Workers' Compensation and Pneumoconiosis - Liability (Details) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | 12 Months Ended | |||
|---|---|---|---|---|---|---|
Jun. 30, 2026 |
Jun. 30, 2025 |
Jun. 30, 2026 |
Jun. 30, 2025 |
Dec. 31, 2025 |
Dec. 31, 2024 |
|
| Reconciliation of changes in the workers' compensation liability | ||||||
| Beginning balance | $ 49,320 | $ 48,511 | $ 49,378 | $ 47,870 | $ 47,870 | |
| Changes in accruals | 3,258 | 3,419 | 6,602 | 6,795 | ||
| Payments | (3,926) | (3,762) | (7,866) | (7,064) | ||
| Interest accretion | 539 | 570 | 1,077 | 1,137 | ||
| Valuation loss (gain) | (614) | 496 | (614) | 496 | ||
| Ending balance | 48,577 | $ 49,234 | $ 48,577 | $ 49,234 | $ 49,378 | $ 47,870 |
| Estimated present value of future obligations and other information | ||||||
| Workers' compensation discount rate | 5.10% | 4.92% | 4.78% | 5.17% | ||
| Receivables for traumatic injury claims | $ 4,100 | $ 4,100 | ||||