Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 65,077	$ 51,417	$ 50,519
Other comprehensive income – unrealized gain on available-for-sale marketable debt securities, net of income tax	0	14	20
Comprehensive income	$ 65,077	$ 51,431	$ 50,539