v3.26.3
Premiums and Reinsurance Related Information - Schedule of A.M. Best Financial Strength Rating and Percent of Total Reinsurance Recoverable (Details) - Reinsurance Recoverable Including Reinsurance Premium Paid - Reinsurer Concentration Risk
9 Months Ended 12 Months Ended
Sep. 30, 2026
Dec. 31, 2025
Ceded Credit Risk [Line Items]    
Reinsurance recoverables (percent) 100.00% 100.00%
AM Best, A Rating    
Ceded Credit Risk [Line Items]    
Reinsurance recoverables (percent) 100.00% 100.00%
Renaissance Reinsurance U.S. Inc | AM Best, A+ Rating    
Ceded Credit Risk [Line Items]    
Reinsurance recoverables (percent) 29.70% 30.10%
Endurance Assurance Corporation | AM Best, A+ Rating    
Ceded Credit Risk [Line Items]    
Reinsurance recoverables (percent) 23.40% 23.50%
Markel Global Reinsurance Company | AM Best, A Rating    
Ceded Credit Risk [Line Items]    
Reinsurance recoverables (percent) 15.90% 18.40%
Ascot Bermuda Limited | AM Best, A Rating    
Ceded Credit Risk [Line Items]    
Reinsurance recoverables (percent) 5.60% 9.10%
American Family Connect Property and Casualty Insurance Company | AM Best, A Rating    
Ceded Credit Risk [Line Items]    
Reinsurance recoverables (percent) 9.90% 7.10%
All other reinsurers | AM Best, A Rating    
Ceded Credit Risk [Line Items]    
Reinsurance recoverables (percent) 15.50% 11.80%