v3.26.3
FINANCING ACTIVITIES - Schedule of Fees Paid to AEP Credit for Customer Accounts Receivable Sold (Details) - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Disaggregation of Revenue [Line Items]        
Total Revenues from Contracts with Customers $ 6,793 $ 5,963 $ 18,175 $ 16,433
APCo        
Disaggregation of Revenue [Line Items]        
Total Revenues from Contracts with Customers 1,132 1,050 3,211 3,156
I&M        
Disaggregation of Revenue [Line Items]        
Total Revenues from Contracts with Customers 904 805 2,672 2,284
OPCo        
Disaggregation of Revenue [Line Items]        
Total Revenues from Contracts with Customers 1,200 1,048 3,270 2,947
PSO        
Disaggregation of Revenue [Line Items]        
Total Revenues from Contracts with Customers 870 694 1,832 1,555
SWEPCo        
Disaggregation of Revenue [Line Items]        
Total Revenues from Contracts with Customers 779 722 1,943 1,814
Servicing Contracts | APCo        
Disaggregation of Revenue [Line Items]        
Total Revenues from Contracts with Customers 4 4 11 11
Servicing Contracts | I&M        
Disaggregation of Revenue [Line Items]        
Total Revenues from Contracts with Customers 4 4 12 11
Servicing Contracts | OPCo        
Disaggregation of Revenue [Line Items]        
Total Revenues from Contracts with Customers 14 7 29 22
Servicing Contracts | PSO        
Disaggregation of Revenue [Line Items]        
Total Revenues from Contracts with Customers 5 4 11 10
Servicing Contracts | SWEPCo        
Disaggregation of Revenue [Line Items]        
Total Revenues from Contracts with Customers $ 4 $ 4 $ 11 $ 12