FINANCING ACTIVITIES - Schedule of Accounts Receivable and Accrued Unbilled Revenues (Details) - USD ($) $ in Millions |
Jun. 30, 2025 |
Dec. 31, 2024 |
|---|---|---|
| APCo | ||
| Short-Term Debt [Line Items] | ||
| Accounts receivable and accrued unbilled revenues | $ 197.4 | $ 192.7 |
| I&M | ||
| Short-Term Debt [Line Items] | ||
| Accounts receivable and accrued unbilled revenues | 182.9 | 160.5 |
| OPCo | ||
| Short-Term Debt [Line Items] | ||
| Accounts receivable and accrued unbilled revenues | 477.4 | 470.7 |
| PSO | ||
| Short-Term Debt [Line Items] | ||
| Accounts receivable and accrued unbilled revenues | 158.1 | 111.4 |
| SWEPCo | ||
| Short-Term Debt [Line Items] | ||
| Accounts receivable and accrued unbilled revenues | $ 189.7 | $ 153.5 |