v3.26.1
Segment Information (Reportable Segment Results) (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
Dec. 31, 2025
Reportable segment results      
Total revenues $ 467,192 $ 449,248  
Mining costs (400,747) (356,696)  
Other operating costs (159,226) (156,989)  
Total operating costs (559,973) (513,685)  
Other and unallocated costs 3,431 (8,379)  
Segment adjusted EBITDA (89,350) (72,816)  
Total assets 2,330,174 2,408,809 $ 2,625,555
Capital expenditures 19,943 120,048  
Other and Corporate [Member]      
Reportable segment results      
Total revenues 0 0  
Mining costs 0 0  
Other operating costs 0 0  
Total operating costs 0 0  
Other and unallocated costs (4,614) (8,350)  
Segment adjusted EBITDA (4,614) (8,350)  
Total assets 94,530 154,742  
Capital expenditures 0 2,365  
Australia Segment [Member] | Operating Segments [Member]      
Reportable segment results      
Total revenues 259,088 273,277  
Mining costs (253,890) (198,204)  
Other operating costs (101,076) (140,163)  
Total operating costs (354,966) (338,367)  
Other and unallocated costs 9,305 246  
Segment adjusted EBITDA (86,573) (64,844)  
Total assets 1,310,835 1,185,488  
Capital expenditures 10,922 49,736  
United States Segment [Member] | Operating Segments [Member]      
Reportable segment results      
Total revenues 208,104 175,971  
Mining costs (146,857) (158,492)  
Other operating costs (58,150) (16,826)  
Total operating costs (205,007) (175,318)  
Other and unallocated costs (1,260) (275)  
Segment adjusted EBITDA 1,837 378  
Total assets 924,809 1,068,579  
Capital expenditures $ 9,021 $ 67,947