| Segment Reporting [Table Text Block] |
| | | Reportable Segments | | | | | | | | | | | | | |
| (In thousands) | | Mineral Rights | | | Soda Ash | | | Total Reportable Segments | | | Corporate and Financing | | | Total | |
| For the Three Months Ended September 30, 2026 | | | | | | | | | | | | | | | | | | | | |
| Revenues | | $ | 48,941 | | | $ | — | | | $ | 48,941 | | | $ | — | | | $ | 48,941 | |
| Equity in loss of Sisecam Wyoming | | | — | | | | (4,126 | ) | | | (4,126 | ) | | | — | | | | (4,126 | ) |
| Gain on asset sales and disposals | | | 5 | | | | — | | | | 5 | | | | — | | | | 5 | |
| Total revenues and other income | | $ | 48,946 | | | $ | (4,126 | ) | | $ | 44,820 | | | $ | — | | | $ | 44,820 | |
| Less: | | | | | | | | | | | | | | | | | | | | |
| Compensation (salaries, benefits and bonus) | | | 1,781 | | | | — | | | | 1,781 | | | | 1,995 | | | | 3,776 | |
| Property taxes | | | 1,650 | | | | — | | | | 1,650 | | | | — | | | | 1,650 | |
| Depreciation, depletion and amortization | | | 6,521 | | | | — | | | | 6,521 | | | | 5 | | | | 6,526 | |
| Other items (1) | | | 2,057 | | | | 52 | | | | 2,109 | | | | 4,217 | | | | 6,326 | |
| Net income (loss) | | $ | 36,937 | | | $ | (4,178 | ) | | $ | 32,759 | | | $ | (6,217 | ) | | $ | 26,542 | |
| | | | | | | | | | | | | | | | | | | | | |
| For the Three Months Ended September 30, 2025 | | | | | | | | | | | | | | | | | | | | |
| Revenues | | $ | 51,415 | | | $ | — | | | $ | 51,415 | | | $ | — | | | $ | 51,415 | |
| Equity in loss of Sisecam Wyoming | | | — | | | | (2,390 | ) | | | (2,390 | ) | | | — | | | | (2,390 | ) |
| Gain on asset sales and disposals | | | 906 | | | | — | | | | 906 | | | | — | | | | 906 | |
| Total revenues and other income | | $ | 52,321 | | | $ | (2,390 | ) | | $ | 49,931 | | | $ | — | | | $ | 49,931 | |
| Less: | | | | | | | | | | | | | | | | | | | | |
| Compensation (salaries, benefits and bonus) | | | 1,692 | | | | — | | | | 1,692 | | | | 1,926 | | | | 3,618 | |
| Property taxes | | | 2,035 | | | | — | | | | 2,035 | | | | — | | | | 2,035 | |
| Depreciation, depletion and amortization | | | 3,864 | | | | — | | | | 3,864 | | | | 4 | | | | 3,868 | |
| Other items (1) | | | 3,871 | | | | 56 | | | | 3,927 | | | | 5,578 | | | | 9,505 | |
| Net income (loss) | | $ | 40,859 | | | $ | (2,446 | ) | | $ | 38,413 | | | $ | (7,508 | ) | | $ | 30,905 | |
| | | | | | | | | | | | | | | | | | | | | |
| For the Nine Months Ended September 30, 2026 | | | | | | | | | | | | | | | | | | | | |
| Revenues | | $ | 149,093 | | | $ | — | | | $ | 149,093 | | | $ | — | | | $ | 149,093 | |
| Equity in loss of Sisecam Wyoming | | | — | | | | (16,859 | ) | | | (16,859 | ) | | | — | | | | (16,859 | ) |
| Gain on asset sales and disposals | | | 49 | | | | — | | | | 49 | | | | — | | | | 49 | |
| Total revenues and other income | | $ | 149,142 | | | $ | (16,859 | ) | | $ | 132,283 | | | $ | — | | | $ | 132,283 | |
| Less: | | | | | | | | | | | | | | | | | | | | |
| Compensation (salaries, benefits and bonus) | | | 5,386 | | | | — | | | | 5,386 | | | | 6,047 | | | | 11,433 | |
| Property taxes | | | 5,405 | | | | — | | | | 5,405 | | | | — | | | | 5,405 | |
| Depreciation, depletion and amortization | | | 25,257 | | | | — | | | | 25,257 | | | | 14 | | | | 25,271 | |
| Other items (1) | | | 6,390 | | | | 203 | | | | 6,593 | | | | 12,244 | | | | 18,837 | |
| Net income (loss) | | $ | 106,704 | | | $ | (17,062 | ) | | $ | 89,642 | | | $ | (18,305 | ) | | $ | 71,337 | |
| As of September 30, 2026 | | | | | | | | | | | | | | | | | | | | |
| Total assets | | $ | 485,668 | | | $ | 274,197 | | | $ | 759,865 | | | $ | 4,078 | | | $ | 763,943 | |
| | | | | | | | | | | | | | | | | | | | | |
| For the Nine Months Ended September 30, 2025 | | | | | | | | | | | | | | | | | | | | |
| Revenues | | $ | 153,942 | | | $ | — | | | $ | 153,942 | | | $ | — | | | $ | 153,942 | |
| Equity in earnings of Sisecam Wyoming | | | — | | | | 4,746 | | | | 4,746 | | | | — | | | | 4,746 | |
| Gain on asset sales and disposals | | | 1,882 | | | | — | | | | 1,882 | | | | — | | | | 1,882 | |
| Total revenues and other income | | $ | 155,824 | | | $ | 4,746 | | | $ | 160,570 | | | $ | — | | | $ | 160,570 | |
| Less: | | | | | | | | | | | | | | | | | | | | |
| Compensation (salaries, benefits and bonus) | | | 5,313 | | | | — | | | | 5,313 | | | | 5,882 | | | | 11,195 | |
| Property taxes | | | 5,594 | | | | — | | | | 5,594 | | | | — | | | | 5,594 | |
| Depreciation, depletion and amortization | | | 11,597 | | | | — | | | | 11,597 | | | | 14 | | | | 11,611 | |
| Asset impairments | | | 20 | | | | — | | | | 20 | | | | — | | | | 20 | |
| Other items (1) | | | 7,542 | | | | 140 | | | | 7,682 | | | | 19,099 | | | | 26,781 | |
| Net income (loss) | | $ | 125,758 | | | $ | 4,606 | | | $ | 130,364 | | | $ | (24,995 | ) | | $ | 105,369 | |
| As of December 31, 2025 | | | | | | | | | | | | | | | | | | | | |
| Total assets | | $ | 492,672 | | | $ | 250,244 | | | $ | 742,916 | | | $ | 5,449 | | | $ | 748,365 | |
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