Quarterly report pursuant to Section 13 or 15(d)

Note 4 - Stock-based Compensation (Details Textual)

v3.21.2
Note 4 - Stock-based Compensation (Details Textual) - USD ($)
3 Months Ended 6 Months Ended
Jun. 30, 2021
Jun. 30, 2020
Jun. 30, 2021
Jun. 30, 2020
Share-based Payment Arrangement, Expense $ 142,000 $ 35,000 $ 263,000 $ 74,000
Share-based Payment Arrangement, Expense, Tax Benefit 0 $ 0 $ 0 $ 0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value (in dollars per share)     $ 1.86  
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Volatility Rate, Maximum     90.22%  
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Risk Free Interest Rate     0.67%  
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Term (Year)     5 years 11 months 19 days  
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount, Total $ 415,000   $ 415,000  
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year)     1 year 7 months 6 days