Fixed Assets and Asset Retirement Obligations (Narrative) (Details) - USD ($) |
3 Months Ended | 6 Months Ended | |||
|---|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
Dec. 31, 2025 |
|
| Asset Retirement Obligations Details [Line Items] | |||||
| Asset retirement obligation balance | $ 256,393,000 | $ 256,393,000 | $ 266,348,000 | ||
| Gain on sale of assets | 17,436,000 | $ 0 | 17,436,000 | $ 0 | |
| Accrued Liabilities | |||||
| Asset Retirement Obligations Details [Line Items] | |||||
| Asset retirement obligation balance | $ 24,600,000 | $ 24,600,000 | $ 24,300,000 | ||