Net Income (Loss) per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net income (loss)	$ 2,239	$ (5,360)	$ (4,735)	$ (10,922)
Weighted average common stock shares used in computing net income (loss) per share, basic (shares)	40,495	39,301	40,283	39,066
Effect of dilutive shares (shares)	1,073	0	0	0
Weighted average common stock shares used in computing net income (loss) per share, diluted (shares)	41,568	39,301	40,283	39,066
Net income (loss) per share, basic (usd per share)	$ 0.06	$ (0.14)	$ (0.12)	$ (0.28)
Net income (loss) per share, diluted (usd per share)	$ 0.05	$ (0.14)	$ (0.12)	$ (0.28)
Total shares excluded as anti-dilutive (shares)	2,647	6,670	5,718	6,670
Equity awards outstanding under the Equity Incentive Plan [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded as anti-dilutive (shares)	2,574	6,595	5,645	6,595
Warrant [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded as anti-dilutive (shares)	73	75	73	75