v3.26.3
FINANCING ACTIVITIES - Schedule of Average Interest Rates for Funds Borrowed from and Loaned to Utility Money Pool (Details) - Utility
9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
AEP Texas    
Short-Term Debt [Line Items]    
Average Interest Rate for Funds Borrowed 3.94% 4.67%
Average Interest Rate for Funds Loaned 3.98% 4.37%
AEPTCo    
Short-Term Debt [Line Items]    
Average Interest Rate for Funds Borrowed 3.98% 4.65%
Average Interest Rate for Funds Loaned 3.99% 4.62%
APCo    
Short-Term Debt [Line Items]    
Average Interest Rate for Funds Borrowed 4.00% 4.67%
Average Interest Rate for Funds Loaned 4.01% 4.58%
I&M    
Short-Term Debt [Line Items]    
Average Interest Rate for Funds Borrowed 3.92% 4.69%
Average Interest Rate for Funds Loaned 3.95% 4.50%
OPCo    
Short-Term Debt [Line Items]    
Average Interest Rate for Funds Borrowed 4.01% 4.61%
Average Interest Rate for Funds Loaned 3.99% 4.70%
PSO    
Short-Term Debt [Line Items]    
Average Interest Rate for Funds Borrowed 4.02% 4.64%
Average Interest Rate for Funds Loaned 3.76% 4.68%
SWEPCo    
Short-Term Debt [Line Items]    
Average Interest Rate for Funds Borrowed 4.03% 4.69%
Average Interest Rate for Funds Loaned 3.99% 4.55%