Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($)	3 Months Ended			9 Months Ended
	Oct. 03, 2020	Dec. 31, 2019	Sep. 28, 2019	Oct. 03, 2020	Sep. 28, 2019
Finite And Indefinite Lived Intangible Assets [Line Items]
Impairment of goodwill		$ 0
Goodwill	$ 2,195,788,000	2,201,063,000		$ 2,195,788,000
Finite-lived intangible assets	678,558,000	$ 742,186,000		678,558,000
Intangible asset amortization expense	20,700,000		$ 22,000,000.0	62,900,000	$ 64,700,000
Future amortization expense, in 2020	83,500,000			83,500,000
Future amortization expense, in 2021	82,300,000			82,300,000
Future amortization expense, in 2022	80,700,000			80,700,000
Future amortization expense, in 2023	80,000,000.0			80,000,000.0
Future amortization expense, in 2024	79,200,000			$ 79,200,000
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		56.00%
Goodwill	352,700,000	$ 356,600,000		$ 352,700,000
Finite-lived intangible assets	59,600,000	67,200,000		59,600,000
Grating unit [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Percentage of fair value exceeded carrying value			17.00%
Goodwill	$ 36,600,000	$ 36,800,000		$ 36,600,000