Consolidated Statement of Shareholder Equity Statement - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment [Member]	Series E Preferred Stock [Member]	Series F Preferred Stock [Member]	Common Stock [Member]	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Retained Earnings [Member] Cumulative Effect, Period of Adoption, Adjustment [Member]	Retained Earnings [Member] Series E Preferred Stock [Member]	Retained Earnings [Member] Series F Preferred Stock [Member]	Treasury Stock [Member]	AOCI Attributable to Parent [Member]
Beginning Balance at Dec. 31, 2018	$ 2,886,515					$ 145,037	$ 937	$ 1,114,394	$ 1,828,303				$ (71,504)	$ (130,652)
Beginning Balance (Accountign Standards Update 2017-08 and 2016-01) at Dec. 31, 2018		$ (513)								$ (513)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	382,723								382,723
Other Comprehensive Income (Loss), Net of Tax	94,580													94,580
Dividends, Common Stock	(141,286)							0	(141,286)
Dividends, Preferred Stock			$ (7,875)								$ (7,875)
Shares Granted, Value, Share-based Payment Arrangement, after Forfeiture	12,626							885	0				11,741
Stock Issued During Period, Value, Stock Options Exercised	619							(2,029)					2,648
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation	(6,616)												(6,616)
Stock Repurchased During Period, Value	(13,003)												(13,003)
Ending Balance at Dec. 31, 2019	$ 3,207,770	$ (51,213)				145,037	937	1,113,250	2,061,352	$ (51,213)			(76,734)	(36,072)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Dividends, Per Share, Declared					$ 1.53
Preferred Stock, Dividends Per Share, Declared			$ 1,312.5
Accounting Standards Update [Extensible Enumeration]	Accounting Standards Update 2016-02 [Member]
Net income	$ 220,621								220,621
Other Comprehensive Income (Loss), Net of Tax	78,328													78,328
Dividends, Common Stock	(145,363)								(145,363)
Dividends, Preferred Stock				$ (7,875)								$ (7,875)
Shares Granted, Value, Share-based Payment Arrangement, after Forfeiture	12,179							(3,524)					15,703
Stock Issued During Period, Value, Stock Options Exercised	240							(194)					434
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation	(3,506)												(3,506)
Stock Repurchased During Period, Value	(76,556)												(76,556)
Ending Balance at Dec. 31, 2020	3,234,625					145,037	937	1,109,532	2,077,522				(140,659)	42,256
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Dividends, Per Share, Declared					1.60
Preferred Stock, Dividends Per Share, Declared				$ 1,312.5
Net income	408,864								408,864
Other Comprehensive Income (Loss), Net of Tax	(64,836)													(64,836)
Dividends, Common Stock	(145,223)								(145,223)
Dividends, Preferred Stock				$ (7,875)								$ (7,875)
Shares Granted, Value, Share-based Payment Arrangement, after Forfeiture	13,662							4,235					9,427
Stock Issued During Period, Value, Stock Options Exercised	3,492							(5,173)					8,665
Share-based Payment Arrangement, Decrease for Tax Withholding Obligation	(4,384)												(4,384)
Ending Balance at Dec. 31, 2021	$ 3,438,325					$ 145,037	$ 937	$ 1,108,594	$ 2,333,288				$ (126,951)	$ (22,580)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Dividends, Per Share, Declared					$ 1.60
Preferred Stock, Dividends Per Share, Declared				$ 1,312.5