Regulatory Matters - GPC Integrated Resource Plan (Details) - GEORGIA POWER CO $ in Millions						9 Months Ended	12 Months Ended
	Jan. 01, 2028 MW	Jan. 01, 2025 MW	Jan. 01, 2024 MW	Aug. 26, 2022 USD ($)	Jul. 21, 2022 agreement ashPond MW	Sep. 30, 2022 USD ($) MW	Dec. 31, 2026 MW
Public Utilities, General Disclosures [Line Items]
Approved capacity increase (in MWs)						970
Approved change in closure method, number of ash ponds | ashPond					1
Number of approved Power Purchase Agreements | agreement					6
Number of approved Approved Power Purchase Agreements | agreement					5
Rejected additional generating capacity					88
Renewable Resources
Public Utilities, General Disclosures [Line Items]
Requested additional generating capacity					2,300
Energy Storage
Public Utilities, General Disclosures [Line Items]
Requested additional generating capacity					500
Biomass Generation
Public Utilities, General Disclosures [Line Items]
Requested additional generating capacity					140
Subsequent Event | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Approved capacity increase (in MWs)	228	380	1,567				265
Plant Wansley Units 1 and 2
Public Utilities, General Disclosures [Line Items]
Capacity of units approved for decertification and retirement of units					926
Approved amounts for decertification and retirement of units, percentage					53.50%
Plant Wansley Unit 1
Public Utilities, General Disclosures [Line Items]
Remaining net book value | $						$ 299
Plant Wansley Unit 2
Public Utilities, General Disclosures [Line Items]
Remaining net book value | $						277
Plant Scherer Unit 3
Public Utilities, General Disclosures [Line Items]
Capacity of units approved for decertification and retirement of units					614
Approved amounts for decertification and retirement of units, percentage					75.00%
Remaining net book value | $						$ 608
Plant Gaston Units 1 through 4
Public Utilities, General Disclosures [Line Items]
Capacity of units approved for decertification and retirement of units					500
Approved amounts for decertification and retirement of units, percentage					50.00%
Plant Bowen Units 1 and 2
Public Utilities, General Disclosures [Line Items]
Capacity of units included in request for decertification of units					1,400
Plant Tugalo
Public Utilities, General Disclosures [Line Items]
Planned expenses to modernize plant | $				$ 115