Segments - Segments (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Oct. 01, 2022	Sep. 30, 2023	Oct. 01, 2022	Dec. 31, 2022
Segment Reporting Information [Line Items]
Net sales	$ 8,775,734	$ 10,500,755	$ 27,008,970	$ 32,788,511
Earnings (losses) before income taxes and noncontrolling interests	1,548,082	2,322,922	5,194,648	8,711,439
Total assets	34,267,786		34,267,786		$ 32,479,210
Operating Segments [Member] | Steel Mills [Member]
Segment Reporting Information [Line Items]
Net sales	5,091,479	5,908,153	15,636,508	19,682,829
Earnings (losses) before income taxes and noncontrolling interests	882,614	1,287,855	3,124,549	6,682,432
Total assets	14,786,460		14,786,460		14,157,229
Operating Segments [Member] | Steel Products [Member]
Segment Reporting Information [Line Items]
Net sales	3,235,969	4,087,107	9,954,828	11,253,143
Earnings (losses) before income taxes and noncontrolling interests	806,731	1,196,845	2,788,322	3,011,644
Total assets	11,199,598		11,199,598		12,087,145
Operating Segments [Member] | Raw Materials [Member]
Segment Reporting Information [Line Items]
Net sales	448,286	505,495	1,417,634	1,852,539
Earnings (losses) before income taxes and noncontrolling interests	71,367	279,189	267,918	638,640
Total assets	3,287,907		3,287,907		3,383,114
Intercompany Eliminations [Member] | Steel Mills [Member]
Segment Reporting Information [Line Items]
Net sales	1,201,648	1,486,378	3,726,346	4,843,199
Intercompany Eliminations [Member] | Steel Products [Member]
Segment Reporting Information [Line Items]
Net sales	132,481	139,146	333,099	391,141
Intercompany Eliminations [Member] | Raw Materials [Member]
Segment Reporting Information [Line Items]
Net sales	2,894,079	3,690,120	9,653,600	11,382,329
Corporate and Eliminations Items [Member]
Segment Reporting Information [Line Items]
Net sales	(4,228,208)	(5,315,644)	(13,713,045)	(16,616,669)
Earnings (losses) before income taxes and noncontrolling interests	(212,630)	$ (440,967)	(986,141)	$ (1,621,277)
Corporate/eliminations [Member]
Segment Reporting Information [Line Items]
Total assets	$ 4,993,821		$ 4,993,821		$ 2,851,722