Condensed Statements of Common Stockholders' Equity (Unaudited) - APC - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Paid-In Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Income (Loss)	Alabama Power	Alabama Power Common Stock	Alabama Power Paid-In Capital	Alabama Power Retained Earnings (Accumulated Deficit)	Alabama Power Accumulated Other Comprehensive Income (Loss)
Beginning balance (in shares) at Dec. 31, 2021							31
Beginning balance at Dec. 31, 2021	$ 32,276	$ 5,279	$ 11,950	$ 10,929	$ (237)	$ 10,713	$ 1,222	$ 6,056	$ 3,448	$ (13)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income after dividends on preferred stock	1,032					347			347
Capital contributions from parent company						626		626
Cash dividends on common stock	(702)			(702)		(254)			(254)
Ending balance (in shares) at Mar. 31, 2022							31
Ending balance at Mar. 31, 2022	32,629	5,286	11,994	11,261	(195)	11,432	$ 1,222	6,682	3,541	(13)
Beginning balance (in shares) at Dec. 31, 2022							31
Beginning balance at Dec. 31, 2022	34,532	5,417	13,673	11,538	(167)	11,687	$ 1,222	6,710	3,764	(9)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income after dividends on preferred stock	862					255			255
Capital contributions from parent company						330		330
Cash dividends on common stock	(742)			(742)		(285)			(285)
Ending balance (in shares) at Mar. 31, 2023							31
Ending balance at Mar. 31, 2023	$ 34,562	$ 5,421	$ 13,715	$ 11,658	$ (211)	$ 11,987	$ 1,222	$ 7,040	$ 3,734	$ (9)