v3.26.1
Segment Information - 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
Segment Reporting Information          
Net sales $ 6,091,557 $ 4,565,123 $ 11,296,415 $ 8,934,318  
Costs of goods sold 5,132,583 3,946,655 9,574,218 7,829,306  
Other segment items 258,495 235,613 483,714 447,013  
Operating income (loss) 700,479 382,855 1,238,483 657,999  
Interest expense, net of capitalized interest 39,120 17,381 72,361 29,512  
Other income, net (22,105) (22,392) (30,555) (40,033)  
Income before income taxes 683,464 387,866 1,196,677 668,520  
Depreciation and amortization 173,922 132,865 333,202 266,621  
Capital expenditures 123,842 288,331 261,821 593,837  
Total Assets 17,113,399   17,113,399   $ 16,419,780
U.S.          
Segment Reporting Information          
Net sales 5,618,901 4,292,462 10,499,276 8,334,382  
Non-U.S.          
Segment Reporting Information          
Net sales 472,656 272,661 797,139 599,936  
Operating Segment | Steel Operations          
Segment Reporting Information          
Net sales 4,138,096 3,384,129 7,794,860 6,538,559  
Costs of goods sold 3,348,457 2,945,794 6,378,561 5,816,292  
Other segment items 69,797 57,241 140,967 112,311  
Operating income (loss) 719,842 381,094 1,275,332 609,956  
Depreciation and amortization 108,357 97,377 214,421 196,307  
Capital expenditures 49,674 76,072 98,128 168,079  
Total Assets 9,560,891   9,560,891    
Operating Segment | Steel Operations | U.S.          
Segment Reporting Information          
Net sales 3,744,196 3,154,477 7,149,047 6,059,017  
Operating Segment | Steel Operations | Non-U.S.          
Segment Reporting Information          
Net sales 261,314 121,074 395,206 283,550  
Operating Segment | Steel Operations | Other segments          
Segment Reporting Information          
Net sales 132,586 108,578 250,607 195,992  
Operating Segment | Metals Recycling Operations          
Segment Reporting Information          
Net sales 1,265,014 1,162,153 2,390,446 2,234,660  
Costs of goods sold 1,186,826 1,113,549 2,237,867 2,133,693  
Other segment items 30,372 27,314 57,296 53,967  
Operating income (loss) 47,816 21,290 95,283 47,000  
Depreciation and amortization 16,814 15,881 33,695 30,851  
Capital expenditures 13,922 26,873 35,094 54,053  
Total Assets 1,622,448   1,622,448    
Operating Segment | Metals Recycling Operations | U.S.          
Segment Reporting Information          
Net sales 445,811 375,526 852,889 747,402  
Operating Segment | Metals Recycling Operations | Non-U.S.          
Segment Reporting Information          
Net sales 207,953 147,195 394,058 310,214  
Operating Segment | Metals Recycling Operations | Other segments          
Segment Reporting Information          
Net sales 611,250 639,432 1,143,499 1,177,044  
Operating Segment | Steel Fabrication Operations          
Segment Reporting Information          
Net sales 393,861 340,672 749,315 693,135  
Costs of goods sold 280,638 220,902 520,045 432,730  
Other segment items 28,630 26,656 55,163 50,545  
Operating income (loss) 84,593 93,114 174,107 209,860  
Depreciation and amortization 3,680 3,250 7,331 6,206  
Capital expenditures 2,078 3,283 3,618 8,527  
Total Assets 746,885   746,885    
Operating Segment | Steel Fabrication Operations | U.S.          
Segment Reporting Information          
Net sales 393,629 340,605 749,059 692,464  
Operating Segment | Steel Fabrication Operations | Non-U.S.          
Segment Reporting Information          
Net sales 177 43 180 491  
Operating Segment | Steel Fabrication Operations | Other segments          
Segment Reporting Information          
Net sales 55 24 76 180  
Operating Segment | Aluminum Operations          
Segment Reporting Information          
Net sales 518,917 93,567 761,016 194,214  
Costs of goods sold 542,690 87,849 840,422 179,320  
Other segment items 26,085 46,345 35,044 84,256  
Operating income (loss) (49,858) (40,627) (114,450) (69,362)  
Depreciation and amortization 31,198 2,840 50,304 5,487  
Capital expenditures 58,249 210,534 134,503 419,125  
Total Assets 4,438,726   4,438,726    
Operating Segment | Aluminum Operations | U.S.          
Segment Reporting Information          
Net sales 497,733 65,632 725,042 132,208  
Operating Segment | Aluminum Operations | Non-U.S.          
Segment Reporting Information          
Net sales 134   218    
Operating Segment | Aluminum Operations | Other segments          
Segment Reporting Information          
Net sales 21,050 27,935 35,756 62,006  
Operating Segment | Other          
Segment Reporting Information          
Net sales 540,881 361,436 1,031,479 709,837  
Costs of goods sold 534,444 348,666 1,015,513 695,254  
Other segment items 103,982 78,429 195,984 146,675  
Operating income (loss) (97,545) (65,659) (180,018) (132,092)  
Depreciation and amortization 14,902 13,517 29,171 27,770  
Capital expenditures 6,068 6,218 13,217 11,713  
Total Assets 4,974,660   4,974,660    
Operating Segment | Other | U.S.          
Segment Reporting Information          
Net sales 537,532 356,222 1,023,239 703,291  
Operating Segment | Other | Non-U.S.          
Segment Reporting Information          
Net sales 3,078 4,349 7,477 5,681  
Operating Segment | Other | Other segments          
Segment Reporting Information          
Net sales 271 865 763 865  
Eliminations          
Segment Reporting Information          
Net sales (765,212) (776,834) (1,430,701) (1,436,087)  
Costs of goods sold (760,472) (770,105) (1,418,190) (1,427,983)  
Other segment items (371) (372) (740) (741)  
Operating income (loss) (4,369) (6,357) (11,771) (7,363)  
Depreciation and amortization (1,029)   (1,720)    
Capital expenditures (6,149) (34,649) (22,739) (67,660)  
Total Assets (4,230,211)   (4,230,211)    
Eliminations | Other segments          
Segment Reporting Information          
Net sales $ (765,212) $ (776,834) $ (1,430,701) $ (1,436,087)