Effect of Recording Equity-Based Compensation (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 30, 2017	Dec. 31, 2016	Jan. 02, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation	$ 4,178	$ 3,744	$ 3,620
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation	1,176	880	963
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation	2,598	2,190	1,711
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Equity-based compensation	$ 404	$ 674	$ 946