SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)

12 Months Ended

Dec. 31, 2023

Accounting Policies [Abstract]

Schedule of costs for affiliate transactions

Costs for these services from SCS in 2023, 2022, and 2021 were as follows:

	Alabama Power		Georgia Power		Mississippi Power		Southern Power		Southern Company Gas
	(in millions)
2023	$	611	$	857	$	113	$	86	$	261
2022	549		762		115		86		262
2021	504		663		120		89		239

Mississippi Power's and Southern Power's power purchases from affiliates through the Southern Company power pool are included in purchased power on their respective statements of income and were as follows:

	Mississippi Power		Southern Power
	(in millions)
2023	$	4	$	13
2022	4		29
2021	9		15

Transportation costs under these agreements in 2023, 2022, and 2021 were as follows:

	Alabama Power		Georgia Power		Southern Power		Southern Company Gas
	(in millions)
2023	$	12	$	101	$	34	$	28
2022	18		99		37		27
2021	14		108		31		29

The approximate rates for 2023, 2022, and 2021 are as follows:

	2023		2022		2021
Alabama Power	4.1	%	2.7	%	2.7	%
Georgia Power	3.8	%	3.3	%	3.3	%
Mississippi Power	3.4	%	3.4	%	3.6	%
Southern Company Gas	2.7	%	2.7	%	2.8	%

Schedule of total AFUDC and interest capitalized

Total AFUDC and interest capitalized for the applicable Registrants in 2023, 2022, and 2021 was as follows:

	Southern Company		Alabama Power		Georgia Power(*)		Southern Power		Southern Company Gas
	(in millions)
2023	$	400	$	109	$	251	$	3	$	37
2022	327		90		213		—		24
2021	282		68		190		6		18

(*)See Note 2 under "Georgia Power – Nuclear Construction" for information on the inclusion of a portion of construction costs related to Plant Vogtle Unit 4 in Georgia Power's rate base.

Schedule of average AFUDC composite rates

The average AFUDC composite rates for 2023, 2022, and 2021 for the traditional electric operating companies and the natural gas distribution utilities were as follows:

	2023		2022		2021
Alabama Power	8.1	%	7.9	%	7.9	%
Georgia Power(a)	7.6	%	7.3	%	7.2	%
Mississippi Power(b)	—	%	5.3	%	2.5	%
Southern Company Gas:
Atlanta Gas Light	7.4	%	7.6	%	7.7	%
Chattanooga Gas	7.1	%	7.1	%	7.1	%
Nicor Gas	4.6	%	2.0	%	0.1	%

(a)Excludes AFUDC related to the construction of Plant Vogtle Units 3 and 4. See Note 2 under "Georgia Power – Nuclear Construction" for additional information.

(b)Mississippi Power's AFUDC was immaterial in 2023.

Schedule of goodwill balances

At December 31, 2023 and 2022, goodwill was as follows:

	At December 31, 2023		At December 31, 2022
	(in millions)
Southern Company	$	5,161	$	5,161
Southern Company Gas:
Gas distribution operations	$	4,034	$	4,034
Gas marketing services	981		981
Southern Company Gas total	$	5,015	$	5,015

Schedule of intangible assets subject to amortization

At December 31, 2023 and 2022, other intangible assets were as follows:

	At December 31, 2023						At December 31, 2022
	Gross Carrying Amount		Accumulated Amortization		Other Intangible Assets, Net		Gross Carrying Amount		Accumulated Amortization		Other Intangible Assets, Net
	(in millions)						(in millions)
Southern Company
Subject to amortization:
Customer relationships	$	212	$	(172)	$	40	$	212	$	(162)	$	50
Trade names	64		(53)		11		64		(44)		20
PPA fair value adjustments	390		(148)		242		390		(129)		261
Other	3		(3)		—		5		(5)		—
Total subject to amortization	$	669	$	(376)	$	293	$	671	$	(340)	$	331
Not subject to amortization:
FCC licenses	75		—		75		75		—		75
Total other intangible assets	$	744	$	(376)	$	368	$	746	$	(340)	$	406
Southern Power(*)
PPA fair value adjustments	$	390	$	(148)	$	242	$	390	$	(129)	$	261
Southern Company Gas(*)
Gas marketing services
Customer relationships	$	156	$	(145)	$	11	$	156	$	(139)	$	17
Trade names	26		(21)		5		26		(17)		9
Total other intangible assets	$	182	$	(166)	$	16	$	182	$	(156)	$	26

(*)All subject to amortization.

Schedule of intangible assets not subject to amortization

At December 31, 2023 and 2022, other intangible assets were as follows:

	At December 31, 2023						At December 31, 2022
	Gross Carrying Amount		Accumulated Amortization		Other Intangible Assets, Net		Gross Carrying Amount		Accumulated Amortization		Other Intangible Assets, Net
	(in millions)						(in millions)
Southern Company
Subject to amortization:
Customer relationships	$	212	$	(172)	$	40	$	212	$	(162)	$	50
Trade names	64		(53)		11		64		(44)		20
PPA fair value adjustments	390		(148)		242		390		(129)		261
Other	3		(3)		—		5		(5)		—
Total subject to amortization	$	669	$	(376)	$	293	$	671	$	(340)	$	331
Not subject to amortization:
FCC licenses	75		—		75		75		—		75
Total other intangible assets	$	744	$	(376)	$	368	$	746	$	(340)	$	406
Southern Power(*)
PPA fair value adjustments	$	390	$	(148)	$	242	$	390	$	(129)	$	261
Southern Company Gas(*)
Gas marketing services
Customer relationships	$	156	$	(145)	$	11	$	156	$	(139)	$	17
Trade names	26		(21)		5		26		(17)		9
Total other intangible assets	$	182	$	(166)	$	16	$	182	$	(156)	$	26

(*)All subject to amortization.

