v3.26.1
PROPERTY, PLANT AND EQUIPMENT - Schedule of Property, Plant and Equipment (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
PROPERTY, PLANT AND EQUIPMENT    
Less: accumulated depreciation, depletion, and amortization $ (261,609) $ (201,055)
Total property, plant, and equipment, net 511,943 482,019
Plant and equipment    
PROPERTY, PLANT AND EQUIPMENT    
Property, plant and equipment, gross 390,359 331,899
Mining property and mineral rights    
PROPERTY, PLANT AND EQUIPMENT    
Property, plant and equipment, gross 139,077 120,532
Construction in process    
PROPERTY, PLANT AND EQUIPMENT    
Property, plant and equipment, gross 22,264 31,048
Capitalized mine development costs    
PROPERTY, PLANT AND EQUIPMENT    
Property, plant and equipment, gross $ 221,852 $ 199,595