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ACQUISITIONS AND DISPOSITIONS - Alabama Power Narrative (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Business Acquisition [Line Items]
Capital expenditures related to qualifying projects		$ 9,095	$ 7,923	$ 7,586
Alabama Power
Business Acquisition [Line Items]
Capital expenditures related to qualifying projects		$ 2,022	$ 2,016	$ 1,753
Alabama Power \| Calhoun Generating Station
Business Acquisition [Line Items]
Purchase price	$ 179
Capital expenditures related to qualifying projects	$ 171