Acquisitions and Dispositions - Schedule of Construction Projects (Details) - SOUTHERN POWER CO - MW	1 Months Ended	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2021
Garland Solar Storage | Garland Solar Storage | Class B Membership Interest
Business Acquisition [Line Items]
Noncontrolling interest, ownership by parent, percentage sold	100.00%
Tranquillity Solar Storage | Tranquillity Solar Storage | Class B Membership Interest
Business Acquisition [Line Items]
Noncontrolling interest, ownership by parent, percentage sold	100.00%
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