Goodwill and Other Intangible Assets - Additional Information (Detail) - USD ($)	3 Months Ended
	Apr. 04, 2020	Dec. 31, 2019	Sep. 28, 2019	Mar. 30, 2019
Finite And Indefinite Lived Intangible Assets [Line Items]
Impairment of goodwill		$ 0
Goodwill	$ 2,182,994,000	2,201,063,000
Finite-lived intangible assets	718,006,000	$ 742,186,000
Intangible asset amortization expense	21,500,000			$ 21,500,000
Future amortization expense, in 2020	83,500,000
Future amortization expense, in 2021	82,300,000
Future amortization expense, in 2022	80,700,000
Future amortization expense, in 2023	80,000,000.0
Future amortization expense, in 2024	$ 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	$ 341,500,000	$ 356,600,000
Finite-lived intangible assets	62,800,000	67,200,000
Grating unit [Member]
Finite And Indefinite Lived Intangible Assets [Line Items]
Percentage of fair value exceeded carrying value			17.00%
Goodwill	$ 36,200,000	$ 36,800,000