Condensed Consolidated Statements of Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Series F Preferred Stock	Series G Preferred Stock	Preferred Stock	Common Stock	Paid-In Capital	Retained Earnings	Retained Earnings Series F Preferred Stock	Retained Earnings Series G Preferred Stock	Treasury Stock, at cost	Accumulated Other Comprehensive Income (Loss), Net of Tax
Beginning 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]
Net (loss) income	108,078						108,078
Other comprehensive (loss), net of tax	(33,982)										(33,982)
Common stock dividends and equivalents	(36,195)						(36,195)
Preferred stock dividends		$ (1,969)						$ (1,969)
Stock-based compensation	2,965					649				2,316
Exercise of stock options	3,314					(5,044)				8,358
Common shares acquired from stock compensation plan activity	(3,908)									(3,908)
Ending Balance at Mar. 31, 2021	3,272,928			145,037	937	1,105,137	2,147,436			(133,893)	8,274
Beginning 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]
Net (loss) income	(16,747)						(16,747)
Other comprehensive (loss), net of tax	(253,143)										(253,143)
Common stock dividends and equivalents	(36,234)						(36,234)
Preferred stock dividends		$ (1,969)	$ (1,463)					$ (1,969)	$ (1,463)
Issued in business combination	5,180,124			138,942	891	5,040,291
Stock-based compensation	9,003					(19,098)				28,101
Exercise of stock options	411					(347)				758
Common shares acquired from stock compensation plan activity	(18,967)									(18,967)
Common stock repurchase program	(122,205)									(122,205)
Ending Balance at Mar. 31, 2022	$ 8,177,135			$ 283,979	$ 1,828	$ 6,129,440	$ 2,276,875			$ (239,264)	$ (275,723)