Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 27, 2019	Sep. 28, 2018	Sep. 27, 2019	Sep. 28, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net income	$ 19,633	$ 17,453	$ 63,339	$ 56,218
Other comprehensive income (loss):
Foreign currency translation adjustments, net of tax	(533)	(304)	(657)	(933)
Unrealized gains (losses) on available- for-sale investment securities arising during the period, net of tax	(30)	(31)	373	(52)
Comprehensive income	$ 19,070	$ 17,118	$ 63,055	$ 55,233

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

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