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

Equity (Schedule of Stock Options Assumptions) (Details)

v3.3.1.900
Equity (Schedule of Stock Options Assumptions) (Details) - $ / shares
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Dividend yield 0.00%    
Stock Options [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Risk-free interest rate, Minimum 1.60% 1.30% 1.40%
Risk-free interest rate, Maximum 1.90% 2.00% 1.70%
Expected option term 6 years    
Expected share price volatility, Minimum 50.10% 45.80% 56.00%
Expected share price volatility, Maximum 53.50% 47.60% 57.00%
Dividend yield
Weighted average grant date fair value (in dollars per share) $ 15.49 $ 60.82 $ 40.94
Minimum [Member] | Stock Options [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Expected option term   4 years 2 months 12 days 5 years 1 month 6 days
Maximum [Member] | Stock Options [Member]      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Expected option term   6 years 6 months 5 years 2 months 12 days