Segment and Related Information - Schedule of Traditional Electric Companies (Details) $ in Millions	3 Months Ended
Mar. 31, 2026 USD ($) segment	Mar. 31, 2025 USD ($)
Segment Reporting Information [Line Items]
Total operating revenues	$ 8,397	$ 7,775
Utility operations and maintenance
Total utility operations and maintenance	1,653	1,619
Other segment items	4,665	4,193
Depreciation and amortization(b)	1,420	1,286
Interest expense(c)	778	714
Income taxes (benefit)	228	280
Consolidated Net Income Attributable to Southern Company	$ 1,356	1,334
Traditional Electric Operating Companies
Utility operations and maintenance
Number of reportable segments \| segment	1
ALABAMA POWER CO
Segment Reporting Information [Line Items]
Total operating revenues	$ 2,092	2,012
Utility operations and maintenance
Total utility operations and maintenance	393	463
Depreciation and amortization(b)	381	370
Interest expense(c)	115	108
Income taxes (benefit)	129	111
Consolidated Net Income Attributable to Southern Company	425	375
GEORGIA POWER CO
Segment Reporting Information [Line Items]
Total operating revenues	3,142	3,037
Utility operations and maintenance
Total utility operations and maintenance	672	634
Depreciation and amortization(b)	484	503
Interest expense(c)	204	187
Income taxes (benefit)	85	98
Consolidated Net Income Attributable to Southern Company	628	596
MISSISSIPPI POWER CO
Segment Reporting Information [Line Items]
Total operating revenues	472	420
Utility operations and maintenance
Total utility operations and maintenance	88	84
Depreciation and amortization(b)	55	52
Interest expense(c)	20	20
Income taxes (benefit)	18	16
Consolidated Net Income Attributable to Southern Company	60	55
SOUTHERN POWER CO
Segment Reporting Information [Line Items]
Total operating revenues	681	567
Utility operations and maintenance
Total utility operations and maintenance	137	123
Depreciation and amortization(b)	278	152
Interest expense(c)	27	26
Income taxes (benefit)	(70)	(1)
Consolidated Net Income Attributable to Southern Company	$ 4	87
Number of reportable segments \| segment	1
Reportable Segment \| ALABAMA POWER CO
Segment Reporting Information [Line Items]
Total operating revenues	$ 2,092	2,012
Utility operations and maintenance
Rate RSE expenses	301	365
Rate CNP Compliance expenses	74	75
Total utility operations and maintenance	375	440
Other segment items	667	608
Depreciation and amortization(b)	381	370
Interest expense(c)	115	108
Income taxes (benefit)	129	111
Consolidated Net Income Attributable to Southern Company	425	375
Capital expenditures	519	560
Reportable Segment \| GEORGIA POWER CO
Segment Reporting Information [Line Items]
Total operating revenues	3,142	3,037
Utility operations and maintenance
Total utility operations and maintenance	578	536
Other segment items	1,163	1,117
Depreciation and amortization(b)	484	503
Interest expense(c)	204	187
Income taxes (benefit)	85	98
Consolidated Net Income Attributable to Southern Company	628	596
Capital expenditures	2,070	1,637
Reportable Segment \| MISSISSIPPI POWER CO
Segment Reporting Information [Line Items]
Total operating revenues	472	420
Operational expenses	64	57
Environmental compliance expenses	4	2
Utility operations and maintenance
Other segment items	251	218
Depreciation and amortization(b)	55	52
Interest expense(c)	20	20
Income taxes (benefit)	18	16
Consolidated Net Income Attributable to Southern Company	60	55
Capital expenditures	82	73
Reportable Segment \| SOUTHERN POWER CO
Segment Reporting Information [Line Items]
Total operating revenues	681	567
Utility operations and maintenance
Other segment items	442	303
Depreciation and amortization(b)	278	152
Interest expense(c)	27	26
Income taxes (benefit)	(70)	(1)
Consolidated Net Income Attributable to Southern Company	$ 4	$ 87
Traditional Electric Operating Companies
Utility operations and maintenance
Number of reportable segments \| segment	1

The current period expense charged against earnings on long-lived, physical assets used in the normal conduct of business and not intended for resale to allocate or recognize the cost of assets over their useful lives; or to record the reduction in book value of an intangible asset over the benefit period of such asset. Excludes amortization of nuclear fuel.

No definition available.