v3.26.1
FINANCING ACTIVITIES - Schedule of Fees Paid to AEP Credit for Customer Accounts Receivable Sold (Details) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Disaggregation of Revenue [Line Items]        
Total Revenues from Contracts with Customers $ 5,461 $ 5,055 $ 11,382 $ 10,470
APPALACHIAN POWER COMPANY        
Disaggregation of Revenue [Line Items]        
Total Revenues from Contracts with Customers 913 940 2,079 2,106
INDIANA MICHIGAN POWER COMPANY        
Disaggregation of Revenue [Line Items]        
Total Revenues from Contracts with Customers 831 724 1,768 1,479
OHIO POWER COMPANY        
Disaggregation of Revenue [Line Items]        
Total Revenues from Contracts with Customers 995 905 2,070 1,899
PUBLIC SERVICE COMPANY OF OKLAHOMA        
Disaggregation of Revenue [Line Items]        
Total Revenues from Contracts with Customers 523 467 962 861
SOUTHWESTERN ELECTRIC POWER COMPANY        
Disaggregation of Revenue [Line Items]        
Total Revenues from Contracts with Customers 593 561 1,164 1,092
Servicing Contracts | APPALACHIAN POWER COMPANY        
Disaggregation of Revenue [Line Items]        
Total Revenues from Contracts with Customers 3 3 7 7
Servicing Contracts | INDIANA MICHIGAN POWER COMPANY        
Disaggregation of Revenue [Line Items]        
Total Revenues from Contracts with Customers 4 3 8 7
Servicing Contracts | OHIO POWER COMPANY        
Disaggregation of Revenue [Line Items]        
Total Revenues from Contracts with Customers 7 8 15 15
Servicing Contracts | PUBLIC SERVICE COMPANY OF OKLAHOMA        
Disaggregation of Revenue [Line Items]        
Total Revenues from Contracts with Customers 3 3 6 6
Servicing Contracts | SOUTHWESTERN ELECTRIC POWER COMPANY        
Disaggregation of Revenue [Line Items]        
Total Revenues from Contracts with Customers $ 3 $ 4 $ 7 $ 8