BENEFIT PLANS - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2025 USD ($) plan	Dec. 31, 2024 USD ($)	Dec. 31, 2023 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan, number of plans | plan	2
Life insurance administrative load		5.00%
Investment gains or losses period	5 years
Employer contribution cost	$ 471	$ 379	$ 396
Withdrawal liability	$ 12,000	$ 12,000
Defined Contribution, Employer Matching Conditions One
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution, percent of match	100.00%
Employer matching contribution, percent of employees contribution	1.00%
Defined Contribution, Employer Matching Conditions One | AEP TEXAS INC.
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution, percent of match	100.00%
Employer matching contribution, percent of employees contribution	1.00%
Defined Contribution, Employer Matching Conditions One | APPALACHIAN POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution, percent of match	100.00%
Employer matching contribution, percent of employees contribution	1.00%
Defined Contribution, Employer Matching Conditions One | PUBLIC SERVICE COMPANY OF OKLAHOMA
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution, percent of match	100.00%
Employer matching contribution, percent of employees contribution	1.00%
Defined Contribution, Employer Matching Conditions One | OHIO POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution, percent of match	100.00%
Employer matching contribution, percent of employees contribution	1.00%
Defined Contribution, Employer Matching Conditions One | INDIANA MICHIGAN POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution, percent of match	100.00%
Employer matching contribution, percent of employees contribution	1.00%
Defined Contribution, Employer Matching Conditions One | SOUTHWESTERN ELECTRIC POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution, percent of match	100.00%
Employer matching contribution, percent of employees contribution	1.00%
Defined Contribution, Employer Matching Conditions Two
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution, percent of match	70.00%
Employer matching contribution, percent of employees contribution	5.00%
Defined Contribution, Employer Matching Conditions Two | AEP TEXAS INC.
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution, percent of match	70.00%
Employer matching contribution, percent of employees contribution	5.00%
Defined Contribution, Employer Matching Conditions Two | APPALACHIAN POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution, percent of match	70.00%
Employer matching contribution, percent of employees contribution	5.00%
Defined Contribution, Employer Matching Conditions Two | PUBLIC SERVICE COMPANY OF OKLAHOMA
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution, percent of match	70.00%
Employer matching contribution, percent of employees contribution	5.00%
Defined Contribution, Employer Matching Conditions Two | OHIO POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution, percent of match	70.00%
Employer matching contribution, percent of employees contribution	5.00%
Defined Contribution, Employer Matching Conditions Two | INDIANA MICHIGAN POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution, percent of match	70.00%
Employer matching contribution, percent of employees contribution	5.00%
Defined Contribution, Employer Matching Conditions Two | SOUTHWESTERN ELECTRIC POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Employer matching contribution, percent of match	70.00%
Employer matching contribution, percent of employees contribution	5.00%
Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	4.55%	5.55%
Pension Plans | AEP TEXAS INC.
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	4.50%	5.70%
Pension Plans | APPALACHIAN POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	4.50%	5.55%
Pension Plans | PUBLIC SERVICE COMPANY OF OKLAHOMA
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	4.65%	5.70%
Pension Plans | OHIO POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	4.80%	6.00%
Pension Plans | INDIANA MICHIGAN POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	4.45%	5.50%
Pension Plans | SOUTHWESTERN ELECTRIC POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	4.50%	5.55%
Minimum | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	3.00%
Minimum | Pension Plans | AEP TEXAS INC.
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	3.00%
Minimum | Pension Plans | APPALACHIAN POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	3.00%
Minimum | Pension Plans | PUBLIC SERVICE COMPANY OF OKLAHOMA
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	3.00%
Minimum | Pension Plans | OHIO POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	3.00%
Minimum | Pension Plans | INDIANA MICHIGAN POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	3.00%
Minimum | Pension Plans | SOUTHWESTERN ELECTRIC POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	3.00%
Maximum | Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	11.50%
Maximum | Pension Plans | AEP TEXAS INC.
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	11.50%
Maximum | Pension Plans | APPALACHIAN POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	11.50%
Maximum | Pension Plans | PUBLIC SERVICE COMPANY OF OKLAHOMA
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	11.50%
Maximum | Pension Plans | OHIO POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	11.50%
Maximum | Pension Plans | INDIANA MICHIGAN POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	11.50%
Maximum | Pension Plans | SOUTHWESTERN ELECTRIC POWER COMPANY
Defined Benefit Plan Disclosure [Line Items]
Rate of compensation increase	11.50%