Condensed Statements of Common Stockholders' Equity (Unaudited) - APC - USD ($) shares in Millions, $ in Millions	Total	Paid-In Capital	Retained Earnings (Accumulated Deficit)	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, 2023					31
Beginning balance at Dec. 31, 2023				$ 12,333	$ 1,222	$ 7,125	$ 3,993	$ (7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income				333			333
Capital contributions from parent company				427		427
Cash dividends on common stock	$ (766)		$ (766)	(295)			(295)
Other	7	$ 10	(1)	(1)			(1)
Ending balance (in shares) at Mar. 31, 2024					31
Ending balance at Mar. 31, 2024				12,797	$ 1,222	7,552	4,030	(7)
Beginning balance (in shares) at Dec. 31, 2023					31
Beginning balance at Dec. 31, 2023				12,333	$ 1,222	7,125	3,993	(7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,332			702
Other comprehensive income				1
Ending balance (in shares) at Jun. 30, 2024					31
Ending balance at Jun. 30, 2024				12,921	$ 1,222	7,602	4,103	(6)
Beginning balance (in shares) at Mar. 31, 2024					31
Beginning balance at Mar. 31, 2024				12,797	$ 1,222	7,552	4,030	(7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,203			369			369
Capital contributions from parent company				50		50
Other comprehensive income				1				1
Cash dividends on common stock	(788)		(788)	(296)			(296)
Other	1	3
Ending balance (in shares) at Jun. 30, 2024					31
Ending balance at Jun. 30, 2024				12,921	$ 1,222	7,602	4,103	(6)
Beginning balance (in shares) at Dec. 31, 2024					31
Beginning balance at Dec. 31, 2024				13,088	$ 1,222	7,657	4,214	(5)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income				375			375
Capital contributions from parent company				527		527
Other comprehensive income				1				1
Cash dividends on common stock	(791)		(791)	(305)			(305)
Other	(5)	(1)	(2)	(1)				(1)
Ending balance (in shares) at Mar. 31, 2025					31
Ending balance at Mar. 31, 2025				13,685	$ 1,222	8,184	4,284	(5)
Beginning balance (in shares) at Dec. 31, 2024					31
Beginning balance at Dec. 31, 2024				13,088	$ 1,222	7,657	4,214	(5)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,214			755
Other comprehensive income				1
Ending balance (in shares) at Jun. 30, 2025					31
Ending balance at Jun. 30, 2025				13,800	$ 1,222	8,222	4,360	(4)
Beginning balance (in shares) at Mar. 31, 2025					31
Beginning balance at Mar. 31, 2025				13,685	$ 1,222	8,184	4,284	(5)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	880			381			381
Capital contributions from parent company				38		38
Other comprehensive income				0
Cash dividends on common stock	(815)		(815)	(304)			(304)
Other	$ 6	$ 6	$ 1	0			(1)	1
Ending balance (in shares) at Jun. 30, 2025					31
Ending balance at Jun. 30, 2025				$ 13,800	$ 1,222	$ 8,222	$ 4,360	$ (4)