items]
Ad Valorem Tax	14	12
MISSISSIPPI POWER CO | Deferred under recovered retail fuel clause revenues
Loss Contingencies [Line Items]
Fuel Cost Recovery	0	50
MISSISSIPPI POWER CO | Receivables – customer accounts, net
Loss Contingencies [Line Items]
Fuel Cost Recovery	6	0
MISSISSIPPI POWER CO | Over recovered retail fuel clause revenues
Loss Contingencies [Line Items]
Fuel Cost Recovery	0	27
MISSISSIPPI POWER CO | Other current liabilities | Wholesale MRA
Loss Contingencies [Line Items]
Fuel Cost Recovery	16	5
SOUTHERN Co GAS | Natural gas cost over recovery
Loss Contingencies [Line Items]
Natural gas cost under recovery	$ 226	$ 214

Regulatory Matters - APC Plant

Regulatory Matters - APC Plant Greene County (Details) $ in Millions			1 Months Ended
	Oct. 24, 2024 USD ($) MW	May 08, 2024 $ / KWH_Kilowatt_hour	Jan. 31, 2026 $ / KWH_Kilowatt_hour	Jul. 31, 2024 USD ($) $ / KWH_Kilowatt_hour	Sep. 18, 2024 USD ($)	Apr. 26, 2024 MW
ALABAMA POWER CO
Public Utilities, General Disclosures [Line Items]
Current billing rates under rate ECR (usd per KWH) | $ / KWH_Kilowatt_hour		0.03270		0.03015
Current billing rates under rate ECR, amount | $				$ 135
Reliability reserve | $					$ 143
ALABAMA POWER CO | Tenaska Alabama Partners, L.P. | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Purchase price | $	$ 622
Approximate nameplate capacity | MW	855
ALABAMA POWER CO | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Current billing rates under rate ECR (usd per KWH) | $ / KWH_Kilowatt_hour			0.05910
ALABAMA POWER CO | Plant Greene County Units 1 and 2
Public Utilities, General Disclosures [Line Items]
Proportionate ownership share						60%
Required fossil-stream generation retirements (in MWs) | MW						300
MISSISSIPPI POWER CO | Plant Greene County Units 1 and 2
Public Utilities, General Disclosures [Line Items]
Proportionate ownership share						40%
Required fossil-stream generation retirements (in MWs) | MW						206

Regulatory Matters - GPC Rate P

Regulatory Matters - GPC Rate Plans and Integrated Resource Plan (Details) $ in Millions

1 Months Ended

3 Months Ended

9 Months Ended

12 Months Ended

Jun. 27, 2024 MW

Apr. 24, 2024 USD ($)

Apr. 16, 2024 MW

Jan. 12, 2024 turbine MW

Sep. 30, 2024 USD ($)

Sep. 30, 2024 USD ($) facility MW

Sep. 30, 2024 USD ($)

Dec. 31, 2028 MW

Dec. 31, 2025 MW

Oct. 01, 2024 USD ($)

Mar. 07, 2024 USD ($)

Dec. 31, 2023 USD ($)

Public Utilities, General Disclosures [Line Items]

Regulatory asset balance related to storm damage

$ 66

GEORGIA POWER CO

Public Utilities, General Disclosures [Line Items]

Requested additional generating capacity (in MWs) | MW

1,258

265

Number of turbines | turbine

3

Number of battery energy storage facilities | facility

4

Damage costs recovered annually

$ 31

Weather-related damages

$ 1,100

Regulatory asset balance related to storm damage

$ 1,200

$ 1,200

$ 1,200

GEORGIA POWER CO | Traditional Base | Subsequent Event

Public Utilities, General Disclosures [Line Items]

Requested rate increase (decrease), amount, due in next fiscal year

$ 194

GEORGIA POWER CO | Traditional Base, Georgia State | Subsequent Event

Public Utilities, General Disclosures [Line Items]

Requested rate increase (decrease), amount, due in next fiscal year

122

GEORGIA POWER CO | Environmental Compliance Cost Recovery, Traditional | Subsequent Event

Public Utilities, General Disclosures [Line Items]

Requested rate increase (decrease), amount, due in next fiscal year

126

GEORGIA POWER CO | Demand Side-Management | Subsequent Event

Public Utilities, General Disclosures [Line Items]

Requested rate increase (decrease), amount, due in next fiscal year

(22)

GEORGIA POWER CO | Municipal Franchise Fee | Subsequent Event

Public Utilities, General Disclosures [Line Items]

Requested rate increase (decrease), amount, due in next fiscal year

$ 9

GEORGIA POWER CO | Scenario, Forecast

Public Utilities, General Disclosures [Line Items]

Requested additional generating capacity (in MWs) | MW

228

380

GEORGIA POWER CO | Maximum

Public Utilities, General Disclosures [Line Items]

Requested additional generating capacity (in MWs) | MW

500

500

GEORGIA POWER CO | Plant Yates | Maximum

Public Utilities, General Disclosures [Line Items]

Requested additional generating capacity (in MWs) | MW

1,400

442

GEORGIA POWER CO | Affiliate PPA

Public Utilities, General Disclosures [Line Items]

Requested additional generating capacity (in MWs) | MW

750

GEORGIA POWER CO | Non-Affiliate PPA

Public Utilities, General Disclosures [Line Items]

Requested additional generating capacity (in MWs) | MW

230

Southern Co and Georgia Power | Disposal Group, Held-for-sale, Not Discontinued Operations

Public Utilities, General Disclosures [Line Items]

Assets held for sale

$ 236

Proceeds from sale of transmission assets

$ 351

Gain (loss) on sale

$ 114

Gain (loss) on sale, after tax

$ 84

Regulatory Matters - GPC Nuclea

Regulatory Matters - GPC Nuclear Construction (Details) - USD ($) $ in Millions	3 Months Ended			9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Loss Contingencies [Line Items]
Credit on plant vogtle units 3 and 4	$ 0		$ (160)	$ 21	$ (160)
GEORGIA POWER CO
Loss Contingencies [Line Items]
Credit on plant vogtle units 3 and 4	0	$ 21	(160)	21	(160)
After tax credit on plant vogtle units 3 and 4		$ 16	$ (120)	16	$ (120)
GEORGIA POWER CO | Plant Vogtle Units 3 And 4
Loss Contingencies [Line Items]
Estimated cost to complete, construction contingency estimate, financing costs	3,530			3,530
Costs recovered to date	$ 3,080			$ 3,080

Regulatory Matters - GPC Nucl_2

Regulatory Matters - GPC Nuclear Construction Cost and Schedule (Details) - GEORGIA POWER CO - Plant Vogtle Units 3 And 4 $ in Millions	9 Months Ended
	Sep. 30, 2024 USD ($)
Loss Contingencies [Line Items]
Total project capital cost forecast	$ 10,732
Net investment as of end of the period	(10,649)
Remaining estimate to complete	83
Estimated cost to complete, costs not shared with other owners	1,200
Capitalized interest accrued	440
Twenty Fifth Vogtle Construction Monitoring Report
Loss Contingencies [Line Items]
Guarantor obligations	1,700
Customer refund	$ 188

Regulatory Matters - GPC Nucl_3

Regulatory Matters - GPC Nuclear Construction Regulatory Matters (Details) - GEORGIA POWER CO - USD ($) $ in Millions				3 Months Ended		9 Months Ended	12 Months Ended
	May 01, 2024	Apr. 29, 2024	Aug. 01, 2023	Sep. 30, 2024	Jun. 30, 2024	Sep. 30, 2024	Dec. 31, 2023
Public Utilities, General Disclosures [Line Items]
Return on equity reduction, negative impact on earnings					$ 10
Recovery of construction and capital costs				$ 10
Plant Vogtle Unit 3
Public Utilities, General Disclosures [Line Items]
Requested rate increase, annual amount			$ 318
Plant Vogtle Units 3 And 4
Public Utilities, General Disclosures [Line Items]
Regulatory asset amortization period				10 years		10 years
Approved rate increase (decrease)		$ 5,462				$ 2,100
Approved recovery of retail rate items						362
Associated retail rate base items		$ 647
Requested rate increase (decrease) amount	$ 730
Requested revenues increase (decrease) percentage	5%
Return on equity reduction, negative impact on earnings					$ 80		$ 310
Public utilities, approved return on equity percentage					0%
Plant Vogtle Units 3 And 4 | Deferred Income Tax Charge, Debt Component
Public Utilities, General Disclosures [Line Items]
Remaining net book value				$ 24		24
Plant Vogtle Units 3 And 4 | Deferred Income Tax Charge
Public Utilities, General Disclosures [Line Items]
Remaining net book value				30		30
Plant Vogtle Units 3 And 4 | Deferred Income Tax Charge, Equity Component
Public Utilities, General Disclosures [Line Items]
Remaining net book value				$ 40		$ 40

Regulatory Matters - MPC (Detai

Regulatory Matters - MPC (Details) $ in Millions	Jun. 13, 2024 USD ($)	May 07, 2024 USD ($)	Apr. 11, 2024 USD ($)	Mar. 29, 2024 USD ($)	Sep. 30, 2024 USD ($)	Apr. 26, 2024 MW
Loss Contingencies [Line Items]
Minimum annual accrual, amount			$ 12
MISSISSIPPI POWER CO
Loss Contingencies [Line Items]
Approved rate increase (decrease)			$ 13
MISSISSIPPI POWER CO | Plant Watson Unit 4
Loss Contingencies [Line Items]
Required fossil-stream generation retirements (in MWs) | MW						268
MISSISSIPPI POWER CO | Plant Greene County Units 1 and 2
Loss Contingencies [Line Items]
Required fossil-stream generation retirements (in MWs) | MW						206
Proportionate ownership share						40%
MISSISSIPPI POWER CO | Plant Daniel Units 1 and 2
Loss Contingencies [Line Items]
Required fossil-stream generation retirements (in MWs) | MW						502
Proportionate ownership share						50%
Remaining net book value					$ 476
MISSISSIPPI POWER CO | Ad Valorem Tax Adjustment
Loss Contingencies [Line Items]
Requested rate increase (decrease) amount	$ (5)	$ 8
MISSISSIPPI POWER CO | Municipal And Rural Associations Tariff
Loss Contingencies [Line Items]
Requested rate increase (decrease) amount				$ 8

