Unaudited Condensed Consolidated Statements of Changes in Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Preferred Stock [Member]	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]	Total
Beginning balance, shares at Dec. 31, 2019	949	13,552
Beginning balance, value at Dec. 31, 2019	$ 1,843	$ 136	$ (362)	$ 56,759	$ (54,777)	$ (43)	$ 3,556
Conversion of preferred shares to common shares, shares converted	(63)	63
Conversion of preferred shares to common shares, value	$ (96)	$ 1		95
Stock-based compensation				19
Exercise of stock options, shares		173
Exercise of stock options, value		$ 1		74
Preferred stock dividends declared, net of waived penalties by shareholders				(33)
Net loss					(465)		(465)
Ending balance, shares at Mar. 31, 2020	886	13,788
Ending balance, value at Mar. 31, 2020	$ 1,747	$ 138	(362)	56,914	(55,242)	(43)	3,152
Beginning balance, shares at Dec. 31, 2020	0	17,428
Beginning balance, value at Dec. 31, 2020	$ 0	$ 174	(362)	77,187	(61,295)	(43)	15,661
Conversion of preferred shares to common shares, value
Stock-based compensation				204
Exercise of stock options, shares		197
Exercise of stock options, value		$ 2		159
Preferred stock dividends declared, net of waived penalties by shareholders
Net loss					(3,903)		(3,903)
Ending balance, shares at Mar. 31, 2021	0	17,625
Ending balance, value at Mar. 31, 2021	$ 0	$ 176	$ (362)	$ 77,550	$ (65,198)	$ (43)	$ 12,123