FINANCING ACTIVITIES - Schedule of Maximum and Minimum Interest Rates for Funds Either Borrowed from or Loaned to Utility Money Pool (Details) - Utility	6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025
AEP TRANSMISSION COMPANY, LLC
Short-Term Debt [Line Items]
Maximum Interest Rate	4.13%	4.83%
Minimum Interest Rate	3.53%	4.14%
APPALACHIAN POWER COMPANY
Short-Term Debt [Line Items]
Maximum Interest Rate	4.13%	4.83%
Minimum Interest Rate	3.53%	4.14%
SOUTHWESTERN ELECTRIC POWER COMPANY
Short-Term Debt [Line Items]
Maximum Interest Rate	4.13%	4.83%
Minimum Interest Rate	3.53%	4.14%
PUBLIC SERVICE COMPANY OF OKLAHOMA
Short-Term Debt [Line Items]
Maximum Interest Rate	4.13%	4.83%
Minimum Interest Rate	3.53%	4.14%
INDIANA MICHIGAN POWER COMPANY
Short-Term Debt [Line Items]
Maximum Interest Rate	4.13%	4.83%
Minimum Interest Rate	3.53%	4.14%
AEP TEXAS INC.
Short-Term Debt [Line Items]
Maximum Interest Rate	4.13%	4.83%
Minimum Interest Rate	3.53%	4.14%
OHIO POWER COMPANY
Short-Term Debt [Line Items]
Maximum Interest Rate	4.13%	4.83%
Minimum Interest Rate	3.53%	4.14%