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, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net income (loss)	$ (15,411)	$ (2,638)	$ (32,973)	$ (6,194)
Weighted average shares used to calculate net income (loss) per share, basic	39,087	38,056	38,922	37,402
Weighted average shares used to calculate net income (loss) per share, diluted	39,087	38,056	38,922	37,402
Basic (in dollars per share)	$ (0.39)	$ (0.07)	$ (0.85)	$ (0.17)
Diluted (in dollars per share)	$ (0.39)	$ (0.07)	$ (0.85)	$ (0.17)
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