Schedule of amortization associated with other intangible assets

Amortization associated with other intangible assets in 2023, 2022, and 2021 was as follows:

	2023		2022		2021
	(in millions)
Southern Company(a)	$	38	$	39	$	44
Southern Power(b)	20		20		20
Southern Company Gas:
Gas marketing services	10		11		15

(a)Includes $20 million annually recorded as a reduction to operating revenues.

(b)Recorded as a reduction to operating revenues.

Schedule of estimated future amortization of other intangible assets

At December 31, 2023, the estimated amortization associated with other intangible assets for the next five years is as follows:

	2024		2025		2026		2027		2028
	(in millions)
Southern Company	$	35	$	32	$	27	$	24	$	24
Southern Power	20		20		20		20		20
Southern Company Gas	7		6		3		—		—

Schedule of cash, cash equivalents, and restricted cash

The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the balance sheets that total to the amount shown in the statements of cash flows for the applicable Registrants:

	Southern Company		Alabama Power		Georgia Power		Southern Power		Southern Company Gas
	(in millions)
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
At December 31, 2022
Cash and cash equivalents	$	1,917	$	687	$	364	$	131	$	81
Restricted cash(a):
Other current assets	62		—		60		—		2
Other deferred charges and assets	58		—		56		3		—
Total cash, cash equivalents, and restricted cash(b)	$	2,037	$	687	$	480	$	133	$	83

(a)For Alabama Power, reflects proceeds from the issuance of solid waste disposal facility revenue bonds in 2023. For Georgia Power, reflects proceeds from the issuance of solid waste disposal facility revenue bonds in 2022. See Note 8 under "Long-term Debt" for additional information. For Southern Power, reflects $17 million at December 31, 2023 resulting from an arbitration award held to fund future replacement costs and $3 million at both December 31, 2023 and 2022 held to fund estimated construction completion costs at the Deuel Harvest wind facility. See Note 3 under "General Litigation Matters – Southern Power" and Note 15 under "Southern Power" for additional information. For Southern Company Gas, reflects collateral for workers' compensation, life insurance, and long-term disability insurance.

(b)Total may not add due to rounding.

Reconciliation of restricted cash and cash equivalents

The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported within the balance sheets that total to the amount shown in the statements of cash flows for the applicable Registrants:

	Southern Company		Alabama Power		Georgia Power		Southern Power		Southern Company Gas
	(in millions)
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
At December 31, 2022
Cash and cash equivalents	$	1,917	$	687	$	364	$	131	$	81
Restricted cash(a):
Other current assets	62		—		60		—		2
Other deferred charges and assets	58		—		56		3		—
Total cash, cash equivalents, and restricted cash(b)	$	2,037	$	687	$	480	$	133	$	83

(a)For Alabama Power, reflects proceeds from the issuance of solid waste disposal facility revenue bonds in 2023. For Georgia Power, reflects proceeds from the issuance of solid waste disposal facility revenue bonds in 2022. See Note 8 under "Long-term Debt" for additional information. For Southern Power, reflects $17 million at December 31, 2023 resulting from an arbitration award held to fund future replacement costs and $3 million at both December 31, 2023 and 2022 held to fund estimated construction completion costs at the Deuel Harvest wind facility. See Note 3 under "General Litigation Matters – Southern Power" and Note 15 under "Southern Power" for additional information. 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 reserves

Storm damage reserve activity for the traditional electric operating companies during 2023 was as follows:

	Southern Company		Alabama Power		Georgia Power		Mississippi Power
	(in millions)
Balance at December 31, 2022	$	216	$	97	$	83	$	36
Accrual	61		18		31		12
Weather-related damages	(211)		(39)		(168)		(4)
Balance at December 31, 2023	$	66	$	76	$	(54)	$	44

The traditional electric operating companies accrued the following amounts related to storm damage recovery in 2022 and 2021:

	Southern Company(a)(b)		Alabama Power(a)		Georgia Power		Mississippi Power(b)
	(in millions)
2022	$	239	$	19	$	213	$	7
2021	286		75		213		(2)

(a)Alabama Power's 2021 amount includes the $65 million additional accrual discussed above.

(b)Mississippi Power's net accrual includes carrying costs, as well as amortization of related excess deferred income tax benefits.

During 2023 and 2022, Alabama Power and Mississippi Power accrued the following amounts to their reliability reserves:

	Southern Company		Alabama Power		Mississippi Power
	(in millions)
2023	$	63	$	52	$	11
2022	191		166		25

Schedule of AOCI (loss) balances, net of tax effects

AOCI (loss) balances, net of tax effects, for Southern Company, Southern Power, and Southern Company Gas were as follows:

	Qualifying Hedges		Pension and Other Postretirement Benefit Plans		Accumulated Other Comprehensive Income (Loss)(*)
	(in millions)
Southern Company
Balance at December 31, 2022	$	(149)	$	(18)	$	(167)
Current period change	28		(38)		(10)
Balance at December 31, 2023	$	(121)	$	(56)	$	(177)
Southern Power
Balance at December 31, 2022	$	(9)	$	(9)	$	(18)
Current period change	8		(7)		1
Balance at December 31, 2023	$	(1)	$	(16)	$	(17)
Southern Company Gas
Balance at December 31, 2022	$	(25)	$	56	$	31
Current period change	1		(16)		(15)
Balance at December 31, 2023	$	(24)	$	40	$	16

(*)May not add due to rounding.