v3.26.3
Derivatives - Classification and Net Impact on Earnings of Derivatives (Details) - Derivatives not designated as hedging instruments - USD ($)
$ in Millions
 3 Months Ended 9 Months Ended
Sep. 30, 2026
Sep. 30, 2025
Sep. 30, 2026
Sep. 30, 2025
Foreign currency forwards        
Derivative Instruments, Gain (Loss) [Line Items]        
Net impact on earnings $ 5.6 $ (5.4) $ (29.9) $ 74.3
Weather derivatives        
Derivative Instruments, Gain (Loss) [Line Items]        
Net impact on earnings (0.1) 0.2 0.1 0.7
Interest rate swaps        
Derivative Instruments, Gain (Loss) [Line Items]        
Net impact on earnings (0.3) (0.2) (0.3) (0.7)
Reinsurance contracts accounted for as derivatives        
Derivative Instruments, Gain (Loss) [Line Items]        
Net impact on earnings $ 0.0 $ (0.3) $ (0.2) $ (0.4)