CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Deficit [Member]	Total
Balance at beginning at Dec. 31, 2017		$ 338	$ 98,563	$ (95,669)	$ 3,232
Balance at beginning (in shares) at Dec. 31, 2017		33,847,793
Stock option exercises		$ 1	28		29
Stock option exercises (in shares)		63,999
Stock-based compensation			204		204
Net loss				(2,081)	(2,081)
Balance at ending at Dec. 31, 2018		$ 339	98,795	(97,750)	1,384
Balance at ending (in shares) at Dec. 31, 2018		33,911,792
Sale of common stock		$ 42	1,635		1,677
Sale of common stock (in shares)		4,189,000
Stock option exercises			14		14
Stock option exercises (in shares)		36,000
Stock-based compensation			242		242
Net loss				(3,006)	(3,006)
Balance at ending at Dec. 31, 2019		$ 381	$ 101,886	$ (100,756)	$ 1,511
Balance at ending (in shares) at Dec. 31, 2019		38,136,792