CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN MEMBER’S EQUITY - AEP Transmission Holdco - USD ($) $ in Millions	Total	Retained Earnings	Noncontrolling Interests	AEP TRANSMISSION COMPANY, LLC	AEP TRANSMISSION COMPANY, LLC Paid-in Capital	AEP TRANSMISSION COMPANY, LLC Retained Earnings	AEP TRANSMISSION COMPANY, LLC Noncontrolling Interests
Beginning balance at Dec. 31, 2024				$ 6,951	$ 3,101	$ 3,850	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Capital Contribution from AEP Member				32	32
Dividends Paid to AEP Member				(42)		(42)
Net Income	$ 802	$ 800	$ 2	211		211
Ending balance at Mar. 31, 2025				7,152	3,133	4,019	0
Beginning balance at Dec. 31, 2025				7,643	4,962	1,651	1,030
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Capital Contribution from AEP Member				233	233
Capital Contributions from Noncontrolling Interest	96		96	96			96
Dividends Paid to Noncontrolling Interest	(35)		(35)	(33)			(33)
Net Income	$ 903	$ 874	$ 29	210		183	27
Ending balance at Mar. 31, 2026				$ 8,149	$ 5,195	$ 1,834	$ 1,120