COMMITMENTS, GUARANTEES AND CONTINGENCIES - Potential Loss on Master Lease Agreements (Details) $ in Millions	Sep. 30, 2026 USD ($)
Other Commitments [Line Items]
Maximum Potential Loss	$ 34
AEP Texas
Other Commitments [Line Items]
Maximum Potential Loss	7
APCo
Other Commitments [Line Items]
Maximum Potential Loss	5
I&M
Other Commitments [Line Items]
Maximum Potential Loss	3
OPCo
Other Commitments [Line Items]
Maximum Potential Loss	6
PSO
Other Commitments [Line Items]
Maximum Potential Loss	3
SWEPCo
Other Commitments [Line Items]
Maximum Potential Loss	$ 4

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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