v3.25.2
Derivatives - Classification and Fair Value of Derivatives (Details) - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Derivative [Line Items]    
Derivative liabilities at fair value $ 12.3 $ 14.3
Derivatives not designated as hedging instruments | Foreign currency forwards    
Derivative [Line Items]    
Derivative assets at fair value 18.7 0.9
Derivative liabilities at fair value 7.0 3.3
Notional Value 1,215.4 768.6
Derivatives not designated as hedging instruments | Weather derivatives    
Derivative [Line Items]    
Derivative assets at fair value 0.0 0.0
Derivative liabilities at fair value 0.0 5.6
Notional Value 0.0 3.7
Derivatives not designated as hedging instruments | Interest rate swaps    
Derivative [Line Items]    
Derivative assets at fair value 0.0 0.0
Derivative liabilities at fair value 0.0 0.0
Notional Value 29.8 29.8
Derivatives not designated as hedging instruments | Credit default swap    
Derivative [Line Items]    
Derivative assets at fair value 0.4 0.0
Derivative liabilities at fair value 0.0 0.5
Notional Value 57.6 49.1
Derivatives not designated as hedging instruments | Reinsurance contracts accounted for as derivatives    
Derivative [Line Items]    
Derivative assets at fair value 0.0 0.0
Derivative liabilities at fair value 5.3 4.9
Notional Value $ 79.3 $ 100.1