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

Share-based compensation (Expected share-based compensation expense) (Details)

v3.8.0.1
Share-based compensation (Expected share-based compensation expense) (Details)
$ in Millions
Dec. 31, 2017
USD ($)
2018  
Unrecognized Share-Based Compensation, Expected Period Of Recognition [Line Items]  
Expected share-based compensation expense $ 75.5
2019  
Unrecognized Share-Based Compensation, Expected Period Of Recognition [Line Items]  
Expected share-based compensation expense 36.0
2020  
Unrecognized Share-Based Compensation, Expected Period Of Recognition [Line Items]  
Expected share-based compensation expense 19.0
2021  
Unrecognized Share-Based Compensation, Expected Period Of Recognition [Line Items]  
Expected share-based compensation expense $ 4.7