Supplemental Balance Sheet Information Related to Leases (Detail) - USD ($) $ in Thousands	Sep. 28, 2020	Dec. 30, 2019
Leases [Abstract]
Operating lease right-of-use assets	$ 22,993	$ 22,173
Other current liabilities	$ 7,945	$ 7,111
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesCurrent	us-gaap:OtherLiabilitiesCurrent
Operating lease liabilities	$ 15,885	$ 15,413
Total operating lease liabilities	$ 23,830	$ 22,524
Weighted average remaining lease term	4 years 1 month 6 days	4 years 4 months 24 days
Weighted average discount rate	3.53%	3.92%