Segments - Segments (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 29, 2024	Jul. 01, 2023	Jun. 29, 2024	Jul. 01, 2023	Dec. 31, 2023
Segment Reporting Information [Line Items]
Net sales	$ 8,077,172	$ 9,523,256	$ 16,214,255	$ 18,233,236
Earnings (losses) before income taxes and noncontrolling interests	898,163	2,049,782	2,123,504	3,646,566
Total assets	34,185,225		34,185,225		$ 35,340,499
Operating Segments [Member] | Steel Mills [Member]
Segment Reporting Information [Line Items]
Net sales	4,858,205	5,565,772	10,026,983	10,545,029
Earnings (losses) before income taxes and noncontrolling interests	645,315	1,403,547	1,747,566	2,241,935
Total assets	15,754,570		15,754,570		15,407,266
Operating Segments [Member] | Steel Products [Member]
Segment Reporting Information [Line Items]
Net sales	2,702,776	3,442,862	5,219,644	6,718,859
Earnings (losses) before income taxes and noncontrolling interests	441,391	1,010,789	952,950	1,981,591
Total assets	11,063,154		11,063,154		10,914,870
Operating Segments [Member] | Raw Materials [Member]
Segment Reporting Information [Line Items]
Net sales	516,191	514,622	967,628	969,348
Earnings (losses) before income taxes and noncontrolling interests	39,396	138,411	48,977	196,551
Total assets	3,477,728		3,477,728		3,546,759
Intercompany Eliminations [Member] | Steel Mills [Member]
Segment Reporting Information [Line Items]
Net sales	1,171,861	1,361,066	2,422,724	2,524,698
Intercompany Eliminations [Member] | Steel Products [Member]
Segment Reporting Information [Line Items]
Net sales	155,025	100,257	292,469	200,618
Intercompany Eliminations [Member] | Raw Materials [Member]
Segment Reporting Information [Line Items]
Net sales	2,749,174	3,588,629	5,859,203	6,759,521
Corporate and Eliminations Items [Member]
Segment Reporting Information [Line Items]
Net sales	(4,076,060)	(5,049,952)	(8,574,396)	(9,484,837)
Earnings (losses) before income taxes and noncontrolling interests	(227,939)	$ (502,965)	(625,989)	$ (773,511)
Corporate/eliminations [Member]
Segment Reporting Information [Line Items]
Total assets	$ 3,889,773		$ 3,889,773		$ 5,471,604