| Mineral Properties Disclosure [Table Text Block] |
| |
|
June 30, 2026 |
|
|
December 31, 2025 |
|
| (In thousands) |
|
Carrying Value |
|
|
Accumulated Depletion |
|
|
Net Book Value |
|
|
Carrying Value |
|
|
Accumulated Depletion |
|
|
Net Book Value |
|
| Coal properties |
|
$ |
653,808 |
|
|
$ |
(319,665 |
) |
|
$ |
334,143 |
|
|
$ |
653,808 |
|
|
$ |
(304,412 |
) |
|
$ |
349,396 |
|
| Aggregates properties |
|
|
8,655 |
|
|
|
(4,520 |
) |
|
|
4,135 |
|
|
|
8,655 |
|
|
|
(4,364 |
) |
|
|
4,291 |
|
| Oil and gas royalty properties |
|
|
12,354 |
|
|
|
(10,658 |
) |
|
|
1,696 |
|
|
|
12,354 |
|
|
|
(10,584 |
) |
|
|
1,770 |
|
| Other |
|
|
13,141 |
|
|
|
(1,612 |
) |
|
|
11,529 |
|
|
|
13,142 |
|
|
|
(1,612 |
) |
|
|
11,530 |
|
| Total mineral rights, net |
|
$ |
687,958 |
|
|
$ |
(336,455 |
) |
|
$ |
351,503 |
|
|
$ |
687,959 |
|
|
$ |
(320,972 |
) |
|
$ |
366,987 |
|
|