Annual and transition report of foreign private issuers pursuant to Section 13 or 15(d)

Equity (Schedule of Stock Options Assumptions) (Details)

v3.7.0.1
Equity (Schedule of Stock Options Assumptions) (Details) - $ / shares
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Dividend yield 0.00%    
Employee Stock Option [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Risk-free interest rate, Minimum 1.10% 1.60% 1.30%
Risk-free interest rate, Maximum 1.50% 1.90% 2.00%
Expected option term (years)   6 years  
Expected share price volatility, Minimum 53.60% 50.10% 45.80%
Expected share price volatility, Maximum 56.10% 53.50% 47.60%
Dividend yield
Weighted average grant date fair value $ 12.36 $ 15.49 $ 60.82
Minimum [Member] | Employee Stock Option [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Expected option term (years) 5 years 2 months 12 days   4 years 2 months 12 days
Maximum [Member] | Employee Stock Option [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Expected option term (years) 6 years   6 years 6 months