Condensed Consolidated Balance Sheets (Parenthetical) (Unaudited) - USD ($) $ in Thousands	Jul. 01, 2017	Dec. 31, 2016
Statement Of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 240	$ 230
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	2,000,000	2,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	30,000,000	30,000,000
Common stock, shares issued	11,559,444	11,304,736
Common stock, shares outstanding	11,559,444	11,304,736