Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common stock	Additional paid-in capital	Retained earnings	Unrealized investment losses:	Change in unrealized losses on securities without an allowance for expected credit losses	Change in unrealized gains on securities with an allowance for expected credit losses	Currency translation adjustments:	Accumulated Other Comprehensive Income (Loss)	Treasury stock	Noncontrolling interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect adjustment resulting from changes in accounting principles		$ 158,705	$ 964,789	$ 11,040,908	$ (586,354)			$ (339,484)	$ (925,838)	$ (3,783,133)	$ 13,806
Beginning of period at Dec. 31, 2023		158,705	964,789	11,040,908	(586,354)			(339,484)	(925,838)	(3,783,133)	13,806
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock units issued			(195)
Restricted stock units expensed			12,979
Net income before noncontrolling interests	$ 442,035			442,471							(436)
Dividends ($0.08 and $0.07 per share, respectively)				(28,221)
Change in unrealized losses on securities without an allowance for expected credit losses	(70,122)					$ (71,109)
Change in unrealized gains on securities with an allowance for expected credit losses							$ 987
Net change in period	(27,570)							(27,570)
Stock exercised/vested										59
Stock repurchased										0
Other	0
Contributions											310
Other comprehensive loss, net of tax	$ (97,692)				(70,122)			(27,570)	(97,692)		0
End of period at Mar. 31, 2024			977,573	11,455,158	(656,476)			(367,054)	(1,023,530)	(3,783,074)	13,680
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock dividends, per share, cash paid (in dollars per share)	$ 0.07
Cumulative effect adjustment resulting from changes in accounting principles			977,573	11,455,158	(656,476)			(367,054)	(1,023,530)	(3,783,074)	13,680
Cumulative effect adjustment resulting from changes in accounting principles	$ 8,407,439	158,705	984,825	12,265,070	(517,170)			(417,099)	(934,269)	(4,079,220)	12,328
Beginning of period at Dec. 31, 2024	8,407,439	$ 158,705	984,825	12,265,070	(517,170)			(417,099)	(934,269)	(4,079,220)	12,328
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock units issued			(4,347)
Restricted stock units expensed			12,423
Net income before noncontrolling interests	417,349			417,571							(222)
Dividends ($0.08 and $0.07 per share, respectively)				(30,338)
Change in unrealized losses on securities without an allowance for expected credit losses	148,273					$ (551)
Change in unrealized gains on securities with an allowance for expected credit losses							$ 148,823
Net change in period	23,930							23,930
Stock exercised/vested										1,050
Stock repurchased										(49,202)
Other	(431)
Contributions											228
Other comprehensive loss, net of tax	172,203				148,273			23,930	172,203		(1)
End of period at Mar. 31, 2025	$ 8,926,372		992,901	12,652,303	(368,898)			(393,169)	(762,067)	(4,127,803)	12,333
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock dividends, per share, cash paid (in dollars per share)	$ 0.08
Cumulative effect adjustment resulting from changes in accounting principles	$ 8,926,372		$ 992,901	$ 12,652,303	$ (368,898)			$ (393,169)	$ (762,067)	$ (4,127,803)	$ 12,333