v3.26.1
Goodwill (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Apr. 01, 2026
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Goodwill [Line Items]          
Goodwill Impairment   $ 460.0 $ 0.0 $ 460.0 $ 0.0
Disposal Group, Disposed of by Sale, Not Discontinued Operations | Newins | Specialty Property & Casualty Insurance          
Goodwill [Line Items]          
Assets of disposal group $ 14.9        
Goodwill of disposal group 7.2        
Pre-tax gain on sale $ 7.5