Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Apr. 02, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Reserves for accounts receivable	$ 941	$ 873
Common stock, par value	$ 0.002	$ 0.002
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	86,646,000	85,939,000