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)
9 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected award life (in years)   3 years 8 months 12 days
Maximum    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected volatility, Maximum 55.00% 57.00%
Risk-free interest rate, Maximum 2.20% 1.00%
Forfeiture rate (options) 6.00% 5.40%
Maximum | Employee Stock Option [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected award life (in years) 3 years 9 months 4 days  
Maximum | Restricted Stock Units (RSUs) [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Forfeiture rate (RSUs) 5.90% 6.20%
Minimum    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected volatility, Minimum 54.00% 57.00%
Risk-free interest rate, Minimum 1.90% 1.00%
Forfeiture rate (options) 6.00% 5.40%
Minimum | Employee Stock Option [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected award life (in years) 3 years 8 months 27 days  
Minimum | Restricted Stock Units (RSUs) [Member]    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Forfeiture rate (RSUs) 5.90% 6.20%
Minimum | Warrants    
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]    
Expected award life (in years) 3 years