Annual report pursuant to Section 13 and 15(d)

Note 10 - Warrant Liability (Details Textual)

v3.20.1
Note 10 - Warrant Liability (Details Textual)
 1 Months Ended 12 Months Ended
Mar. 29, 2018
$ / shares
shares
Feb. 29, 2016
USD ($)
Feb. 28, 2018
USD ($)
shares
Feb. 29, 2016
$ / shares
shares
Dec. 31, 2019
USD ($)
shares
Dec. 31, 2018
USD ($)
shares
Dec. 31, 2017
USD ($)
Feb. 29, 2016
USD ($)
shares
Proceeds from Warrant Exercises | $         $ 607,000    
Warrants and Rights Outstanding | $           $ 84,000  
Stock Issued During Period, Shares, Exercise of Common Stock Warrants           128,594    
Warrants Issued in Private Placement [Member]                
Class of Warrant or Right, Outstanding               117,188
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right 1              
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares $ 7              
Stock Issued During Period, Shares, Exercise of Common Stock Warrants         0      
Compensation Warrants Issued In Connection With Private Placement [Member]                
Class of Warrant or Right, Outstanding               10,915
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right               1
Class of Warrant or Right, Exercise Price of Warrants or Rights | $ / shares       $ 5        
Proceeds from Warrant Exercises | $   $ 281,000 $ 483,000          
Warrants and Rights Outstanding | $               $ 24,000
Stock Issued During Period, Shares, Exercise of Common Stock Warrants     121,256          
Class of Warrant or Right, Warrants Expired During Period     4,346          
Compensation Warrants Issued In Connection With Private Placement [Member] | Measurement Input, Price Volatility [Member]                
Warrants and Rights Outstanding, Measurement Input     0.167          
Compensation Warrants Issued In Connection With Private Placement [Member] | Measurement Input, Price Volatility [Member] | Minimum [Member]                
Warrants and Rights Outstanding, Measurement Input               1.918
Compensation Warrants Issued In Connection With Private Placement [Member] | Measurement Input, Price Volatility [Member] | Maximum [Member]                
Warrants and Rights Outstanding, Measurement Input               2.25
Compensation Warrants Issued In Connection With Private Placement [Member] | Measurement Input, Risk Free Interest Rate [Member]                
Warrants and Rights Outstanding, Measurement Input     0.018          
Compensation Warrants Issued In Connection With Private Placement [Member] | Measurement Input, Risk Free Interest Rate [Member] | Minimum [Member]                
Warrants and Rights Outstanding, Measurement Input               0.0043
Compensation Warrants Issued In Connection With Private Placement [Member] | Measurement Input, Risk Free Interest Rate [Member] | Maximum [Member]                
Warrants and Rights Outstanding, Measurement Input               0.0049
Compensation Warrants Issued In Connection With Private Placement [Member] | Measurement Input, Expected Term [Member]                
Warrants and Rights Outstanding, Measurement Input               2
Compensation Warrants Issued In Connection With Private Placement [Member] | Measurement Input, Expected Term [Member] | Minimum [Member]                
Warrants and Rights Outstanding, Measurement Input     0.01          
Compensation Warrants Issued In Connection With Private Placement [Member] | Measurement Input, Expected Term [Member] | Maximum [Member]                
Warrants and Rights Outstanding, Measurement Input     0.03          
Private Placement [Member]                
Units Issued During Period, Units, New Issues 1,322,965     234,375        
Units, Number of Common Shares Per Unit 1             1
Units, Number of Common Share Purchase Warrant Per Unit 0.5             0.5