Fair Value of Financial Instruments - Summary of Reconciliation of Acquisition Related Contingent Consideration (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 27, 2015	Sep. 28, 2014	Sep. 27, 2015	Sep. 28, 2014
Fair Value Disclosures [Abstract]
Opening balance	$ 94,068	$ 13,000
Increase due to acquisitions	0	0	$ 50,312	$ 13,000
Decrease due to measurement period adjustments	(3,371)	0	(3,371)	0
Payments/accruals	(1,625)	0	(3,730)	0
Fair value adjustment - (income) expense	3,992	0	3,003	0
Ending balance	$ 93,064	$ 13,000	$ 93,064	$ 13,000