v3.26.1
Schedule V - Valuation and Qualifying Accounts (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Premiums receivable from underwriting activities      
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Balance at Beginning of Year $ 24.6 $ 21.0 $ 25.0
Charged to Costs and Expenses 1.7 3.6 (4.0)
Charged to Other Accounts 0.0 0.0 0.0
Deductions 0.0 0.0 0.0
Balance at End of  Year 22.9 24.6 21.0
Reinsurance      
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Balance at Beginning of Year 27.5 0.0 0.0
Charged to Costs and Expenses 11.3 (27.5)  
Charged to Other Accounts 0.0 0.0 0.0
Deductions 0.0 0.0 0.0
Balance at End of  Year 16.2 27.5 0.0
Deferred tax valuation allowance      
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]      
Balance at Beginning of Year 64.0 172.7 145.7
Charged to Costs and Expenses (17.7) (105.5) (21.5)
Charged to Other Accounts (2.9) 3.2 (5.5)
Deductions 0.0 0.0 0.0
Balance at End of  Year $ 49.2 $ 64.0 $ 172.7