v3.25.1
Related Party Transactions (Narrative) (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Dec. 31, 2024
Related Party Transaction [Line Items]      
Services and other revenues $ 660,583 $ 617,638  
Premiums ceded 1,907,939 1,708,362  
Reinsurance recoverables 12,617,479   $ 11,604,844
Nephila Reinsurers [Member]      
Related Party Transaction [Line Items]      
Reinsurance recoverables 1,100,000   968,900
Hagerty, Inc. [Member]      
Related Party Transaction [Line Items]      
Gross premium volume 219,927 198,282  
Premiums ceded 169,685 152,685  
Reinsurance recoverables 312,200   $ 308,800
Insurance-linked Securities Operations [Member] | Unconsolidated entities managed by Nephila [Member]      
Related Party Transaction [Line Items]      
Services and other revenues 25,500 19,200  
Industry Loss Warranties (ILW) Program | Nephila Reinsurers [Member]      
Related Party Transaction [Line Items]      
Gross premium volume 13,700    
Premiums ceded 13,700    
Fronting | Nephila Reinsurers [Member]      
Related Party Transaction [Line Items]      
Gross premium volume 389,300 353,100  
Premiums ceded 389,300 353,100  
Revenues from Program Services and ILS Fronting $ 4,200 $ 4,500