Loss Per Share - (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share [Abstract]
Net loss	$ (10,277)	$ (16,240)
Less: Dividend paid in-kind to preferred stockholders	(336)	(264)
Less: Deemed dividend on preferred stock	(513)	(4,099)
Earnings Per Share, Basic [Abstract]
Net loss	$ (11,126)	$ (20,603)
Denominator for basic loss per share (in shares)	7,693,191	3,092,543
Basic loss per common share (in dollars per share)	$ (1.45)	$ (6.66)
Earnings Per Share, Diluted [Abstract]
Numerator for basic loss per share	$ (11,126)	$ (20,603)
Warrant revaluation income (expense) for dilutive warrants	0	(34)
Numerator for diluted loss per share	$ (11,126)	$ (20,637)
Denominator for basic loss per share (in shares)	7,693,191	3,092,543
Incremental shares underlying in the money warrants outstanding (in shares)	0	1,184
Denominator for diluted loss per share (in shares)	7,693,191	3,093,727
Diluted net income (loss) per share (in dollars per share)	$ (1.45)	$ (6.67)