CONSOLIDATED STATEMENTS OF CASH FLOWS - AEP Transmission Holdco - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Adjustments to Reconcile Net Income to Net Cash Flows from Operating Activities:
Depreciation and Amortization	$ 3,380	$ 3,290	$ 3,090
Deferred Income Taxes	311	58	185
Allowance for Equity Funds Used During Construction	(245)	(211)	(175)
Property Taxes	(42)	(45)	(41)
Change in Other Noncurrent Assets	(559)	(348)	(446)
Change in Other Noncurrent Liabilities	269	306	29
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	(246)	(156)	236
Materials and Supplies	115	172	(504)
Accounts Payable	252	85	(253)
Accrued Taxes, Net	32	240	22
Other Current Assets	85	(13)	(44)
Other Current Liabilities	103	182	(162)
Net Cash Flows from Operating Activities	6,944	6,804	5,012
INVESTING ACTIVITIES
Construction Expenditures	(8,453)	(7,631)	(7,378)
Acquisitions of Assets	(3,453)	(399)	(155)
Other Investing Activities	118	143	122
Net Cash Flows Used for Investing Activities	(11,939)	(7,596)	(6,267)
FINANCING ACTIVITIES
Capital Contribution from Noncontrolling Interest	38	0	0
Issuance of Long-term Debt	8,261	5,117	5,463
Retirement of Long-term Debt – Nonaffiliated	(3,649)	(2,685)	(2,196)
Proceeds from the Midwest Transmission Holdings Noncontrolling Interest Transaction, Net of Transaction Costs	2,783	0	0
Dividends Paid on Noncontrolling Interest	(108)	(6)	(8)
Net Cash Flows from Financing Activities	5,017	659	1,077
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	22	(133)	(178)
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	246	379	557
Cash, Cash Equivalents and Restricted Cash at End of Period	268	246	379
SUPPLEMENTARY INFORMATION
Cash Paid for Interest, Net of Capitalized Amounts	1,894	1,838	1,674
Construction Expenditures Included in Current Liabilities as of December 31,	1,935	1,312	842
AEP TRANSMISSION COMPANY, LLC
OPERATING ACTIVITIES
Net Income	1,184	688	614
Adjustments to Reconcile Net Income to Net Cash Flows from Operating Activities:
Depreciation and Amortization	478	431	394
Deferred Income Taxes	(152)	110	44
Allowance for Equity Funds Used During Construction	(93)	(89)	(83)
Property Taxes	(17)	(22)	(20)
Change in Other Noncurrent Assets	(80)	(1)	8
Change in Other Noncurrent Liabilities	(127)	(17)	134
Changes in Certain Components of Working Capital:
Accounts Receivable, Net	(53)	13	(41)
Materials and Supplies	0	0	11
Accounts Payable	75	10	23
Accrued Taxes, Net	(16)	97	43
Accrued Interest	1	5	11
Other Current Assets	7	(1)	0
Other Current Liabilities	(22)	14	0
Net Cash Flows from Operating Activities	1,185	1,238	1,138
INVESTING ACTIVITIES
Construction Expenditures	(1,569)	(1,477)	(1,496)
Change in Advances to Affiliates, Net	(41)	37	(63)
Acquisitions of Assets	(10)	(5)	(7)
Other Investing Activities	42	17	7
Net Cash Flows Used for Investing Activities	(1,578)	(1,428)	(1,559)
FINANCING ACTIVITIES
Capital Contribution from AEP Member	70	62	30
Capital Contribution from Noncontrolling Interest	34	0	0
Return of Capital to Parent	0	(5)	(8)
Issuance of Long-term Debt	929	446	689
Retirement of Long-term Debt – Nonaffiliated	(102)	(95)	(60)
Change in Advances from Affiliates, Net	58	(90)	(55)
Proceeds from the Midwest Transmission Holdings Noncontrolling Interest Transaction, Net of Transaction Costs	2,783	0	0
Dividends Paid to AEP Member	(3,274)	(128)	(175)
Dividends Paid on Noncontrolling Interest	(105)	0	0
Net Cash Flows from Financing Activities	393	190	421
Net Increase (Decrease) in Cash, Cash Equivalents and Restricted Cash	0	0	0
Cash, Cash Equivalents and Restricted Cash at Beginning of Period	0	0	0
Cash, Cash Equivalents and Restricted Cash at End of Period	0	0	0
SUPPLEMENTARY INFORMATION
Cash Paid for Interest, Net of Capitalized Amounts	227	204	180
Construction Expenditures Included in Current Liabilities as of December 31,	$ 343	$ 263	$ 178