FINANCING ACTIVITIES - Schedule of Maximum, Minimum and Average Interest Rates for Funds Borrowed from and Loaned to the Nonutility Money Pool (Details) - Nonutility	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
AEP TEXAS INC.
Short-Term Debt [Line Items]
Maximum Interest Rate for Funds Loaned	4.10%	4.76%
Minimum Interest Rate for Funds Loaned	3.83%	4.64%
Average Interest Rate for Funds Loaned	3.91%	4.69%
SOUTHWESTERN ELECTRIC POWER COMPANY
Short-Term Debt [Line Items]
Maximum Interest Rate for Funds Loaned	0.00%	4.76%
Minimum Interest Rate for Funds Loaned	0.00%	4.64%
Average Interest Rate for Funds Loaned	0.00%	4.69%