v3.25.4
Property, Plant and Equipment (Schedule of Property, Plant and Equipment) (Details) - USD ($)
$ in Thousands
Dec. 31, 2025
Dec. 31, 2024
Property Plant And Equipment [Line Items]    
Total cost of property, plant and equipment $ 2,951,214 $ 2,630,683
Less accumulated depreciation, depletion and amortization 1,296,759 1,123,553
Property, plant and equipment, net 1,654,455 1,507,130
Land [Member]    
Property Plant And Equipment [Line Items]    
Total cost of property, plant and equipment 29,008 28,130
Buildings And Improvements [Member]    
Property Plant And Equipment [Line Items]    
Total cost of property, plant and equipment 138,771 123,662
Plant, Machinery, Mining Equipment And Transportation Vehicles [Member]    
Property Plant And Equipment [Line Items]    
Total cost of property, plant and equipment 1,516,095 1,259,620
Mineral Rights And Reserves [Member]    
Property Plant And Equipment [Line Items]    
Total cost of property, plant and equipment 370,393 379,065
Office And Computer Equipment [Member]    
Property Plant And Equipment [Line Items]    
Total cost of property, plant and equipment 20,063 9,654
Mine Development [Member]    
Property Plant And Equipment [Line Items]    
Total cost of property, plant and equipment 694,779 550,110
Asset Retirement Obligation Asset [Member]    
Property Plant And Equipment [Line Items]    
Total cost of property, plant and equipment 79,094 90,318
Construction In Progress [Member]    
Property Plant And Equipment [Line Items]    
Total cost of property, plant and equipment $ 103,011 $ 190,124