Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Series C Preferred Stock	Series D Preferred Stock	Series E Preferred Stock	Series F Preferred Stock	Board Authorized Purchase Program [Member]	Performance/Service Based RSAs, RSA,	Cumulative Effect, Period Of Adoption, Adjustment	Preferred Equity	Preferred Equity Series C Preferred Stock	Preferred Equity Series D Preferred Stock	Common Stock	Surplus	Retained Earnings	Retained Earnings Series C Preferred Stock	Retained Earnings Series D Preferred Stock	Retained Earnings Cumulative Effect, Period Of Adoption, Adjustment	Accumulated Other Comprehensive (Loss)	Treasury Stock	Treasury Stock Board Authorized Purchase Program [Member]	Treasury Stock Performance/Service Based RSAs, RSA,
Beginning balance at Dec. 31, 2020	$ 4,090,933								$ 353,512			$ 1,752	$ 1,720,329	$ 2,458,920				$ 12,618	$ (456,198)
Comprehensive (loss):
Net income	94,301													94,301
Net other comprehensive (loss) during period	(16,811)																	(16,811)
Comprehensive income	77,490
Common stock issued
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	10,556												(16,986)	0					27,542
Purchase of treasury stock,						$ (17,973)	$ (3,593)													$ (17,973)	$ (3,593)
Cash dividends
Common stock	(27,870)													(27,870)
Preferred stock(b)	(5,207)													(5,207)
Stock-based compensation expense, net	3,444												3,444
Ending balance at Mar. 31, 2021	4,127,780								353,512			1,752	1,706,786	2,520,144				(4,193)	(450,222)
Cash dividends
Preferred Stock, Dividends, Per Share, Cash Paid		$ 0.3828125	$ 0.3359375	$ 0.3671875	$ 0.3515625
Beginning balance at Dec. 31, 2020	4,090,933								353,512			1,752	1,720,329	2,458,920				12,618	(456,198)
Comprehensive (loss):
Net income	274,117													274,117
Net other comprehensive (loss) during period	(23,431)																	(23,431)
Comprehensive income	250,685
Ending balance at Sep. 30, 2021	3,994,961								193,195			1,752	1,711,867	2,628,421				(10,813)	(529,461)
Beginning balance at Mar. 31, 2021	4,127,780								353,512			1,752	1,706,786	2,520,144				(4,193)	(450,222)
Comprehensive (loss):
Net income	91,007													91,007
Net other comprehensive (loss) during period	7,082																	7,082
Comprehensive income	98,088
Common stock issued
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	7,618												(3,632)	0					11,250
Purchase of treasury stock,						(29,972)	(856)													(29,972)	(856)
Cash dividends
Common stock	(27,822)													(27,822)
Preferred stock(b)	(4,875)													(4,875)
Stock-based compensation expense, net	5,092												5,092
Ending balance at Jun. 30, 2021	4,110,052								290,200			1,752	1,708,246	2,576,766				2,889	(469,801)
Cash dividends
Preferred Stock, Dividends, Per Share, Cash Paid		$ 0.3197115	0.3359375	0.3671875	0.3515625
Stock Redeemed or Called During Period, Value		$ (65,000)								$ (63,313)					$ (1,687)
Net income	88,809													88,809
Net other comprehensive (loss) during period	(13,702)																	(13,702)
Comprehensive income	75,107
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	455												6	0					449
Purchase of treasury stock,						$ (59,998)	(112)													$ (59,998)	(112)
Common stock	(30,546)													(30,546)
Preferred stock(b)	(4,155)													(4,155)
Stock-based compensation expense, net	3,616												3,616
Ending balance at Sep. 30, 2021	3,994,961								193,195			1,752	1,711,867	2,628,421				(10,813)	(529,461)
Cash dividends
Preferred Stock, Dividends, Per Share, Cash Paid			$ 0.2842548	0.3671875	0.3515625
Stock Redeemed or Called During Period, Value			$ (99,458)								$ (97,004)					$ (2,454)
Beginning balance at Dec. 31, 2021	4,024,853								193,195			1,752	1,713,851	2,672,601				(10,317)	(546,229)
Beginning balance (Mortgage Servicing Rights, Accounting Policy Change From At Cost to Fair Value) at Dec. 31, 2021	4,026,566							$ 1,713	193,195			1,752	1,713,851	2,674,314			$ 1,713	(10,317)	(546,229)
Comprehensive (loss):
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)						18,565
Purchase of treasury stock,							(5,193)														(5,193)
Cash dividends
Common stock	(30,583)													(30,583)
Preferred stock(b)	(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								193,195			1,752	1,713,851	2,672,601				(10,317)	(546,229)
Beginning balance (Mortgage Servicing Rights, Accounting Policy Change From At Cost to Fair Value) at Dec. 31, 2021	4,026,566							$ 1,713	193,195			1,752	1,713,851	2,674,314			$ 1,713	(10,317)	(546,229)
Comprehensive (loss):
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 (loss):
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)						1,910
Purchase of treasury stock,							(884)														(884)
Cash dividends
Common stock	(30,331)													(30,331)
Preferred stock(b)	(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)
Comprehensive (loss):
Net income	96,275													96,275
Net other comprehensive (loss) during period	(72,603)																	(72,603)
Comprehensive income	23,672
Common stock issued
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	1,266												(3,274)						4,540
Purchase of treasury stock,							$ (181)														$ (181)
Cash dividends
Common stock	(30,342)													(30,342)
Preferred stock(b)	(2,875)													(2,875)
Stock-based compensation expense, net	3,030												3,030
Stockholders' Equity, Other	0								(916)					916
Ending balance at Sep. 30, 2022	$ 3,953,952								$ 194,112			$ 1,752	$ 1,710,075	$ 2,830,877				$ (255,391)	$ (527,473)