Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 28, 2019	Sep. 29, 2018	Sep. 28, 2019	Sep. 29, 2018	Dec. 31, 2018
Finite And Indefinite Lived Intangible Assets [Line Items]
Goodwill	$ 2,186,499		$ 2,186,499		$ 2,184,336
Finite-lived intangible assets	764,267		764,267		828,504
Intangible asset amortization expense	22,000	$ 22,100	64,700	$ 66,700
Future amortization expense, in 2019	87,100		87,100
Future amortization expense, in 2020	84,700		84,700
Future amortization expense, in 2021	83,500		83,500
Future amortization expense, in 2022	81,200		81,200
Future amortization expense, in 2023	80,000		$ 80,000
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			8.00%
Goodwill	354,900		$ 354,900		353,000
Finite-lived intangible assets	69,400		$ 69,400		$ 76,700
Grating unit [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Percentage of fair value exceeded carrying value			17.00%
Goodwill	36,700		$ 36,700
Finite-lived intangible assets	$ 3,300		$ 3,300