CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN EQUITY - SWEPCo - USD ($) $ in Millions	Total	Common Stock	Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interests	SOUTHWESTERN ELECTRIC POWER COMPANY	SOUTHWESTERN ELECTRIC POWER COMPANY Common Stock	SOUTHWESTERN ELECTRIC POWER COMPANY Paid-in Capital	SOUTHWESTERN ELECTRIC POWER COMPANY Retained Earnings	SOUTHWESTERN ELECTRIC POWER COMPANY Accumulated Other Comprehensive Income (Loss)	SOUTHWESTERN ELECTRIC POWER COMPANY Noncontrolling Interests
Beginning balance at Dec. 31, 2024	$ 26,986	$ 3,472	$ 9,606	$ 13,869	$ (3)	$ 42	$ 3,905	$ 0	$ 1,550	$ 2,352	$ 3	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock Dividends – Nonaffiliated							(1)					(1)
Net Income	802			800		2	49			48		1
Ending balance at Mar. 31, 2025	27,364	3,479	9,652	14,169	21	43	3,953	0	1,550	2,400	3	0
Beginning balance at Dec. 31, 2025	32,218	3,523	12,138	15,441	36	1,080	4,899	0	2,151	2,740	8	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock Dividends – Nonaffiliated	(35)					(35)	(1)					(1)
Capital Contribution from Parent							128		128
Net Income	903			874		29	57			56		1
Ending balance at Mar. 31, 2026	$ 32,978	$ 3,544	$ 12,447	$ 15,795	$ 22	$ 1,170	$ 5,083	$ 0	$ 2,279	$ 2,796	$ 8	$ 0