Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 04, 2015	Jun. 28, 2014	Jul. 04, 2015	Jun. 28, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 11,038	$ 8,481	$ 39,837	$ 25,473
Other comprehensive (loss) income– unrealized (loss) gain on available-for-sale marketable debt securities, net of income tax	(20)	20	52	30
Comprehensive income	$ 11,018	$ 8,501	$ 39,889	$ 25,503