Unaudited Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jul. 02, 2017	Jan. 01, 2017
Statement Of Financial Position [Abstract]
Allowance for doubtful accounts receivable, current	$ 40	$ 42
Accumulated amortization on other assets	$ 1,508	$ 1,420
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	24,921,672	24,784,367
Common stock, shares outstanding	22,139,456	22,012,651
Treasury stock, shares	2,782,216	2,771,716