CONSOLIDATED STATEMENT OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Series A-2 Preferred Stock	Series D Preferred Stock	Preferred Stock Series A-2 Preferred Stock	Preferred Stock Series B Preferred Stock	Preferred Stock Series C Preferred Stock	Preferred Stock Series D Preferred Stock	Preferred Stock Series E Preferred Stock	Common Stock	Common Stock Series C Preferred Stock	Treasury Stock	Additional Paid-In Capital	Accumulated Deficit
Beginning Balance (in shares) at Dec. 31, 2018				32	75	525	0	0	5,114,000		133,000
Beginning Balance at Dec. 31, 2018	$ 6,830			$ 0	$ 0	$ 0	$ 0	$ 0	$ 1		$ (496)	$ 184,998	$ (177,673)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(7,761)												(7,761)
Stock-based compensation	110										$ (51)	110
Issuance of preferred stock in merger (in shares)							1,736,626
Issuance of preferred stock in merger	$ 18,862											18,862
Forfeiture of preferred stock (in shares)	(10,063)						(1,725)
Preferred stock conversion (in shares)					75	50			43,919	16,667
Preferred stock dividends	$ 27											27
Issuance of stock on vested restricted stock units (in shares)									109,000		(76,000)
Issuance of stock on vested restricted stock units	0										$ 382	(382)
Proceeds from Series E equity offering (in shares)								131,579
Proceeds from Series E equity offering	3,750											3,750
Series D exchanged for taxes (in shares)											(48,000)
Preferred stock dividends	(27)											(27)
Forfeiture of restricted stock agreement (in shares)									0
Repurchase of treasury stock (in shares)											48,000
Repurchase of treasury stock	(51)										$ (51)
Issuance of warrants to purchase common stock in connection with long term debt	72											72
Ending Balance (in shares) at Dec. 31, 2019				32	0	475	1,734,901	131,579	5,267,000		105,000
Ending Balance at Dec. 31, 2019	21,785			$ 0	$ 0	$ 0	$ 0	$ 0	$ 1		$ (165)	207,383	(185,434)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(7,421)												(7,421)
Stock-based compensation (in shares)									8,000
Stock-based compensation	198										$ (16)	198
Issuance of preferred stock for accrued dividends (in shares)				13
Issuance of preferred stock for accrued dividends	99											99
Forfeiture of preferred stock (in shares)							(28,618)
Preferred stock conversion (in shares)		13	1,686,659			475			158,333	158,333
Preferred stock dividends	17											17
Issuance of stock on vested restricted stock units (in shares)									23,000		8,000
Issuance of stock on vested restricted stock units	(16)										$ (16)
Series D exchanged for taxes (in shares)							(8,325)				(8,000)
Preferred stock dividends	(17)											(17)
Forfeiture of restricted stock agreement (in shares)									(9,321)
Issuance of common shares from financing, net of offering costs (in shares)									2,293,000
Issuance of common shares from financing, net of offering costs	7,371											7,371
Issuance of common shares from warrant exercise (in shares)									72,000
Issuance of warrants to purchase common stock in connection with long term debt												72
Issuance of shares for professional service fees (in shares)									50,000
Issuance of shares for professional service fees	58											58
Ending Balance (in shares) at Dec. 31, 2020				45	0	0	1,697,958	131,579	7,862,000		113,000
Ending Balance at Dec. 31, 2020	$ 22,057			$ 0	$ 0	$ 0	$ 0	$ 0	$ 1		$ (181)	$ 215,092	$ (192,855)