Regulatory Matters - Southern C

Regulatory Matters - Southern Company Gas (Details) - USD ($) $ in Millions	Aug. 01, 2024	Jul. 31, 2024	Jul. 02, 2024	Jun. 07, 2024
SOUTHERN Co GAS | SAVE
Public Utilities, General Disclosures [Line Items]
Approved investment amount				$ 355
Approved investment variance amount				$ 5
Program duration period				5 years
SOUTHERN Co GAS | SAVE | 2025
Public Utilities, General Disclosures [Line Items]
Approved investment amount				$ 70
SOUTHERN Co GAS | SAVE | 2026
Public Utilities, General Disclosures [Line Items]
Approved investment amount				70
SOUTHERN Co GAS | SAVE | 2027
Public Utilities, General Disclosures [Line Items]
Approved investment amount				70
SOUTHERN Co GAS | SAVE | 2028
Public Utilities, General Disclosures [Line Items]
Approved investment amount				70
SOUTHERN Co GAS | SAVE | 2029
Public Utilities, General Disclosures [Line Items]
Approved investment amount				$ 70
Atlanta Gas Light
Public Utilities, General Disclosures [Line Items]
Recovery of capital investments			$ 600
Approved rate increase (decrease)		$ 120
Virginia Natural Gas | Virginia Commission
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease) amount	$ 63
Public utilities, approved return on equity percentage	10.45%
Public utilities, approved equity capital structure percentage	54.92%
Virginia Natural Gas | SAVE | Virginia Commission
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease) amount	$ 17

Contingencies - General Litigat

Contingencies - General Litigation Matters (Details) $ in Millions	1 Months Ended	3 Months Ended	12 Months Ended	16 Months Ended
	Mar. 31, 2019 plaintiff	Mar. 31, 2022 USD ($)	Dec. 31, 2018 USD ($) defendant plaintiff	Jan. 31, 2023 claim	Sep. 30, 2024 USD ($)	Dec. 31, 2023 USD ($)	Dec. 31, 2021 project	Dec. 31, 2016 USD ($)	Dec. 31, 2010 USD ($)
MISSISSIPPI POWER CO | Kemper IGCC
Loss Contingencies [Line Items]
DOE awards								$ 137	$ 270
Government grants received			$ 387
MISSISSIPPI POWER CO | Pending Litigation | Purported Violations of Mississippi Consumer Protection Act
Loss Contingencies [Line Items]
Number of plaintiffs | plaintiff			10
Number of defendants | defendant			3
Number of additional plaintiffs | plaintiff	4
Underpayment of refunds			$ 23.5
GEORGIA POWER CO | Pending Litigation | Class Action Lawsuit
Loss Contingencies [Line Items]
Complaints filed | claim				8
SOUTHERN POWER CO | Proceeds From Issuance Of Solid Waste Disposal Facility Revenue Bonds
Loss Contingencies [Line Items]
Restricted cash					$ 16	$ 17
SOUTHERN POWER CO | Settled Litigation | Southern Power vs First Solar
Loss Contingencies [Line Items]
Number of solar projects | project							5
Proceeds from legal settlements		$ 36

Contingencies - Environmental R

Contingencies - Environmental Remediation (Details) $ in Millions	Sep. 30, 2024 USD ($) site	Dec. 31, 2023 USD ($)
GEORGIA POWER CO
Loss Contingencies [Line Items]
Environmental remediation liability, current and former sites	$ 13	$ 14
SOUTHERN Co GAS
Loss Contingencies [Line Items]
Environmental remediation liability, current and former sites	$ 230	$ 222
Plant site, potential investigation and remediation | site	1

Contingencies - Nuclear Fuel Di

Contingencies - Nuclear Fuel Disposal Costs (Details) - Court Of Federal Claims - USD ($) $ in Millions	Jun. 07, 2024	Sep. 30, 2024
ALABAMA POWER CO
Loss Contingencies [Line Items]
Amount awarded	$ 100
Receivable		$ 100
Payable		100
GEORGIA POWER CO
Loss Contingencies [Line Items]
Amount awarded	$ 121
Receivable		259
Payable		$ 138

Contingencies - Other Matters (

Contingencies - Other Matters (Details) - ALABAMA POWER CO - AT&T $ in Millions	1 Months Ended
	Apr. 30, 2019 USD ($)
Loss Contingencies [Line Items]
Potential refund amount owed	$ 87
Refund payment period	6 years

Revenue from Contracts with C_3

Revenue from Contracts with Customers and Lease Income - Schedule of Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 7,481	$ 7,107	$ 20,513	$ 18,886
Total operating revenues	7,274	6,980	20,383	19,208
Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	2,651	2,543	6,551	5,717
Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,991	1,845	5,075	4,464
Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,184	1,116	3,019	2,770
Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	33	30	94	84
Retail electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	5,859	5,534	14,739	13,035
Natural gas distribution revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	610	612	2,749	2,952
Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	212	217	1,244	1,443
Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	55	56	300	370
Transportation
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	294	275	959	878
Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	4	4	25	33
Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	45	60	221	228
Wholesale electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	557	569	1,512	1,542
PPA energy revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	300	317	838	853
PPA capacity revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	190	151	495	490
Non-PPA revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	67	101	179	199
Other natural gas revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	57	62	368	386
Gas marketing services
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	51	54	352	358
Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	6	8	16	28
Other revenue sources
Disaggregation of Revenue [Line Items]
Other revenues	(207)	(127)	(130)	322
Other revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	398	330	1,145	971
ALABAMA POWER CO
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	2,244	2,230	5,926	5,638
Total operating revenues	2,138	2,083	5,803	5,420
ALABAMA POWER CO | Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	975	969	2,477	2,277
ALABAMA POWER CO | Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	607	599	1,583	1,493
ALABAMA POWER CO | Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	483	498	1,338	1,324
ALABAMA POWER CO | Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	3	3	9	10
ALABAMA POWER CO | Retail electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	2,068	2,069	5,407	5,104
ALABAMA POWER CO | Wholesale electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	116	107	345	375
ALABAMA POWER CO | PPA energy revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	58	66	171	196
ALABAMA POWER CO | PPA capacity revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	24	26	71	130
ALABAMA POWER CO | Non-PPA revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	34	15	103	49
ALABAMA POWER CO | Other revenue sources
Disaggregation of Revenue [Line Items]
Other revenues	(106)	(147)	(123)	(218)
ALABAMA POWER CO | Other revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	60	54	174	159
GEORGIA POWER CO
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	3,740	3,388	9,259	7,754
Total operating revenues	3,472	3,237	8,745	7,805
GEORGIA POWER CO | Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,580	1,473	3,832	3,202
GEORGIA POWER CO | Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1,288	1,151	3,243	2,733
GEORGIA POWER CO | Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	606	528	1,424	1,195
GEORGIA POWER CO | Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	28	25	78	68
GEORGIA POWER CO | Retail electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	3,502	3,177	8,577	7,198
GEORGIA POWER CO | Wholesale electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	68	65	175	134
GEORGIA POWER CO | PPA energy revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	26	31	66	66
GEORGIA POWER CO | PPA capacity revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	42	13	106	38
GEORGIA POWER CO | Non-PPA revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	21	3	30
GEORGIA POWER CO | Other revenue sources
Disaggregation of Revenue [Line Items]
Other revenues	(268)	(151)	(514)	51
GEORGIA POWER CO | Other revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	170	146	507	422
MISSISSIPPI POWER CO
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	424	440	1,131	1,123
Total operating revenues	412	436	1,118	1,137
MISSISSIPPI POWER CO | Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	96	101	242	238
MISSISSIPPI POWER CO | Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	96	95	249	238
MISSISSIPPI POWER CO | Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	95	90	257	251
MISSISSIPPI POWER CO | Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	2	2	7	6
MISSISSIPPI POWER CO | Retail electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	289	288	755	733
MISSISSIPPI POWER CO | Wholesale electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	122	142	342	359
MISSISSIPPI POWER CO | PPA energy revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	1	2	3	8
MISSISSIPPI POWER CO | PPA capacity revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	15	3	47	36
MISSISSIPPI POWER CO | Non-PPA revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	106	137	292	315
MISSISSIPPI POWER CO | Other revenue sources
Disaggregation of Revenue [Line Items]
Other revenues	(12)	(4)	(13)	14
MISSISSIPPI POWER CO | Other revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	13	10	34	31
SOUTHERN POWER CO
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	423	480	1,143	1,248
Total operating revenues	600	653	1,597	1,686
SOUTHERN POWER CO | Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
SOUTHERN POWER CO | Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
SOUTHERN POWER CO | Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
SOUTHERN POWER CO | Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
SOUTHERN POWER CO | Retail electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	0	0	0	0
SOUTHERN POWER CO | Wholesale electric revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	414	462	1,112	1,202
SOUTHERN POWER CO | PPA energy revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	222	226	616	601
SOUTHERN POWER CO | PPA capacity revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	125	110	320	289
SOUTHERN POWER CO | Non-PPA revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	67	126	176	312
SOUTHERN POWER CO | Other revenue sources
Disaggregation of Revenue [Line Items]
Other revenues	177	173	454	438
SOUTHERN POWER CO | Other revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	9	18	31	46
SOUTHERN Co GAS
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	667	674	3,117	3,338
Total operating revenues	682	689	3,220	3,417
SOUTHERN Co GAS | Natural gas distribution revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	610	612	2,749	2,952
SOUTHERN Co GAS | Residential
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	212	217	1,244	1,443
SOUTHERN Co GAS | Commercial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	55	56	300	370
SOUTHERN Co GAS | Transportation
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	294	275	959	878
SOUTHERN Co GAS | Industrial
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	4	4	25	33
SOUTHERN Co GAS | Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	45	60	221	228
SOUTHERN Co GAS | Other natural gas revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	57	62	368	386
SOUTHERN Co GAS | Gas marketing services
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	51	54	352	358
SOUTHERN Co GAS | Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	6	8	16	28
SOUTHERN Co GAS | Other revenue sources
Disaggregation of Revenue [Line Items]
Other revenues	15	15	103	79
SOUTHERN Co GAS | Other revenues
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 0	$ 0	$ 0	$ 0

Revenue from Contracts with C_4

Revenue from Contracts with Customers and Lease Income - Schedule of Contract Balances (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Disaggregation of Revenue [Line Items]
Accounts Receivable	$ 2,946	$ 2,820
Contract Assets	379	271
Contract Liabilities	181	116
ALABAMA POWER CO
Disaggregation of Revenue [Line Items]
Accounts Receivable	978	821
Contract Assets	7	2
Contract Liabilities	0	0
GEORGIA POWER CO
Disaggregation of Revenue [Line Items]
Accounts Receivable	1,347	1,011
Contract Assets	202	121
Contract Liabilities	49	1
MISSISSIPPI POWER CO
Disaggregation of Revenue [Line Items]
Accounts Receivable	111	90
Contract Assets	0	0
Contract Liabilities	0	0
SOUTHERN POWER CO
Disaggregation of Revenue [Line Items]
Accounts Receivable	125	122
Contract Assets	0	0
Contract Liabilities	2	4
SOUTHERN Co GAS
Disaggregation of Revenue [Line Items]
Accounts Receivable	306	684
Contract Assets	71	56
Contract Liabilities	$ 3	$ 0

