Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common stock	Additional paid-in capital	Retained earnings	Accumulated Other Comprehensive Income (Loss)	Unrealized investment gain	Currency Translation Adjustments	Treasury stock	Noncontrolling interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect adjustment resulting from changes in accounting principles		$ 105,803	$ 981,104	$ 9,015,135	$ (281,955)	$ 90,900	$ (372,855)	$ (3,167,076)	$ 14,719
Beginning of period at Dec. 31, 2021		105,803	981,104	9,015,135	(281,955)	90,900	(372,855)	(3,167,076)	14,719
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock units issued			(530)
Restricted stock units expensed			11,438
Net income before noncontrolling interests	$ 593,030			590,638					2,392
Dividends ($0.60 and $0.09 per share, respectively)				(22,983)
Change in unrealized gains (losses) on securities without an allowance for expected credit losses	(423,545)					(423,839)
Change in unrealized gains on securities with an allowance for expected credit losses						293
Net change in period	56,272						56,272
Stock exercised/vested								203
Stock repurchased								0
Other	0
Contributions									6,186
Other comprehensive loss, net of tax	$ (367,273)				(367,273)		56,272		(1)
End of period at Mar. 31, 2022			992,012	9,582,790	(649,229)	(332,646)	(316,583)	(3,166,873)	23,296
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock dividends, per share, cash paid (in dollars per share)	$ 0.09
Cumulative effect adjustment resulting from changes in accounting principles			992,012	9,582,790	(649,229)	(332,646)	(316,583)	(3,166,873)	23,296
Cumulative effect adjustment resulting from changes in accounting principles	$ 6,768,161	105,803	997,534	10,161,005	(1,264,581)	(892,905)	(371,676)	(3,251,429)	19,829
Beginning of period at Dec. 31, 2022	6,768,161	$ 105,803	997,534	10,161,005	(1,264,581)	(892,905)	(371,676)	(3,251,429)	19,829
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock units issued			(1,200)
Restricted stock units expensed			11,794
Net income before noncontrolling interests	295,729			294,126					1,603
Dividends ($0.60 and $0.09 per share, respectively)				(158,592)
Change in unrealized gains (losses) on securities without an allowance for expected credit losses	180,799					177,342
Change in unrealized gains on securities with an allowance for expected credit losses						3,456
Net change in period	4,866						4,866
Stock exercised/vested								395
Stock repurchased								(135,152)
Other	(1,352)
Contributions									177
Other comprehensive loss, net of tax	185,665				185,665		4,866		(1)
End of period at Mar. 31, 2023	$ 6,965,623		1,008,128	10,296,539	(1,078,917)	(712,107)	(366,810)	(3,387,538)	21,608
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock dividends, per share, cash paid (in dollars per share)	$ 0.60
Cumulative effect adjustment resulting from changes in accounting principles	$ 6,965,623		$ 1,008,128	$ 10,296,539	$ (1,078,917)	$ (712,107)	$ (366,810)	$ (3,387,538)	$ 21,608