Condensed Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Treasury Stock [Member]	Total
Balance at Dec. 31, 2019		$ 50	$ 258,767	$ (240,610)	$ (500)	$ 17,707
Balance, shares at Dec. 31, 2019	5,659	50,250,378
Stock based compensation			43			43
Public offering of common shares, net of offering costs		$ 4	1,548			1,552
Public offering of common shares, net of offering costs, shares		3,730,540
Net loss				(1,369)		(1,369)
Balance at Mar. 31, 2020		$ 54	260,358	(241,979)	(500)	17,933
Balance, shares at Mar. 31, 2020	5,659	53,980,918
Balance at Dec. 31, 2020		$ 69	268,729	(252,058)	(500)	16,240
Balance, shares at Dec. 31, 2020	5,659	68,890,819
Exercising of options			364			$ 364
Exercising of options, shares		227,792				244,651
Stock based compensation			13			$ 13
Exercise of common stock warrants		$ 3	5,059			5,062
Exercise of common stock warrants, shares		3,019,247
Net loss				(7,378)		(7,378)
Balance at Mar. 31, 2021		$ 72	$ 274,165	$ (259,436)	$ (500)	$ 14,301
Balance, shares at Mar. 31, 2021	5,659	72,137,858