Goodwill and Other Intangible Assets - Schedule of Change in Net Carrying Amount of Goodwill by Segment (Detail) $ in Thousands	9 Months Ended
	Sep. 30, 2023 USD ($)
Goodwill [Line Items]
Balance, beginning of period	$ 3,920,060
Acquisitions	(2,120)
Translation	4,327
Balance, end of period	3,922,267
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	2,510,045
Acquisitions	(2,120)
Translation	4,327
Balance, end of period	2,512,252
Raw Materials [Member]
Goodwill [Line Items]
Balance, beginning of period	734,829
Balance, end of period	$ 734,829