FINANCING ACTIVITIES - Schedule of Proceeds on Sale of Receivables to AEP Credit (Details) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| APPALACHIAN POWER COMPANY | ||||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||||
| Proceeds from sale of receivables to AEP Credit | $ 416 | $ 430 | $ 959 | $ 1,035 |
| INDIANA MICHIGAN POWER COMPANY | ||||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||||
| Proceeds from sale of receivables to AEP Credit | 648 | 545 | 1,345 | 1,130 |
| OHIO POWER COMPANY | ||||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||||
| Proceeds from sale of receivables to AEP Credit | 817 | 736 | 1,729 | 1,596 |
| PUBLIC SERVICE COMPANY OF OKLAHOMA | ||||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||||
| Proceeds from sale of receivables to AEP Credit | 501 | 432 | 913 | 807 |
| SOUTHWESTERN ELECTRIC POWER COMPANY | ||||
| Accounts, Notes, Loans and Financing Receivable [Line Items] | ||||
| Proceeds from sale of receivables to AEP Credit | $ 474 | $ 456 | $ 895 | $ 884 |