v3.25.2
Third-Party Reinsurance - Reinsurance Recoverables (Details) - P&C Insurance and Reinsurance (Ark/WM Outrigger) - USD ($)
$ in Millions
Jun. 30, 2025
Dec. 31, 2024
Segment Reporting Information [Line Items]    
Reinsurance recoverables on unpaid losses $ 468.5 $ 434.4
Reinsurance recoverables on paid losses 69.5 57.5
Ceded unearned premiums 506.1 97.1
Reinsurance recoverables 1,044.1 589.0
Ark    
Segment Reporting Information [Line Items]    
Reinsurance recoverables on unpaid losses (33.7) (31.8)
Reinsurance recoverables on paid losses (6.6) (3.1)
Ceded unearned premiums $ (65.4) $ (4.3)