BENEFIT PLANS - Schedule of Defined Benefit Assumptions (Details)	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Health Care Trend Rates
Initial	6.00%	6.50%
Ultimate	4.50%	4.50%
Year Ultimate Reached	2031	2029
AEP TEXAS INC.
Health Care Trend Rates
Initial	6.00%	6.50%
Ultimate	4.50%	4.50%
Year Ultimate Reached	2031	2029
APPALACHIAN POWER COMPANY
Health Care Trend Rates
Initial	6.00%	6.50%
Ultimate	4.50%	4.50%
Year Ultimate Reached	2031	2029
INDIANA MICHIGAN POWER COMPANY
Health Care Trend Rates
Initial	6.00%	6.50%
Ultimate	4.50%	4.50%
Year Ultimate Reached	2031	2029
OHIO POWER COMPANY
Health Care Trend Rates
Initial	6.00%	6.50%
Ultimate	4.50%	4.50%
Year Ultimate Reached	2031	2029
PUBLIC SERVICE COMPANY OF OKLAHOMA
Health Care Trend Rates
Initial	6.00%	6.50%
Ultimate	4.50%	4.50%
Year Ultimate Reached	2031	2029
SOUTHWESTERN ELECTRIC POWER COMPANY
Health Care Trend Rates
Initial	6.00%	6.50%
Ultimate	4.50%	4.50%
Year Ultimate Reached	2031	2029
Pension Plans
Assumption
Discount Rate	5.50%	5.65%
Interest Crediting Rate	4.40%	4.55%
Rate of Compensation Increase	4.55%	5.55%
Assumption
Discount Rate	5.65%	5.20%	5.50%
Interest Crediting Rate	4.55%	4.05%	4.25%
Expected Return on Plan Assets	7.00%	7.30%	7.50%
Rate of Compensation Increase	5.75%	5.10%	5.05%
Pension Plans | AEP TEXAS INC.
Assumption
Discount Rate	5.50%	5.65%
Interest Crediting Rate	4.40%	4.55%
Rate of Compensation Increase	4.50%	5.70%
Assumption
Discount Rate	5.65%	5.20%	5.50%
Interest Crediting Rate	4.55%	4.05%	4.25%
Expected Return on Plan Assets	7.00%	7.30%	7.50%
Rate of Compensation Increase	5.90%	5.25%	5.20%
Pension Plans | APPALACHIAN POWER COMPANY
Assumption
Discount Rate	5.50%	5.65%
Interest Crediting Rate	4.40%	4.55%
Rate of Compensation Increase	4.50%	5.55%
Assumption
Discount Rate	5.65%	5.20%	5.50%
Interest Crediting Rate	4.55%	4.05%	4.25%
Expected Return on Plan Assets	7.00%	7.30%	7.50%
Rate of Compensation Increase	5.80%	5.10%	4.95%
Pension Plans | INDIANA MICHIGAN POWER COMPANY
Assumption
Discount Rate	5.50%	5.65%
Interest Crediting Rate	4.40%	4.55%
Rate of Compensation Increase	4.45%	5.50%
Assumption
Discount Rate	5.65%	5.20%	5.50%
Interest Crediting Rate	4.55%	4.05%	4.25%
Expected Return on Plan Assets	7.00%	7.30%	7.50%
Rate of Compensation Increase	5.60%	5.10%	5.05%
Pension Plans | OHIO POWER COMPANY
Assumption
Discount Rate	5.50%	5.65%
Interest Crediting Rate	4.40%	4.55%
Rate of Compensation Increase	4.80%	6.00%
Assumption
Discount Rate	5.65%	5.20%	5.50%
Interest Crediting Rate	4.55%	4.05%	4.25%
Expected Return on Plan Assets	7.00%	7.30%	7.50%
Rate of Compensation Increase	6.10%	5.50%	5.45%
Pension Plans | PUBLIC SERVICE COMPANY OF OKLAHOMA
Assumption
Discount Rate	5.50%	5.65%
Interest Crediting Rate	4.40%	4.55%
Rate of Compensation Increase	4.65%	5.70%
Assumption
Discount Rate	5.65%	5.20%	5.50%
Interest Crediting Rate	4.55%	4.05%	4.25%
Expected Return on Plan Assets	7.00%	7.30%	7.50%
Rate of Compensation Increase	5.90%	5.20%	5.20%
Pension Plans | SOUTHWESTERN ELECTRIC POWER COMPANY
Assumption
Discount Rate	5.50%	5.65%
Interest Crediting Rate	4.40%	4.55%
Rate of Compensation Increase	4.50%	5.55%
Assumption
Discount Rate	5.65%	5.20%	5.50%
Interest Crediting Rate	4.55%	4.05%	4.25%
Expected Return on Plan Assets	7.00%	7.30%	7.50%
Rate of Compensation Increase	5.70%	5.10%	5.00%
OPEB
Assumption
Discount Rate	5.50%	5.60%
Assumption
Discount Rate	5.60%	5.15%	5.50%
Expected Return on Plan Assets	6.50%	6.75%	7.25%
OPEB | AEP TEXAS INC.
Assumption
Discount Rate	5.50%	5.60%
Assumption
Discount Rate	5.60%	5.15%	5.50%
Expected Return on Plan Assets	6.50%	6.75%	7.25%
OPEB | APPALACHIAN POWER COMPANY
Assumption
Discount Rate	5.50%	5.60%
Assumption
Discount Rate	5.60%	5.15%	5.50%
Expected Return on Plan Assets	6.50%	6.75%	7.25%
OPEB | INDIANA MICHIGAN POWER COMPANY
Assumption
Discount Rate	5.50%	5.60%
Assumption
Discount Rate	5.60%	5.15%	5.50%
Expected Return on Plan Assets	6.50%	6.75%	7.25%
OPEB | OHIO POWER COMPANY
Assumption
Discount Rate	5.50%	5.60%
Assumption
Discount Rate	5.60%	5.15%	5.50%
Expected Return on Plan Assets	6.50%	6.75%	7.25%
OPEB | PUBLIC SERVICE COMPANY OF OKLAHOMA
Assumption
Discount Rate	5.50%	5.60%
Assumption
Discount Rate	5.60%	5.15%	5.50%
Expected Return on Plan Assets	6.50%	6.75%	7.25%
OPEB | SOUTHWESTERN ELECTRIC POWER COMPANY
Assumption
Discount Rate	5.50%	5.60%
Assumption
Discount Rate	5.60%	5.15%	5.50%
Expected Return on Plan Assets	6.50%	6.75%	7.25%