Acquisitions - Additional Information (Detail) - USD ($)			12 Months Ended
	Jul. 31, 2015	Feb. 05, 2015	Dec. 29, 2017	Dec. 30, 2016	Dec. 25, 2015
Business Acquisition [Line Items]
Business acquisition, potential cash earn-out payments					$ 1,280,000
Change in the fair value of the contingent earn out			$ (278,000)	$ 1,446,000	(449,000)
Net sales			924,351,000	562,759,000	469,103,000
Operating income			89,397,000	22,391,000	5,841,000
Amortization of finite-lived intangibles			5,437,000	5,758,000	6,212,000
Miconex [Member]
Business Acquisition [Line Items]
Percentage of shareholding interest acquired	100.00%
Cash paid for acquisition	$ 15,600,000
Business acquisition, potential cash earn-out payments			0	300,000
Business acquisition, potential cash payments period	2 years
Change in the fair value of the contingent earn out			$ (300,000)
Net sales					14,200,000
Operating income					2,000,000
Amortization of finite-lived intangibles					500,000
Miconex [Member] | General and Administrative [Member]
Business Acquisition [Line Items]
Acquisition costs					400,000
Miconex [Member] | Maximum [Member]
Business Acquisition [Line Items]
Business acquisition, potential cash earn-out payments	$ 4,000,000			2,000,000
Miconex [Member] | Common Stock [Member]
Business Acquisition [Line Items]
Shares of newly issued common stock	500,000
Marchi Thermal Systems Inc [Member]
Business Acquisition [Line Items]
Cash paid for acquisition		$ 29,900,000
Shares of newly issued common stock		1,437,500
Net sales					12,900,000
Operating income					4,800,000
Amortization of finite-lived intangibles				2,400,000
Acquisition costs		$ 200,000
Total purchase price		43,700,000
Amount borrowed to finance cash portion of acquisition		$ 29,700,000
Marchi Thermal Systems Inc [Member] | General and Administrative [Member]
Business Acquisition [Line Items]
Acquisition costs				$ 200,000
Marchi Thermal Systems Inc and Miconex S.r.o. [Member]
Business Acquisition [Line Items]
Acquisition related costs					$ 600,000