SUPPLEMENTAL CASH FLOW INFORMATION (Cash Transactions) (Details) - USD ($) $ in Thousands |
1 Months Ended | 9 Months Ended | ||||
|---|---|---|---|---|---|---|
Oct. 01, 2026 |
Jul. 31, 2026 |
Apr. 30, 2026 |
Dec. 31, 2025 |
Sep. 30, 2026 |
Sep. 30, 2025 |
|
| Public Utilities, General Disclosures [Line Items] | ||||||
| Interest Paid, Net of Amounts Capitalized | $ 67,000 | $ 59,000 | ||||
| Income Taxes Paid (Refunds) | ||||||
| Income Taxes Paid (Net of Refunds) | (89,000) | 3,000 | ||||
| Proceeds from sale of investment tax credit | $ 91,830 | $ 0 | ||||
| Roadrunner Reserve I | ||||||
| Income Taxes Paid (Refunds) | ||||||
| Proceeds from sale of investment tax credit | $ 46,000 | $ 46,000 | ||||
| Roadrunner Reserve II | ||||||
| Income Taxes Paid (Refunds) | ||||||
| Proceeds from sale of investment tax credit | $ 46,000 | |||||
| Roadrunner Reserve II | Subsequent Event | ||||||
| Income Taxes Paid (Refunds) | ||||||
| Proceeds from sale of investment tax credit | $ 37,000 | |||||