COMMITMENTS, GUARANTEES AND CONTINGENCIES - Potential Loss on Master Lease Agreements (Details) $ in Millions	Mar. 31, 2025 USD ($)
Other Commitments [Line Items]
Maximum Potential Loss	$ 38.4
AEP Texas
Other Commitments [Line Items]
Maximum Potential Loss	8.4
APCo
Other Commitments [Line Items]
Maximum Potential Loss	4.9
I&M
Other Commitments [Line Items]
Maximum Potential Loss	3.8
OPCo
Other Commitments [Line Items]
Maximum Potential Loss	6.5
PSO
Other Commitments [Line Items]
Maximum Potential Loss	3.6
SWEPCo
Other Commitments [Line Items]
Maximum Potential Loss	$ 4.4