SCHEDULE I - CONDENSED FINANCIAL INFORMATION OF PARENT COMPANY - AEPTCO PARENT - CONDENSED STATEMENTS OF INCOME (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
EXPENSES
Other Operation	$ 2,950	$ 3,127	$ 2,811
TOTAL EXPENSES	16,557	15,417	15,426
OPERATING INCOME	5,319	4,304	3,556
Other Income (Expense):
Interest Expense	(2,026)	(1,863)	(1,807)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS	3,724	2,843	2,209
Income Tax Expense	129	(39)	55
Equity Earnings of Unconsolidated Subsidiaries	101	94	59
Parent Company
EXPENSES
Other Operation	35	66	17
TOTAL EXPENSES	15	46	1
OPERATING INCOME	(8)	(40)	4
Other Income (Expense):
Interest Income - Affiliated	102	108	181
Interest Expense	(548)	(532)	(526)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS	(454)	(464)	(341)
Income Tax Expense	(126)	(151)	(81)
Equity Earnings of Unconsolidated Subsidiaries	3,908	3,280	2,468
NET INCOME	3,580	2,967	2,208
AEP TRANSMISSION COMPANY, LLC
EXPENSES
Other Operation	154	137	109
TOTAL EXPENSES	984	898	806
OPERATING INCOME	1,335	993	865
Other Income (Expense):
Interest Expense	(234)	(214)	(195)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS	1,199	878	761
Income Tax Expense	15	190	147
NET INCOME	1,184	688	614
AEP TRANSMISSION COMPANY, LLC | Parent Company
EXPENSES
Other Operation	0	2	0
TOTAL EXPENSES	0	2	0
OPERATING INCOME	0	(2)	0
Other Income (Expense):
Interest Income - Affiliated	308	241	218
Interest Expense	(257)	(239)	(215)
INCOME BEFORE INCOME TAX EXPENSE (BENEFIT) AND EQUITY EARNINGS	51	0	3
Income Tax Expense	11	0	2
Equity Earnings of Unconsolidated Subsidiaries	1,035	688	613
NET INCOME	$ 1,075	$ 688	$ 614