CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Preferred Stock [Member] Convertible Preferred Stock - Series C [Member]	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Total
Beginning balance at Dec. 31, 2018	$ 1	$ 30	$ 241,988	$ (210,771)	$ 31,248
Beginning balance (in shares) at Dec. 31, 2018	9,968	29,943,086
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	$ 0	$ 0	323	0	323
Conversion of convertible preferred stock into common stock	$ 0	$ 1	(1)	0	0
Conversion of convertible preferred stock into common stock (in shares)	(3,090)	1,148,698
Exercise of stock options	$ 0	$ 0	0	0	0
Exercise of stock options (in shares)	0	28,824
Net loss	$ 0	$ 0	0	(1,333)	(1,333)
Ending balance at Mar. 31, 2019	$ 1	$ 31	242,310	(212,104)	30,238
Ending balance (in shares) at Mar. 31, 2019	6,878	31,120,608
Beginning balance at Dec. 31, 2019	$ 1	$ 33	243,180	(214,561)	28,653
Beginning balance (in shares) at Dec. 31, 2019	2,103	32,932,273
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	$ 0	$ 0	430	0	430
Conversion of convertible preferred stock into common stock	$ (1)	$ 1	0	0	0
Conversion of convertible preferred stock into common stock (in shares)	(2,103)	782,089
Net loss	$ 0	$ 0	0	(1,035)	(1,035)
Ending balance at Mar. 31, 2020	$ 0	$ 34	$ 243,610	$ (215,596)	$ 28,048
Ending balance (in shares) at Mar. 31, 2020	0	33,714,362