Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 28, 2019	Dec. 29, 2018	Dec. 30, 2017
Consolidated Statements of Comprehensive Income [Abstract]
Net income	$ 67,983	$ 62,738	$ 98,414
Available-for-sale marketable securities
Unrealized holding gains (losses) arising during period (Net of deferred taxes of $498, $62 and $19, respectively)	1,255	(177)	(43)
Accumulated change in effective tax rate			1,042
Reclassification adjustment for (gains) losses included in net income (Net of deferred taxes of $14, $14 and $11, respectively)	(37)	40	29
Other comprehensive income (loss), net of tax	1,218	(137)	1,028
Comprehensive income, net of tax	$ 69,201	$ 62,601	$ 99,442