Regulatory Matters - GPC Rate Plan (Details) - GEORGIA POWER CO - USD ($) $ in Millions	Oct. 12, 2021	Oct. 01, 2021	Jan. 01, 2021
Subsequent Event
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease) amount	$ 252
Traditional Base | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease) amount		$ 192
Environmental Compliance Cost Recovery | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease) amount		(12)
Demand-Side Management | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease) amount		(25)
Municipal Franchise Fee | Subsequent Event
Public Utilities, General Disclosures [Line Items]
Requested rate increase (decrease) amount		$ 2
Plant Vogtle Units 3 And 4
Public Utilities, General Disclosures [Line Items]
Approved reduction in amortization of CCR ARO costs			$ 90