Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - SPC - USD ($) $ in Millions	Total	Paid-In Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests	Southern Power	Southern Power Total Common Stockholders' Equity	Southern Power Paid-In Capital	Southern Power Retained Earnings (Accumulated Deficit)	Southern Power Accumulated Other Comprehensive Income (Loss)	Southern Power Noncontrolling Interests
Beginning balance at Dec. 31, 2020	$ 32,234	$ 11,834	$ 11,311	$ (395)	$ 4,262	$ 6,631	$ 2,369	$ 914	$ 1,522	$ (67)	$ 4,262
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,107					65	97		97		(32)
Return of capital to parent company						(271)	(271)	(271)
Other comprehensive income (loss)	28			28		16	16			16
Cash dividends on common stock	(678)		(678)			(51)	(51)		(51)
Capital contributions from noncontrolling interests	403				403	403					403
Distributions to noncontrolling interests	(46)				(46)	(46)					(46)
Other	1	2			(1)	(3)	(2)	(2)	1	(1)	(1)
Ending balance at Mar. 31, 2021	33,068	11,854	11,768	(367)	4,586	6,744	2,158	641	1,569	(52)	4,586
Beginning balance at Dec. 31, 2021	32,276	11,950	10,929	(237)	4,402	6,598	2,196	638	1,585	(27)	4,402
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	991					27	72		72		(45)
Other comprehensive income (loss)	42			42		5	5			5
Cash dividends on common stock	(702)		(702)			(49)	(49)		(49)
Capital contributions from noncontrolling interests	73				73	73					73
Distributions to noncontrolling interests	(98)				(98)	(98)					(98)
Other	7	7	2
Ending balance at Mar. 31, 2022	$ 32,629	$ 11,994	$ 11,261	$ (195)	$ 4,332	$ 6,556	$ 2,224	$ 638	$ 1,608	$ (22)	$ 4,332