v3.25.4
Goodwill and Intangible Assets - Schedule of Definite and Indefinite Life Intangible Assets (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Finite-Lived Intangible Assets [Line Items]    
Finite-Lived Intangible Assets, Gross $ 693.1 $ 758.0
Indefinite-lived Intangible Assets (Excluding Goodwill) 49.3 49.4
Intangible Assets, Gross (Excluding Goodwill), Total 742.4 807.4
Finite-Lived Intangible Assets, Accumulated Amortization 466.6 491.9
Finite-Lived Intangible Assets, Net $ 226.5 266.1
Impairment Intangible Asset Statement Of Income Or Comprehensive Income Extensible Enumeration Not Disclosed Flag Internal-Use Software1  
Intangible Assets, Net (Including Goodwill) $ 275.8 315.5
Impairment of Intangible Assets (Excluding Goodwill) 21.7  
Trade Names    
Finite-Lived Intangible Assets [Line Items]    
Indefinite-lived Intangible Assets (Excluding Goodwill) 5.2 5.2
Insurance Licenses    
Finite-Lived Intangible Assets [Line Items]    
Indefinite-lived Intangible Assets (Excluding Goodwill) 44.1 44.2
Value of Business Acquired    
Finite-Lived Intangible Assets [Line Items]    
Finite-Lived Intangible Assets, Gross 237.5 237.5
Finite-Lived Intangible Assets, Accumulated Amortization 227.0 225.4
Finite-Lived Intangible Assets, Net 10.5 12.1
Customer Relationships    
Finite-Lived Intangible Assets [Line Items]    
Finite-Lived Intangible Assets, Gross 43.8 43.8
Finite-Lived Intangible Assets, Accumulated Amortization 42.7 42.3
Finite-Lived Intangible Assets, Net 1.1 1.5
Agent Relationships    
Finite-Lived Intangible Assets [Line Items]    
Finite-Lived Intangible Assets, Gross 81.7 81.6
Finite-Lived Intangible Assets, Accumulated Amortization 48.8 43.9
Finite-Lived Intangible Assets, Net 32.9 37.7
Trade Names    
Finite-Lived Intangible Assets [Line Items]    
Finite-Lived Intangible Assets, Gross 0.0 0.0
Finite-Lived Intangible Assets, Accumulated Amortization 0.0 0.0
Finite-Lived Intangible Assets, Net 0.0 0.0
Internal Use Software    
Finite-Lived Intangible Assets [Line Items]    
Finite-Lived Intangible Assets, Gross 330.1 395.1
Finite-Lived Intangible Assets, Accumulated Amortization 148.1 180.3
Finite-Lived Intangible Assets, Net $ 182.0 $ 214.8