Acquisitions and Dispositions - Schedule of Construction Projects (Details) - SOUTHERN POWER CO $ in Millions	1 Months Ended		3 Months Ended
	Aug. 31, 2021 MW	Jul. 28, 2021 USD ($)	Dec. 31, 2021 MW	Dec. 31, 2020
Subsequent Event
Business Acquisition [Line Items]
Proceeds from tax equity transaction | $		$ 11
Glass Sands | Glass Sands
Business Acquisition [Line Items]
Ownership percentage by parent				100.00%
Scenario, Forecast | Garland Solar Storage
Business Acquisition [Line Items]
Approximate Nameplate Capacity (MW)	88
PPA Contract Period	20 years
Scenario, Forecast | Tranquillity Solar Storage
Business Acquisition [Line Items]
Approximate Nameplate Capacity (MW)			72
PPA Contract Period			20 years
Scenario, Forecast | Glass Sands
Business Acquisition [Line Items]
Approximate Nameplate Capacity (MW)			118
PPA Contract Period			12 years