Fair Values of Financial Instruments - Summary of Reconciliation of Acquisition Related Contingent Consideration Liability (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Business Combination, Contingent Consideration, Liability [Roll Forward]
Payments of acquisition related contingent consideration			$ (20,531)	$ (12,836)
Increase in fair value			15,260	43,268
Level 3
Business Combination, Contingent Consideration, Liability [Roll Forward]
Beginning balance - Level 3 liability	$ 437,094	$ 393,007	446,684	382,898
Payments of acquisition related contingent consideration	(10,079)	(6,599)	(20,531)	(12,836)
Reclassification to current payables	(450)	(3,180)	(300)	(880)
Increase in fair value	14,548	29,222	15,260	43,268
Ending balance - Level 3 liability	$ 441,113	$ 412,450	$ 441,113	$ 412,450