Consolidated Statements of Changes in Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjusted Balance	Cumulative Effect, Period of Adoption, Adjustment	Common Stock [Member]	Common Stock [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	Capital Surplus [Member]	Capital Surplus [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	Retained Earnings [Member]	Retained Earnings [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	Retained Earnings [Member] Cumulative Effect, Period of Adoption, Adjustment	Treasury Stock [Member]	Treasury Stock [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Other Comprehensive Income (Loss) [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	Total Shareholders' Equity [Member]	Total Shareholders' Equity [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	Total Shareholders' Equity [Member] Cumulative Effect, Period of Adoption, Adjustment	Non-Controlling Interests [Member]	Non-Controlling Interests [Member] Cumulative Effect, Period of Adoption, Adjusted Balance
Balance, beginning of period (in shares) at Dec. 31, 2018				75,711	75,711						3,589	3,589
Balance, beginning of period at Dec. 31, 2018	$ 4,443,045	$ 4,445,907	$ 2,862	$ 5	$ 5	$ 1,334,030	$ 1,334,030	$ 3,369,654	$ 3,372,516	$ 2,862	$ (198,995)	$ (198,995)	$ (72,585)	$ (72,585)	$ 4,432,109	$ 4,434,971	$ 2,862	$ 10,936	$ 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				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
Balance, beginning of period (in shares) at Dec. 31, 2019				75,759	75,759						5,179	5,179
Balance, beginning of period at Dec. 31, 2019	4,863,919	$ 4,817,223	$ (46,696)	$ 5	$ 5	1,350,995	$ 1,350,995	3,729,778	$ 3,683,082	$ (46,696)	$ (329,906)	$ (329,906)	104,923	$ 104,923	4,855,795	$ 4,809,099	$ (46,696)	8,124	$ 8,124
Net income	280,362							280,806							280,806			(444)
Other comprehensive income (loss)	260,247												260,247		260,247
Repurchase of common stock (in shares)											442
Repurchase of common stock	(33,380)										$ (33,380)				(33,380)
Stock options exercised (in shares)				10
Stock options exercised	586					586									586
Non-vested shares awarded, net (in shares)				229
Non-vested shares awarded, net						0
Vesting of non-vested shares (in shares)											72
Vesting of non-vested shares	(5,608)										$ (5,608)				(5,608)
Share-based compensation	14,879					14,879									14,879
Cash dividends on common stock	(107,842)							(107,842)							(107,842)
Capital calls and distributions, net	(358)																	(358)
Balance, end of period (in shares) at Sep. 30, 2020				75,998							5,693
Balance, end of period at Sep. 30, 2020	5,226,109			$ 5		1,366,460		3,856,046			$ (368,894)		365,170		5,218,787			7,322
Balance, beginning of period (in shares) at Jun. 30, 2020				75,999							5,693
Balance, beginning of period at Jun. 30, 2020	5,104,423			$ 5		1,357,706		3,737,862			$ (368,894)		370,316		5,096,995			7,428
Net income	154,092							154,034							154,034			58
Other comprehensive income (loss)	(5,146)												(5,146)		(5,146)
Repurchase of common stock (in shares)											0
Repurchase of common stock	0										$ 0				0
Stock options exercised (in shares)				0
Stock options exercised	0					0									0
Non-vested shares awarded, net (in shares)				(1)
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	8,754					8,754									8,754
Cash dividends on common stock	(35,850)							(35,850)							(35,850)
Capital calls and distributions, net	(164)																	(164)
Balance, end of period (in shares) at Sep. 30, 2020				75,998							5,693
Balance, end of period at Sep. 30, 2020	$ 5,226,109			$ 5		$ 1,366,460		$ 3,856,046			$ (368,894)		$ 365,170		$ 5,218,787			$ 7,322