Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Series E Preferred Stock	Series F Preferred Stock	Performance/Service Based RSAs, RSA,	Cumulative Effect, Period Of Adoption, Adjustment	Preferred Equity	Preferred Equity Cumulative Effect, Period Of Adoption, Adjustment	Common Stock	Common Stock Cumulative Effect, Period Of Adoption, Adjustment	Surplus	Surplus Cumulative Effect, Period Of Adoption, Adjustment	Retained Earnings [Member]	Retained Earnings [Member] Cumulative Effect, Period Of Adoption, Adjustment	Accumulated Other Comprehensive (Loss)	Accumulated Other Comprehensive (Loss) Cumulative Effect, Period Of Adoption, Adjustment	Treasury Stock, Common	Treasury Stock, Common Performance/Service Based RSAs, RSA,	Treasury Stock, Common Cumulative Effect, Period Of Adoption, Adjustment
Beginning balance at Dec. 31, 2021	$ 4,024,853				$ 4,026,566	$ 193,195	$ 193,195	$ 1,752	$ 1,752	$ 1,713,851	$ 1,713,851	$ 2,672,601	$ 2,674,314	$ (10,317)	$ (10,317)	$ (546,229)		$ (546,229)
Beginning balance (Accounting Standards Update 2016-13) at Dec. 31, 2021					1,713								1,713
Comprehensive income:
Net income	74,262											74,262
Net other comprehensive loss during period	(126,708)													(126,708)
Comprehensive income	(52,445)
Common stock issued:
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	6,654									(11,911)		0				18,565
Purchase of treasury stock,	(5,193)																$ (5,193)
Cash dividends:
Common stock	(30,583)											(30,583)
Preferred stock(a)	(2,875)											(2,875)
Stock-based compensation expense, net	6,164									6,164
Ending balance at Mar. 31, 2022	3,948,287					193,195		1,752		1,708,104		2,715,118		(137,024)		(532,858)
Cash dividends:
Preferred Stock, Dividends, Per Share, Cash Paid		$ 0.3671875	$ 0.3515625
Beginning balance at Dec. 31, 2021	4,024,853				4,026,566	193,195	$ 193,195	1,752	$ 1,752	1,713,851	$ 1,713,851	2,672,601	2,674,314	(10,317)	$ (10,317)	(546,229)		$ (546,229)
Beginning balance (Accounting Standards Update 2016-13) at Dec. 31, 2021					$ 1,713								$ 1,713
Comprehensive income:
Net income	257,360											257,360
Net other comprehensive loss during period	(245,074)													(245,074)
Comprehensive income	12,286
Ending balance at Sep. 30, 2022	3,953,952					194,112		1,752		1,710,075		2,830,877		(255,391)		(527,473)
Beginning balance at Mar. 31, 2022	3,948,287					193,195		1,752		1,708,104		2,715,118		(137,024)		(532,858)
Comprehensive income:
Net income	86,824											86,824
Net other comprehensive loss during period	(45,764)													(45,764)
Comprehensive income	41,060
Common stock issued:
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	139									(1,771)		0				1,910
Purchase of treasury stock,	(884)																(884)
Cash dividends:
Common stock	(30,331)											(30,331)
Preferred stock(a)	(2,875)											(2,875)
Stock-based compensation expense, net	3,986									3,986
Ending balance at Jun. 30, 2022	3,959,382					193,195		1,752		1,710,319		2,768,736		(182,788)		(531,832)
Cash dividends:
Preferred Stock, Dividends, Per Share, Cash Paid		0.3671875	0.3515625
Net income	96,275											96,275
Net other comprehensive loss during period	(72,603)													(72,603)
Comprehensive income	23,672
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	1,266									(3,274)		0				4,540
Purchase of treasury stock,				$ (181)													(181)
Common stock	(30,342)											(30,342)
Preferred stock(a)	(2,875)											(2,875)
Stock-based compensation expense, net	3,030									3,030
Ending balance at Sep. 30, 2022	3,953,952					194,112		1,752		1,710,075		2,830,877		(255,391)		(527,473)
Cash dividends:
Preferred Stock, Dividends, Per Share, Cash Paid		0.3671875	0.3515625
Other	0					916						(916)
Beginning balance at Dec. 31, 2022	4,015,490					194,112		1,752		1,712,733		2,904,882		(272,799)		(525,190)
Comprehensive income:
Net income	103,360											103,360
Net other comprehensive loss during period	39,211													39,211
Comprehensive income	142,571
Common stock issued:
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	1,766									(12,612)						14,379
Purchase of treasury stock,	(5,362)																(5,362)
Cash dividends:
Common stock	(32,013)											(32,013)
Preferred stock(a)	(2,875)											(2,875)
Stock-based compensation expense, net	6,086									6,086
Ending balance at Mar. 31, 2023	4,125,663					194,112		1,752		1,706,206		2,973,354		(233,588)		(516,173)
Cash dividends:
Preferred Stock, Dividends, Per Share, Cash Paid		0.3671875	0.3515625
Beginning balance at Dec. 31, 2022	4,015,490					194,112		1,752		1,712,733		2,904,882		(272,799)		(525,190)
Comprehensive income:
Net income	273,762											273,762
Net other comprehensive loss during period	(66,340)													(66,340)
Comprehensive income	207,422
Ending balance at Sep. 30, 2023	4,127,643					194,112		1,752		1,711,454		3,074,014		(339,140)		(514,549)
Beginning balance at Mar. 31, 2023	4,125,663					194,112		1,752		1,706,206		2,973,354		(233,588)		(516,173)
Comprehensive income:
Net income	87,154											87,154
Net other comprehensive loss during period	(58,054)													(58,054)
Comprehensive income	29,100
Common stock issued:
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	93									(1,677)						1,770
Purchase of treasury stock,	(884)																(884)
Cash dividends:
Common stock	(31,996)											(31,996)
Preferred stock(a)	(2,875)											(2,875)
Stock-based compensation expense, net	3,773									3,773
Ending balance at Jun. 30, 2023	4,122,874					194,112		1,752		1,708,303		3,025,637		(291,642)		(515,287)
Cash dividends:
Preferred Stock, Dividends, Per Share, Cash Paid		0.3671875	0.3515625
Net income	83,248											83,248
Net other comprehensive loss during period	(47,497)													(47,497)
Comprehensive income	35,751
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	503									(497)						999
Purchase of treasury stock,				$ (261)													$ (261)
Common stock	(31,996)											(31,996)
Preferred stock(a)	(2,875)											(2,875)
Stock-based compensation expense, net	3,648									3,648
Ending balance at Sep. 30, 2023	$ 4,127,643					$ 194,112		$ 1,752		$ 1,711,454		$ 3,074,014		$ (339,140)		$ (514,549)
Cash dividends:
Preferred Stock, Dividends, Per Share, Cash Paid		$ 0.3671875	$ 0.3515625