Net Loss per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Net loss - Basic	$ (5,764)	$ (13,623)	$ (16,842)	$ (25,981)
Change in fair value of warrant liability	(3,513)	3,895	(3,015)	8,047
Net loss - Dilutive	$ (9,277)	$ (13,623)	$ (19,857)	$ (25,981)
Weighted Average Number of Shares Outstanding, Basic, Total	91,015,733	72,736,829	90,921,243	72,674,650
Dilutive shares related to warrants	2,914,807		1,729,974
Weighted Average Number of Shares Outstanding, Diluted, Total	93,930,540	72,736,829	92,651,215	72,674,650
Earnings Per Share, Basic, Total	$ (0.06)	$ (0.19)	$ (0.18)	$ (0.36)
Earnings Per Share, Diluted, Total	$ (0.10)	$ (0.19)	$ (0.21)	$ (0.36)