Business Acquisitions - ChanTest, Additional Information (Details) - USD ($)		9 Months Ended
	Oct. 29, 2014	Sep. 26, 2015	Sep. 27, 2014
Business Acquisition [Line Items]
Total purchase price allocation		$ 211,974,000	$ 183,151,000
ChanTest
Business Acquisition [Line Items]
Preliminary purchase price	$ 59,200,000
Contingent consideration	300,000
Maximum contingent consideration limit	2,000,000
Total purchase price allocation	52,029,000
Cash acquired from acquisition	$ 7,200,000