Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019
Consolidated Statements of Comprehensive Income [Abstract]
Net income	$ 41,472	$ 20,475	$ 68,161	$ 34,780
Available-for-sale marketable securities
Unrealized holding gains (losses) arising during period (Net of deferred taxes of $396 and $179, respectively for the thirteen weeks ended and $433 and $423, respectively for the twenty-six weeks ended)	1,023	454	1,118	1,075
Reclassification adjustment for (gains) losses included in net income (Net of deferred taxes of $2 and $0, respectively for the thirteen weeks ended and $0 and $0, respectively for the twenty-six weeks ended)	6
Other comprehensive income gain (loss), net of tax	1,029	454	1,118	1,075
Comprehensive income, net of tax	$ 42,501	$ 20,929	$ 69,279	$ 35,855