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 CO	SOUTHERN POWER CO Total Common Stockholders' Equity	SOUTHERN POWER CO Paid-In Capital	SOUTHERN POWER CO Retained Earnings (Accumulated Deficit)	SOUTHERN POWER CO Accumulated Other Comprehensive Income (Loss)	SOUTHERN POWER CO Noncontrolling Interests
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)
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
Beginning balance at Dec. 31, 2022	34,532	13,673	11,538	(167)	4,124	6,916	2,792	1,069	1,741	(18)	4,124
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	799					39	102		102		(63)
Other comprehensive income (loss)	(44)			(44)		(7)	(7)			(7)
Cash dividends on common stock	(742)		(742)			(63)	(63)		(63)
Capital contributions from noncontrolling interests	21				21	21					21
Distributions to noncontrolling interests	(48)				(48)	(48)					(48)
Ending balance at Mar. 31, 2023	$ 34,562	$ 13,715	$ 11,658	$ (211)	$ 4,034	$ 6,858	$ 2,824	$ 1,069	$ 1,780	$ (25)	$ 4,034