Loss Per Share - Earnings 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
Loss per share - basic:
Numerator for basic loss per share	$ (8,092)	$ (6,756)	$ (9,499)	$ (15,281)
Denominator for basic loss per share (shares)	43,898,785	40,889,732	43,898,785	40,875,704
Basic loss per common share (usd per share)	$ (0.18)	$ (0.17)	$ (0.22)	$ (0.37)
Loss per share - diluted:
Numerator for diluted loss per share	$ (8,092)	$ (6,756)	$ (9,499)	$ (15,281)
Adjust: Warrant revaluation income (expense) for dilutive warrants	0	0	1,958	0
Net loss attributable to common share	$ (8,092)	$ (6,756)	$ (11,457)	$ (15,281)
Denominator for basic loss per share (shares)	43,898,785	40,889,732	43,898,785	40,875,704
Plus: Incremental shares underlying dilutive warrants outstanding (shares)	0	0	36,034	0
Denominator for diluted loss per share (shares)	43,898,785	40,889,732	43,934,819	40,875,704
Diluted net loss per common share (usd per share)	$ (0.18)	$ (0.17)	$ (0.26)	$ (0.37)