REGULATORY MATTERS - GPC Rate Plans, Integrated Resource Plan and COVID-19 Costs (Details) $ in Millions							1 Months Ended		12 Months Ended
	Jan. 01, 2024 MW	Aug. 31, 2022 MW	Aug. 26, 2022 USD ($)	Jul. 21, 2022 agreement MW	Jan. 01, 2022 USD ($)	Jan. 01, 2021 USD ($)	Nov. 30, 2021 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2028 MW	Dec. 31, 2026 MW	Dec. 31, 2025 USD ($) MW	Dec. 31, 2024 USD ($) MW	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($) ashPond MW	Dec. 31, 2021 USD ($) MW	Dec. 31, 2020 USD ($)	Dec. 31, 2019
Public Utilities, General Disclosures [Line Items]
Net regulatory assets														$ 5,833.0	$ 4,711.0
Customer Refunds
Public Utilities, General Disclosures [Line Items]
Net regulatory assets														$ (183.0)	$ (189.0)
Georgia Power
Public Utilities, General Disclosures [Line Items]
Approved rate decrease					$ 10.0
Approved rate increase						$ 90.0
Public utilities, approved rate increase (decrease), amount							$ 252.0									$ (44.0)
Requested additional generating capacity (in MW) | MW				2,300											970
Approved additional generating capacity (in MW) | MW															970
Number of ash ponds | ashPond														1
Net regulatory assets														$ 4,663.0	$ 3,928.0
Requested number of power purchase agreements to be certified | agreement				6
Requested number of affiliate power purchase agreements to be certified | agreement				5
Incremental COVID-19 costs deferred														$ 25.0	21.0
Georgia Power | ECCR
Public Utilities, General Disclosures [Line Items]
Regulatory asset amortization period														4 years
Approved rate decrease														$ 20.0
Georgia Power | 2022 Alternate Rate Plan
Public Utilities, General Disclosures [Line Items]
Retail rate of return on common equity														10.50%
Equity rate of return on common equity														56.00%
Portion of actual earnings above approved ROE band applied to reduce regulatory assets														40.00%
Portion of actual earnings above approved ROE band refunded to customers														40.00%
Portion of actual earnings above approved ROE band retained by subsidiary company														20.00%
Georgia Power | 2019 Alternate Rate Plan
Public Utilities, General Disclosures [Line Items]
Retail rate of return on common equity																	10.50%
Portion of actual earnings above approved ROE band applied to reduce regulatory assets																	40.00%
Portion of actual earnings above approved ROE band refunded to customers																	40.00%
Portion of actual earnings above approved ROE band retained by subsidiary company																	20.00%
Customer refund liability in absence of base rate case														$ 119.0	5.0
Georgia Power | Energy Storage
Public Utilities, General Disclosures [Line Items]
Requested additional generating capacity (in MW) | MW				500
Georgia Power | Biomass Generation
Public Utilities, General Disclosures [Line Items]
Requested additional generating capacity (in MW) | MW				140
Georgia Power | Scenario, Forecast
Public Utilities, General Disclosures [Line Items]
Incremental COVID-19 costs recovered, period											3 years
Georgia Power | Scenario, Forecast | ECCR
Public Utilities, General Disclosures [Line Items]
Compliance costs expected to be incurred											$ 510.0	$ 410.0	$ 320.0
Georgia Power | Scenario, Forecast | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Requested additional generating capacity (in MW) | MW	1,567								228	265	380	88
Georgia Power | Plant Vogtle Unit 3
Public Utilities, General Disclosures [Line Items]
Public utilities, approved rate increase (decrease), amount							2,100.0
Requested rate increase (decrease), amount							3,600.0
Approved depreciation expense deferred, annual amount							$ 40.0
Requested rate increase, annual amount								$ 302.0
Georgia Power | Plant Wansley Unit 1
Public Utilities, General Disclosures [Line Items]
Net regulatory assets														292.0
Georgia Power | Plant Wansley Unit 2
Public Utilities, General Disclosures [Line Items]
Net regulatory assets														270.0
Net regulatory assets, unusable materials and supplies inventory														$ 13.0
Georgia Power | Plant Scherer Unit 3
Public Utilities, General Disclosures [Line Items]
Capacity of units included in request for decertification of units | MW														614
Request for decertification of units, percentage of ownership														75.00%
Net regulatory assets														$ 601.0
Georgia Power | Plant Gaston Units 1 through 4
Public Utilities, General Disclosures [Line Items]
Capacity of units included in request for decertification of units | MW														500
Request for decertification of units, percentage of ownership														50.00%
Georgia Power | Plant Bowen Units 1 and 2
Public Utilities, General Disclosures [Line Items]
Regulatory asset amortization period														4 years
Capacity of units included in request for decertification of units | MW														1,400
Georgia Power | Plant Tugalo
Public Utilities, General Disclosures [Line Items]
Planned expenses to modernize plant			$ 115.0
Georgia Power | Plant Wansley Units 1 and 2
Public Utilities, General Disclosures [Line Items]
Capacity of units included in request for decertification of units | MW		926
Request for decertification of units, percentage of ownership		53.50%
Georgia Power | Customer Refunds
Public Utilities, General Disclosures [Line Items]
Net regulatory assets														$ (121.0)	(8.0)
Georgia Power | Customer Refunds | 2019 Alternate Rate Plan
Public Utilities, General Disclosures [Line Items]
Portion of actual earnings above approved ROE band refunded to customers, value														119.0	5.0
Remaining Net Book Value of Retired Assets
Public Utilities, General Disclosures [Line Items]
Net regulatory assets														1,543.0	1,050.0
Remaining Net Book Value of Retired Assets | Georgia Power
Public Utilities, General Disclosures [Line Items]
Net regulatory assets														$ 962.0	$ 455.0
Remaining Net Book Value of Retired Assets | Georgia Power | Plant Scherer Unit 3
Public Utilities, General Disclosures [Line Items]
Regulatory asset amortization period														6 years
Net regulatory assets														$ 43.0
Remaining Net Book Value of Retired Assets | Georgia Power | Plant Bowen Units 1 and 2
Public Utilities, General Disclosures [Line Items]
Net regulatory assets														$ 40.0
Remaining Net Book Value of Retired Assets | Georgia Power | Plant Wansley Units 1 and 2
Public Utilities, General Disclosures [Line Items]
Regulatory asset amortization period														8 years
Net regulatory assets														$ 562.0
Maximum | Georgia Power | 2022 Alternate Rate Plan
Public Utilities, General Disclosures [Line Items]
Retail rate of return on common equity														11.90%
Maximum | Georgia Power | 2019 Alternate Rate Plan
Public Utilities, General Disclosures [Line Items]
Retail rate of return on common equity														12.00%
Maximum | Remaining Net Book Value of Retired Assets | Georgia Power
Public Utilities, General Disclosures [Line Items]
Regulatory asset amortization period														3 years	4 years
Minimum | Georgia Power | 2022 Alternate Rate Plan
Public Utilities, General Disclosures [Line Items]
Retail rate of return on common equity														9.50%
Minimum | Georgia Power | 2019 Alternate Rate Plan
Public Utilities, General Disclosures [Line Items]
Retail rate of return on common equity																	9.50%