Revenue from Contracts with C_5

Revenue from Contracts with Customers and Lease Income - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2024	Dec. 31, 2023
Disaggregation of Revenue [Line Items]
Contract liabilities	$ 181	$ 181	$ 116
Contract assets	379	379	271
Revenue from contracts with customers recognized	20	97
GEORGIA POWER CO
Disaggregation of Revenue [Line Items]
Contract liabilities	49	49	1
Contract assets	202	202	121
Revenue from contracts with customers recognized	0	0
SOUTHERN Co GAS
Disaggregation of Revenue [Line Items]
Contract liabilities	3	3	0
Contract assets	71	71	56
Revenue from contracts with customers recognized	0	0
ALABAMA POWER CO
Disaggregation of Revenue [Line Items]
Contract liabilities	0	0	0
Contract assets	7	7	2
Revenue from contracts with customers recognized	0	0
MISSISSIPPI POWER CO
Disaggregation of Revenue [Line Items]
Contract liabilities	0	0	0
Contract assets	0	0	0
Revenue from contracts with customers recognized	0	0
SOUTHERN POWER CO
Disaggregation of Revenue [Line Items]
Contract liabilities	2	2	4
Contract assets	0	0	0
Revenue from contracts with customers recognized	0	$ 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	68	$ 68
Unregulated Distributed Generation
Disaggregation of Revenue [Line Items]
Contract liabilities	132	132	115
Contract assets	$ 102	$ 102	$ 91

Revenue from Contracts with C_6

Revenue from Contracts with Customers and Lease Income - Schedule of Remaining Performance Obligations (Details) $ in Millions	Sep. 30, 2024 USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 303
Performance obligation, expected timing of satisfaction	3 months
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	$ 884
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	$ 375
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	$ 336
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	$ 325
Performance obligation, expected timing of satisfaction	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2029-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 2,180
Performance obligation, expected timing of satisfaction
ALABAMA POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 11
Performance obligation, expected timing of satisfaction	3 months
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	$ 11
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	1 year
ALABAMA POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2029-01-01
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]: 2024-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 21
Performance obligation, expected timing of satisfaction	3 months
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	$ 64
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	$ 26
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	$ 17
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	$ 17
Performance obligation, expected timing of satisfaction	1 year
GEORGIA POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2029-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 17
Performance obligation, expected timing of satisfaction
MISSISSIPPI POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 15
Performance obligation, expected timing of satisfaction	3 months
MISSISSIPPI 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	$ 63
Performance obligation, expected timing of satisfaction	1 year
MISSISSIPPI 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	$ 66
Performance obligation, expected timing of satisfaction	1 year
MISSISSIPPI 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	$ 69
Performance obligation, expected timing of satisfaction	1 year
MISSISSIPPI 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	$ 73
Performance obligation, expected timing of satisfaction	1 year
MISSISSIPPI POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2029-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 0
Performance obligation, expected timing of satisfaction
SOUTHERN POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 73
Performance obligation, expected timing of satisfaction	3 months
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	$ 312
Performance obligation, expected timing of satisfaction	1 year
SOUTHERN POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 299
Performance obligation, expected timing of satisfaction	1 year
SOUTHERN POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 306
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	$ 297
Performance obligation, expected timing of satisfaction	1 year
SOUTHERN POWER CO | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2029-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 2,169
Performance obligation, expected timing of satisfaction
SOUTHERN Co GAS | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-10-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 3
Performance obligation, expected timing of satisfaction	3 months
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	$ 2
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	1 year
SOUTHERN Co GAS | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2029-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation	$ 0
Performance obligation, expected timing of satisfaction

Revenue from Contracts with C_7

Revenue from Contracts with Customers and Lease Income - Schedule of Lease Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Lessor, Lease, Description [Line Items]
Lease income - interest income on sales-type leases	$ 5	$ 6	$ 18	$ 18
Lease income - operating leases	38	36	108	129
Variable lease income	142	134	343	327
Total lease income	185	176	469	474
ALABAMA POWER CO
Lessor, Lease, Description [Line Items]
Lease income - interest income on sales-type leases	0	0	0	0
Lease income - operating leases	2	3	6	32
Variable lease income	0	0	0	1
Total lease income	2	3	6	33
GEORGIA POWER CO
Lessor, Lease, Description [Line Items]
Lease income - interest income on sales-type leases	0	0	0	0
Lease income - operating leases	13	7	28	22
Variable lease income	0	0	0	0
Total lease income	13	7	28	22
MISSISSIPPI POWER CO
Lessor, Lease, Description [Line Items]
Lease income - interest income on sales-type leases	3	4	11	11
Lease income - operating leases	0	0	2	2
Variable lease income	0	0	0	0
Total lease income	3	4	13	13
SOUTHERN POWER CO
Lessor, Lease, Description [Line Items]
Lease income - interest income on sales-type leases	2	2	7	7
Lease income - operating leases	20	21	63	64
Variable lease income	152	144	370	351
Total lease income	174	167	440	422
SOUTHERN Co GAS
Lessor, Lease, Description [Line Items]
Lease income - interest income on sales-type leases	0	0	0	0
Lease income - operating leases	9	9	27	27
Variable lease income	0	0	0	0
Total lease income	$ 9	$ 9	$ 27	$ 27

Consolidated Entities and Equ_3

Consolidated Entities and Equity Method Investments - Narrative (Details) $ in Millions	9 Months Ended
	Sep. 30, 2024 USD ($) investor	Dec. 31, 2023 USD ($)
Schedule of Equity Method Investments [Line Items]
Equity investments in unconsolidated subsidiaries	$ 1,414	$ 1,368
Assets	143,956	139,331
Liabilities	107,051	104,106
Southern Holdings Company
Schedule of Equity Method Investments [Line Items]
Equity investments in unconsolidated subsidiaries	127	126
SOUTHERN POWER CO
Schedule of Equity Method Investments [Line Items]
Assets	12,646	12,761
Liabilities	$ 6,044	6,063
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	$ 5,600	5,600
Liabilities	378	399
Noncontrolling interests related to other partners' interests	1,000	1,000
Variable Interest Entity, Primary Beneficiary | SP Wind | SOUTHERN POWER CO
Schedule of Equity Method Investments [Line Items]
Assets	2,100	2,100
Liabilities	184	187
Noncontrolling interests related to other partners' interests	$ 36	38
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	$ 1,700	1,700
Liabilities	240	230
Noncontrolling interests related to other partners' interests	$ 710	$ 761

Consolidated Entities and Equ_4

Consolidated Entities and Equity Method Investments - Schedule of Equity Method Investments (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Schedule of Equity Method Investments [Line Items]
Investment Balance	$ 1,414	$ 1,368
SOUTHERN Co GAS
Schedule of Equity Method Investments [Line Items]
Investment Balance	1,279	1,235
SOUTHERN Co GAS | SNG
Schedule of Equity Method Investments [Line Items]
Investment Balance	1,246	1,202
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		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Schedule of Equity Method Investments [Line Items]
Earnings from equity method investments	$ 31	$ 32	$ 107	$ 110
SOUTHERN Co GAS
Schedule of Equity Method Investments [Line Items]
Earnings from equity method investments	34	32	110	104
SOUTHERN Co GAS | SNG
Schedule of Equity Method Investments [Line Items]
Earnings from equity method investments	$ 34	$ 32	$ 110	$ 104

Financing and Leases - Schedule

Financing and Leases - Schedule of Credit Arrangements (Details) $ in Millions	Sep. 30, 2024 USD ($)
Line of Credit Facility [Line Items]
Expires, 2025	$ 580
Expires, 2026	650
Expires, 2027	275
Expires, 2028	6,400
Total	7,905
Unused	7,877
Expires within One Year	580
Southern Company parent
Line of Credit Facility [Line Items]
Expires, 2025	150
Expires, 2026	0
Expires, 2027	0
Expires, 2028	1,850
Total	2,000
Unused	1,998
Expires within One Year	150
ALABAMA POWER CO
Line of Credit Facility [Line Items]
Expires, 2025	0
Expires, 2026	650
Expires, 2027	0
Expires, 2028	700
Total	1,350
Unused	1,350
Expires within One Year	0
GEORGIA POWER CO
Line of Credit Facility [Line Items]
Expires, 2025	300
Expires, 2026	0
Expires, 2027	0
Expires, 2028	1,750
Total	2,050
Unused	2,026
Expires within One Year	300
MISSISSIPPI POWER CO
Line of Credit Facility [Line Items]
Expires, 2025	0
Expires, 2026	0
Expires, 2027	275
Expires, 2028	0
Total	275
Unused	275
Expires within One Year	0
SOUTHERN POWER CO
Line of Credit Facility [Line Items]
Expires, 2025	0
Expires, 2026	0
Expires, 2027	0
Expires, 2028	600
Total	600
Unused	600
Expires within One Year	0
SOUTHERN POWER CO | Continuing Letter of Credit Facility A
Line of Credit Facility [Line Items]
Expires, 2025	75
Expires, 2026	100
Unused	10
SOUTHERN POWER CO | Continuing Letter of Credit Facility B
Line of Credit Facility [Line Items]
Unused	11
SOUTHERN Co GAS
Line of Credit Facility [Line Items]
Expires, 2025	100
Expires, 2026	0
Expires, 2027	0
Expires, 2028	1,500
Total	1,600
Unused	1,598
Expires within One Year	100
SEGCO
Line of Credit Facility [Line Items]
Expires, 2025	30
Expires, 2026	0
Expires, 2027	0
Expires, 2028	0
Total	30
Unused	30
Expires within One Year	30
Southern Company and Southern Power
Line of Credit Facility [Line Items]
Expires, 2028	2,450
Southern Company Gas Capital
Line of Credit Facility [Line Items]
Expires, 2028	800
Nicor Gas
Line of Credit Facility [Line Items]
Expires, 2024	100
Expires, 2028	$ 700

Financing and Leases - Bank Cre

Financing and Leases - Bank Credit Agreements Narrative (Details) - USD ($) $ in Millions	Sep. 30, 2024	Jun. 30, 2024
Debt Instrument [Line Items]
Expires, 2025	$ 580
Variable rate pollution control revenue bonds outstanding	1,700
MISSISSIPPI POWER CO
Debt Instrument [Line Items]
Restated amount of LOC	150	$ 125
Expires, 2025	0
Variable rate pollution control revenue bonds outstanding	69
ALABAMA POWER CO
Debt Instrument [Line Items]
Expires, 2025	0
Variable rate pollution control revenue bonds outstanding	796
Fixed rate pollution control revenue bonds outstanding	207
GEORGIA POWER CO
Debt Instrument [Line Items]
Expires, 2025	300
Variable rate pollution control revenue bonds outstanding	819
Fixed rate pollution control revenue bonds outstanding	157
Southern Company parent
Debt Instrument [Line Items]
Expires, 2025	150
SOUTHERN Co GAS
Debt Instrument [Line Items]
Expires, 2025	100
SEGCO
Debt Instrument [Line Items]
Expires, 2025	$ 30

