Schedule for Gross Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016
Income Tax Disclosure [Line Items]
Gross unrecognized tax benefits - beginning of the year	$ 2,635	$ 2,704
Gross increases related to current year tax positions	645	428
Gross increases related to prior year tax positions	2,189	596
Gross decreases related to prior year tax positions	(75)	(399)
Settlements	(100)	(133)
Lapse of statute of limitations	(482)	(561)
Gross unrecognized tax benefits - end of the year	$ 4,812	$ 2,635