Derivative Financial Instruments - Summary of Pre-Tax Changes in Fair Value (Detail) - Commodity Contract [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss)	$ (469)	$ 3,401	$ (3,139)	$ 2,541
Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss)	(260)	2,042	(2,776)	2,066
Selling, Delivery and Administrative Expenses [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Total gain (loss)	$ (209)	$ 1,359	$ (363)	$ 475