Financing and Leases - Converti

Financing and Leases - Convertible Senior Notes Narrative (Details) $ / shares in Units, $ in Billions	1 Months Ended	9 Months Ended
	May 31, 2024 USD ($) tradingDay businessDay $ / shares	Sep. 30, 2024
Line of Credit Facility [Line Items]
Conversion ratio	0.0108166
Series 2024A Convertible Senior Notes Due 2027 | Convertible Debt
Line of Credit Facility [Line Items]
Aggregate principal amount | $	$ 1.5
Interest rate	4.50%
Conversion price (in dollars per share) | $ / shares	$ 92.45
Redemption price		100%
Series 2024A Convertible Senior Notes Due 2027 | Convertible Debt | Debt Conversion Terms One
Line of Credit Facility [Line Items]
Trading day threshold	20
Consecutive trading day threshold	30
Stock price trigger threshold, percentage	130%
Series 2024A Convertible Senior Notes Due 2027 | Convertible Debt | Debt Conversion Terms Two
Line of Credit Facility [Line Items]
Trading day threshold | businessDay	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 Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Debt Disclosure [Abstract]
As reported shares (in shares)	1,097	1,092	1,096	1,092
Effect of stock-based compensation (in shares)	6	7	6	6
Diluted (in shares)	1,103	1,099	1,102	1,098

Financing and Leases - Georgia

Financing and Leases - Georgia Power Lease Modification (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Lessor, Lease, Description [Line Items]
Operating lease right-of-use assets, net of amortization	$ 1,415	$ 1,432
GEORGIA POWER CO
Lessor, Lease, Description [Line Items]
Operating lease right-of-use assets, net of amortization	879	$ 884
GEORGIA POWER CO | Revision of Prior Period, Adjustment
Lessor, Lease, Description [Line Items]
Operating lease right-of-use assets, net of amortization	8
Lease obligations	10
Finance lease ROU assets, net	44
Finance lease obligations	$ 45

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Income Tax Contingency [Line Items]
Effective tax (benefit) rate	19%	13.90%
Unrecognized tax positions	$ 73		$ 116
ALABAMA POWER CO
Income Tax Contingency [Line Items]
Effective tax (benefit) rate	21.20%	8.30%
GEORGIA POWER CO
Income Tax Contingency [Line Items]
Effective tax (benefit) rate	18.70%	18.20%
Unrecognized tax positions	$ 34		$ 77
MISSISSIPPI POWER CO
Income Tax Contingency [Line Items]
Effective tax (benefit) rate	20%	16.90%

Retirement Benefits (Details)

Retirement Benefits (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, expected future employer contributions, remainder of fiscal year	$ 0		$ 0
Pension Plans and Postretirement Plans
Service cost	73,000,000	$ 69,000,000	219,000,000	$ 207,000,000
Interest cost	159,000,000	156,000,000	476,000,000	469,000,000
Expected return on plan assets	(316,000,000)	(307,000,000)	(947,000,000)	(922,000,000)
Amortization:
Prior service costs	0	0	0	0
Regulatory asset	0	0	0	0
Net (gain) loss	14,000,000	8,000,000	41,000,000	24,000,000
Net periodic pension income	(70,000,000)	(74,000,000)	(211,000,000)	(222,000,000)
Pension Plans | ALABAMA POWER CO
Pension Plans and Postretirement Plans
Service cost	17,000,000	16,000,000	51,000,000	48,000,000
Interest cost	37,000,000	37,000,000	111,000,000	109,000,000
Expected return on plan assets	(77,000,000)	(75,000,000)	(230,000,000)	(223,000,000)
Amortization:
Prior service costs	0	0	0	0
Regulatory asset	0	0	0	0
Net (gain) loss	4,000,000	2,000,000	12,000,000	7,000,000
Net periodic pension income	(19,000,000)	(20,000,000)	(56,000,000)	(59,000,000)
Pension Plans | GEORGIA POWER CO
Pension Plans and Postretirement Plans
Service cost	18,000,000	17,000,000	53,000,000	51,000,000
Interest cost	47,000,000	48,000,000	143,000,000	143,000,000
Expected return on plan assets	(99,000,000)	(97,000,000)	(296,000,000)	(289,000,000)
Amortization:
Prior service costs	0	0	1,000,000	1,000,000
Regulatory asset	0	0	0	0
Net (gain) loss	6,000,000	4,000,000	15,000,000	10,000,000
Net periodic pension income	(28,000,000)	(28,000,000)	(84,000,000)	(84,000,000)
Pension Plans | MISSISSIPPI POWER CO
Pension Plans and Postretirement Plans
Service cost	3,000,000	2,000,000	9,000,000	8,000,000
Interest cost	7,000,000	7,000,000	21,000,000	21,000,000
Expected return on plan assets	(14,000,000)	(13,000,000)	(43,000,000)	(41,000,000)
Amortization:
Prior service costs	0	0	0	0
Regulatory asset	0	0	0	0
Net (gain) loss	0	1,000,000	2,000,000	1,000,000
Net periodic pension income	(4,000,000)	(3,000,000)	(11,000,000)	(11,000,000)
Pension Plans | SOUTHERN POWER CO
Pension Plans and Postretirement Plans
Service cost	2,000,000	2,000,000	5,000,000	5,000,000
Interest cost	2,000,000	2,000,000	6,000,000	6,000,000
Expected return on plan assets	(4,000,000)	(4,000,000)	(12,000,000)	(12,000,000)
Amortization:
Prior service costs	0	0	0	0
Regulatory asset	0	0	0	0
Net (gain) loss	(1,000,000)	0	0	0
Net periodic pension income	(1,000,000)	0	(1,000,000)	(1,000,000)
Pension Plans | SOUTHERN Co GAS
Pension Plans and Postretirement Plans
Service cost	7,000,000	6,000,000	21,000,000	18,000,000
Interest cost	11,000,000	11,000,000	32,000,000	32,000,000
Expected return on plan assets	(21,000,000)	(22,000,000)	(64,000,000)	(65,000,000)
Amortization:
Prior service costs	(1,000,000)	(1,000,000)	(2,000,000)	(2,000,000)
Regulatory asset	4,000,000	4,000,000	11,000,000	11,000,000
Net (gain) loss	0	(1,000,000)	0	(3,000,000)
Net periodic pension income	0	(3,000,000)	(2,000,000)	(9,000,000)
Postretirement Benefits
Pension Plans and Postretirement Plans
Service cost	4,000,000	4,000,000	11,000,000	11,000,000
Interest cost	16,000,000	18,000,000	49,000,000	53,000,000
Expected return on plan assets	(22,000,000)	(21,000,000)	(66,000,000)	(62,000,000)
Amortization:
Prior service costs	1,000,000	0	2,000,000	1,000,000
Regulatory asset	0	0	0	0
Net (gain) loss	(4,000,000)	(4,000,000)	(12,000,000)	(10,000,000)
Net periodic pension income	(5,000,000)	(3,000,000)	(16,000,000)	(7,000,000)
Postretirement Benefits | ALABAMA POWER CO
Pension Plans and Postretirement Plans
Service cost	1,000,000	1,000,000	3,000,000	3,000,000
Interest cost	4,000,000	5,000,000	12,000,000	13,000,000
Expected return on plan assets	(9,000,000)	(9,000,000)	(26,000,000)	(26,000,000)
Amortization:
Prior service costs	0	0	0	0
Regulatory asset	0	0	0	0
Net (gain) loss	0	(1,000,000)	(2,000,000)	(2,000,000)
Net periodic pension income	(4,000,000)	(4,000,000)	(13,000,000)	(12,000,000)
Postretirement Benefits | GEORGIA POWER CO
Pension Plans and Postretirement Plans
Service cost	1,000,000	1,000,000	3,000,000	3,000,000
Interest cost	6,000,000	6,000,000	17,000,000	19,000,000
Expected return on plan assets	(8,000,000)	(7,000,000)	(24,000,000)	(22,000,000)
Amortization:
Prior service costs	1,000,000	1,000,000	1,000,000	1,000,000
Regulatory asset	0	0	0	0
Net (gain) loss	(3,000,000)	(1,000,000)	(4,000,000)	(3,000,000)
Net periodic pension income	(3,000,000)	0	(7,000,000)	(2,000,000)
Postretirement Benefits | MISSISSIPPI POWER CO
Pension Plans and Postretirement Plans
Service cost	0	0	0	0
Interest cost	1,000,000	1,000,000	2,000,000	2,000,000
Expected return on plan assets	(1,000,000)	(1,000,000)	(1,000,000)	(1,000,000)
Amortization:
Prior service costs	0	0	0	0
Regulatory asset	0	0	0	0
Net (gain) loss	1,000,000	0	0	0
Net periodic pension income	1,000,000	0	1,000,000	1,000,000
Postretirement Benefits | SOUTHERN POWER CO
Pension Plans and Postretirement Plans
Service cost	0	0	0	0
Interest cost	0	0	0	0
Expected return on plan assets	0	0	0	0
Amortization:
Prior service costs	0	0	0	0
Regulatory asset	0	0	0	0
Net (gain) loss	0	0	0	0
Net periodic pension income	0	0	0	0
Postretirement Benefits | SOUTHERN Co GAS
Pension Plans and Postretirement Plans
Service cost	0	0	1,000,000	1,000,000
Interest cost	2,000,000	2,000,000	6,000,000	6,000,000
Expected return on plan assets	(2,000,000)	(2,000,000)	(6,000,000)	(5,000,000)
Amortization:
Prior service costs	0	0	0	0
Regulatory asset	2,000,000	2,000,000	5,000,000	5,000,000
Net (gain) loss	(1,000,000)	(1,000,000)	(4,000,000)	(3,000,000)
Net periodic pension income	$ 1,000,000	$ 1,000,000	$ 2,000,000	$ 4,000,000

