Net Loss Per Share (Computation of Loss Per Share) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Numerators:
Loss from continuing operations attributable to common stockholders	$ (4,263)	$ (2,324)	$ (3,334)	$ (3,743)	$ (2,675)	$ (2,445)	$ (2,377)	$ (12,620)	$ (13,664)	$ (20,117)	$ (8,555)
Income (loss) from discontinued operations attributable to common stockholders	0	0	0	0	0	0	0	0	0	0	(642)
Preferred stock dividends and accretion	0	0	0	0	(204)	(445)	(440)	(435)	0	(1,524)	(98)
Net loss attributable to common shareholders	$ (4,263)	$ (2,324)	$ (3,334)	$ (3,743)	$ (2,879)	$ (2,890)	$ (2,817)	$ (13,055)	$ (13,664)	$ (21,641)	$ (9,295)
Denominator:
Weighted–average common shares outstanding, basic and diluted									14,939,601	4,889,901	1,196,668
Loss from continuing operations per share, basic and diluted (in USD per share)									$ (0.91)	$ (4.43)	$ (7.23)
Loss from discontinued operations per share, basic and diluted (in USD per share)									0.00	0.00	(0.54)
Net loss per common share, basic and diluted (in USD per share)	$ (0.28)	$ (0.16)	$ (0.22)	$ (0.25)	$ (0.30)	$ (0.80)	$ (0.80)	$ (4.48)	$ (0.91)	$ (4.43)	$ (7.77)