v3.26.1
PROPERTY, PLANT AND EQUIPMENT - Depreciation and amortization (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
PROPERTY, PLANT AND EQUIPMENT    
Depreciation of plant and equipment $ 11,230 $ 10,365
Amortization of right of use assets (finance leases) 1,699 1,892
Amortization and depletion of capitalized mine development costs and mineral rights 3,684 5,285
Total depreciation, depletion, and amortization $ 16,613 $ 17,542