Fair Value Measurements - Sched

Fair Value Measurements - Schedule of Assets and Liabilities Measured at Fair Value (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Assets:
Derivatives	$ 34	$ 32
Liabilities:
Derivatives	469	659
Other	22
Collateral already posted, assets, aggregate fair value	22
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	9
ALABAMA POWER CO
Assets:
Derivatives	8	5
Liabilities:
Derivatives	52	100
Collateral already posted, assets, aggregate fair value	0
GEORGIA POWER CO
Assets:
Derivatives	3	2
Liabilities:
Derivatives	54	113
MISSISSIPPI POWER CO
Assets:
Derivatives	1	1
Liabilities:
Derivatives	38	47
SOUTHERN POWER CO
Assets:
Derivatives	3	3
Liabilities:
Derivatives	16	27
Other	22
Collateral already posted, assets, aggregate fair value	0
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	9
SOUTHERN Co GAS
Assets:
Derivatives	19	21
Liabilities:
Derivatives	63	87
Total
Collateral already posted, assets, aggregate fair value	22	$ 62
Fair Value, Measurements, Recurring
Assets:
Cash equivalents and restricted cash	352
Other investments	45
Total	3,130
Liabilities:
Contingent consideration	20
Total	567
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Cash equivalents and restricted cash	336
Other investments	9
Total	1,388
Liabilities:
Contingent consideration	3
Total	16
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Assets:
Cash equivalents and restricted cash	16
Other investments	28
Total	1,546
Liabilities:
Contingent consideration	0
Total	525
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents and restricted cash	0
Other investments	8
Total	8
Liabilities:
Contingent consideration	17
Total	26
Fair Value, Measurements, Recurring | Net Asset Value as a Practical Expedient (NAV)
Assets:
Total	188
Fair Value, Measurements, Recurring | Energy-related derivatives
Assets:
Derivatives	67
Liabilities:
Derivatives	202
Fair Value, Measurements, Recurring | Energy-related derivatives | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Derivatives	8
Liabilities:
Derivatives	13
Fair Value, Measurements, Recurring | Energy-related derivatives | Significant Other Observable Inputs (Level 2)
Assets:
Derivatives	59
Liabilities:
Derivatives	189
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	1
Liabilities:
Derivatives	218
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	1
Liabilities:
Derivatives	218
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	1,098
Fair Value, Measurements, Recurring | Domestic equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	843
Fair Value, Measurements, Recurring | Domestic equity | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	255
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	352
Fair Value, Measurements, Recurring | Foreign equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	163
Fair Value, Measurements, Recurring | Foreign equity | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	189
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	368
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	368
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	50
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	50
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	464
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	464
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	106
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	106
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	179
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	179
Fair Value, Measurements, Recurring | Cash and cash equivalents
Assets:
Investments in trusts	1
Fair Value, Measurements, Recurring | Cash and cash equivalents | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	1
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	40
Fair Value, Measurements, Recurring | Other | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	28
Fair Value, Measurements, Recurring | Other | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	3
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	105
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	105
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 and restricted cash	213
Other investments	28
Total	1,659
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Cash equivalents and restricted cash	197
Other investments	0
Total	825
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Significant Other Observable Inputs (Level 2)
Assets:
Cash equivalents and restricted cash	16
Other investments	28
Total	646
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents and restricted cash	0
Other investments	0
Total	0
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Net Asset Value as a Practical Expedient (NAV)
Assets:
Total	188
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Energy-related derivatives
Assets:
Derivatives	21
Liabilities:
Derivatives	65
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	21
Liabilities:
Derivatives	65
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	706
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Domestic equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	460
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Domestic equity | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	246
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	163
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Foreign equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	163
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	18
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	18
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	286
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	286
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	29
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	29
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	179
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	179
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Other
Assets:
Investments in trusts	15
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Other | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	5
Fair Value, Measurements, Recurring | ALABAMA POWER CO | Other | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	1
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	1,265
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Total	406
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Significant Other Observable Inputs (Level 2)
Assets:
Total	859
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Significant Unobservable Inputs (Level 3)
Assets:
Total	0
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Energy-related derivatives
Assets:
Derivatives	13
Liabilities:
Derivatives	65
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	13
Liabilities:
Derivatives	65
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
Assets:
Derivatives	1
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Interest rate derivatives | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Derivatives	0
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Interest rate derivatives | Significant Other Observable Inputs (Level 2)
Assets:
Derivatives	1
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Interest rate derivatives | Significant Unobservable Inputs (Level 3)
Assets:
Derivatives	0
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Domestic equity
Assets:
Investments in trusts	384
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Domestic equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	383
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	188
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	188
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	350
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	350
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	49
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	49
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	178
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	178
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	77
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	77
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	25
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Other | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Investments in trusts	23
Fair Value, Measurements, Recurring | GEORGIA POWER CO | Other | Significant Other Observable Inputs (Level 2)
Assets:
Investments in trusts	2
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 | Energy-related derivatives
Assets:
Derivatives	14
Liabilities:
Derivatives	51
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	14
Liabilities:
Derivatives	51
Fair Value, Measurements, Recurring | MISSISSIPPI POWER CO | Energy-related derivatives | Significant Unobservable Inputs (Level 3)
Assets:
Derivatives	0
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring | SOUTHERN POWER CO
Liabilities:
Contingent consideration	20
Total	59
Fair Value, Measurements, Recurring | SOUTHERN POWER CO | Quoted Prices in Active Markets for Identical Assets (Level 1)
Liabilities:
Contingent consideration	3
Total	3
Fair Value, Measurements, Recurring | SOUTHERN POWER CO | Significant Other Observable Inputs (Level 2)
Liabilities:
Contingent consideration	0
Total	30
Fair Value, Measurements, Recurring | SOUTHERN POWER CO | Significant Unobservable Inputs (Level 3)
Liabilities:
Contingent consideration	17
Total	26
Fair Value, Measurements, Recurring | SOUTHERN POWER CO | Energy-related derivatives
Assets:
Derivatives	4
Liabilities:
Derivatives	2
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	4
Liabilities:
Derivatives	2
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	15
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	15
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 and restricted cash	10
Total	42
Liabilities:
Total	81
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Cash equivalents and restricted cash	10
Total	19
Liabilities:
Total	13
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Significant Other Observable Inputs (Level 2)
Assets:
Cash equivalents and restricted cash	0
Total	23
Liabilities:
Total	68
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Significant Unobservable Inputs (Level 3)
Assets:
Cash equivalents and restricted cash	0
Total	0
Liabilities:
Total	0
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Energy-related derivatives
Assets:
Derivatives	15
Liabilities:
Derivatives	19
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Energy-related derivatives | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Derivatives	8
Liabilities:
Derivatives	13
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Energy-related derivatives | Significant Other Observable Inputs (Level 2)
Assets:
Derivatives	7
Liabilities:
Derivatives	6
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Energy-related derivatives | Significant Unobservable Inputs (Level 3)
Assets:
Derivatives	0
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Interest rate derivatives
Liabilities:
Derivatives	62
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Interest rate derivatives | Quoted Prices in Active Markets for Identical Assets (Level 1)
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Interest rate derivatives | Significant Other Observable Inputs (Level 2)
Liabilities:
Derivatives	62
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Interest rate derivatives | Significant Unobservable Inputs (Level 3)
Liabilities:
Derivatives	0
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Domestic equity
Assets:
Non-qualified deferred compensation trusts	8
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Domestic equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Non-qualified deferred compensation trusts	0
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Domestic equity | Significant Other Observable Inputs (Level 2)
Assets:
Non-qualified deferred compensation trusts	8
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Domestic equity | Significant Unobservable Inputs (Level 3)
Assets:
Non-qualified deferred compensation trusts	0
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Foreign equity
Assets:
Non-qualified deferred compensation trusts	1
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Foreign equity | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Non-qualified deferred compensation trusts	0
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Foreign equity | Significant Other Observable Inputs (Level 2)
Assets:
Non-qualified deferred compensation trusts	1
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Foreign equity | Significant Unobservable Inputs (Level 3)
Assets:
Non-qualified deferred compensation trusts	0
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Pooled funds – fixed income
Assets:
Non-qualified deferred compensation trusts	7
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Pooled funds – fixed income | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Non-qualified deferred compensation trusts	0
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Pooled funds – fixed income | Significant Other Observable Inputs (Level 2)
Assets:
Non-qualified deferred compensation trusts	7
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Pooled funds – fixed income | Significant Unobservable Inputs (Level 3)
Assets:
Non-qualified deferred compensation trusts	0
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Cash and cash equivalents
Assets:
Non-qualified deferred compensation trusts	1
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Cash and cash equivalents | Quoted Prices in Active Markets for Identical Assets (Level 1)
Assets:
Non-qualified deferred compensation trusts	1
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Cash and cash equivalents | Significant Other Observable Inputs (Level 2)
Assets:
Non-qualified deferred compensation trusts	0
Fair Value, Measurements, Recurring | SOUTHERN Co GAS | Cash and cash equivalents | Significant Unobservable Inputs (Level 3)
Assets:
Non-qualified deferred compensation trusts	$ 0

Fair Value Measurements - Sch_2

Fair Value Measurements - Schedule of Increase (Decrease) In Fair Value Of Funds (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Fair Value, Option, Quantitative Disclosures [Line Items]
Increase (decrease) in fair value of funds	$ 97	$ (4)	$ 230	$ 211
ALABAMA POWER CO
Fair Value, Option, Quantitative Disclosures [Line Items]
Increase (decrease) in fair value of funds	67	(36)	153	54
GEORGIA POWER CO
Fair Value, Option, Quantitative Disclosures [Line Items]
Increase (decrease) in fair value of funds	$ 30	$ 32	$ 77	$ 157

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) - ALABAMA POWER CO - Private equity $ in Millions	Sep. 30, 2024 USD ($)
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value	$ 188
Unfunded commitments	$ 89

Fair Value Measurements - Sch_3

Fair Value Measurements - Schedule of Financial Instruments for which Carrying Amount did not Equal Fair Value (Details) $ in Billions	Sep. 30, 2024 USD ($)
Long-term debt, including securities due within one year:
Carrying amount	$ 62.6
Fair value	59.8
ALABAMA POWER CO
Long-term debt, including securities due within one year:
Carrying amount	11.2
Fair value	10.3
GEORGIA POWER CO
Long-term debt, including securities due within one year:
Carrying amount	17.4
Fair value	16.3
MISSISSIPPI POWER CO
Long-term debt, including securities due within one year:
Carrying amount	1.7
Fair value	1.5
SOUTHERN POWER CO
Long-term debt, including securities due within one year:
Carrying amount	2.7
Fair value	2.7
SOUTHERN Co GAS
Long-term debt, including securities due within one year:
Carrying amount	8.4
Fair value	$ 7.7

Derivatives - Schedule of Energ

Derivatives - Schedule of Energy-Related Derivatives (Details) - Energy-related, Natural Gas MMBTU in Millions	Sep. 30, 2024 MMBTU
Energy-related derivative contracts
Net Purchased mmBtu	479
ALABAMA POWER CO
Energy-related derivative contracts
Net Purchased mmBtu	130
GEORGIA POWER CO
Energy-related derivative contracts
Net Purchased mmBtu	127
MISSISSIPPI POWER CO
Energy-related derivative contracts
Net Purchased mmBtu	109
SOUTHERN POWER CO
Energy-related derivative contracts
Net Purchased mmBtu	6
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	118
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	11

