Consolidated Balance Sheets (Current Period Unaudited) (Parentheticals) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	930,000	930,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	27,539,229	27,539,229
Common stock, shares outstanding (in shares)	27,539,229	27,539,229
Series A Convertible Preferred Stock [Member]
Convertible preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Convertible preferred stock, shares authorized (in shares)	45,000	45,000
Convertible preferred stock, shares issued (in shares)	12,642	12,642
Convertible preferred stock, shares outstanding (in shares)	12,642	12,642
Convertible preferred stock, liquidation value	$ 12,642,000	$ 12,642,000
Series B Convertible Preferred Stock [Member]
Convertible preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Convertible preferred stock, shares authorized (in shares)	25,000	25,000
Convertible preferred stock, shares issued (in shares)	2,364	2,364
Convertible preferred stock, shares outstanding (in shares)	2,364	2,364
Convertible preferred stock, liquidation value	$ 2,492,722	$ 2,492,722