| Equity Method Investments [Table Text Block] |
| | | For the Three Months Ended September 30, | | | For the Nine Months Ended September 30, | |
| (In thousands) | | 2026 | | | 2025 | | | 2026 | | | 2025 | |
| Balance at beginning of period | | $ | 277,475 | | | $ | 258,498 | | | $ | 250,244 | | | $ | 257,355 | |
| Income (loss) allocation to NRP’s equity interests (1) | | | (3,013 | ) | | | (1,342 | ) | | | (13,531 | ) | | | 8,074 | |
| Amortization of basis difference | | | (1,112 | ) | | | (1,048 | ) | | | (3,327 | ) | | | (3,327 | ) |
| Capital investment | | | — | | | | — | | | | 39,200 | | | | — | |
| Other comprehensive income (loss) | | | 847 | | | | (2,391 | ) | | | 1,611 | | | | (545 | ) |
| Distributions | | | — | | | | — | | | | — | | | | (7,840 | ) |
| Balance at end of period | | $ | 274,197 | | | $ | 253,717 | | | $ | 274,197 | | | $ | 253,717 | |
| | | For the Three Months Ended September 30, | | | For the Nine Months Ended September 30, | |
| (In thousands) | | 2026 | | | 2025 | | | 2026 | | | 2025 | |
| Net sales | | $ | 113,155 | | | $ | 123,847 | | | $ | 373,288 | | | $ | 413,754 | |
| Gross profit (loss) | | | 1,458 | | | | 4,264 | | | | (2,491 | ) | | | 38,467 | |
| Net income (loss) | | | (6,149 | ) | | | (2,739 | ) | | | (27,614 | ) | | | 16,477 | |
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