v3.3.1.900
Fair value of financial instruments (Details) - USD ($)
$ in Millions
Dec. 31, 2015
Dec. 31, 2014
Fair value of financial instruments    
Cash and cash equivalents   $ 106.0
Restricted cash $ 15.2 22.5
Derivative assets non-current 0.3 1.1
Derivative liabilities current 36.7 36.1
Derivative liabilities non-current 20.8 47.5
Long term debt, including current portion 733.3  
Carrying Amount    
Fair value of financial instruments    
Cash and cash equivalents 72.4 106.0
Restricted cash 15.2 22.5
Derivative assets non-current 0.3 1.1
Derivative liabilities current 36.7 36.1
Derivative liabilities non-current 20.8 47.5
Long term debt, including current portion 733.3 1,165.9
Convertible debentures 285.4 340.6
Fair Value    
Fair value of financial instruments    
Cash and cash equivalents 72.4 106.0
Restricted cash 15.2 22.5
Derivative assets non-current 0.3 1.1
Derivative liabilities current 36.7 36.1
Derivative liabilities non-current 20.8 47.5
Long term debt, including current portion 686.5 1,119.5
Convertible debentures $ 231.4 $ 269.9