| Segment Reporting [Table Text Block] |
| | | Operating Segments | | | | | | | | | | | | | |
| (In thousands) | | Mineral Rights | | | Soda Ash | | | Total Operating Segments | | | Corporate and Financing | | | Total | |
| For the Three Months Ended March 31, 2026 | | | | | | | | | | | | | | | | | | | | |
| Revenues | | $ | 47,182 | | | $ | — | | | $ | 47,182 | | | $ | — | | | $ | 47,182 | |
| Equity in earnings of Sisecam Wyoming | | | — | | | | (7,828 | ) | | | (7,828 | ) | | | — | | | | (7,828 | ) |
| Gain on asset sales and disposals | | | (1 | ) | | | — | | | | (1 | ) | | | — | | | | (1 | ) |
| Total revenues and other income | | $ | 47,181 | | | $ | (7,828 | ) | | $ | 39,353 | | | $ | — | | | $ | 39,353 | |
| Less: | | | | | | | | | | | | | | | | | | | | |
| Compensation (salaries, benefits and bonus) | | $ | 1,797 | | | $ | — | | | $ | 1,797 | | | $ | 2,064 | | | $ | 3,861 | |
| Long-term incentive compensation (1) | | | 262 | | | | — | | | | 262 | | | | 907 | | | | 1,169 | |
| Property taxes | | | 1,879 | | | | — | | | | 1,879 | | | | — | | | | 1,879 | |
| Depreciation, depletion and amortization | | | 7,610 | | | | — | | | | 7,610 | | | | 4 | | | | 7,614 | |
| Asset impairments | | | — | | | | — | | | | — | | | | — | | | | — | |
| Interest expense, net (2) | | | — | | | | — | | | | — | | | | 973 | | | | 973 | |
| Other segment items (3) | | | 2,103 | | | | 72 | | | | 2,175 | | | | 2,063 | | | | 4,238 | |
| Net income (loss) | | $ | 33,530 | | | $ | (7,900 | ) | | $ | 25,630 | | | $ | (6,011 | ) | | $ | 19,619 | |
| As of March 31, 2026 | | | | | | | | | | | | | | | | | | | | |
| Total assets | | $ | 484,989 | | | $ | 281,477 | | | $ | 766,466 | | | $ | 5,191 | | | $ | 771,657 | |
| | | | | | | | | | | | | | | | | | | | | |
| For the Three Months Ended March 31, 2025 | | | | | | | | | | | | | | | | | | | | |
| Revenues | | $ | 55,681 | | | $ | — | | | $ | 55,681 | | | $ | — | | | $ | 55,681 | |
| Equity in earnings of Sisecam Wyoming | | | — | | | | 4,610 | | | | 4,610 | | | | — | | | | 4,610 | |
| Gain on asset sales and disposals | | | 247 | | | | — | | | | 247 | | | | — | | | | 247 | |
| Total revenues and other income | | $ | 55,928 | | | $ | 4,610 | | | $ | 60,538 | | | $ | — | | | $ | 60,538 | |
| Less: | | | | | | | | | | | | | | | | | | | | |
| Compensation (salaries, benefits and bonus) | | $ | 1,938 | | | $ | — | | | $ | 1,938 | | | $ | 2,109 | | | $ | 4,047 | |
| Long-term incentive compensation (4) | | | 464 | | | | — | | | | 464 | | | | 2,261 | | | | 2,725 | |
| Property taxes | | | 1,792 | | | | — | | | | 1,792 | | | | — | | | | 1,792 | |
| Depreciation, depletion and amortization | | | 3,985 | | | | — | | | | 3,985 | | | | 4 | | | | 3,989 | |
| Asset impairments | | | 20 | | | | — | | | | 20 | | | | — | | | | 20 | |
| Interest expense, net (2) | | | — | | | | — | | | | — | | | | 2,668 | | | | 2,668 | |
| Other segment items (3) | | | 2,521 | | | | 60 | | | | 2,581 | | | | 2,463 | | | | 5,044 | |
| Net income (loss) | | $ | 45,208 | | | $ | 4,550 | | | $ | 49,758 | | | $ | (9,505 | ) | | $ | 40,253 | |
| As of December 31, 2025 | | | | | | | | | | | | | | | | | | | | |
| Total assets | | $ | 492,672 | | | $ | 250,244 | | | $ | 742,916 | | | $ | 5,449 | | | $ | 748,365 | |
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