Annual report pursuant to Section 13 and 15(d)

Stock Options (Details)

v3.19.3.a.u2
Stock Options (Details) - USD ($)
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected life of stock option grants 7 years  
Dividends assumption  
Minimum [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Risk-free interest rate 1.77% 2.79%
Expected life of stock option grants   5 years
Expected volatility of underlying stock 49.48% 45.64%
Dividends assumption  
Maximum [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Risk-free interest rate 2.66% 3.01%
Expected life of stock option grants   6 years
Expected volatility of underlying stock 106.16% 46.18%
Dividends assumption