Components of and Changes in Accumulated Other Comprehensive Income, Net of Related Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 30, 2019	Mar. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ 686,824
Other comprehensive income (loss)	1,549	$ (389)
Ending Balance	728,260
Unrealized Holding (Losses) Gains on Available-for-Sale Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(930)
Other comprehensive income (loss)	995
Ending Balance	65
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(4,945)
Other comprehensive income (loss)	554
Ending Balance	(4,391)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(5,875)
Ending Balance	$ (4,326)