v3.26.1
FINANCING ACTIVITIES - Schedule of Direct Borrowing Activity (Details) - Direct Borrowing
$ in Millions
6 Months Ended
Jun. 30, 2026
USD ($)
AEP TRANSMISSION COMPANY, LLC  
Short-Term Debt [Line Items]  
Maximum Borrowings $ 0
Maximum Loans 578
Average Borrowings 0
Average Loans 144
Borrowings 0
Loans 156
Authorized Short-term Borrowing Limit 0
SWTCo  
Short-Term Debt [Line Items]  
Maximum Borrowings 2
Maximum Loans 0
Average Borrowings 2
Average Loans 0
Borrowings 2
Loans 0
Authorized Short-term Borrowing Limit $ 50