BENEFIT PLANS - Schedule of Pension and OPEB Assets (Details)	Dec. 31, 2025	Dec. 31, 2024
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Asset allocations	100.00%	100.00%
Pension Plans | AEP TEXAS INC.
Defined Benefit Plan Disclosure [Line Items]
Asset allocations	8.10%	7.90%
Pension Plans | APPALACHIAN POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Asset allocations	13.20%	13.30%
Pension Plans | INDIANA MICHIGAN POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Asset allocations	13.70%	13.80%
Pension Plans | OHIO POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Asset allocations	10.10%	10.40%
Pension Plans | PUBLIC SERVICE COMPANY OF OKLAHOMA
Defined Benefit Plan Disclosure [Line Items]
Asset allocations	5.40%	5.50%
Pension Plans | SOUTHWESTERN ELECTRIC POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Asset allocations	5.30%	5.20%
OPEB
Defined Benefit Plan Disclosure [Line Items]
Asset allocations	100.00%	100.00%
OPEB | AEP TEXAS INC.
Defined Benefit Plan Disclosure [Line Items]
Asset allocations	8.50%	8.30%
OPEB | APPALACHIAN POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Asset allocations	14.40%	14.40%
OPEB | INDIANA MICHIGAN POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Asset allocations	12.00%	11.90%
OPEB | OHIO POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Asset allocations	10.20%	10.40%
OPEB | PUBLIC SERVICE COMPANY OF OKLAHOMA
Defined Benefit Plan Disclosure [Line Items]
Asset allocations	5.50%	5.40%
OPEB | SOUTHWESTERN ELECTRIC POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Asset allocations	7.00%	6.80%