Fair Values of Financial Instruments - Summary of Reconciliation of Acquisition Related Contingent Consideration (Detail) - USD ($) $ in Thousands		12 Months Ended
		Dec. 29, 2019	Dec. 30, 2018	Dec. 31, 2017
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Payment of acquisition related contingent consideration		$ 27,182	$ 24,683	$ 16,738
Increase in fair value		92,788	28,767	3,226
Level 3 [Member]
Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning balance - Level 3 liability		382,898	381,291
Measurement period adjustments	[1]		813
Payment of acquisition related contingent consideration		(27,182)	(24,683)
Reclassification to current payables		(1,820)	(3,290)
Increase in fair value		92,788	28,767
Ending balance - Level 3 liability		$ 446,684	$ 382,898	$ 381,291

[1] Measurement period adjustments relate to post-closing adjustments made in accordance with the terms and conditions of the applicable asset purchase agreement for distribution territories acquired by the Company in April 2017 and October 2017 as part of the System Transformation. All final post-closing adjustments for these transactions were completed during 2018.