v3.25.4
Business Segments - Segment Net Income (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Segment Reporting Information [Line Items]      
Revenues $ 4,789.7 $ 4,638.6 $ 4,944.2
Less: Net Loss attributable to Noncontrolling Interest (10.7) (5.3) (0.2)
Goodwill Impairment Charges 0.0 0.0 (49.6)
Net Income (Loss) 143.3 317.8 (272.1)
Operating Segments      
Segment Reporting Information [Line Items]      
Revenues 4,729.0 4,337.7 4,388.4
Segment Net Operating Income (Loss) 255.6 426.5 (5.3)
Operating Segments | Specialty Property & Casualty Insurance      
Segment Reporting Information [Line Items]      
Revenues 4,145.8 3,772.1 3,806.9
Expenses (3,958.7) (3,395.8) (3,864.0)
Segment Net Operating Income (Loss) 187.1 376.3 (57.1)
Operating Segments | Life Insurance      
Segment Reporting Information [Line Items]      
Revenues 583.2 565.6 581.5
Expenses (514.7) (515.4) (529.7)
Segment Net Operating Income (Loss) 68.5 50.2 51.8
Corporate and Other      
Segment Reporting Information [Line Items]      
Segment Net Operating Income (Loss) (40.8) (50.3) (42.1)
Non-Core Operations      
Segment Reporting Information [Line Items]      
Revenues 84.9 282.4 558.4
Change in Fair Value of Equity and Convertible Securities (3.4) (2.1) 3.7
Net Realized Investment Gains (Losses) 4.3 10.4 (14.7)
Impairment Losses (8.5) (4.6) (0.9)
Acquisition and Disposition Related Transaction, Integration, Restructuring and Other Costs (43.1) (31.8) (95.0)
Debt Extinguishment, Pension Settlement, and Other Charges 0.4 (7.4) (55.5)
Goodwill Impairment Charges 0.0 0.0 (45.5)
Net Income (Loss) $ (31.9) $ (28.2) $ (17.0)