v3.26.1
Reserves for Claims and Claim Expenses (Details) - USD ($)
$ in Thousands
 6 Months Ended
Jun. 30, 2026
Dec. 31, 2025
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]    
Reserves for claims and claim expenses, beginning balance $ 0  
Reinsurance recoverable on unpaid losses, beginning balance 0  
Net reserve for claims and claim expenses, beginning balance 0  
Acquired net reserve for claims and claim expenses 1,535,414  
Net Losses incurred during the period related to:    
Current period 54,548  
Prior period 662  
Total net losses incurred 55,210  
Net losses paid during the period related to:    
Current period (3,584)  
Prior period (35,438)  
Total net losses paid (39,022)  
Foreign exchange (gains) losses (50)  
Net reserve for claims and claim expenses, ending balance 1,551,552  
Reinsurance recoverable on unpaid losses, ending balance 563,864  
Reserves for claims and claim expenses, ending balance 2,115,416  
Reinsurance recoverable on paid and unpaid losses 601,602 $ 0
Reinsurance recoverable for paid claims and claims adjustments 37,700  
Vantage Group Holdings Ltd.    
Net losses paid during the period related to:    
Reinsurance recoverable on unpaid losses, ending balance 554,800  
Reserves for claims and claim expenses, ending balance 2,100,000  
Reinsurance recoverable on paid and unpaid losses $ 44,300