Unaudited Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 27, 2015	Dec. 28, 2014
Statement Of Financial Position [Abstract]
Allowance for doubtful accounts receivable, current	$ 46	$ 110
Accumulated amortization on other assets	$ 1,199	$ 1,067
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	24,551,384	24,445,345
Common stock, shares outstanding	22,008,255	22,180,458
Treasury stock, shares	2,543,129	2,264,887