Revenue - Schedule of Net Sales Disaggregates by Major Source (Detail) - USD ($) $ in Thousands	3 Months Ended
	Apr. 01, 2023	Apr. 02, 2022
Revenue from Contract with Customers [Line Items]
Revenues	$ 8,709,980	$ 10,493,282
Sheet [Member]
Revenue from Contract with Customers [Line Items]
Revenues	2,102,694	3,183,063
Bar [Member]
Revenue from Contract with Customers [Line Items]
Revenues	1,598,128	1,827,731
Structural [Member]
Revenue from Contract with Customers [Line Items]
Revenues	638,307	783,271
Plate [Member]
Revenue from Contract with Customers [Line Items]
Revenues	640,128	724,544
Tubular Products [Member]
Revenue from Contract with Customers [Line Items]
Revenues	438,983	610,300
Rebar Fabrication [Member]
Revenue from Contract with Customers [Line Items]
Revenues	498,117	445,232
Joist [Member]
Revenue from Contract with Customers [Line Items]
Revenues	635,816	612,235
Deck [Member]
Revenue from Contract with Customers [Line Items]
Revenues	485,443	550,909
Other Steel Products [Member]
Revenue from Contract with Customers [Line Items]
Revenues	1,217,638	1,104,412
Raw Materials [Member]
Revenue from Contract with Customers [Line Items]
Revenues	454,726	651,585
Steel Mills [Member]
Revenue from Contract with Customers [Line Items]
Revenues	4,979,257	6,518,609
Steel Mills [Member] | Sheet [Member]
Revenue from Contract with Customers [Line Items]
Revenues	2,102,694	3,183,063
Steel Mills [Member] | Bar [Member]
Revenue from Contract with Customers [Line Items]
Revenues	1,598,128	1,827,731
Steel Mills [Member] | Structural [Member]
Revenue from Contract with Customers [Line Items]
Revenues	638,307	783,271
Steel Mills [Member] | Plate [Member]
Revenue from Contract with Customers [Line Items]
Revenues	640,128	724,544
Steel Products [Member]
Revenue from Contract with Customers [Line Items]
Revenues	3,275,997	3,323,088
Steel Products [Member] | Tubular Products [Member]
Revenue from Contract with Customers [Line Items]
Revenues	438,983	610,300
Steel Products [Member] | Rebar Fabrication [Member]
Revenue from Contract with Customers [Line Items]
Revenues	498,117	445,232
Steel Products [Member] | Joist [Member]
Revenue from Contract with Customers [Line Items]
Revenues	635,816	612,235
Steel Products [Member] | Deck [Member]
Revenue from Contract with Customers [Line Items]
Revenues	485,443	550,909
Steel Products [Member] | Other Steel Products [Member]
Revenue from Contract with Customers [Line Items]
Revenues	1,217,638	1,104,412
Raw Materials [Member]
Revenue from Contract with Customers [Line Items]
Revenues	454,726	651,585
Raw Materials [Member] | Raw Materials [Member]
Revenue from Contract with Customers [Line Items]
Revenues	$ 454,726	$ 651,585