Derivatives - Narrative (Detail

Derivatives - Narrative (Details) MMBTU in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) MMBTU	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Derivative [Line Items]
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints | MMBTU			13
Gain (Loss) Recognized in OCI on Derivatives	$ (2,000,000)	$ 5,000,000	$ (7,000,000)	$ (45,000,000)
Collateral already posted, assets, aggregate fair value	22,000,000		22,000,000
Derivatives	469,000,000		469,000,000		$ 659,000,000
Interest rate derivatives
Derivative [Line Items]
Cash flow hedge gain (loss) to be reclassified within twelve months	(14,000,000)		(14,000,000)
Derivatives	61,000,000		61,000,000
Interest rate derivatives | Cash Flow Hedging
Derivative [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	(8,000,000)	(3,000,000)	16,000,000	(12,000,000)
Interest rate derivatives | Cash Flow Hedging | Interest Expense
Derivative [Line Items]
Gain (loss) on hedges	(4,000,000)	(22,000,000)	(12,000,000)	(31,000,000)
Interest rate derivatives | Fair Value Hedging | Interest Expense
Derivative [Line Items]
Gain (loss) on hedges	78,000,000	(47,000,000)	47,000,000	(50,000,000)
Energy-related derivatives | Energy-related derivatives not designated as hedging instruments | Cost of Natural Gas
Derivative [Line Items]
Derivative instruments not designated as hedging instruments, gain (loss), net	6,000,000	7,000,000	69,000,000	36,000,000
Energy-related derivatives | Cash Flow Hedging
Derivative [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	(7,000,000)	(4,000,000)	(11,000,000)	(55,000,000)
Foreign currency derivatives | Cash Flow Hedging
Derivative [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	15,000,000	(15,000,000)	(4,000,000)	(6,000,000)
Foreign currency derivatives | Cash Flow Hedging | Interest Expense
Derivative [Line Items]
Gain (loss) on hedges	(3,000,000)	(3,000,000)	(9,000,000)	(8,000,000)
Foreign currency derivatives | Fair Value Hedging
Derivative [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	(2,000,000)	27,000,000	$ (8,000,000)	28,000,000
SOUTHERN POWER CO
Derivative [Line Items]
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints | MMBTU			3
Energy-related derivative hedge gain (loss) to be reclassified within twelve months	0		$ 0
Foreign currency cash flow hedge gain (loss) to be reclassified during next 12 months	0		0
Gain (Loss) Recognized in OCI on Derivatives	13,000,000	(15,000,000)	(6,000,000)	(20,000,000)
Collateral already posted, assets, aggregate fair value	0		0
Derivatives	16,000,000		16,000,000		27,000,000
SOUTHERN POWER CO | Interest rate derivatives
Derivative [Line Items]
Cash flow hedge gain (loss) to be reclassified within twelve months	0		0
Derivatives	0		0
SOUTHERN POWER CO | Energy-related derivatives
Derivative [Line Items]
Derivatives	0		0
SOUTHERN POWER CO | Energy-related derivatives | Energy-related derivatives not designated as hedging instruments
Derivative [Line Items]
Derivative instruments not designated as hedging instruments, gain (loss), net	0	0	0	0
SOUTHERN POWER CO | Energy-related derivatives | Cash Flow Hedging
Derivative [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	(2,000,000)	0	(2,000,000)	(14,000,000)
SOUTHERN POWER CO | Foreign currency derivatives | Cash Flow Hedging
Derivative [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	15,000,000	(15,000,000)	(4,000,000)	(6,000,000)
SOUTHERN POWER CO | Foreign currency derivatives | Cash Flow Hedging | Interest Expense
Derivative [Line Items]
Gain (loss) on hedges	(3,000,000)	(3,000,000)	(9,000,000)	(8,000,000)
SOUTHERN Co GAS
Derivative [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	(10,000,000)	(8,000,000)	(14,000,000)	(41,000,000)
Collateral already posted, assets, aggregate fair value	22,000,000		22,000,000		62,000,000
Derivatives	63,000,000		63,000,000		87,000,000
SOUTHERN Co GAS | Interest rate derivatives
Derivative [Line Items]
Cash flow hedge gain (loss) to be reclassified within twelve months	0		0
SOUTHERN Co GAS | Interest rate derivatives | Cash Flow Hedging
Derivative [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	(6,000,000)	(4,000,000)	(5,000,000)	0
SOUTHERN Co GAS | Interest rate derivatives | Cash Flow Hedging | Interest Expense
Derivative [Line Items]
Gain (loss) on hedges	0	(18,000,000)	0	(18,000,000)
SOUTHERN Co GAS | Interest rate derivatives | Fair Value Hedging | Interest Expense
Derivative [Line Items]
Gain (loss) on hedges	28,000,000	(11,000,000)	18,000,000	(14,000,000)
SOUTHERN Co GAS | Energy-related derivatives | Cash Flow Hedging
Derivative [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	(4,000,000)	(4,000,000)	$ (9,000,000)	(41,000,000)
ALABAMA POWER CO
Derivative [Line Items]
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints | MMBTU			3
Collateral already posted, assets, aggregate fair value	0		$ 0
Derivatives	52,000,000		52,000,000		100,000,000
ALABAMA POWER CO | Interest rate derivatives
Derivative [Line Items]
Cash flow hedge gain (loss) to be reclassified within twelve months	0		0
ALABAMA POWER CO | Energy-related derivatives | Energy-related derivatives not designated as hedging instruments
Derivative [Line Items]
Derivative instruments not designated as hedging instruments, gain (loss), net	0	0	0	0
ALABAMA POWER CO | Energy-related derivatives | Cash Flow Hedging
Derivative [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	0	0	$ 0	0
GEORGIA POWER CO
Derivative [Line Items]
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints | MMBTU			5
Derivatives	54,000,000		$ 54,000,000		113,000,000
GEORGIA POWER CO | Interest rate derivatives
Derivative [Line Items]
Cash flow hedge gain (loss) to be reclassified within twelve months	0		0
GEORGIA POWER CO | Interest rate derivatives | Cash Flow Hedging
Derivative [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	1,000,000	0	17,000,000	(3,000,000)
GEORGIA POWER CO | Energy-related derivatives | Energy-related derivatives not designated as hedging instruments
Derivative [Line Items]
Derivative instruments not designated as hedging instruments, gain (loss), net	0	0	$ 0	0
MISSISSIPPI POWER CO
Derivative [Line Items]
Expected volume of natural gas subject to option to sell back excess gas due to operational constraints | MMBTU			2
Derivatives	38,000,000		$ 38,000,000		$ 47,000,000
MISSISSIPPI POWER CO | Interest rate derivatives
Derivative [Line Items]
Cash flow hedge gain (loss) to be reclassified within twelve months	0		0
MISSISSIPPI POWER CO | Interest rate derivatives | Cash Flow Hedging
Derivative [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	0	0	7,000,000	0
MISSISSIPPI POWER CO | Energy-related derivatives | Energy-related derivatives not designated as hedging instruments
Derivative [Line Items]
Derivative instruments not designated as hedging instruments, gain (loss), net	0	0	0	0
Registrants | Derivative Counterparties
Derivative [Line Items]
Collateral already posted, assets, aggregate fair value	0		0
Traditional Electric Operating Companies | Interest rate derivatives | Cash Flow Hedging | Interest Expense
Derivative [Line Items]
Gain (loss) on hedges	0	0	0	0
Traditional Electric Operating Companies | Interest rate derivatives | Fair Value Hedging | Interest Expense
Derivative [Line Items]
Gain (loss) on hedges	0	$ 0	0	$ 0
Traditional Electric Operating Companies | Energy-related derivatives
Derivative [Line Items]
Derivatives	$ 0		$ 0

Derivatives - Schedule of Inter

Derivatives - Schedule of Interest Rate Derivatives (Details) - Interest rate derivatives $ in Millions	9 Months Ended
	Sep. 30, 2024 USD ($)
Derivative [Line Items]
Notional Amount	$ 2,250
Fair Value Gain (Loss)	(217)
GEORGIA POWER CO | Cash Flow Hedges of Forecasted Debt | Date One
Derivative [Line Items]
Notional Amount	$ 350
Weighted Average Interest Rate Paid	3.53%
Fair Value Gain (Loss)	$ 1
Southern Company parent | Fair Value Hedges of Existing Debt | Date One
Derivative [Line Items]
Notional Amount	$ 400
Weighted Average Interest Rate Paid	0.80%
Interest Rate Received	1.75%
Fair Value Gain (Loss)	$ (32)
Southern Company parent | Fair Value Hedges of Existing Debt | Date Two
Derivative [Line Items]
Notional Amount	$ 1,000
Weighted Average Interest Rate Paid	2.48%
Interest Rate Received	3.70%
Fair Value Gain (Loss)	$ (124)
SOUTHERN Co GAS | Fair Value Hedges of Existing Debt
Derivative [Line Items]
Fair Value Gain (Loss)	(62)
SOUTHERN Co GAS | Fair Value Hedges of Existing Debt | Date Three
Derivative [Line Items]
Notional Amount	$ 500
Weighted Average Interest Rate Paid	0.49%
Interest Rate Received	1.75%

Derivatives - Schedule of Forei

Derivatives - Schedule of Foreign Currency Derivatives (Details) - 9 months ended Sep. 30, 2024 - Foreign currency derivatives € in Millions, $ in Millions	USD ($)	EUR (€)
Derivative [Line Items]
Pay Notional	$ 2,040
Receive Notional | €		€ 1,750
Fair Value Gain (Loss)	(105)
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)	$ (15)
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)	$ (90)

