Loss Per Share - Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Earnings Per Share [Abstract]
Net loss	$ (2,894)	$ (14,018)	$ (5,795)	$ (19,025)
Less: Dividend paid in-kind to preferred stockholders	(83)	(80)	(165)	(100)
Less: Deemed dividend on preferred stock	(126)	(136)	(247)	(3,870)
Net loss attributable to common stockholders	(3,103)	(14,234)	(6,207)	(22,995)
Loss per share - basic:
Numerator for basic loss per share	$ (3,103)	$ (14,234)	$ (6,207)	$ (22,995)
Denominator for basic loss per share (shares)	6,376,048	2,940,899	6,026,454	2,940,763
Basic loss per common share (usd per share)	$ (0.49)	$ (4.84)	$ (1.03)	$ (7.82)
Loss per share - diluted:
Numerator for basic loss per share	$ (3,103)	$ (14,234)	$ (6,207)	$ (22,995)
Plus: Warrant revaluation income for dilutive warrants	0	0	0	0
Net loss attributable to common stockholders - diluted	$ (3,103)	$ (14,234)	$ (6,207)	$ (22,995)
Denominator for basic loss per share (shares)	6,376,048	2,940,899	6,026,454	2,940,763
Incremental shares underlying dilutive in the money warrants outstanding (shares)	0	0	0	0
Denominator for diluted loss per share (shares)	6,376,048	2,940,899	6,026,454	2,940,763
Diluted net loss per common share (usd per share)	$ (0.49)	$ (4.84)	$ (1.03)	$ (7.82)