v3.26.1
Investments - Gross Unrealized Losses and Fair Value of Available for Sale Securities (Details) - USD ($)
$ in Thousands
Jun. 30, 2026
Dec. 31, 2025
Debt Securities, Available-for-sale [Line Items]    
Fair value, less than 12 months $ 2,980,691 $ 228,242
Unrealized losses, less than 12 months (28,745) (2,636)
Fair value, 12 months or greater 1,858,411 2,142,209
Unrealized losses, 12 months or greater (321,346) (314,736)
Fair value, total 4,839,102 2,370,451
Unrealized losses, total (350,091) (317,372)
U.S. government and agency securities    
Debt Securities, Available-for-sale [Line Items]    
Fair value, less than 12 months 174,059 0
Unrealized losses, less than 12 months (1,683) 0
Fair value, 12 months or greater 94,790 98,287
Unrealized losses, 12 months or greater (28,623) (27,958)
Fair value, total 268,849 98,287
Unrealized losses, total (30,306) (27,958)
State and municipal obligations    
Debt Securities, Available-for-sale [Line Items]    
Fair value, less than 12 months 72,008 10,256
Unrealized losses, less than 12 months (572) (167)
Fair value, 12 months or greater 85,337 96,240
Unrealized losses, 12 months or greater (13,162) (13,938)
Fair value, total 157,345 106,496
Unrealized losses, total (13,734) (14,105)
Corporate bonds and notes    
Debt Securities, Available-for-sale [Line Items]    
Fair value, less than 12 months 1,689,592 100,367
Unrealized losses, less than 12 months (18,610) (1,739)
Fair value, 12 months or greater 950,054 1,102,930
Unrealized losses, 12 months or greater (199,357) (195,916)
Fair value, total 2,639,646 1,203,297
Unrealized losses, total (217,967) (197,655)
RMBS    
Debt Securities, Available-for-sale [Line Items]    
Fair value, less than 12 months 570,888 27,202
Unrealized losses, less than 12 months (5,518) (105)
Fair value, 12 months or greater 498,903 567,936
Unrealized losses, 12 months or greater (67,493) (62,325)
Fair value, total 1,069,791 595,138
Unrealized losses, total (73,011) (62,430)
CMBS    
Debt Securities, Available-for-sale [Line Items]    
Fair value, less than 12 months 89,228 2,820
Unrealized losses, less than 12 months (852) (122)
Fair value, 12 months or greater 193,127 232,409
Unrealized losses, 12 months or greater (10,632) (12,875)
Fair value, total 282,355 235,229
Unrealized losses, total (11,484) (12,997)
CLO    
Debt Securities, Available-for-sale [Line Items]    
Fair value, less than 12 months 168,420 56,480
Unrealized losses, less than 12 months (281) (125)
Fair value, 12 months or greater 0 5,650
Unrealized losses, 12 months or greater 0 (30)
Fair value, total 168,420 62,130
Unrealized losses, total (281) (155)
Other ABS    
Debt Securities, Available-for-sale [Line Items]    
Fair value, less than 12 months 215,707 31,117
Unrealized losses, less than 12 months (1,222) (378)
Fair value, 12 months or greater 36,200 38,757
Unrealized losses, 12 months or greater (2,079) (1,694)
Fair value, total 251,907 69,874
Unrealized losses, total (3,301) $ (2,072)
Mortgage insurance-linked notes    
Debt Securities, Available-for-sale [Line Items]    
Fair value, less than 12 months 789  
Unrealized losses, less than 12 months (7)  
Fair value, 12 months or greater 0  
Unrealized losses, 12 months or greater 0  
Fair value, total 789  
Unrealized losses, total $ (7)