Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jul. 01, 2017	Jun. 30, 2018	Jul. 01, 2017
Consolidated Statements of Comprehensive Income [Abstract]
Net income	$ 19,095	$ 18,475	$ 35,286	$ 30,311
Other comprehensive income (loss) by component, net of tax:
Unrealized holding losses arising during period (Net of deferred taxes of $14 and $137, respectively for the thirteen Weeks Ended and $172 and $126, respectively for the twenty six Weeks Ended)	(42)	(198)	(445)	(134)
Reclassification adjustment for losses included in net income (Net of deferred taxes of $15 and $0, respectively for the twenty six Weeks Ended)			39
Other comprehensive loss, net of tax	(42)	(198)	(406)	(134)
Comprehensive income, net of tax	$ 19,053	$ 18,277	$ 34,880	$ 30,177