v3.26.1
Reinsurance - Narrative (Details) - USD ($)
$ in Thousands
Jul. 31, 2019
Jun. 30, 2026
Mar. 31, 2026
Dec. 31, 2025
Jul. 18, 2025
Jun. 30, 2025
Mar. 31, 2025
Dec. 31, 2024
Dec. 31, 2018
Dec. 27, 2018
Reinsurance Retention Policy [Line Items]                    
Reinsurance recoverable on unpaid losses   $ 412,121   $ 461,197            
Reinsurance recoverable, allowance for credit loss   1,613 $ 1,930 1,740   $ 1,655 $ 0 $ 0    
Reinsurance, excess retention, amount reinsured, per policy $ 2,178,535                  
Reinsurance, amount retained, per policy 600,000                  
Reinsurance recoverable for paid and unpaid claims and claims adjustments, adverse development cover                 $ 155,000  
Collateral by third party   351,466   362,501            
Cavello                    
Reinsurance Retention Policy [Line Items]                    
Reinsurance recoverable on unpaid losses         $ 46,700          
Additional claims estimated         $ 25,000          
Maximum                    
Reinsurance Retention Policy [Line Items]                    
Reinsurance recoverables on paid losses, gross   312,786                
Diversified Reinsurance Segment                    
Reinsurance Retention Policy [Line Items]                    
Reinsurance recoverable on unpaid losses   31,521   32,791            
Reinsurance recoverable, allowance for credit loss   710   689            
Percentage of assets and liabilities associated with reinsurance business retroceded                   100.00%
AmTrust Reinsurance                    
Reinsurance Retention Policy [Line Items]                    
Reinsurance recoverable on unpaid losses $ 445,000                  
Reinsurance recoverable, allowance for credit loss   901   1,048            
Reinsurance recoverables on unpaid losses   $ 379,391   $ 427,013