Condensed Consolidated Statements of Stockholder's Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Treasury Stock [Member]
Balance at Dec. 31, 2019	$ 34,893	$ 50	$ 41,576	$ (6,153)	$ (580)
Balance (in shares) at Dec. 31, 2019		4,933,063
Net income	183			183
Exercise of stock options	58		58
Exercise of stock options (in shares)		14,000
At-the-market stock sales, net of costs	3,254	$ 3	3,251
At-the-market stock sales, net of costs (in shares)		263,725
Stock-based compensation	10		10
Balance at Mar. 31, 2020	38,398	$ 53	44,895	(5,970)	(580)
Balance (in shares) at Mar. 31, 2020		5,210,788
Balance at Dec. 31, 2020	$ 39,765	$ 53	45,477	(5,185)	(580)
Balance (in shares) at Dec. 31, 2020	5,272,204	5,272,204
Net income	$ 27			27
Stock-based compensation	78		78
Balance at Mar. 31, 2021	$ 39,870	$ 53	$ 45,555	$ (5,158)	$ (580)
Balance (in shares) at Mar. 31, 2021	5,272,204	5,272,204