Goodwill and Other Intangible Assets - Schedule of Change in Net Carrying Amount of Goodwill by Segment (Detail) $ in Thousands	6 Months Ended
	Jun. 29, 2024 USD ($)
Goodwill [Line Items]
Balance, beginning of period	$ 3,968,847
Acquisitions	37,897
Translation	(6,600)
Balance, end of period	4,000,144
Steel Mills [Member]
Goodwill [Line Items]
Balance, beginning of period	675,186
Balance, end of period	675,186
Steel Products [Member]
Goodwill [Line Items]
Balance, beginning of period	2,514,172
Acquisitions	46,063
Translation	(6,600)
Balance, end of period	2,553,635
Raw Materials [Member]
Goodwill [Line Items]
Balance, beginning of period	779,489
Acquisitions	(8,166)
Balance, end of period	$ 771,323