v3.26.1
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
3 Months Ended 12 Months Ended
Mar. 31, 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) 29.90% 30.10%
Endurance Assurance Corporation | AM Best, A+ Rating    
Ceded Credit Risk [Line Items]    
Reinsurance recoverables (percent) 23.20% 23.50%
Markel Global Reinsurance Company | AM Best, A Rating    
Ceded Credit Risk [Line Items]    
Reinsurance recoverables (percent) 17.40% 18.40%
American Family Connect Property and Casualty Insurance Company | AM Best, A Rating    
Ceded Credit Risk [Line Items]    
Reinsurance recoverables (percent) 9.60% 9.10%
Ascot Bermuda Limited | AM Best, A Rating    
Ceded Credit Risk [Line Items]    
Reinsurance recoverables (percent) 6.80% 7.10%
All other reinsurers | AM Best, A Rating    
Ceded Credit Risk [Line Items]    
Reinsurance recoverables (percent) 13.10% 11.80%