Components of and Changes in Accumulated Other Comprehensive Income, Net of Related Income Taxes (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 26, 2021	Jun. 27, 2020	Jun. 26, 2021	Jun. 27, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			$ 691,835
Other comprehensive (loss) gain	$ 1,101	$ 4,548	147	$ (4,933)
Ending Balance	830,173		830,173
Unrealized Holding (Losses) Gains on Available-for-Sale Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			2,808
Other comprehensive (loss) gain			(883)
Ending Balance	1,925		1,925
Foreign Currency Translation
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(4,807)
Other comprehensive (loss) gain			1,030
Ending Balance	(3,777)		(3,777)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(1,999)
Other comprehensive (loss) gain			147
Ending Balance	$ (1,852)		$ (1,852)