Stockholders' Equity - Components of Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 29, 2017	Sep. 30, 2016	Sep. 29, 2017	Sep. 30, 2016	Dec. 31, 2016
Equity [Abstract]
Foreign currency translation adjustments	$ (120)		$ (120)		$ (7,267)
Unrealized gain on investments	(331)		(331)		276
Actuarial Loss	(279)		(279)		(279)
Accumulated Other Comprehensive Loss	(730)		(730)		$ (7,270)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, before Tax	2,265	$ 523	7,147	$ (154)
Other Comprehensive Income (Loss), Available-for-sale Securities Adjustment, before Tax	$ 8	$ (1,208)	(605)	$ (1,178)
Other Comprehensive Income (Loss), before Reclassifications, before Tax			6,542
Other Comprehensive Income (Loss), Foreign Currency Translation Gain (Loss) Arising During Period, Tax			0
Other Comprehensive Income (Loss), Available-for-sale Securities, Tax			(2)
Other Comprehensive Income (Loss), Tax, Portion Attributable to Parent			$ (2)