Commitments and Contingencies - Summary of Company's Purchases from Manufacturing Cooperatives (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jul. 01, 2018	Jun. 30, 2019	Jul. 01, 2018
Loss Contingencies [Line Items]
Total purchases from manufacturing cooperatives	$ 76,607	$ 75,881	$ 148,379	$ 143,126
SAC [Member]
Loss Contingencies [Line Items]
Total purchases from manufacturing cooperatives	39,993	41,084	77,439	79,160
Southeastern [Member]
Loss Contingencies [Line Items]
Total purchases from manufacturing cooperatives	$ 36,614	$ 34,797	$ 70,940	$ 63,966