Net Income (Loss) per Share (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
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Net Income (Loss) Attributable to Parent	$ 1,437	$ 5,394	$ (3,298)	$ (5,528)
Weighted average common stock shares used in computing net income (loss) per share, basic (shares)	40,940	39,767	40,504	39,340
Effect of dilutive shares (shares)	1,194	1,203	0	0
Weighted average common stock shares used in computing net income (loss) per share, diluted (shares)	42,134	40,970	40,504	39,340
Net income (loss) per share, basic (usd per share)	$ 0.04	$ 0.14	$ (0.08)	$ (0.14)
Net income (loss) per share, diluted (usd per share)	$ 0.03	$ 0.13	$ (0.08)	$ (0.14)
Total shares excluded as anti-dilutive (shares)	2,222	2,395	5,444	6,196
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)	2,149	2,320	5,371	6,121
Warrant [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total shares excluded as anti-dilutive (shares)	73	75	73	75