Basic and Diluted Net Income (Loss) Per Share - Earnings (Loss) Per Share Calculation (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net income (loss)	$ (2,638)	$ (2,066)	$ (6,194)	$ (13,238)
Weighted average shares used to calculate net income (loss) per share, basic	38,056	36,830	37,402	36,740
Weighted average shares used to calculate net income (loss) per share, diluted	38,056	36,830	37,402	36,740
Basic (in dollars per share)	$ (0.07)	$ (0.06)	$ (0.17)	$ (0.36)
Diluted (in dollars per share)	$ (0.07)	$ (0.06)	$ (0.17)	$ (0.36)
Restricted Stock Units (RSUs) [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Effect of dilutive equity awards	0	0	0	0
Stock Options [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Effect of dilutive equity awards	0	0	0	0