Quarterly report pursuant to Section 13 or 15(d)

Note 5 - Equity (Details Textual)

v3.20.2
Note 5 - Equity (Details Textual)
$ / shares in Units, $ in Thousands
1 Months Ended 9 Months Ended
Feb. 10, 2020
USD ($)
$ / shares
shares
Oct. 30, 2020
shares
Aug. 31, 2020
shares
Jul. 31, 2020
USD ($)
$ / shares
shares
Apr. 30, 2020
USD ($)
$ / shares
shares
Sep. 30, 2020
USD ($)
shares
Sep. 30, 2019
USD ($)
Jun. 15, 2018
shares
Proceeds from Issuance of Common Stock           $ 17,077 $ 19,292  
Share Based Compensation Arrangement by Share Based Payment Award, Options, Grants in Period, Aggregate Fair Value           1,300    
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value           $ 1,200 $ 1,000  
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares) | shares       1,349,750   1,554,750    
Director [Member] | Subsequent Event [Member]                
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares) | shares   40,000            
Company Founder and Chair of Scientific Advisory Board [Member]                
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares) | shares     100,000          
Share-based Payment Arrangement, Option [Member]                
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)           10 years    
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total           $ 3,000    
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)           2 years 7 months 24 days    
Share-based Payment Arrangement, Option [Member] | Employees [Member]                
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)           4 years    
Share-based Payment Arrangement, Option [Member] | Director [Member] | Subsequent Event [Member]                
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)   3 years            
Share-based Payment Arrangement, Option [Member] | Director [Member] | Minimum [Member]                
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)           1 year    
Share-based Payment Arrangement, Option [Member] | Director [Member] | Maximum [Member]                
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year)           3 years    
Restricted Stock Units (RSUs) [Member]                
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total           $ 600    
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)           3 years 3 months 18 days    
Share Based Compensation Arrangement by Share Based Payment Award, Number of Installment Periods           4    
The 2015 Stock Plan [Member]                
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares) | shares               10,500,000
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant (in shares) | shares           4,409,132    
Warrants Issued in Connection with the February 2020 Stock Offering [Member]                
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | shares 5,625,000              
The 2019 ATM Agreement [Member]                
Stock Issued During Period, Shares, New Issues (in shares) | shares       1,301,126 7,170,964      
Shares Issued, Average Price Per Share (in dollars per share) | $ / shares       $ 1.47 $ 1.44      
Proceeds from Issuance of Common Stock       $ 1,900 $ 10,300      
Payments of Stock Issuance Costs       $ 100 $ 300      
February 2020 Stock Offering [Member]                
Stock Issued During Period, Shares, New Issues (in shares) | shares 7,500,000              
Payments of Stock Issuance Costs $ 700              
Shares and Warrants Issued in Period, Purchase Price Per Share and Related Warrant (in dollars per share) | $ / shares $ 0.80              
Proceeds from Issuance or Sale of Equity, Total $ 6,000