Condensed Consolidated Statements of Comprehensive Income (Unaudited) - Southern - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Statement of Comprehensive Income [Abstract]
Net income	$ 991	$ 1,107
Qualifying hedges:
Changes in fair value, net of tax	19	(30)
Reclassification adjustment for amounts included in net income, net of tax	20	55
Pension and other postretirement benefit plans:
Reclassification adjustment for amounts included in net income, net of tax	3	3
Total other comprehensive income	42	28
Comprehensive Income	1,033	1,135
Dividends on preferred stock of subsidiaries	4	4
Comprehensive loss attributable to noncontrolling interests	(45)	(32)
Comprehensive Income	$ 1,074	$ 1,163