Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jul. 01, 2017	Dec. 31, 2016
Statement Of Financial Position [Abstract]
Allowance for doubtful accounts, accounts receivable	$ 313	$ 101
Preferred stock, shares authorized	2,000,000	2,000,000
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares outstanding	0	0
Common stock, shares authorized	50,000,000	50,000,000
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares outstanding	27,050,779	26,936,021