XML 40 R28.htm IDEA: XBRL DOCUMENT v3.21.2
Note 5 - Share-based Compensation - Black-Scholes Options Pricing Model (Details)
9 Months Ended
Sep. 30, 2021
Risk-Free interest rate, minimum 0.13%
Risk-Free interest rate, maximum 0.85%
Expected stock price volatility, minimum 54.52%
Expected stock price volatility, maximum 60.53%
Minimum [Member]  
Expected life of options (Year) 2 years
Maximum [Member]  
Expected life of options (Year) 6 years 3 months