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	205,354									205,109							245
Other comprehensive income (loss)	173,567														173,567
Distributions to non-controlling interest	(3,464)																(3,464)
Purchase of treasury stock	(86,079)												(86,079)
Issuance of stock, under purchase and equity compensation plans	(3)							(14,212)					14,209
Stock-based compensation	6,879							6,879
Cash dividends per share, Common Stock, Cash	(57,540)									(57,540)
Dividends per share, Preferred Stock, Cash	(4,500)									(4,500)
Balance at Jun. 30, 2019	3,171,363			144,784		559,432		2,077,491		384,232			(106,106)		108,898		2,632
Balance at Mar. 31, 2019	3,043,213			144,784		559,432		2,074,912		307,193			(60,547)		11,981		5,458
Net income	108,299									107,971							328
Other comprehensive income (loss)	96,917														96,917
Distributions to non-controlling interest	(3,154)																(3,154)
Purchase of treasury stock	(46,380)												(46,380)
Issuance of stock, under purchase and equity compensation plans	1							(820)					821
Stock-based compensation	3,399							3,399
Cash dividends per share, Common Stock, Cash	(28,682)									(28,682)
Dividends per share, Preferred Stock, Cash	(2,250)									(2,250)
Balance at Jun. 30, 2019	3,171,363			144,784		559,432		2,077,491		384,232			(106,106)		108,898		2,632
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	88,334									91,720							(3,386)
Other comprehensive income (loss)	238,817														238,817
Distributions to non-controlling interest	(100)																(100)
Purchase of treasury stock	(53,593)												(53,593)
Issuance of stock, under purchase and equity compensation plans	(27)							(22,056)					22,029
Stock-based compensation	7,466							7,466
Cash dividends per share, Common Stock, Cash	(60,466)									(60,466)
Dividends per share, Preferred Stock, Cash	(4,500)									(4,500)
Balance at Jun. 30, 2020	3,358,169			144,784		563,978		2,136,874		232,082			(69,112)		349,261		302
Balance at Mar. 31, 2020	3,252,464			144,784		563,978		2,133,623		224,643			(69,149)		253,136		1,449
Net income	38,731									39,863							(1,132)
Other comprehensive income (loss)	96,125														96,125
Distributions to non-controlling interest	(15)																(15)
Purchase of treasury stock	(448)												(448)
Issuance of stock, under purchase and equity compensation plans	(3)							(488)					485
Stock-based compensation	3,739							3,739
Cash dividends per share, Common Stock, Cash	(30,174)									(30,174)
Dividends per share, Preferred Stock, Cash	(2,250)									(2,250)
Balance at Jun. 30, 2020	$ 3,358,169			$ 144,784		$ 563,978		$ 2,136,874		$ 232,082			$ (69,112)		$ 349,261		$ 302