CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Income Statement [Abstract]
Revenues	$ 277,198	$ 237,708
Cost of sales	238,725	207,952
Gross profit	38,473	29,756
Earnings of unconsolidated operations	61,823	57,476
Business interruption insurance recoveries	0	13,612
Operating expenses
Selling, general and administrative expenses	77,851	69,754
Amortization of intangible assets	750	531
Gain on sale of assets	(286)	(5,146)
Operating expenses	78,315	65,139
Operating profit	21,981	35,705
Other expense (income)
Interest expense	5,754	5,566
Interest income	(3,052)	(4,428)
Closed mine obligations	457	2,381
Loss (gain) on equity securities	726	(1,805)
Gain on settlement of excess funding liability	(3,590)	0
Pension settlement charge	7,804	0
Other, net	738	345
Other (income) expense	8,837	2,059
Income before income tax benefit	13,144	33,646
Income tax benefit	(4,430)	(95)
Net income	$ 17,574	$ 33,741
Earnings per share:
Basic earnings (loss) per share (in dollars per share)	$ 2.37	$ 4.58
Diluted earnings (loss) per share (in dollars per share)	$ 2.35	$ 4.55
Basic weighted average shares outstanding (in shares)	7,423	7,363
Diluted weighted average shares outstanding (in shares)	7,481	7,411