v3.20.2
Fair value of financial instruments - recurring (Details) - Recurring - USD ($)
$ in Millions
Sep. 30, 2020
Dec. 31, 2019
Assets:    
Cash and cash equivalents $ 30.3 $ 74.9
Restricted cash 2.6 7.7
Derivative instruments asset   0.7
Total 32.9 83.3
Liabilities:    
Derivative instruments liability 19.7 27.9
Total 19.7 27.9
Level 1    
Assets:    
Cash and cash equivalents 30.3 74.9
Restricted cash 2.6 7.7
Total 32.9 82.6
Level 2    
Assets:    
Derivative instruments asset   0.7
Total   0.7
Liabilities:    
Derivative instruments liability 18.2 24.7
Total 18.2 24.7
Level 3    
Liabilities:    
Derivative instruments liability 1.5 3.2
Total $ 1.5 $ 3.2