Statements of Stockholders' Equity - APC - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Alabama Power	Alabama Power Common Stock	Alabama Power Paid-In Capital	Alabama Power Retained Earnings	Alabama Power Accumulated Other Comprehensive Income (Loss)
Beginning balance (in shares) at Dec. 31, 2018		1,035					31
Beginning balance at Dec. 31, 2018	$ 29,039	$ 5,164	$ 11,094	$ 8,706	$ (203)	$ 7,477	$ 1,222	$ 3,508	$ 2,775	$ (28)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated Net Income	4,739					1,070			1,070
Capital contributions from parent company						1,247		1,247
Other comprehensive income (loss)	(118)				(118)	4				4
Cash dividends on common stock	(2,570)			(2,570)		(844)			(844)
Other	18		21	2		1				1
Ending balance (in shares) at Dec. 31, 2019		1,054					31
Ending balance at Dec. 31, 2019	31,759	$ 5,257	11,734	10,877	(321)	8,955	$ 1,222	4,755	3,001	(23)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated Net Income	3,119					1,150			1,150
Capital contributions from parent company						658		658
Other comprehensive income (loss)	(75)				(75)	4				4
Cash dividends on common stock	(2,685)			(2,685)		(957)			(957)
Other	(12)		(10)		1
Ending balance (in shares) at Dec. 31, 2020		1,058					31
Ending balance at Dec. 31, 2020	32,234	$ 5,268	11,834	11,311	(395)	9,810	$ 1,222	5,413	3,194	(19)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Consolidated Net Income	2,393					1,238			1,238
Capital contributions from parent company						643		643
Other comprehensive income (loss)	158				158	6				6
Cash dividends on common stock	(2,777)			(2,777)		(984)			(984)
Other	(7)		(8)	2
Ending balance (in shares) at Dec. 31, 2021		1,061					31
Ending balance at Dec. 31, 2021	$ 32,276	$ 5,279	$ 11,950	$ 10,929	$ (237)	$ 10,713	$ 1,222	$ 6,056	$ 3,448	$ (13)