v3.26.3
BUSINESS SEGMENTS (Segment Reconciliation) (Details) - USD ($)
$ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Segment Reporting [Line Items]        
Total consolidated sales $ 51,034 $ 50,807 $ 216,404 $ 212,870
Total segment gross margin 10,041 9,952 44,362 35,634
Selling and administrative 9,679 8,992 30,974 27,072
Impairment of long-lived assets 0 0 0 1,866
Loss (gain) on disposal of assets 74 2 40 (1,420)
Accretion of asset retirement obligation 776 649 2,329 1,948
Other operating income (1,294) (1,145) (3,583) (3,650)
Other operating expense 597 970 7,105 4,220
Other operating expense 597 970 7,105 4,220
Equity in loss of unconsolidated entities 2 86 13 318
Interest Expense 0 36 0 207
Interest income (1,422) (776) (3,416) (1,802)
Other non-operating (income) expense (96) (24) (217) 796
Income from Continuing Operations Before Income Taxes 1,725 1,162 11,117 6,079
Mineral [Member]        
Segment Reporting [Line Items]        
Cost of goods sold (30,803) (31,261) (126,090) (130,782)
Freight Costs [Member]        
Segment Reporting [Line Items]        
Cost of goods sold (7,137) (6,579) (34,917) (35,081)
Operating Segments [Member]        
Segment Reporting [Line Items]        
Total consolidated sales 51,034 50,847 216,404 213,027
Intersegment Eliminations [Member]        
Segment Reporting [Line Items]        
Total consolidated sales 0 (40) 0 (157)
Total segment gross margin 0 0 0 0
Intersegment Eliminations [Member] | Mineral [Member]        
Segment Reporting [Line Items]        
Total consolidated sales 0   0  
Cost of goods sold 0 0 0 0
Intersegment Eliminations [Member] | Freight Costs [Member]        
Segment Reporting [Line Items]        
Cost of goods sold $ 0 $ 40 $ 0 $ 157