Property and Equipment (Detail) - USD ($) $ in Thousands	Dec. 30, 2017	Dec. 31, 2016
Property Plant And Equipment [Abstract]
Equipment	$ 70,126	$ 63,597
Leasehold improvements	71,469	68,959
Property, Plant and Equipment, Gross, Total	141,595	132,556
Less: Accumulated depreciation and amortization	(93,617)	(82,982)
Property and equipment, net	$ 47,978	$ 49,574