CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - AEP Transmission Holdco - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
OPERATING ACTIVITIES
Net Income	$ 903	$ 802
Adjustments to Reconcile Net Income to Net Cash Flows from Operating Activities:
Depreciation and Amortization	907	833
Deferred Income Taxes	188	165
Allowance for Equity Funds Used During Construction	(70)	(57)
Property Taxes	(108)	(88)
Change in Other Noncurrent Assets	(351)	(131)
Change in Other Noncurrent Liabilities	433	142
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	(36)	(2)
Accounts Payable	108	6
Accrued Taxes, Net	(244)	(153)
Other Current Assets	(115)	(23)
Other Current Liabilities	(66)	(93)
Net Cash Flows from Operating Activities	1,519	1,450
INVESTING ACTIVITIES
Construction Expenditures	(2,830)	(2,100)
Contribution in Aid of Construction Advances	260	55
Other Investing Activities	(1)	(5)
Net Cash Flows Used for Investing Activities	(3,569)	(2,102)
FINANCING ACTIVITIES
Capital Contribution from Noncontrolling Interest	96	0
Issuance of Long-term Debt – Nonaffiliated	2,906	562
Retirement of Long-term Debt – Nonaffiliated	(678)	(229)
Dividends Paid to Noncontrolling Interest	(35)	(1)
Net Cash Flows from (Used for) Financing Activities	2,121	698
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	71	46
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	268	246
Cash, Cash Equivalents and Restricted Cash at End of Period	339	292
SUPPLEMENTARY INFORMATION
Cash Paid for Interest, Net of Capitalized Amounts	450	350
Construction Expenditures Included in Current Liabilities as of March 31,	1,434	1,041
AEP TRANSMISSION COMPANY, LLC
OPERATING ACTIVITIES
Net Income	210	211
Adjustments to Reconcile Net Income to Net Cash Flows from Operating Activities:
Depreciation and Amortization	128	114
Deferred Income Taxes	23	33
Allowance for Equity Funds Used During Construction	(22)	(22)
Property Taxes	46	39
Change in Other Noncurrent Assets	(15)	(3)
Change in Other Noncurrent Liabilities	4	10
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	(8)	(21)
Accounts Payable	104	(1)
Accrued Taxes, Net	(71)	(75)
Other Current Assets	(2)	0
Other Current Liabilities	30	11
Net Cash Flows from Operating Activities	427	296
INVESTING ACTIVITIES
Construction Expenditures	(403)	(422)
Change in Advances to Affiliates, Net	(301)	(30)
Contribution in Aid of Construction Advances	107	6
Other Investing Activities	2	9
Net Cash Flows Used for Investing Activities	(595)	(437)
FINANCING ACTIVITIES
Capital Contribution from AEP Member	233	32
Capital Contribution from Noncontrolling Interest	96	0
Issuance of Long-term Debt – Nonaffiliated	114	0
Retirement of Long-term Debt – Nonaffiliated	(101)	(50)
Change in Advances from Affiliates, Net	(141)	201
Dividends Paid to AEP Member	0	(42)
Dividends Paid to Noncontrolling Interest	(33)	0
Net Cash Flows from (Used for) Financing Activities	168	141
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	0	0
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	0	0
Cash, Cash Equivalents and Restricted Cash at End of Period	0	0
SUPPLEMENTARY INFORMATION
Cash Paid for Interest, Net of Capitalized Amounts	37	33
Construction Expenditures Included in Current Liabilities as of March 31,	$ 270	$ 230