Fair Values of Financial Instruments - Summary of Reconciliation of Acquisition Related Contingent Consideration (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 01, 2017	Oct. 02, 2016	Oct. 01, 2017	Oct. 02, 2016
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
(Favorable)/unfavorable fair value adjustment			$ 23,140	$ 26,060
Level 3 [Member]
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Opening balance - Level 3 liability	$ 319,102	$ 228,768	253,437	136,570
Increase due to acquisitions			46,086	68,039
Payments/current payables	(4,944)	(2,995)	(13,730)	(12,261)
(Favorable)/unfavorable fair value adjustment	(5,225)	(7,365)	23,140	26,060
Ending balance - Level 3 liability	$ 308,933	$ 218,408	$ 308,933	$ 218,408