Derivatives - Schedule of Deriv

Derivatives - Schedule of Derivative Category and Balance Sheet Location (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	$ 68	$ 55
Derivative asset, Gross amounts offset	(34)	(23)
Derivative asset, net amounts recognized in the balance sheets	34	32
Derivative liability, gross amount recognized	525	744
Derivative liability, Gross amounts offset	(56)	(85)
Derivative liability, net amounts recognized in the balance sheets	469	659
Collateral already posted, assets, aggregate fair value	22
Interest rate derivatives
Derivatives, Fair Value [Line Items]
Derivative liability, net amounts recognized in the balance sheets	61
Energy-related derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	4	9
Derivative liability, gross amount recognized	4	10
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	3	8
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	4	8
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
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	2
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	59	43
Derivative liability, gross amount recognized	187	315
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	26	12
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	114	198
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	33	31
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	73	117
Derivatives designated as hedging instruments in cash flow and fair value hedges | Energy-related derivatives designated as hedging instruments for regulatory purposes
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	5	3
Derivative liability, gross amount recognized	334	419
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	1	0
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	10	29
Derivatives designated as hedging instruments in cash flow and fair value hedges | Energy-related derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Other deferred charges and assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	3	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 | Other deferred credits and liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	1	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	1	0
Derivatives designated as hedging instruments in cash flow and fair value hedges | Energy-related derivatives designated as hedging instruments for regulatory purposes | Interest rate derivatives | Liabilities from risk management activities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	63	74
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	155	190
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	34	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	71	88
ALABAMA POWER CO
Derivatives, Fair Value [Line Items]
Derivative asset, Gross amounts offset	(13)	(10)
Derivative asset, net amounts recognized in the balance sheets	8	5
Derivative liability, Gross amounts offset	(13)	(10)
Derivative liability, net amounts recognized in the balance sheets	52	100
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	21	15
Derivative liability, gross amount recognized	65	110
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	9	6
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	40	69
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	12	9
ALABAMA POWER CO | Energy-related derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Other deferred credits and liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	25	41
GEORGIA POWER CO
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	14	13
Derivative asset, Gross amounts offset	(11)	(11)
Derivative asset, net amounts recognized in the balance sheets	3	2
Derivative liability, gross amount recognized	65	124
Derivative liability, Gross amounts offset	(11)	(11)
Derivative liability, net amounts recognized in the balance sheets	54	113
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	1
GEORGIA POWER CO | Energy-related derivatives not designated as hedging instruments | Energy-related derivatives | Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	0	0
GEORGIA POWER CO | Energy-related derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives designated as hedging instruments for regulatory purposes
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	12	12
Derivative liability, gross amount recognized	65	124
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	2	2
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	46	82
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	10	10
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	19	42
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	1	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	0	0
MISSISSIPPI POWER CO
Derivatives, Fair Value [Line Items]
Derivative asset, Gross amounts offset	(13)	(14)
Derivative asset, net amounts recognized in the balance sheets	1	1
Derivative liability, Gross amounts offset	(13)	(14)
Derivative liability, net amounts recognized in the balance sheets	38	47
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	14	15
Derivative liability, gross amount recognized	51	61
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	3	3
MISSISSIPPI POWER CO | Energy-related derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	22	27
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	11	12
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	29	34
SOUTHERN POWER CO
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	4	3
Derivative asset, Gross amounts offset	(1)	0
Derivative asset, net amounts recognized in the balance sheets	3	3
Derivative liability, gross amount recognized	17	27
Derivative liability, Gross amounts offset	(1)	0
Derivative liability, net amounts recognized in the balance sheets	16	27
Collateral already posted, assets, aggregate fair value	0
SOUTHERN POWER CO | Energy-related derivatives
Derivatives, Fair Value [Line Items]
Derivative liability, net amounts recognized in the balance sheets	0
SOUTHERN POWER CO | Interest rate derivatives
Derivatives, Fair Value [Line Items]
Derivative liability, net amounts recognized in the balance sheets	0
SOUTHERN POWER CO | Energy-related derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	1	0
Derivative liability, gross amount recognized	1	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	0
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	1	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	0
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	3	3
Derivative liability, gross amount recognized	16	27
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	1	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 charges and assets
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	3	3
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	4	11
SOUTHERN Co GAS
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	15	9
Derivative asset, Gross amounts offset	4	12
Derivative asset, net amounts recognized in the balance sheets	19	21
Derivative liability, gross amount recognized	81	137
Derivative liability, Gross amounts offset	(18)	(50)
Derivative liability, net amounts recognized in the balance sheets	63	87
Collateral already posted, assets, aggregate fair value	22	62
SOUTHERN Co GAS | Energy-related derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative asset, gross amount recognized	2	8
Derivative liability, gross amount recognized	3	10
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	2	7
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	3	8
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	0	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	0	2
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	12	1
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	6	20
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	0
Derivative liability, gross amount recognized	72	107
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	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 | Energy-related derivatives | Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	9	24
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	0
SOUTHERN Co GAS | Derivatives designated as hedging instruments in cash flow and fair value hedges | Energy-related derivatives designated as hedging instruments for regulatory purposes | Energy-related derivatives | Other deferred credits and liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	1	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	0	0
SOUTHERN Co GAS | Derivatives designated as hedging instruments in cash flow and fair value hedges | Energy-related derivatives designated as hedging instruments for regulatory purposes | Interest rate derivatives | Other current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability, gross amount recognized	15	20
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	$ 47	$ 59

Derivatives - Schedule of Pre-t

Derivatives - Schedule of Pre-tax Effects of Unrealized Derivative Gains (Losses) (Details) - Energy-related derivatives - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	$ (130)	$ (257)
Other regulatory assets, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(102)	(180)
Other regulatory assets, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(43)	(87)
Other regulatory liabilities, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	12	9
Other regulatory assets, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	3	1
ALABAMA POWER CO
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(44)	(95)
ALABAMA POWER CO | Other regulatory assets, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(37)	(67)
ALABAMA POWER CO | Other regulatory assets, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(14)	(32)
ALABAMA POWER CO | Other regulatory liabilities, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	6	4
ALABAMA POWER CO | Other regulatory assets, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	1	0
GEORGIA POWER CO
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(53)	(112)
GEORGIA POWER CO | Other regulatory assets, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(44)	(80)
GEORGIA POWER CO | Other regulatory assets, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(10)	(33)
GEORGIA POWER CO | Other regulatory liabilities, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	0	0
GEORGIA POWER CO | Other regulatory assets, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	1	1
MISSISSIPPI POWER CO
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(37)	(46)
MISSISSIPPI POWER CO | Other regulatory assets, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(19)	(25)
MISSISSIPPI POWER CO | Other regulatory assets, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(19)	(22)
MISSISSIPPI POWER CO | Other regulatory liabilities, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	0	1
MISSISSIPPI POWER CO | Other regulatory assets, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	1	0
SOUTHERN Co GAS
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	4	(4)
SOUTHERN Co GAS | Other regulatory assets, current
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	(2)	(8)
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)	6	4
SOUTHERN Co GAS | Other regulatory assets, deferred
Derivative Instruments, Gain (Loss) [Line Items]
Total energy-related derivative gains (losses)	$ 0	$ 0

Derivatives - Schedule of Pre_2

Derivatives - Schedule of Pre-Tax Effects of Hedging on AOCI (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	$ (2)	$ 5	$ (7)	$ (45)
Cash Flow Hedging | Energy-related derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	(7)	(4)	(11)	(55)
Cash Flow Hedging | Interest rate derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	(8)	(3)	16	(12)
Cash Flow Hedging | Foreign currency derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	15	(15)	(4)	(6)
Fair Value Hedging | Foreign currency derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	(2)	27	(8)	28
GEORGIA POWER CO | Cash Flow Hedging | Interest rate derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	1	0	17	(3)
MISSISSIPPI POWER CO | Cash Flow Hedging | Interest rate derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	0	0	7	0
SOUTHERN POWER CO
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	13	(15)	(6)	(20)
SOUTHERN POWER CO | Cash Flow Hedging | Energy-related derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	(2)	0	(2)	(14)
SOUTHERN POWER CO | Cash Flow Hedging | Foreign currency derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	15	(15)	(4)	(6)
SOUTHERN Co GAS
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	(10)	(8)	(14)	(41)
SOUTHERN Co GAS | Cash Flow Hedging | Energy-related derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	(4)	(4)	(9)	(41)
SOUTHERN Co GAS | Cash Flow Hedging | Interest rate derivatives
Derivative Instruments, Gain (Loss) [Line Items]
Gain (Loss) Recognized in OCI on Derivatives	$ (6)	$ (4)	$ (5)	$ 0

Derivatives - Schedule of Pre_3

Derivatives - Schedule of Pre-Tax Effects of Cash Flow and Fair Value Hedging on Income (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Derivative [Line Items]
Total other operations and maintenance	$ 1,662	$ 1,424	$ 4,543	$ 4,352
Depreciation and amortization	1,210	1,143	3,537	3,365
Total interest expense, net of amounts capitalized	(692)	(620)	(2,050)	(1,812)
Total other income (expense), net	147	141	450	428
Natural gas
Derivative [Line Items]
Total cost of sales	98	102	852	1,199
Other Income (Expense)
Derivative [Line Items]
Amount excluded from effectiveness testing recognized in earnings	3	(27)	8	(28)
Cash Flow Hedging | Energy-related derivatives | Cost of Sales
Derivative [Line Items]
Gain (loss) on hedges	(4)	(4)	(34)	(32)
Cash Flow Hedging | Energy-related derivatives | Operating Expense
Derivative [Line Items]
Gain (loss) on hedges	0	(1)	(1)	(2)
Cash Flow Hedging | Energy-related derivatives | Depreciation and Amortization
Derivative [Line Items]
Gain (loss) on hedges	(3)	(5)	(5)	(18)
Cash Flow Hedging | Interest rate derivatives | Interest Expense
Derivative [Line Items]
Gain (loss) on hedges	(4)	(22)	(12)	(31)
Cash Flow Hedging | Foreign currency derivatives | Interest Expense
Derivative [Line Items]
Gain (loss) on hedges	(3)	(3)	(9)	(8)
Cash Flow Hedging | Foreign currency derivatives | Other Income (Expense)
Derivative [Line Items]
Gain (loss) on hedges	24	(14)	7	(4)
Fair Value Hedging | Interest rate derivatives | Interest Expense
Derivative [Line Items]
Gain (loss) on hedges	78	(47)	47	(50)
Fair Value Hedging | Foreign currency derivatives | Other Income (Expense)
Derivative [Line Items]
Gain (loss) on hedges	58	(7)	79	19
SOUTHERN POWER CO
Derivative [Line Items]
Total other operations and maintenance	126	104	367	327
Depreciation and amortization	133	130	378	380
Total interest expense, net of amounts capitalized	(30)	(32)	(89)	(98)
Total other income (expense), net	2	4	8	8
SOUTHERN POWER CO | Cash Flow Hedging | Energy-related derivatives | Depreciation and Amortization
Derivative [Line Items]
Gain (loss) on hedges	(3)	(5)	(5)	(18)
SOUTHERN POWER CO | Cash Flow Hedging | Foreign currency derivatives | Interest Expense
Derivative [Line Items]
Gain (loss) on hedges	(3)	(3)	(9)	(8)
SOUTHERN POWER CO | Cash Flow Hedging | Foreign currency derivatives | Other Income (Expense)
Derivative [Line Items]
Gain (loss) on hedges	24	(14)	7	(4)
SOUTHERN Co GAS
Derivative [Line Items]
Total cost of sales	98	102	852	1,199
Total other operations and maintenance	295	264	877	879
Depreciation and amortization	162	145	475	429
Total interest expense, net of amounts capitalized	(84)	(77)	(250)	(226)
Total other income (expense), net	16	19	49	50
SOUTHERN Co GAS | Natural gas
Derivative [Line Items]
Total cost of sales	98	102	852	1,199
SOUTHERN Co GAS | Cash Flow Hedging | Energy-related derivatives | Cost of Sales
Derivative [Line Items]
Gain (loss) on hedges	(4)	(4)	(34)	(32)
SOUTHERN Co GAS | Cash Flow Hedging | Energy-related derivatives | Operating Expense
Derivative [Line Items]
Gain (loss) on hedges	0	(1)	(1)	(2)
SOUTHERN Co GAS | Cash Flow Hedging | Interest rate derivatives | Interest Expense
Derivative [Line Items]
Gain (loss) on hedges	0	(18)	0	(18)
SOUTHERN Co GAS | Fair Value Hedging | Interest rate derivatives | Interest Expense
Derivative [Line Items]
Gain (loss) on hedges	$ 28	$ (11)	$ 18	$ (14)

