Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	100,000	100,000
Common stock, par value	$ 0.006	$ 0.006
Common stock, shares authorized	180,000,000	180,000,000
Common stock, shares issued	11,112,708	10,869,530
Common stock, shares outstanding	11,112,708	10,869,530
Series C Convertible Preferred Stock [Member]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	1,200	1,200
Preferred stock, liquidation preference value	$ 5,100	$ 5,100
Preferred stock, shares issued	100	100
Preferred stock, shares outstanding	100	100
Series D Convertible Preferred Stock [Member]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	220	220
Preferred stock, liquidation preference value	$ 300	$ 300
Preferred stock, shares issued	40	40
Preferred stock, shares outstanding	40	40
Series E Convertible Preferred Stock [Member]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	3,500	3,500
Preferred stock, liquidation preference value	$ 5,000	$ 5,000
Preferred stock, shares issued	3,458	3,478
Preferred stock, shares outstanding	3,458	3,478
Series F Convertible Preferred Stock [Member]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	2,200	2,200
Preferred stock, liquidation preference value	$ 5,000	$ 5,000
Preferred stock, shares issued	361	361
Preferred stock, shares outstanding	361	361
Series G Convertible Preferred Stock [Member]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	6,000	6,000
Preferred stock, liquidation preference value	$ 5,000	$ 5,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0