Business Segments - Net Sales by Geographic Location (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Oct. 01, 2017	Jun. 25, 2017	Mar. 26, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 25, 2016
Revenues from External Customers and Long-Lived Assets [Line Items]
NET SALES	$ 378,823	$ 347,612	$ 388,944	$ 386,448	$ 361,803	$ 331,404	$ 240,628	$ 174,220	$ 1,501,827	$ 1,108,055	$ 732,677
U.S. [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
NET SALES									127,178	124,711	120,395
Mexico [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
NET SALES									673,205	607,707	$ 612,282
Germany [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
NET SALES									279,631	155,227
Poland [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
NET SALES									$ 421,813	$ 220,410