v3.26.1
Environmental and other provisions (Schedule of detailed information about provisions) (Details) - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disclosure of other provisions [line items]      
Current provisions $ 90.2 $ 29.9  
Non-current provisions 312.6 300.8  
Total provisions 402.8 330.7 $ 344.2
Decommissioning, restoration and similar liabilities [Member]      
Disclosure of other provisions [line items]      
Current provisions 20.6 4.0  
Non-current provisions 297.8 292.9  
Total provisions 318.4 296.9 315.4
Deferred share units [Member]      
Disclosure of other provisions [line items]      
Current provisions 21.5 12.3  
Non-current provisions 0.0 0.0  
Total provisions 21.5 12.3 8.7
Restricted share units [Member]      
Disclosure of other provisions [line items]      
Current provisions 20.5 6.4  
Non-current provisions 5.6 3.2  
Total provisions 26.1 9.6 5.0
Performance share units [Member]      
Disclosure of other provisions [line items]      
Current provisions 19.0 1.9  
Non-current provisions 7.9 3.6  
Total provisions 26.9 5.5 2.6
Other [Member]      
Disclosure of other provisions [line items]      
Current provisions 8.6 5.3  
Non-current provisions 1.3 1.1  
Total provisions $ 9.9 $ 6.4 $ 12.5