Consolidated Statements Of Changes In Equity - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, Adjusted Balance	Preferred Stock [Member]	Preferred Stock [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	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, Adjustment	Retained Earnings [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	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	Non-Controlling Interest [Member]	Non-Controlling Interest [Member] Cumulative Effect, Period of Adoption, Adjusted Balance
Balance at Dec. 31, 2018	$ 2,937,149			$ 144,784		$ 559,432		$ 2,084,824		$ 241,163			$ (34,236)		$ (64,669)		$ 5,851
Net income	315,434									314,351							1,083
Other comprehensive income (loss)	208,842														208,842
Distributions to non-controlling interest	(3,520)																(3,520)
Purchase of treasury stock	(119,970)												(119,970)
Accelerated Share Repurchase Program, Adjustment	(150,000)							(37,500)					(112,500)
Issuance of stock, under purchase and equity compensation plans	(3)							(15,046)					15,043
Stock-based compensation	10,365							10,365
Cash dividends per share, Common Stock, Cash	(85,533)									(85,533)
Dividends per share, Preferred Stock, Cash	(6,750)									(6,750)
Balance at Sep. 30, 2019	3,106,014			144,784		559,432		2,042,643		463,231			(251,663)		144,173		3,414
Balance at Jun. 30, 2019	3,171,363			144,784		559,432		2,077,491		384,232			(106,106)		108,898		2,632
Net income	110,080									109,242							838
Other comprehensive income (loss)	35,275														35,275
Distributions to non-controlling interest	(56)																(56)
Purchase of treasury stock	(33,891)												(33,891)
Accelerated Share Repurchase Program, Adjustment	(150,000)							(37,500)					(112,500)
Issuance of stock, under purchase and equity compensation plans	0							(834)					834
Stock-based compensation	3,486							3,486
Cash dividends per share, Common Stock, Cash	(27,993)									(27,993)
Dividends per share, Preferred Stock, Cash	(2,250)									(2,250)
Balance at Sep. 30, 2019	3,106,014			144,784		559,432		2,042,643		463,231			(251,663)		144,173		3,414
Balance at Dec. 31, 2019	3,138,472	$ 3,766	$ 3,142,238	144,784	$ 144,784	563,978	$ 563,978	2,151,464	$ 2,151,464	201,562	$ 3,766	$ 205,328	(37,548)	$ (37,548)	110,444	$ 110,444	3,788	$ 3,788
Net income	221,689									224,168							(2,479)
Other comprehensive income (loss)	232,991														232,991
Distributions to non-controlling interest	(708)																(708)
Purchase of treasury stock	(53,760)												(53,760)
Redemption of preferred stock	(150,000)			(144,784)						(5,216)
Issuance of stock, under purchase and equity compensation plans	(27)							(22,285)					22,258
Stock-based compensation	11,231							11,231
Cash dividends per share, Common Stock, Cash	(90,640)									(90,640)
Dividends per share, Preferred Stock, Cash	(6,750)									(6,750)
Balance at Sep. 30, 2020	3,306,264			0		563,978		2,140,410		326,890			(69,050)		343,435		601
Balance at Jun. 30, 2020	3,358,169			144,784		563,978		2,136,874		232,082			(69,112)		349,261		302
Net income	133,355									132,448							907
Other comprehensive income (loss)	(5,826)														(5,826)
Distributions to non-controlling interest	(608)																(608)
Purchase of treasury stock	(167)												(167)
Redemption of preferred stock	(150,000)			(144,784)						(5,216)
Issuance of stock, under purchase and equity compensation plans	0							(229)					229
Stock-based compensation	3,765							3,765
Cash dividends per share, Common Stock, Cash	(30,174)									(30,174)
Dividends per share, Preferred Stock, Cash	(2,250)									(2,250)
Balance at Sep. 30, 2020	$ 3,306,264			$ 0		$ 563,978		$ 2,140,410		$ 326,890			$ (69,050)		$ 343,435		$ 601