v3.26.1
Comprehensive Income (Loss) - Schedule of Components of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Beginning of period     $ 3,608,975  
OCI before reclassifications     (86,060)  
Amounts reclassified from AOCI     12,642  
Other comprehensive income (loss) $ (2,477) $ 41,426 (73,418) $ 106,203
End of period 3,662,987 3,369,379 3,662,987 3,369,379
Total AOCI        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Beginning of period (222,601) (272,068) (151,660) (336,845)
Other comprehensive income (loss) (2,477) 41,426 (73,418) 106,203
End of period (225,078) (230,642) (225,078) (230,642)
Investments Subtotal        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Beginning of period     (69,834)  
OCI before reclassifications     (86,060)  
Amounts reclassified from AOCI     11,368  
Other comprehensive income (loss) (3,114) 40,737 (74,692) 104,825
End of period (144,526)   (144,526)  
Credit Loss Related        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Beginning of period     (44,973)  
OCI before reclassifications 4,107 8,707 (10,551) 18,793
Amounts reclassified from AOCI 992 (701) 7,433 (1,198)
Other comprehensive income (loss)     (3,118)  
End of period (48,091)   (48,091)  
All Other        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Beginning of period     (24,861)  
OCI before reclassifications (10,835) 33,074 (75,509) 87,789
Amounts reclassified from AOCI 2,622 (343) 3,935 (559)
Other comprehensive income (loss)     (71,574)  
End of period (96,435)   (96,435)  
Defined Benefit Pension and Post-Retirement Plans        
AOCI Attributable to Parent, Net of Tax [Roll Forward]        
Beginning of period     (81,826)  
OCI before reclassifications     0  
Amounts reclassified from AOCI     1,274  
Other comprehensive income (loss) 637 $ 689 1,274 $ 1,378
End of period $ (80,552)   $ (80,552)