v3.26.1
Segment Information (Reportable Segment Results) (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Reportable segment results          
Total revenues $ 514,129 $ 467,879 $ 981,321 $ 917,127  
Mining cash costs (403,766) (364,777) (804,515) (721,474)  
Other operating costs (92,202) (97,506) (251,426) (254,494)  
Total operating costs (495,968) (462,283) (1,055,941) (975,968)  
Other and unallocated costs (11,331) (6,166) (7,897) (14,545)  
Segment adjusted EBITDA 6,830 (570) (82,517) (73,386)  
Total assets 2,333,672 2,578,382 2,333,672 2,578,382 $ 2,625,555
Capital expenditures 26,520 84,121 46,463 204,169  
Other and Corporate [Member]          
Reportable segment results          
Total revenues 0 0 0 0  
Mining cash costs 0 0 0 0  
Other operating costs 0 0 0 0  
Total operating costs 0 0 0 0  
Other and unallocated costs (10,492) (7,551) (15,102) (15,915)  
Segment adjusted EBITDA (10,492) (7,551) (15,102) (15,915)  
Total assets 115,593 195,828 115,593 195,828  
Capital expenditures 0 2,872 0 5,237  
Australia Segment [Member] | Operating Segments [Member]          
Reportable segment results          
Total revenues 326,614 259,845 585,701 533,122  
Mining cash costs (296,384) (214,000) (550,274) (412,206)  
Other operating costs (41,627) (57,472) (142,702) (197,634)  
Total operating costs (338,011) (271,472) (692,976) (609,840)  
Other and unallocated costs (398) 1,427 8,907 1,674  
Segment adjusted EBITDA (11,795) (10,200) (98,368) (75,044)  
Total assets 1,371,099 1,325,017 1,371,099 1,325,017  
Capital expenditures 16,976 46,277 27,898 96,013  
United States Segment [Member] | Operating Segments [Member]          
Reportable segment results          
Total revenues 187,515 208,034 395,620 384,005  
Mining cash costs (107,382) (150,777) (254,241) (309,268)  
Other operating costs (50,575) (40,034) (108,724) (56,860)  
Total operating costs (157,957) (190,811) (362,965) (366,128)  
Other and unallocated costs (441) (42) (1,702) (304)  
Segment adjusted EBITDA 29,117 17,181 30,953 17,573  
Total assets 846,980 1,057,537 846,980 1,057,537  
Capital expenditures $ 9,544 $ 34,972 $ 18,565 $ 102,919