CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, Adjusted Balance	Series A Preferred Stock	Series B Preferred Stock	Common Stock	Preferred Stock	Preferred Stock Cumulative Effect, Period of Adoption, Adjusted Balance	Common Stock	Common Stock Cumulative Effect, Period of Adoption, Adjusted Balance	Common Stock Common Stock	Surplus	Surplus Cumulative Effect, Period of Adoption, Adjusted Balance	Surplus Common Stock	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	Retained Earnings Cumulative Effect, Period of Adoption, Adjusted Balance	Retained Earnings Series A Preferred Stock	Retained Earnings Series B Preferred Stock	Retained Earnings Common Stock	Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Loss Cumulative Effect, Period of Adoption, Adjusted Balance	Treasury Stock	Treasury Stock Cumulative Effect, Period of Adoption, Adjusted Balance
Beginning balance at Dec. 31, 2018	$ 3,350,454		$ 3,353,422				$ 209,691	$ 209,691	$ 116,240	$ 116,240		$ 2,796,499	$ 2,796,499		$ 299,642		$ 302,610				$ (69,431)	$ (69,431)	$ (2,187)	$ (2,187)
Beginning balance (ASU 2016-02) at Dec. 31, 2018		$ 4,414														$ 4,414
Beginning balance (ASU 2017-08) at Dec. 31, 2018		(1,446)														(1,446)
Beginning balance (in shares) at Dec. 31, 2018									331,431	331,431
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible Enumeration]	Accounting Standards Update 2016-13 [Member]
Net income	$ 309,793														309,793
Other comprehensive income (loss), net of tax	37,217																				37,217
Cash dividends declared on preferred stock				$ (7,188)	$ (5,500)													$ (7,188)	$ (5,500)
Cash dividends declared on common stock						$ (154,689)														$ (154,689)
Effect of stock incentive plan, net (in shares)									726
Effect of stock incentive plan, net	15,878								$ 291			15,346			(1,467)								1,708
Common stock issued (in shares)											71,121
Common stock issued						835,255					$ 24,892			$ 810,363
Ending balance at Dec. 31, 2019	4,384,188	$ (28,187)	$ 4,356,001				209,691	$ 209,691	$ 141,423	$ 141,423		3,622,208	$ 3,622,208		443,559	$ (28,187)	$ 415,372				(32,214)	$ (32,214)	(479)	$ (479)
Ending balance (in shares) at Dec. 31, 2019									403,278	403,278
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	390,606														390,606
Other comprehensive income (loss), net of tax	24,496																				24,496
Cash dividends declared on preferred stock				(7,188)	(5,500)													(7,188)	(5,500)
Cash dividends declared on common stock						(179,277)														(179,277)
Effect of stock incentive plan, net (in shares)									581
Effect of stock incentive plan, net	12,982								$ 323			15,260			(2,855)								254
Ending balance at Dec. 31, 2020	4,592,120						209,691		$ 141,746			3,637,468			611,158						(7,718)		(225)
Ending balance (in shares) at Dec. 31, 2020									403,859
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	473,840														473,840
Other comprehensive income (loss), net of tax	(10,214)																				(10,214)
Cash dividends declared on preferred stock				$ (7,188)	$ (5,500)													$ (7,188)	$ (5,500)
Cash dividends declared on common stock						(182,370)														$ (182,370)
Effect of stock incentive plan, net (in shares)									3,484
Effect of stock incentive plan, net	35,358								$ 1,238			39,931			(6,295)								484
Common stock issued (in shares)											15,709
Common stock issued						$ 211,134					$ 5,498			$ 205,636
Purchase of treasury stock (in shares)									(1,615)
Purchase of treasury stock	(23,114)																						(23,114)
Ending balance at Dec. 31, 2021	$ 5,084,066						$ 209,691		$ 148,482			$ 3,883,035			$ 883,645						$ (17,932)		$ (22,855)
Ending balance (in shares) at Dec. 31, 2021									421,437