Customer Lists and Other Identifiable Intangible Assets, Net (Detail) - Customer lists and other identifiable intangible assets, net - USD ($) $ in Thousands	Sep. 27, 2020	Dec. 29, 2019
Finite-Lived Intangible Assets [Line Items]
Customer lists and other identifiable intangible assets at cost	$ 25,288	$ 25,288
Less: Accumulated amortization	12,024	10,645
Intangible assets, net	$ 13,264	$ 14,643