Quarterly report pursuant to Section 13 or 15(d)

Note 10 - Stock-based Compensation - Fair Value Assumptions of Options Granted (Details)

v3.19.2
Note 10 - Stock-based Compensation - Fair Value Assumptions of Options Granted (Details) - Share-based Payment Arrangement, Option [Member]
6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Expected volatility 35.00%  
Expected term (Year) 7 years 7 years
Risk-free rate 2.61%  
Forfeiture rate 20.00% 20.00%
Minimum [Member]    
Expected volatility   42.00%
Risk-free rate   2.53%
Maximum [Member]    
Expected volatility   43.00%
Expected term (Year)   5 years 182 days
Risk-free rate   2.63%