v3.26.3
Investments - Securities in an Unrealized Loss Position Segregated by Type and Length of Time in an Unrealized Loss Position (Details) - USD ($)
$ in Thousands
Sep. 30, 2026
Dec. 31, 2025
Fair value    
Less than 12 months $ 2,293,595 $ 303,929
12 months and greater 1,016,817 1,356,745
Total Fair Value 3,310,412 1,660,674
Amortized Cost    
Amortized cost, less than 12 months 2,397,690 306,596
12 months and greater 1,206,281 1,494,513
Total Amortized Cost 3,603,971 1,801,109
Unrealized Loss    
Less than 12 months (104,095) (2,667)
12 months and greater (189,464) (137,768)
Total Unrealized Loss (293,559) (140,435)
U.S. government    
Fair value    
Less than 12 months 212,038 8,610
12 months and greater 33,934 80,088
Total Fair Value 245,972 88,698
Amortized Cost    
Amortized cost, less than 12 months 220,509 8,620
12 months and greater 34,908 80,997
Total Amortized Cost 255,417 89,617
Unrealized Loss    
Less than 12 months (8,471) (10)
12 months and greater (974) (909)
Total Unrealized Loss (9,445) (919)
U.S. Agency    
Fair value    
Less than 12 months 14,686  
12 months and greater 7,413 19,797
Total Fair Value 22,099 19,797
Amortized Cost    
Amortized cost, less than 12 months 15,554  
12 months and greater 7,509 19,926
Total Amortized Cost 23,063 19,926
Unrealized Loss    
Less than 12 months (868)  
12 months and greater (96) (129)
Total Unrealized Loss (964) (129)
Non-U.S. government    
Fair value    
Less than 12 months 11,504  
12 months and greater 4,127 4,244
Total Fair Value 15,631 4,244
Amortized Cost    
Amortized cost, less than 12 months 12,083  
12 months and greater 4,803 4,802
Total Amortized Cost 16,886 4,802
Unrealized Loss    
Less than 12 months (579)  
12 months and greater (676) (558)
Total Unrealized Loss (1,255) (558)
Agency MBS    
Fair value    
Less than 12 months 398,264 34,783
12 months and greater 173,317 239,581
Total Fair Value 571,581 274,364
Amortized Cost    
Amortized cost, less than 12 months 423,723 34,917
12 months and greater 211,600 267,839
Total Amortized Cost 635,323 302,756
Unrealized Loss    
Less than 12 months (25,459) (134)
12 months and greater (38,283) (28,258)
Total Unrealized Loss (63,742) (28,392)
ABS/CMBS/MBS    
Fair value    
Less than 12 months 508,786 110,600
12 months and greater 134,151 142,903
Total Fair Value 642,937 253,503
Amortized Cost    
Amortized cost, less than 12 months 524,822 110,826
12 months and greater 153,568 157,989
Total Amortized Cost 678,390 268,815
Unrealized Loss    
Less than 12 months (16,036) (226)
12 months and greater (19,417) (15,086)
Total Unrealized Loss (35,453) (15,312)
Corporate    
Fair value    
Less than 12 months 1,095,945 146,177
12 months and greater 393,497 545,897
Total Fair Value 1,489,442 692,074
Amortized Cost    
Amortized cost, less than 12 months 1,145,126 148,444
12 months and greater 436,516 571,560
Total Amortized Cost 1,581,642 720,004
Unrealized Loss    
Less than 12 months (49,181) (2,267)
12 months and greater (43,019) (25,663)
Total Unrealized Loss (92,200) (27,930)
Municipal    
Fair value    
Less than 12 months 52,372 3,759
12 months and greater 270,378 324,235
Total Fair Value 322,750 327,994
Amortized Cost    
Amortized cost, less than 12 months 55,873 3,789
12 months and greater 357,377 391,400
Total Amortized Cost 413,250 395,189
Unrealized Loss    
Less than 12 months (3,501) (30)
12 months and greater (86,999) (67,165)
Total Unrealized Loss $ (90,500) $ (67,195)