Consolidated Statements of Changes in Equity (Unaudited) - USD ($) $ in Thousands	Series B Preferred Stock [Member]		Series C Preferred Stock [Member]		Series D Preferred Stock [Member]		Series B Convertible Preferred Stock [Member]		Series C Convertible Preferred Stock [Member]		Common Stock [Member]		Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Total
Balance at Dec. 31, 2017		[1]		[1]		[1]						[1]	$ 143,079	$ (140,352)	$ 2,727
Balance, shares at Dec. 31, 2017	27,075		741,651		750						30,106
Net loss														(2,389)	(2,389)
Issuance of common shares, net of $496 issuance costs												[1]	2,504		2,504
Issuance of common shares, net of $496 issuance costs, shares											20,000
Redemption of Series D Preferred Stock						[1]							(450)		(450)
Redemption of Series D Preferred Stock, shares					(450)
Conversion of Series B Preferred Stock to common shares		[1]										[1]	274		274
Conversion of Series B Preferred Stock to common shares, shares	(9,772)										1,613
Conversion of Series C Preferred Stock to common shares				[1]								[1]	936		936
Conversion of Series C Preferred Stock to common shares, shares			(289,956)								16,515
Classification of preferred shares													(3,200)		(3,200)
Accretion of redeemable preferred shares													47		47
Exercise of Unit Purchase Option												[1]	557		557
Exercise of Unit Purchase Option, shares											2,229
Share-based compensation related to restricted stock and stock options award													38		38
Balance at Mar. 31, 2018		[1]		[1]		[1]						[1]	143,785	(142,741)	1,044
Balance, shares at Mar. 31, 2018	17,303		451,695		300						70,463
Balance at Dec. 31, 2018								[1]		[1]		[1]	156,355	(147,592)	8,763
Balance, shares at Dec. 31, 2018							17,303		61,423		768,615
Net loss														(3,207)	(3,207)
Issuance of common shares, net of $496 issuance costs											$ 16,017
Issuance of common shares, net of $496 issuance costs, shares											32,034
Exercise of pre-funded warrants												[1]	16		16
Exercise of pre-funded warrants, shares											32,034
Conversion of Series C Convertible Preferred Stock to common shares										[1]
Conversion of Series C Convertible Preferred Stock to common shares, shares									(2,000)		854
Share-based compensation related to restricted stock and stock options award												[1]	68		68
Share-based compensation related to restricted stock and stock options award, shares											70,369
Balance at Mar. 31, 2019								[1]		[1]		[1]	$ 156,439	$ (150,799)	$ 5,640
Balance, shares at Mar. 31, 2019							17,303		59,423		871,872

[1] Represents an amount less than $1 thousand