Acquisitions and Dispositions - Alabama Power Narrative (Details) - USD ($) $ in Millions		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2022	Sep. 30, 2021
Business Acquisition [Line Items]
Net assets recorded within property, plant, and equipment		$ 5,502	$ 5,222
ALABAMA POWER CO
Business Acquisition [Line Items]
Net assets recorded within property, plant, and equipment		$ 1,483	$ 1,235
ALABAMA POWER CO | Calhoun Generating Station
Business Acquisition [Line Items]
Purchase price	$ 179
Net assets recorded within property, plant, and equipment	$ 171