Derivatives - Schedule of Cumul

Derivatives - Schedule of Cumulative Basis Adjustments for Fair Value Hedges (Details) - Fair Value Hedging - Long-term debt - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Derivative [Line Items]
Carrying Amount of the Hedged Item	$ (3,085)	$ (3,024)
Cumulative Amount of Fair Value Hedging Adjustment included in Carrying Amount of the Hedged Item	193	235
SOUTHERN Co GAS
Derivative [Line Items]
Carrying Amount of the Hedged Item	(440)	(427)
Cumulative Amount of Fair Value Hedging Adjustment included in Carrying Amount of the Hedged Item	$ 57	$ 70

Acquisitions and Dispositions_2

Acquisitions and Dispositions (Details) - SOUTHERN POWER CO $ in Millions	1 Months Ended	9 Months Ended
	Oct. 30, 2024 MW	Sep. 30, 2024 USD ($) MW
South Cheyenne Solar Facility
Business Acquisition [Line Items]
Nameplate capacity placed in service (in MWs)		150
Approximate nameplate capacity		150
Life output of plant (in years)		20 years
Millers Branch Solar Development Phase 1
Business Acquisition [Line Items]
Approximate nameplate capacity		200
Life output of plant (in years)		20 years
Millers Branch Solar Development Phase 2
Business Acquisition [Line Items]
Approximate nameplate capacity		180
Life output of plant (in years)		15 years
Millers Branch Solar Development Phase 3
Business Acquisition [Line Items]
Approximate nameplate capacity		90
Life output of plant (in years)		15 years
Millers Branch Solar Development Phase 3 | Subsequent Event
Business Acquisition [Line Items]
Additional capacity	42
Millers Branch Solar Development
Business Acquisition [Line Items]
Construction work in progress | $		$ 159
Millers Branch Solar Development | Subsequent Event
Business Acquisition [Line Items]
Additional capacity	512

Segment and Related Informati_3

Segment and Related Information - Narrative (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024 USD ($) state	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) state segment	Sep. 30, 2023 USD ($)
Segment Reporting Information [Line Items]
Number of states in which entity operates | state	3		3
Operating revenues	$ 7,481	$ 7,107	$ 20,513	$ 18,886
SOUTHERN POWER CO
Segment Reporting Information [Line Items]
Operating revenues	$ 423	480	$ 1,143	1,248
SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Number of states in which entity operates | state	4		4
Operating revenues	$ 667	674	$ 3,117	3,338
Number of reportable segments | segment			3
SOUTHERN Co GAS | Southern Natural Gas Company, LLC
Segment Reporting Information [Line Items]
Ownership percentage, equity method investment	50%		50%
SOUTHERN Co GAS | Dalton Pipeline
Segment Reporting Information [Line Items]
Ownership percentage, equity method investment	50%		50%
Traditional Electric Operating Companies | Wholesale revenues, affiliates | SOUTHERN POWER CO
Segment Reporting Information [Line Items]
Operating revenues	$ 102	156	$ 280	406
Traditional Electric Operating Companies | Natural Gas | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues	$ 0	$ 0	$ 0	$ 0

Segment and Related Informati_4

Segment and Related Information - Schedule of Financial Data for Business Segments (Details) - USD ($) $ in Millions	3 Months Ended						9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Segment Reporting Information [Line Items]
Operating revenues	$ 7,274			$ 6,980			$ 20,383	$ 19,208
Net income	1,535			1,422			3,867	3,121
Goodwill	5,161						5,161		$ 5,161
Total assets	143,956						143,956		139,331
Estimated loss on Plant Vogtle Units 3 and 4	0			160			(21)	160
SOUTHERN POWER CO
Segment Reporting Information [Line Items]
Operating revenues	600			653			1,597	1,686
Net income	82			100			264	288
Total assets	12,646						12,646		12,761
Amount awarded	18						18
Amount awarded after tax	9						9
SOUTHERN POWER CO | Disposal Group, Disposed of by Sale | Spare Parts
Segment Reporting Information [Line Items]
Gain (loss) on sale							16
Gain (loss) on sale, after tax							12
SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues	682			689			3,220	3,417
Net income	38			82			555	475
Goodwill	5,015						5,015		5,015
Total assets	25,545						25,545		25,083
Nicor Gas
Segment Reporting Information [Line Items]
Pre-tax charge to income							38
After-tax charge to income							28
GEORGIA POWER CO
Segment Reporting Information [Line Items]
Operating revenues	3,472			3,237			8,745	7,805
Total assets	60,498						60,498		56,817
Estimated loss on Plant Vogtle Units 3 and 4	0	$ (21)		160			(21)	160
After tax credit on plant vogtle units 3 and 4		(16)		120			(16)	120
ALABAMA POWER CO
Segment Reporting Information [Line Items]
Operating revenues	2,138			2,083			5,803	5,420
Net income	493	$ 369	$ 333	565	$ 312	$ 255
Total assets	36,340						36,340		35,780
Pre tax impairment loss	36
After tax impairment loss	27
Electric Utilities
Segment Reporting Information [Line Items]
Operating revenues	6,422			6,167			16,693	15,414
SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues	682			689			3,220	3,417
Gas distribution operations | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Goodwill	4,034						4,034		4,034
Operating Segments | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues	677			683			3,210	3,402
Net income	43			96			552	484
Total assets	26,735						26,735		26,055
Operating Segments | Electric Utilities
Segment Reporting Information [Line Items]
Operating revenues	6,422			6,167			16,693	15,414
Net income	1,700			1,519			3,894	3,140
Goodwill	2						2		2
Total assets	116,664						116,664		112,645
Operating Segments | Traditional Electric Operating Companies
Segment Reporting Information [Line Items]
Operating revenues	5,927			5,674			15,389	14,145
Net income	1,618			1,419			3,630	2,852
Goodwill	0						0		0
Total assets	104,565						104,565		100,429
Operating Segments | SOUTHERN POWER CO
Segment Reporting Information [Line Items]
Operating revenues	600			653			1,597	1,686
Net income	82			100			264	288
Goodwill	2						2		2
Total assets	12,646						12,646		12,761
Operating Segments | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues	682			689			3,220	3,417
Net income	38			82			555	475
Goodwill	5,015						5,015		5,015
Total assets	25,545						25,545		25,083
Operating Segments | All Other
Segment Reporting Information [Line Items]
Operating revenues	215			154			598	499
Net income	(201)			(179)			(569)	(490)
Goodwill	144						144		144
Total assets	2,347						2,347		2,446
Operating Segments | All Other | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues	6			8			19	30
Net income	(5)			(14)			3	(9)
Total assets	9,910						9,910		9,675
Operating Segments | Gas distribution operations | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues	616			619			2,828	3,002
Net income	21			70			403	352
Total assets	23,543						23,543		22,906
Eliminations
Segment Reporting Information [Line Items]
Operating revenues	(45)			(30)			(128)	(122)
Net income	(2)			0			(13)	(4)
Goodwill	0						0		0
Total assets	(600)						(600)		(843)
Eliminations | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Operating revenues	(1)			(2)			(9)	(15)
Net income	0			0			0	0
Total assets	(11,100)						(11,100)		(10,647)
Eliminations | Electric Utilities
Segment Reporting Information [Line Items]
Operating revenues	(105)			(160)			(293)	(417)
Net income	0			$ 0			0	$ 0
Goodwill	0						0		0
Total assets	$ (547)						$ (547)		$ (545)

Segment and Related Informati_5

Segment and Related Information - Schedule of Financial Data for Products and Services (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Concentration Risk [Line Items]
Operating revenues	$ 7,274	$ 6,980	$ 20,383	$ 19,208
Electric Utilities
Concentration Risk [Line Items]
Operating revenues	6,422	6,167	16,693	15,414
Southern Company Gas' Revenues
Concentration Risk [Line Items]
Operating revenues	682	689	3,220	3,417
Retail electric revenues
Concentration Risk [Line Items]
Operating revenues	5,366	5,139	13,793	12,597
Retail electric revenues | Electric Utilities
Concentration Risk [Line Items]
Operating revenues	5,366	5,139	13,793	12,597
Wholesale electric revenues
Concentration Risk [Line Items]
Operating revenues	721	727	1,919	1,930
Wholesale electric revenues | Electric Utilities
Concentration Risk [Line Items]
Operating revenues	721	727	1,919	1,930
Other Revenue | Electric Utilities
Concentration Risk [Line Items]
Operating revenues	335	301	981	887
Gas Distribution Operations | Southern Company Gas' Revenues
Concentration Risk [Line Items]
Operating revenues	616	617	2,828	2,989
Gas marketing services | Southern Company Gas' Revenues
Concentration Risk [Line Items]
Operating revenues	53	56	358	376
Other | Southern Company Gas' Revenues
Concentration Risk [Line Items]
Operating revenues	$ 13	$ 16	$ 34	$ 52

Segment and Related Informati_6

Segment and Related Information - Schedule of Business Segment Financial Data (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Segment Reporting Information [Line Items]
Total operating revenues	$ 7,274	$ 6,980	$ 20,383	$ 19,208
Net income	1,535	1,422	3,867	3,121
Total assets	143,956		143,956		$ 139,331
SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Total operating revenues	682	689	3,220	3,417
Net income	38	82	555	475
Total assets	25,545		25,545		25,083
GEORGIA POWER CO
Segment Reporting Information [Line Items]
Total operating revenues	3,472	3,237	8,745	7,805
Total assets	60,498		60,498		56,817
SOUTHERN POWER CO
Segment Reporting Information [Line Items]
Total operating revenues	600	653	1,597	1,686
Net income	82	100	264	288
Total assets	12,646		12,646		12,761
Nicor Gas
Segment Reporting Information [Line Items]
Pre-tax charge to income			38
After-tax charge to income			28
Operating Segments | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Total operating revenues	677	683	3,210	3,402
Net income	43	96	552	484
Total assets	26,735		26,735		26,055
Operating Segments | Gas distribution operations | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Total operating revenues	616	619	2,828	3,002
Net income	21	70	403	352
Total assets	23,543		23,543		22,906
Operating Segments | Gas Pipeline Investments | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Total operating revenues	8	8	24	24
Net income	24	24	77	73
Total assets	1,573		1,573		1,534
Operating Segments | Gas marketing services | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Total operating revenues	53	56	358	376
Net income	(2)	2	72	59
Total assets	1,619		1,619		1,615
Operating Segments | All Other
Segment Reporting Information [Line Items]
Total operating revenues	215	154	598	499
Net income	(201)	(179)	(569)	(490)
Total assets	2,347		2,347		2,446
Operating Segments | All Other | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Total operating revenues	6	8	19	30
Net income	(5)	(14)	3	(9)
Total assets	9,910		9,910		9,675
Eliminations
Segment Reporting Information [Line Items]
Total operating revenues	(45)	(30)	(128)	(122)
Net income	(2)	0	(13)	(4)
Total assets	(600)		(600)		(843)
Eliminations | SOUTHERN Co GAS
Segment Reporting Information [Line Items]
Total operating revenues	(1)	(2)	(9)	(15)
Net income	0	$ 0	0	$ 0
Total assets	$ (11,100)		$ (11,100)		$ (10,647)