v3.26.1
Segment Information - Schedule of Reconciliations of Segment Information to Consolidated Amounts (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
Segment Reporting Information [Line Items]          
Total revenues $ 509,690 $ 297,523 $ 968,278 $ 597,466  
Operating income (loss) 94,521 7,723 173,889 (9,661)  
Assets 2,900,461   2,900,461   $ 2,783,799
Depreciation and depletion 58,293 43,255 110,566 88,532  
Operating Segments          
Segment Reporting Information [Line Items]          
Total revenues 509,690 297,523 968,278 597,466  
Transportation and royalties 143,290 75,067 256,910 157,684  
Assets 2,900,461 2,645,402 2,900,461 2,645,402  
Depreciation and depletion 58,293 43,255 110,566 88,532  
Capital expenditures 28,923 74,966 109,052 143,476  
Mining          
Segment Reporting Information [Line Items]          
Depreciation and depletion 58,293 43,255 110,566 88,532  
Mining | Operating Segments          
Segment Reporting Information [Line Items]          
Total revenues 503,594 288,491 952,063 583,424  
Cash cost of sales [1] 338,107 224,504 626,802 468,532  
Other segment items [2] 1,939 1,908 3,662 3,615  
Operating income (loss) 163,548 62,079 321,599 111,277  
Transportation and royalties 143,290 75,067 256,910 157,684  
Assets 2,740,774 2,288,119 2,740,774 2,288,119  
Depreciation and depletion 56,453 41,014 106,643 84,005  
Capital expenditures 26,989 73,828 104,592 141,246  
All other | Operating Segments          
Segment Reporting Information [Line Items]          
Total revenues 6,096 9,032 16,215 14,042  
Transportation and royalties 0 0 0 0  
Assets 159,687 357,283 159,687 357,283  
Depreciation and depletion 1,840 2,241 3,923 4,527  
Capital expenditures $ 1,934 $ 1,138 $ 4,460 $ 2,230  
[1] The significant expense category and amounts align with the segment-level information that is regularly reviewed by the CODM. Cash cost of sales includes transportation and royalties and excludes depreciation and depletion as presented above.
[2] Other segment items include non-cash charges to cost of sales of asset retirement obligation accretion and valuation adjustments and stock compensation expense.