Consolidated Statements of Changes in Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Capital Surplus [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total Shareholders' Equity [Member]	Non-Controlling Interests [Member]
Transition adjustment for new accounting principle in period of adoption	$ (2,709)			$ 2,709		$ (2,709)
Balance, beginning of period, adjusted	3,518,334	$ 4	$ 1,035,895	3,051,196	$ (552,845)	(38,883)	$ 3,495,367	$ 22,967
Balance, beginning of period (in shares) at Dec. 31, 2017		75,148			9,753
Balance, beginning of period at Dec. 31, 2017	3,518,334	$ 4	1,035,895	3,048,487	$ (552,845)	(36,174)	3,495,367	22,967
Net income	338,047			337,190			337,190	857
Other comprehensive income (loss)	(123,479)					(123,479)	(123,479)
Repurchase of common stock (in shares)					90
Repurchase of common stock	(8,408)				$ (8,408)		(8,408)
Stock options exercised (in shares)		49
Stock options exercised	2,560		2,560				2,560
Non-vested shares awarded, net (in shares)		112
Non-vested shares awarded, net			0
Vesting of non-vested shares (in shares)					31
Vesting of non-vested shares	(2,870)				$ (2,870)		(2,870)
Share-based compensation	5,975		5,975				5,975
Cash dividends on common stock	(91,303)			(91,303)			(91,303)
Capital calls and distributions, net	(13,096)							(13,096)
Balance, end of period (in shares) at Sep. 30, 2018		75,309			9,874
Balance, end of period at Sep. 30, 2018	3,625,760	$ 4	1,044,430	3,297,083	$ (564,123)	(162,362)	3,615,032	10,728
Balance, beginning of period (in shares) at Jun. 30, 2018		75,314			9,874
Balance, beginning of period at Jun. 30, 2018	3,576,045	$ 4	1,040,202	3,212,653	$ (564,123)	(135,305)	3,553,431	22,614
Net income	117,545			117,256			117,256	289
Other comprehensive income (loss)	(27,057)					(27,057)	(27,057)
Repurchase of common stock (in shares)					0
Repurchase of common stock	0				$ 0		0
Stock options exercised (in shares)		3
Stock options exercised	134		134				134
Non-vested shares awarded, net (in shares)		(8)
Non-vested shares awarded, net			0
Vesting of non-vested shares (in shares)					0
Vesting of non-vested shares	0				$ 0		0
Share-based compensation	4,094		4,094				4,094
Cash dividends on common stock	(32,826)			(32,826)			(32,826)
Capital calls and distributions, net	(12,175)							(12,175)
Balance, end of period (in shares) at Sep. 30, 2018		75,309			9,874
Balance, end of period at Sep. 30, 2018	3,625,760	$ 4	1,044,430	3,297,083	$ (564,123)	(162,362)	3,615,032	10,728
Transition adjustment for new accounting principle in period of adoption	2,862			2,862			2,862
Balance, beginning of period, adjusted	4,445,907	$ 5	1,334,030	3,372,516	$ (198,995)	(72,585)	4,434,971	10,936
Balance, beginning of period (in shares) at Dec. 31, 2018		75,711			3,589
Balance, beginning of period at Dec. 31, 2018	4,443,045	$ 5	1,334,030	3,369,654	$ (198,995)	(72,585)	4,432,109	10,936
Net income	389,903			390,406			390,406	(503)
Other comprehensive income (loss)	206,338					206,338	206,338
Repurchase of common stock (in shares)					1,292
Repurchase of common stock	(106,639)				$ (106,639)		(106,639)
Stock options exercised (in shares)		21
Stock options exercised	1,080		1,080				1,080
Non-vested shares awarded, net (in shares)		25
Non-vested shares awarded, net			0
Vesting of non-vested shares (in shares)					18
Vesting of non-vested shares	(1,428)				$ (1,428)		(1,428)
Share-based compensation	11,620		11,620				11,620
Cash dividends on common stock	(107,332)			(107,332)			(107,332)
Capital calls and distributions, net	(1,784)							(1,784)
Balance, end of period (in shares) at Sep. 30, 2019		75,757			4,899
Balance, end of period at Sep. 30, 2019	4,837,665	$ 5	1,346,730	3,655,590	$ (307,062)	133,753	4,829,016	8,649
Balance, beginning of period (in shares) at Jun. 30, 2019		75,756			4,562
Balance, beginning of period at Jun. 30, 2019	4,718,475	$ 5	1,343,082	3,548,907	$ (281,125)	98,569	4,709,438	9,037
Net income	141,858			142,231			142,231	(373)
Other comprehensive income (loss)	35,184					35,184	35,184
Repurchase of common stock (in shares)					337
Repurchase of common stock	(25,937)				$ (25,937)		(25,937)
Stock options exercised (in shares)		3
Stock options exercised	177		177				177
Non-vested shares awarded, net (in shares)		(2)
Non-vested shares awarded, net			0
Vesting of non-vested shares (in shares)					0
Vesting of non-vested shares					$ 0		0
Share-based compensation	3,471		3,471				3,471
Cash dividends on common stock	(35,548)			(35,548)			(35,548)
Capital calls and distributions, net	(15)							(15)
Balance, end of period (in shares) at Sep. 30, 2019		75,757			4,899
Balance, end of period at Sep. 30, 2019	$ 4,837,665	$ 5	$ 1,346,730	$ 3,655,590	$ (307,062)	$ 133,753	$ 4,829,016	$ 8,649