Related-Party Transactions - Craft Foundations (Details) - USD ($) $ in Thousands |
6 Months Ended | ||
|---|---|---|---|
Jan. 29, 2026 |
Jun. 30, 2026 |
Jun. 30, 2025 |
|
| Related Party Transaction [Line Items] | |||
| Amount paid towards coal reserve acquisition | $ 9,370 | $ 2,740 | |
| Related Party | Special General Partner | Coal reserves together with surface rights | |||
| Related Party Transaction [Line Items] | |||
| Amount paid towards coal reserve acquisition | $ 15,500 | ||
| Related Party | Kathleen S Craft Foundation | Coal reserves together with surface rights | |||
| Related Party Transaction [Line Items] | |||
| Amount paid towards coal reserve acquisition | 7,750 | ||
| Related Party | Joseph W Craft III Foundation | Coal reserves together with surface rights | |||
| Related Party Transaction [Line Items] | |||
| Amount paid towards coal reserve acquisition | $ 1,800 | ||
| Craft Foundation Installment Purchase Arrangement | Related Party | Joseph W Craft III Foundation | |||
| Related Party Transaction [Line Items] | |||
| Term | 6 years | ||