Fair Values of Financial Instruments - Summary of Reconciliation of Acquisition Related Contingent Consideration (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jul. 01, 2018	Jul. 02, 2017	Jul. 01, 2018	Jul. 02, 2017
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Payment of acquisition related contingent consideration				$ 11,263	$ 6,556
Unfavorable fair value adjustment				3,957	28,365
Level 3 [Member]
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning balance - Level 3 liability		$ 368,804	$ 303,952	381,291	253,437
Measurement period adjustment	[1]	3,151		2,092
Payment of acquisition related contingent consideration		(5,381)	(6,556)	(11,263)	(6,556)
Reclassification to current payables		(1,180)	1,817	(1,540)	(2,230)
Unfavorable fair value adjustment		9,143	16,119	3,957	28,365
Ending balance - Level 3 liability		$ 374,537	319,102	$ 374,537	319,102
Level 3 [Member] | System Transformation Transactions [Member]
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Increase due to acquisitions			$ 3,770		$ 46,086

[1] Measurement period adjustments relate to post-closing adjustments made in relation to the April 2017 Transactions and the October 2017 Transactions in accordance with the terms and conditions of the applicable asset purchase agreement or asset exchange agreement. See Note 3 to the consolidated condensed financial statements for additional information on the System Transformation Transactions.