Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($)	3 Months Ended			6 Months Ended		12 Months Ended
	Jul. 03, 2021	Dec. 31, 2020	Jul. 04, 2020	Jul. 03, 2021	Jul. 04, 2020	Dec. 31, 2020
Finite And Indefinite Lived Intangible Assets [Line Items]
Impairment of goodwill		$ 0
Goodwill	$ 2,241,558,000	2,229,672,000		$ 2,241,558,000		$ 2,229,672,000
Finite-lived intangible assets	627,201,000	668,021,000		627,201,000		$ 668,021,000
Intangible asset amortization expense	20,800,000		$ 20,700,000	41,900,000	$ 42,200,000
Future amortization expense, in 2021	82,700,000			82,700,000
Future amortization expense, in 2022	81,100,000			81,100,000
Future amortization expense, in 2023	80,400,000			80,400,000
Future amortization expense, in 2024	79,600,000			79,600,000
Future amortization expense, in 2025	78,600,000			$ 78,600,000
Minimum [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets, useful life				5 years
Maximum [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Intangible assets, useful life				22 years
Rebar Fabrication [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Percentage of fair value exceeded carrying value						99.00%
Goodwill	374,100,000	364,300,000		$ 374,100,000		$ 364,300,000
Finite-lived intangible assets	55,200,000	58,800,000		55,200,000		$ 58,800,000
Grating unit [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Percentage of fair value exceeded carrying value						88.00%
Goodwill	$ 37,400,000	$ 37,000,000.0		$ 37,400,000		$ 37,000,000.0