Quarterly report pursuant to Section 13 or 15(d)

Note 10 - Shareholders' Equity (Details Textual)

v3.20.2
Note 10 - Shareholders' Equity (Details Textual) - USD ($)
 3 Months Ended 9 Months Ended
Aug. 10, 2020
Feb. 13, 2020
Mar. 31, 2020
Jun. 30, 2019
Sep. 30, 2020
Sep. 30, 2019
Sep. 11, 2020
Stock Issued During Period, Shares, New Issues (in shares) 4,600,000 2,125,000          
Shares Issued, Price Per Share (in dollars per share) $ 5 $ 4          
Proceeds from Issuance of Common Stock $ 23,000,000 $ 8,500,000     $ 28,872,000  
Proceeds from Issuance of Common Stock, Net $ 21,200,000 $ 7,700,000          
Stock Issued During Period, Value, Stock Options Exercised     $ 16,000 $ 75,000      
Private Placement [Member]              
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period (in shares)         7,200 50,000  
Stock Issued During Period, Value, Stock Options Exercised         $ 16,000 $ 75,000  
Warrant Issued for Strategic Advisory Services [Member] | Craig-Hallum Capital Group LLC [Member]              
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)             10,000
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share)             $ 4
Warrants Issued in Private Placement [Member]              
Stock Issued During Period, Shares, Exercise of Common Stock Warrants (in shares)         0 0