Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 02, 2020	Sep. 27, 2019	Oct. 02, 2020	Sep. 27, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 18,084	$ 19,633	$ 60,712	$ 63,339
Other comprehensive income (loss):
Foreign currency translation adjustments, net of tax	550	(533)	(1,052)	(657)
Unrealized gains (losses) on available- for-sale investment securities arising during the period, net of tax	(129)	(30)	(172)	373
Comprehensive income	$ 18,505	$ 19,070	$ 59,488	$ 63,055