Quarterly report pursuant to Section 13 or 15(d)

Note 10 - Shareholders' Equity (Details Textual)

v3.19.2
Note 10 - Shareholders' Equity (Details Textual) - USD ($)
 6 Months Ended
Mar. 29, 2018
Jun. 30, 2019
Jun. 30, 2018
Dec. 31, 2018
Common Stock, No Par Value   $ 0   $ 0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period     16,954  
Stock Issued During Period, Shares, Exercise of Common Stock Warrants     122,606  
Proceeds from Warrant Exercises   $ 490,000  
Proceeds from Stock Options Exercised   $ 75,000 $ 43,000  
Warrants Issued in Private Placement [Member]        
Stock Issued During Period, Shares, Exercise of Common Stock Warrants   0    
Class of Warrant or Right, Issued During Period 661,482      
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 $ 7      
Warrants and Rights Outstanding, Expiration, Stock Price Trigger $ 12      
Compensation Warrants [Member]        
Class of Warrant or Right, Issued During Period 80,510      
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 $ 4.90      
Warrants and Rights Outstanding, Term 2 years      
Private Placement [Member]        
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period   50,000    
Stock Issued During Period, Value, Stock Options Exercised   $ 75,000    
Units Issued During Period, Units, New Issues 1,322,965      
Shares Issued, Price Per Share $ 4.90      
Proceeds From Issuance of Units $ 6,300,000      
Units, Number of Common Shares Per Unit 1      
Units, Number of Common Share Purchase Warrant Per Unit 0.5      
Payment for Finders Fee $ 384,000