CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS’ EQUITY (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Preferred Series A	Preferred Series B	Common Stock	Preferred Stock	Common Stock	Surplus	Retained Earnings	Retained Earnings Preferred Series A	Retained Earnings Preferred Series B	Retained Earnings Common Stock	Accumulated Other Comprehensive Loss	Treasury Stock
Beginning balance at Dec. 31, 2020	$ 4,592,120				$ 209,691	$ 141,746	$ 3,637,468	$ 611,158				$ (7,718)	$ (225)
Beginning balance (in shares) at Dec. 31, 2020						403,859
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	115,710							115,710
Other comprehensive income (loss), net of tax	(9,287)											(9,287)
Cash dividends declared:
Cash dividends declared on preferred stock		$ (1,797)	$ (1,375)						$ (1,797)	$ (1,375)
Cash dividends declared on common stock				$ (45,281)							$ (45,281)
Effect of stock incentive plan, net (in shares)						1,939
Effect of stock incentive plan, net	9,580					$ 689	14,480	(5,764)					175
Ending balance at Mar. 31, 2021	4,659,670				209,691	$ 142,435	3,651,948	672,651				(17,005)	(50)
Ending balance (in shares) at Mar. 31, 2021						405,798
Beginning balance at Dec. 31, 2021	5,084,066				209,691	$ 148,482	3,883,035	883,645				(17,932)	(22,855)
Beginning balance (in shares) at Dec. 31, 2021						421,437
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	116,728							116,728
Other comprehensive income (loss), net of tax	(38,166)											(38,166)
Cash dividends declared:
Cash dividends declared on preferred stock		$ (1,797)	$ (1,375)						$ (1,797)	$ (1,375)
Cash dividends declared on common stock				$ (46,803)							$ (46,803)
Effect of stock incentive plan, net (in shares)						972
Effect of stock incentive plan, net	(2,752)						(10,799)	(5,173)					13,220
Purchase of treasury stock (in shares)						(1,015)
Purchase of treasury stock	(13,517)												(13,517)
Ending balance at Mar. 31, 2022	$ 5,096,384				$ 209,691	$ 148,482	$ 3,872,236	$ 945,225				$ (56,098)	$ (23,152)
Ending balance (in shares) at Mar. 31, 2022						421,394