v3.26.1
Investments - Summary of Contractual Maturities of Fixed Maturity Securities Available-For-Sale (Details) - USD ($)
$ in Thousands
Mar. 31, 2026
Dec. 31, 2025
Amortized cost    
Due one year or less $ 343,393  
Due after one year through five years 1,185,756  
Due after five years through ten years 2,546,363  
Due after ten years 569,382  
Subtotal 4,644,894  
Amortized cost 6,229,802 $ 6,081,997
Fair value    
Due one year or less 341,767  
Due after one year through five years 1,151,219  
Due after five years through ten years 2,507,986  
Due after ten years 557,445  
Subtotal 4,558,417  
Fair value 6,133,789 6,050,542
Residential mortgage-backed    
Amortized cost    
Residential mortgage-backed and other asset-backed, amortization 338,304  
Amortized cost 338,304 342,915
Fair value    
Residential mortgage-backed and other asset-backed, fair value 341,484  
Fair value 341,484 349,333
Commercial mortgage-backed    
Amortized cost    
Residential mortgage-backed and other asset-backed, amortization 199,514  
Amortized cost 199,514 128,692
Fair value    
Residential mortgage-backed and other asset-backed, fair value 198,632  
Fair value 198,632 129,562
Other asset-backed    
Amortized cost    
Residential mortgage-backed and other asset-backed, amortization 1,047,090  
Amortized cost 1,047,090 1,063,044
Fair value    
Residential mortgage-backed and other asset-backed, fair value 1,035,256  
Fair value $ 1,035,256 $ 1,056,123