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	220,502			219,934			219,934	568
Other comprehensive income (loss)	(96,422)					(96,422)	(96,422)
Repurchase of common stock (in shares)					90
Repurchase of common stock	(8,408)				$ (8,408)		(8,408)
Stock options exercised (in shares)		46
Stock options exercised	2,426		2,426				2,426
Non-vested shares awarded, net (in shares)		120
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	1,881		1,881				1,881
Cash dividends on common stock	(58,477)			(58,477)			(58,477)
Capital calls and distributions, net	(921)							(921)
Balance, end of period (in shares) at Jun. 30, 2018		75,314			9,874
Balance, end 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
Balance, beginning of period (in shares) at Mar. 31, 2018		75,318			9,859
Balance, beginning of period at Mar. 31, 2018	3,517,342	$ 4	1,041,242	3,127,575	$ (562,601)	(111,191)	3,495,029	22,313
Net income	115,155			114,372			114,372	783
Other comprehensive income (loss)	(24,114)					(24,114)	(24,114)
Repurchase of common stock (in shares)					7
Repurchase of common stock	(824)				$ (824)		(824)
Stock options exercised (in shares)		3
Stock options exercised	152		152				152
Non-vested shares awarded, net (in shares)		(7)
Non-vested shares awarded, net			0
Vesting of non-vested shares (in shares)					8
Vesting of non-vested shares	(698)				$ (698)		(698)
Share-based compensation	(1,192)		(1,192)				(1,192)
Cash dividends on common stock	(29,294)			(29,294)			(29,294)
Capital calls and distributions, net	(482)							(482)
Balance, end of period (in shares) at Jun. 30, 2018		75,314			9,874
Balance, end 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
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	248,045			248,175			248,175	(130)
Other comprehensive income (loss)	171,154					171,154	171,154
Repurchase of common stock (in shares)					955
Repurchase of common stock	(80,702)				$ (80,702)		(80,702)
Stock options exercised (in shares)		18
Stock options exercised	903		903				903
Non-vested shares awarded, net (in shares)		27
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	8,149		8,149				8,149
Cash dividends on common stock	(71,784)			(71,784)			(71,784)
Capital calls and distributions, net	(1,769)							(1,769)
Balance, end of period (in shares) at Jun. 30, 2019		75,756			4,562
Balance, end 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
Balance, beginning of period (in shares) at Mar. 31, 2019		75,762			4,312
Balance, beginning of period at Mar. 31, 2019	4,531,709	$ 5	1,340,323	3,447,076	$ (261,000)	(3,531)	4,522,873	8,836
Net income	137,780			137,563			137,563	217
Other comprehensive income (loss)	102,100					102,100	102,100
Repurchase of common stock (in shares)					250
Repurchase of common stock	(20,125)				$ (20,125)		(20,125)
Stock options exercised (in shares)		0
Stock options exercised	24		24				24
Non-vested shares awarded, net (in shares)		(6)
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	2,735		2,735				2,735
Cash dividends on common stock	(35,732)			(35,732)			(35,732)
Capital calls and distributions, net	(16)							(16)
Balance, end of period (in shares) at Jun. 30, 2019		75,756			4,562
Balance, end 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