v3.26.1
Changes in accumulated other comprehensive income - Schedule of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2026
Mar. 31, 2025
AOCI Attributable to Parent, Net of Tax [Roll Forward]    
Beginning balance $ 5,355,181 $ 4,996,096
Other comprehensive income (loss) before reclassifications (57,158) 52,502
Amounts reclassified from other comprehensive income (loss) 4,590 2,471
Total other comprehensive income (loss) (52,568) 54,973
Ending balance 5,343,548 5,119,407
Total    
AOCI Attributable to Parent, Net of Tax [Roll Forward]    
Beginning balance (30,143) (207,455)
Ending balance (82,711) (152,482)
Net unrealized investment gains (losses)    
AOCI Attributable to Parent, Net of Tax [Roll Forward]    
Beginning balance (24,591) (207,624)
Other comprehensive income (loss) before reclassifications (55,310) 56,423
Amounts reclassified from other comprehensive income (loss) 4,590 2,471
Total other comprehensive income (loss) (50,720) 58,894
Ending balance (75,311) (148,730)
Foreign currency translation    
AOCI Attributable to Parent, Net of Tax [Roll Forward]    
Beginning balance (5,552) 169
Other comprehensive income (loss) before reclassifications (1,848) (3,921)
Amounts reclassified from other comprehensive income (loss) 0 0
Total other comprehensive income (loss) (1,848) (3,921)
Ending balance $ (7,400) $ (3,752)