v3.26.1
Other employee benefits (Schedule of additional information about other employee benefit plans, balance by member group) - (Details) - Other employee benefits [Member] - USD ($)
$ in Millions
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Other Employee Benefits [Line Items]      
Closing defined benefit obligation $ 83.6 $ 81.5 $ 103.2
Active members [Member]      
Other Employee Benefits [Line Items]      
Closing defined benefit obligation 26.6 26.7  
Inactive members [Member]      
Other Employee Benefits [Line Items]      
Closing defined benefit obligation $ 57.0 $ 54.8