Segments - Schedule of Net Sale by Product to External Customers (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2023	Sep. 30, 2023	Jul. 01, 2023	Apr. 01, 2023	Dec. 31, 2022	Oct. 01, 2022	Jul. 02, 2022	Apr. 02, 2022	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax	$ 7,704,531	$ 8,775,734	$ 9,523,256	$ 8,709,980	$ 8,723,956	$ 10,500,755	$ 11,794,474	$ 10,493,282	$ 34,713,501	$ 41,512,467	$ 36,483,939
Sheet [Member]
Segment Reporting Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									9,146,676	11,437,799	12,675,679
Bar [Member]
Segment Reporting Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									5,993,751	7,031,798	6,039,187
Structural [Member]
Segment Reporting Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									2,429,211	2,928,072	2,597,768
Plate [Member]
Segment Reporting Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									2,523,024	2,792,188	2,832,762
Tubular Products [Member]
Segment Reporting Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									1,588,211	1,944,532	2,194,732
Rebar Fabrication [Member]
Segment Reporting Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									2,181,929	2,205,960	1,794,658
Joist [Member]
Segment Reporting Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									2,211,965	2,958,235	1,351,235
Deck [Member]
Segment Reporting Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									1,712,474	2,392,438	1,167,162
Other Steel Products [Member]
Segment Reporting Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									5,064,360	5,559,164	3,220,155
Raw Materials [Member]
Segment Reporting Information [Line Items]
Revenue From Contract With Customer Excluding Assessed Tax									$ 1,861,900	$ 2,262,281	$ 2,610,601