Basic and Diluted Net Income (Loss) Per Share - Earnings (Loss) Per Share Calculation (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net income (loss)	$ (7,053)	$ (10,434)
Interest on convertible notes, net of tax benefit	0	0
Net income (loss), diluted	$ (7,053)	$ (10,434)
Weighted average shares used to calculate net income (loss) per share, basic	36,649	29,864
Effect of convertible notes	0	0
Weighted average shares used to calculate net income (loss) per share, diluted	36,649	29,864
Basic (in dollars per share)	$ (0.19)	$ (0.35)
Diluted (in dollars per share)	$ (0.19)	$ (0.35)
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
Stock Options [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Effect of dilutive equity awards	0	0