Revenue - Schedule of Net Sales Disaggregates by Major Source (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2022	Oct. 02, 2021	Oct. 01, 2022	Oct. 02, 2021
Revenue from Contract with Customers [Line Items]
Revenues	$ 10,500,755	$ 10,313,223	$ 32,788,511	$ 26,119,527
Sheet [Member]
Revenue from Contract with Customers [Line Items]
Revenues	2,712,426	3,643,599	9,511,822	9,099,358
Bar [Member]
Revenue from Contract with Customers [Line Items]
Revenues	1,761,335	1,633,641	5,581,529	4,409,798
Structural [Member]
Revenue from Contract with Customers [Line Items]
Revenues	785,930	765,440	2,352,322	1,862,176
Plate [Member]
Revenue from Contract with Customers [Line Items]
Revenues	648,462	819,453	2,237,156	2,009,487
Tubular Products [Member]
Revenue from Contract with Customers [Line Items]
Revenues	459,427	595,689	1,583,818	1,482,845
Rebar Fabrication [Member]
Revenue from Contract with Customers [Line Items]
Revenues	628,923	475,861	1,653,155	1,343,145
Joist [Member]
Revenue from Contract with Customers [Line Items]
Revenues	789,249	381,737	2,089,366	868,068
Deck [Member]
Revenue from Contract with Customers [Line Items]
Revenues	634,901	326,436	1,768,224	747,597
Other Steel Products [Member]
Revenue from Contract with Customers [Line Items]
Revenues	1,574,607	964,556	4,158,580	2,353,786
Raw Materials [Member]
Revenue from Contract with Customers [Line Items]
Revenues	505,495	706,811	1,852,539	1,943,267
Steel Mills [Member]
Revenue from Contract with Customers [Line Items]
Revenues	5,908,153	6,862,133	19,682,829	17,380,819
Steel Mills [Member] | Sheet [Member]
Revenue from Contract with Customers [Line Items]
Revenues	2,712,426	3,643,599	9,511,822	9,099,358
Steel Mills [Member] | Bar [Member]
Revenue from Contract with Customers [Line Items]
Revenues	1,761,335	1,633,641	5,581,529	4,409,798
Steel Mills [Member] | Structural [Member]
Revenue from Contract with Customers [Line Items]
Revenues	785,930	765,440	2,352,322	1,862,176
Steel Mills [Member] | Plate [Member]
Revenue from Contract with Customers [Line Items]
Revenues	648,462	819,453	2,237,156	2,009,487
Steel Products [Member]
Revenue from Contract with Customers [Line Items]
Revenues	4,087,107	2,744,279	11,253,143	6,795,441
Steel Products [Member] | Tubular Products [Member]
Revenue from Contract with Customers [Line Items]
Revenues	459,427	595,689	1,583,818	1,482,845
Steel Products [Member] | Rebar Fabrication [Member]
Revenue from Contract with Customers [Line Items]
Revenues	628,923	475,861	1,653,155	1,343,145
Steel Products [Member] | Joist [Member]
Revenue from Contract with Customers [Line Items]
Revenues	789,249	381,737	2,089,366	868,068
Steel Products [Member] | Deck [Member]
Revenue from Contract with Customers [Line Items]
Revenues	634,901	326,436	1,768,224	747,597
Steel Products [Member] | Other Steel Products [Member]
Revenue from Contract with Customers [Line Items]
Revenues	1,574,607	964,556	4,158,580	2,353,786
Raw Materials [Member]
Revenue from Contract with Customers [Line Items]
Revenues	505,495	706,811	1,852,539	1,943,267
Raw Materials [Member] | Raw Materials [Member]
Revenue from Contract with Customers [Line Items]
Revenues	$ 505,495	$ 706,811	$ 1,852,539	$ 1,943,267