Consolidated Statements of Comprehensive (Loss) Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning of period	$ 8,407,439
Other comprehensive income (loss)	172,203	$ (97,692)
End of period	8,926,372
Net realized and unrealized gains on investments	15,711	11,503
Income before income taxes	538,606	574,071
Tax effect	(121,257)	(132,036)
Net income before noncontrolling interests	417,349	442,035
Total change in unrealized investment gains (losses)	185,855	(89,297)
Net change in period	23,930	(27,570)
Other comprehensive income (loss), pre-tax	209,785	(116,867)
Other comprehensive income (loss), tax effect	(37,582)	19,175
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning of period	(934,269)	(925,838)
Other comprehensive income before reclassifications	168,032	(128,882)
Amounts reclassified from AOCI	4,171	31,190
Other comprehensive income (loss)	172,203	(97,692)
Unrealized investment loss related to noncontrolling interest	(1)	0
End of period	(762,067)	(1,023,530)
Accumulated Other Comprehensive Income (Loss) | Amounts reclassified from AOCI
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Income before income taxes	5,280	39,481
Tax effect	(1,109)	(8,291)
Net income before noncontrolling interests	4,171	31,190
Unrealized investment losses:
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning of period	(517,170)	(586,354)
Other comprehensive income before reclassifications	144,102	(101,312)
Amounts reclassified from AOCI	4,171	31,190
Other comprehensive income (loss)	148,273	(70,122)
Unrealized investment loss related to noncontrolling interest	(1)	0
End of period	(368,898)	(656,476)
Total change in unrealized investment gains (losses)	185,855	(89,297)
Unrealized investment gains, tax effect	(37,582)	19,175
Unrealized investment gains (losses), after-tax amounts	148,273	(70,122)
Unrealized investment losses: | Amounts reclassified from AOCI
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Net realized and unrealized gains on investments	5,280	39,481
Tax effect	(1,109)	(8,291)
Net income before noncontrolling interests	4,171	31,190
Currency Translation Adjustments
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning of period	(417,099)	(339,484)
Other comprehensive income before reclassifications	23,930	(27,570)
Amounts reclassified from AOCI	0	0
Other comprehensive income (loss)	23,930	(27,570)
Unrealized investment loss related to noncontrolling interest	0	0
End of period	(393,169)	(367,054)
Currency translation adjustment, pre-tax	23,930	(27,570)
Currency translation adjustment, tax effect	0	0
Net change in period	23,930	(27,570)
Currency Translation Adjustments | Amounts reclassified from AOCI
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Income before income taxes	0	0
Tax effect	0	0
Net income before noncontrolling interests	$ 0	$ 0