v3.26.1
SEGMENT REPORTING - Reconciliation of Adjusted EBITDA (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Segment Reporting [Line Items]        
Price protection agreement income $ 17,580 $ 0 $ 59,853 $ 0
Revenue (including related party) 108,490 57,393 199,139 118,203
Operating Segments        
Segment Reporting [Line Items]        
Segment Adjusted EBITDA 40,037 (4,589) 86,361 (338)
Revenue (including related party) 112,153   205,408  
Segment capital expenditures 230,030 28,998 307,187 59,465
Operating Segments | External Customers        
Segment Reporting [Line Items]        
Revenue (including related party) 108,490 57,393 199,139 118,203
Operating Segments | Intersegment Customers        
Segment Reporting [Line Items]        
Revenue (including related party) 3,663   6,269  
Operating Segments | Materials Segment        
Segment Reporting [Line Items]        
Price protection agreement income 17,580   59,853  
Cost of sales (excluding depreciation, depletion and amortization and stock-based compensation expense)(2) 69,325 40,264 136,105 84,741
Selling, general and administrative (excluding stock-based compensation expense)(3) 10,522 9,542 20,624 16,551
Other segment items(4) 857 404 1,693 779
Segment Adjusted EBITDA 32,505 (12,678) 69,237 (8,920)
Revenue (including related party) 95,629 37,532 167,806 93,151
Segment capital expenditures 85,773 12,581 116,319 27,924
Operating Segments | Materials Segment | External Customers        
Segment Reporting [Line Items]        
Revenue (including related party) 91,966 37,532 161,537 93,151
Operating Segments | Materials Segment | Intersegment Customers        
Segment Reporting [Line Items]        
Revenue (including related party) 3,663   6,269  
Operating Segments | Magnetics Segment        
Segment Reporting [Line Items]        
Price protection agreement income 0   0  
Cost of sales (excluding depreciation, depletion and amortization and stock-based compensation expense)(2) 4,349 8,918 11,877 11,294
Selling, general and administrative (excluding stock-based compensation expense)(3) 4,048 2,686 7,521 4,971
Other segment items(4) 595 168 1,080 205
Segment Adjusted EBITDA 7,532 8,089 17,124 8,582
Revenue (including related party) 16,524   37,602  
Segment capital expenditures 144,257 16,417 190,868 31,541
Operating Segments | Magnetics Segment | External Customers        
Segment Reporting [Line Items]        
Revenue (including related party) 16,524 19,861 37,602 25,052
Operating Segments | Magnetics Segment | Intersegment Customers        
Segment Reporting [Line Items]        
Revenue (including related party) 0   0  
Intersegment Eliminations        
Segment Reporting [Line Items]        
Segment Adjusted EBITDA 561   688  
Revenue (including related party) (3,663) 0 (6,269) 0
Segment Reporting, Reconciling Item, Corporate Nonsegment        
Segment Reporting [Line Items]        
Segment capital expenditures $ 305 $ 8 $ 524 $ 8