CONDENSED CONSOLIDATED STATEMENTS OF INCOME - AEP Transmission Holdco - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
REVENUES
TOTAL REVENUES	$ 6,020	$ 5,463
EXPENSES
Other Operation	750	752
Maintenance	411	319
Depreciation and Amortization	907	833
Taxes Other Than Income Taxes	443	422
TOTAL EXPENSES	4,660	4,179
OPERATING INCOME	1,360	1,284
Other Income (Expense):
Allowance for Equity Funds Used During Construction	70	57
Interest Expense	(552)	(495)
INCOME (LOSS) BEFORE INCOME TAX EXPENSE (BENEFIT)	922	889
Income Tax Expense	44	125
NET INCOME	903	802
Net Income Attributable to Noncontrolling Interest	29	2
EARNINGS ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS, Basic	874	800
EARNINGS ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS, Diluted	874	800
Nonrelated Party
REVENUES
TOTAL REVENUES	6,020	5,463
AEP TRANSMISSION COMPANY, LLC
REVENUES
TOTAL REVENUES	578	527
EXPENSES
Other Operation	41	29
Maintenance	10	5
Depreciation and Amortization	128	114
Taxes Other Than Income Taxes	88	74
TOTAL EXPENSES	267	222
OPERATING INCOME	311	305
Other Income (Expense):
Interest Income	2	0
Allowance for Equity Funds Used During Construction	22	22
Interest Expense	(65)	(55)
INCOME (LOSS) BEFORE INCOME TAX EXPENSE (BENEFIT)	270	272
Income Tax Expense	60	61
NET INCOME	210	211
Net Income Attributable to Noncontrolling Interest	27	0
EARNINGS ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS, Basic	183	211
EARNINGS ATTRIBUTABLE TO AEP COMMON SHAREHOLDERS, Diluted	183	211
AEP TRANSMISSION COMPANY, LLC | Affiliated Entity
REVENUES
TOTAL REVENUES	468	423
AEP TRANSMISSION COMPANY, LLC | Nonrelated Party
REVENUES
TOTAL REVENUES	110	104
Transmission Revenues | AEP TRANSMISSION COMPANY, LLC
REVENUES
TOTAL REVENUES	110	106
Sales to AEP Affiliates | AEP TRANSMISSION COMPANY, LLC
REVENUES
TOTAL REVENUES	470	430
Provision for Refund | AEP TRANSMISSION COMPANY, LLC | Affiliated Entity
REVENUES
TOTAL REVENUES	(2)	(7)
Provision for Refund | AEP TRANSMISSION COMPANY, LLC | Nonrelated Party
REVENUES
TOTAL REVENUES	$ 0	$ (2)