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														(3,016)	(3,016)
Issuance of common shares												[1]	6,942		6,942
Issuance of common shares, shares											77,143
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													274		274
Conversion of Series B Preferred Stock to common shares, shares	(9,772)										1,613
Classification of preferred shares													(3,200)		(3,200)
Conversion of Series C Preferred Stock to common shares				[1]								[1]	936		936
Conversion of Series C Preferred Stock to common shares, shares			(315,936)								18,416
Exercise of Unit Purchase Option												[1]	557		557
Exercise of Unit Purchase Option, shares											2,229
Accretion of redeemable preferred shares													(438)		(438)
Share-based compensation related to restricted stock and stock options award, net of forfeitures of shares													66		66
Share-based compensation related to restricted stock and stock options award, net of forfeitures of shares, shares											(2)
Redemption of Series C Preferred Stock				[1]									(300)		(300)
Redemption of Series C Preferred Stock, shares			(46,875)
Balance at Jun. 30, 2018		[1]		[1]		[1]						[1]	147,466	(143,368)	4,098
Balance, shares at Jun. 30, 2018	17,303		378,840		300						129,505
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
Net loss														(627)	(627)
Issuance of common shares												[1]	4,438		4,438
Issuance of common shares, shares											57,143
Accretion of redeemable preferred shares													(485)		(485)
Share-based compensation related to restricted stock and stock options award, net of forfeitures of shares													28		28
Share-based compensation related to restricted stock and stock options award, net of forfeitures of shares, shares											(2)
Redemption of Series C Preferred Stock				[1]									(300)		(300)
Redemption of Series C Preferred Stock, shares			(46,875)
Conversion of Series C Convertible Preferred Stock to common shares				[1]								[1]
Conversion of Series C Convertible Preferred Stock to common shares, shares			(25,980)								1,901
Balance at Jun. 30, 2018		[1]		[1]		[1]						[1]	147,466	(143,368)	4,098
Balance, shares at Jun. 30, 2018	17,303		378,840		300						129,505
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														(5,413)	(5,413)
Issuance of common shares												[1]	2,030		2,030
Issuance of common shares, shares											499,350
Share-based compensation related to restricted stock and stock options award, net of forfeitures of shares												[1]	178		178
Share-based compensation related to restricted stock and stock options award, net of forfeitures of shares, shares											69,886
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]		[1]
Conversion of Series C Convertible Preferred Stock to common shares, shares									(22,617)		27,248
Balance at Jun. 30, 2019								[1]		[1]		[1]	158,579	(153,005)	5,574
Balance, shares at Jun. 30, 2019							17,303		38,806		1,397,133
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
Net loss														(2,206)	(2,206)
Issuance of common shares												[1]	2,030		2,030
Issuance of common shares, shares											499,350
Share-based compensation related to restricted stock and stock options award, net of forfeitures of shares												[1]	110		110
Share-based compensation related to restricted stock and stock options award, net of forfeitures of shares, shares											(483)
Conversion of Series C Convertible Preferred Stock to common shares
Conversion of Series C Convertible Preferred Stock to common shares, shares									(20,617)		26,394
Balance at Jun. 30, 2019								[1]		[1]		[1]	$ 158,579	$ (153,005)	$ 5,574
Balance, shares at Jun. 30, 2019							17,303		38,806		1,397,133

[1] Represents an amount less than $1 thousand