Net Loss Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended					3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Dec. 31, 2013 Convertible Debt	Dec. 10, 2013 Convertible Debt	Sep. 30, 2014 Common stock options	Sep. 30, 2013 Common stock options	Sep. 30, 2014 Common stock options	Sep. 30, 2013 Common stock options	Sep. 30, 2014 Restricted Stock	Sep. 30, 2013 Restricted Stock	Sep. 30, 2014 Restricted Stock	Sep. 30, 2013 Restricted Stock	Sep. 30, 2014 Restricted stock units	Sep. 30, 2013 Restricted stock units	Sep. 30, 2014 Restricted stock units	Sep. 30, 2013 Restricted stock units
Earnings Per Share, Basic and Diluted [Abstract]
Net Income (Loss) Attributable to Parent	$ (13,938)	$ (8,990)	$ (17,636)	$ (12,655)
Shares used in computing basic and diluted net loss per share (shares)	65,494	62,730	63,444	62,407
Basic and diluted loss per share (in dollars per share)	$ (0.21)	$ (0.14)	$ (0.28)	$ (0.20)
Weighted Average Number of Shares Outstanding, Diluted [Abstract]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	2,218	3,017	2,432	3,024				1,816	2,390	1,881	2,411	240	398	360	394	162	229	191	219
Convertible notes	$ 69,554		$ 69,554		$ 67,101		$ 86,300
Stated interest rate						2.25%
Potential Dilutive Effect of Securities [Abstract]
Conversion of the Notes	3,588	0	3,588	0