Quarterly report pursuant to Section 13 or 15(d)

Stock Options (Details)

v3.10.0.1
Stock Options (Details) - USD ($)
6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Risk-free interest rate   2.27%
Expected life of option grants   7 years
Expected volatility of underlying stock   47.34%
Dividends assumption  
Minimum [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Risk-free interest rate 2.79%  
Expected life of option grants 5 years  
Expected volatility of underlying stock 45.64%  
Dividends assumption  
Maximum [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Risk-free interest rate 3.01%  
Expected life of option grants 6 years  
Expected volatility of underlying stock 46.18%  
Dividends assumption