Quarterly report pursuant to Section 13 or 15(d)

Shareholders' Equity and Capital Stock - assumptions (Details)

v3.10.0.1
Shareholders' Equity and Capital Stock - assumptions (Details)
6 Months Ended
Jun. 30, 2018
Jun. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected award life (in years) 3 years 8 months 27 days 3 years 8 months 12 days
Expected volatility 54.59%  
Expected dividend rate 0.00%  
Risk-free interest rate, Minimum 1.90% 1.00%
Risk-free interest rate, Maximum 1.90% 1.00%
Maximum    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected volatility 55.00% 57.00%
Forfeiture rate (options) 6.00% 5.40%
Minimum    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected award life (in years) 3 years 8 months 27 days  
Expected volatility 55.00% 57.00%
Risk-free interest rate 1.90%  
Forfeiture rate (options) 6.00% 5.40%