Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 541	$ 535
Preferred stock, shares authorized	500,000	500,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	75,000,000	75,000,000
Common stock, shares issued	40,198,000	40,097,000
Common stock, shares outstanding	40,198,000	40,097,000