FINANCING ACTIVITIES - Debt Covenants Narrative (Details) - AEP TRANSMISSION COMPANY, LLC $ in Millions	Mar. 31, 2026 USD ($)
Debt Instrument [Line Items]
Sub-limit of secured debt	$ 50
Maximum percentage of consolidated tangible net assets	10.00%

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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+ Details