Consolidated Statements of Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning of period			$ 8,407,439
Other comprehensive income (loss)	$ 189,683	$ (10,111)	361,886	$ (107,803)
End of period	9,304,808		9,304,808
Net realized and unrealized gains (losses) on investments	30,533	(60,306)	46,244	(48,803)
Income before income taxes	521,863	487,673	1,060,469	1,061,744
Tax effect	(121,155)	(115,788)	(242,411)	(247,824)
Net income before noncontrolling interests	400,708	371,885	818,058	813,920
Total change in unrealized investment gains (losses)	157,858	(20,640)	343,713	(109,937)
Net change in period	69,418	3,227	93,348	(24,343)
Other comprehensive income (loss), pre-tax	227,276	(17,413)	437,061	(134,280)
Other comprehensive income (loss), tax effect	(37,593)	7,302	(75,175)	26,477
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning of period	(762,067)	(1,023,530)	(934,269)	(925,838)
Other comprehensive income before reclassifications	167,936	(51,484)	335,968	(180,366)
Amounts reclassified from AOCI	21,747	41,373	25,918	72,563
Other comprehensive income (loss)	189,683	(10,111)	361,886	(107,803)
Unrealized investment loss related to noncontrolling interest	0	1	(1)	1
End of period	(572,384)	(1,033,640)	(572,384)	(1,033,640)
Accumulated Other Comprehensive Income (Loss) | Amounts reclassified from AOCI
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Income before income taxes	27,528	52,371	32,808	91,852
Tax effect	(5,781)	(10,998)	(6,890)	(19,289)
Net income before noncontrolling interests	21,747	41,373	25,918	72,563
Unrealized investment losses:
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning of period	(368,898)	(656,476)	(517,170)	(586,354)
Other comprehensive income before reclassifications	98,518	(54,711)	242,620	(156,023)
Amounts reclassified from AOCI	21,747	41,373	25,918	72,563
Other comprehensive income (loss)	120,265	(13,338)	268,538	(83,460)
Unrealized investment loss related to noncontrolling interest	0	1	(1)	1
End of period	(248,633)	(669,813)	(248,633)	(669,813)
Total change in unrealized investment gains (losses)	157,858	(20,640)	343,713	(109,937)
Unrealized investment gains, tax effect	(37,593)	7,302	(75,175)	26,477
Unrealized investment gains (losses), after-tax amounts	120,265	(13,338)	268,538	(83,460)
Unrealized investment losses: | Amounts reclassified from AOCI
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Net realized and unrealized gains (losses) on investments	27,528	52,371	32,808	91,852
Tax effect	(5,781)	(10,998)	(6,890)	(19,289)
Net income before noncontrolling interests	21,747	41,373	25,918	72,563
Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning of period	(393,169)	(367,054)	(417,099)	(339,484)
Other comprehensive income before reclassifications	69,418	3,227	93,348	(24,343)
Amounts reclassified from AOCI	0	0	0	0
Other comprehensive income (loss)	69,418	3,227	93,348	(24,343)
Unrealized investment loss related to noncontrolling interest	0	0	0	0
End of period	(323,751)	(363,827)	(323,751)	(363,827)
Currency translation adjustment, pre-tax	69,418	3,227	93,348	(24,343)
Currency translation adjustment, tax effect	0	0	0	0
Net change in period	69,418	3,227	93,348	(24,343)
Currency Translation Adjustments | Amounts reclassified from AOCI
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Income before income taxes	0	0	0	0
Tax effect	0	0	0	0
Net income before noncontrolling interests	$ 0	$ 0	$ 0	$ 0