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	$ 977,215	$ 8,348,381	$ (62,172)	$ 289,714	$ (351,886)	$ (3,058,425)	$ 14,995
Beginning of period at Dec. 31, 2020		105,803	977,215	8,348,381	(62,172)	289,714	(351,886)	(3,058,425)	14,995
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock units issued			72
Restricted stock units expensed			22,611
Net income before noncontrolling interests	$ 469,394			466,763					2,631
Dividends ($0.60, $0.42, $0.69 and $0.50 per share, respectively)				(133,056)
Change in unrealized (losses) gains on securities without an allowance for expected credit losses	(66,858)					(77,145)
Change in unrealized (losses) gains on securities with an allowance for expected credit losses						10,286
Net change in period	6,587						6,587
Stock exercised/vested								1,039
Stock repurchased								(29,683)
(Contributions) distributions									(7,947)
Other comprehensive loss, net of tax	$ (60,271)				(60,271)		6,587		(1)
End of period at Jun. 30, 2021			999,898	8,682,088	(122,444)	222,855	(345,299)	(3,087,069)	9,678
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock dividends, per share, cash paid (in dollars per share)	$ 0.50
Cumulative effect adjustment resulting from changes in accounting principles		105,803	988,288	8,556,621	(148,252)	199,584	(347,836)	(3,087,860)	15,684
Beginning of period at Mar. 31, 2021		105,803	988,288	8,556,621	(148,252)	199,584	(347,836)	(3,087,860)	15,684
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock units issued			597
Restricted stock units expensed			11,013
Net income before noncontrolling interests	$ 237,678			237,238					440
Dividends ($0.60, $0.42, $0.69 and $0.50 per share, respectively)				(111,771)
Change in unrealized (losses) gains on securities without an allowance for expected credit losses	23,272					23,340
Change in unrealized (losses) gains on securities with an allowance for expected credit losses						(69)
Net change in period	2,537						2,537
Stock exercised/vested								791
Stock repurchased								0
(Contributions) distributions									(6,445)
Other comprehensive loss, net of tax	$ 25,809				25,809		2,537		(1)
End of period at Jun. 30, 2021			999,898	8,682,088	(122,444)	222,855	(345,299)	(3,087,069)	9,678
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock dividends, per share, cash paid (in dollars per share)	$ 0.42
Cumulative effect adjustment resulting from changes in accounting principles			999,898	8,682,088	(122,444)	222,855	(345,299)	(3,087,069)	9,678
Cumulative effect adjustment resulting from changes in accounting principles	$ 6,667,730	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	6,667,730	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			(2,370)
Restricted stock units expensed			22,359
Net income before noncontrolling interests	772,496			769,960					2,536
Dividends ($0.60, $0.42, $0.69 and $0.50 per share, respectively)				(182,147)
Change in unrealized (losses) gains on securities without an allowance for expected credit losses	(760,553)					(743,969)
Change in unrealized (losses) gains on securities with an allowance for expected credit losses						(16,585)
Net change in period	12,879						12,879
Stock exercised/vested								1,347
Stock repurchased								0
(Contributions) distributions									5,134
Other comprehensive loss, net of tax	(747,674)				(747,674)		12,879		(1)
End of period at Jun. 30, 2022	$ 6,536,873		1,001,093	9,602,948	(1,029,630)	(669,654)	(359,976)	(3,165,729)	22,388
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock dividends, per share, cash paid (in dollars per share)	$ 0.69
Cumulative effect adjustment resulting from changes in accounting principles		105,803	992,012	9,582,790	(649,229)	(332,646)	(316,583)	(3,166,873)	23,296
Beginning of period at Mar. 31, 2022		$ 105,803	992,012	9,582,790	(649,229)	(332,646)	(316,583)	(3,166,873)	23,296
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock units issued			(1,840)
Restricted stock units expensed			10,921
Net income before noncontrolling interests	$ 179,467			179,322					145
Dividends ($0.60, $0.42, $0.69 and $0.50 per share, respectively)				(159,164)
Change in unrealized (losses) gains on securities without an allowance for expected credit losses	(337,008)					(320,130)
Change in unrealized (losses) gains on securities with an allowance for expected credit losses						(16,878)
Net change in period	(43,393)						(43,393)
Stock exercised/vested								1,144
Stock repurchased								0
(Contributions) distributions									(1,053)
Other comprehensive loss, net of tax	(380,401)				(380,401)		(43,393)		0
End of period at Jun. 30, 2022	$ 6,536,873		1,001,093	9,602,948	(1,029,630)	(669,654)	(359,976)	(3,165,729)	22,388
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	$ 6,536,873		$ 1,001,093	$ 9,602,948	$ (1,029,630)	$ (669,654)	$ (359,976)	$ (3,165,729)	$ 22,388