Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - SPC - USD ($) $ in Millions	Total	Paid-In Capital	Retained Earnings	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	SOUTHERN POWER CO Accumulated Other Comprehensive Income (Loss)	SOUTHERN POWER CO Noncontrolling Interests	SOUTHERN POWER CO Total Common Stockholders' Equity
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 (loss)						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)
Other	0	2
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
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 (loss)	1,622					109
Ending balance at Jun. 30, 2023	34,648	13,742	11,732	(168)	3,976	6,847	2,871	1,083	1,802	(14)	3,976
Beginning 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
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	823					70	85		85		(15)
Capital contributions from parent company						14	14	14
Other comprehensive income (loss)	43			43		10	10			10
Cash dividends on common stock	(764)		(764)			(63)	(63)		(63)
Distributions to noncontrolling interests	(42)				(42)	(42)					(42)
Other	0	2			(1)	0	1	0		1	(1)
Ending balance at Jun. 30, 2023	34,648	13,742	11,732	(168)	3,976	6,847	2,871	1,083	1,802	(14)	3,976
Beginning balance at Dec. 31, 2023	35,225	13,775	12,482	(177)	3,781	6,698	2,917	1,088	1,846	(17)	3,781
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)						38	96		96		(58)
Other comprehensive income (loss)	37			37		2	2			2
Cash dividends on common stock	(766)		(766)			(65)	(65)		(65)
Capital contributions from noncontrolling interests	9				9	9					9
Distributions to noncontrolling interests	(38)				(38)	(38)					(38)
Other	7	10	(1)			(1)	(1)		(1)
Ending balance at Mar. 31, 2024	35,614	13,846	12,844	(140)	3,694	6,643	2,949	1,088	1,876	(15)	3,694
Beginning balance at Dec. 31, 2023	35,225	13,775	12,482	(177)	3,781	6,698	2,917	1,088	1,846	(17)	3,781
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	2,259					109
Ending balance at Jun. 30, 2024	36,111	13,947	13,259	(130)	3,662	6,643	2,981	1,097	1,896	(12)	3,662
Beginning balance at Mar. 31, 2024	35,614	13,846	12,844	(140)	3,694	6,643	2,949	1,088	1,876	(15)	3,694
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	1,188					71	86		86		(15)
Capital contributions from parent company						8		8				$ 8
Other comprehensive income (loss)	10			10		3	3			3
Cash dividends on common stock	(788)		(788)			(66)	(66)		(66)
Capital contributions from noncontrolling interests	2				2	2					2
Distributions to noncontrolling interests	(19)				(19)	(19)					(19)
Other	1	3	0	0	0	1	1	1	0	0	0
Ending balance at Jun. 30, 2024	$ 36,111	$ 13,947	$ 13,259	$ (130)	$ 3,662	$ 6,643	$ 2,981	$ 1,097	$ 1,896	$ (12)	$ 3,662