Segments - Segments (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2024	Apr. 01, 2023	Dec. 31, 2023
Segment Reporting Information [Line Items]
Net sales	$ 8,137,083	$ 8,709,980
Earnings (losses) before income taxes and noncontrolling interests	1,225,341	1,596,784
Total assets	33,932,525		$ 35,340,499
Operating Segments [Member] | Steel Mills [Member]
Segment Reporting Information [Line Items]
Net sales	5,168,778	4,979,257
Earnings (losses) before income taxes and noncontrolling interests	1,102,251	838,388
Total assets	15,557,704		15,407,266
Operating Segments [Member] | Steel Products [Member]
Segment Reporting Information [Line Items]
Net sales	2,516,868	3,275,997
Earnings (losses) before income taxes and noncontrolling interests	511,559	970,802
Total assets	11,012,416		10,914,870
Operating Segments [Member] | Raw Materials [Member]
Segment Reporting Information [Line Items]
Net sales	451,437	454,726
Earnings (losses) before income taxes and noncontrolling interests	9,581	58,140
Total assets	3,443,812		3,546,759
Intercompany Eliminations [Member] | Steel Mills [Member]
Segment Reporting Information [Line Items]
Net sales	1,250,863	1,163,632
Intercompany Eliminations [Member] | Steel Products [Member]
Segment Reporting Information [Line Items]
Net sales	137,444	100,361
Intercompany Eliminations [Member] | Raw Materials [Member]
Segment Reporting Information [Line Items]
Net sales	3,110,029	3,170,892
Corporate and Eliminations Items [Member]
Segment Reporting Information [Line Items]
Net sales	(4,498,336)	(4,434,885)
Earnings (losses) before income taxes and noncontrolling interests	(398,050)	$ (270,546)
Corporate/eliminations [Member]
Segment Reporting Information [Line Items]
Total assets	$ 3,918,593		$ 5,471,604