v3.26.1
MINERAL PROPERTIES, PLANT AND EQUIPMENT, NET - Components of Mineral Properties, Plant and Equipment, Net (Details) - USD ($)
$ in Thousands
Mar. 31, 2026
Dec. 31, 2025
Property, Plant and Equipment [Line Items]    
Total mineral properties, plant, and equipment $ 3,034,493 $ 2,960,540
Accumulated depreciation, plant and equipment (673,658) (658,438)
Accumulated depletion, mineral properties (475,489) (466,380)
Mineral properties, plant, and equipment, net 1,885,346 1,835,722
Finance lease, right-of-use asset, before accumulated amortization 200 500
Plant and equipment    
Property, Plant and Equipment [Line Items]    
Total mineral properties, plant, and equipment 1,120,453 1,090,741
Construction in process    
Property, Plant and Equipment [Line Items]    
Total mineral properties, plant, and equipment 223,644 192,611
Mineral properties subject to depletion    
Property, Plant and Equipment [Line Items]    
Total mineral properties, plant, and equipment 866,345 833,213
Mineral properties not yet subject to depletion    
Property, Plant and Equipment [Line Items]    
Total mineral properties, plant, and equipment 737,412 749,509
Exploration and evaluation assets    
Property, Plant and Equipment [Line Items]    
Total mineral properties, plant, and equipment $ 86,639 $ 94,466