Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Treasury Stock, Common
Total shareholders’ equity at beginning of period at Dec. 31, 2022	$ 3,137,228	$ 145,452	$ 643	$ 1,029,756	$ 3,309,671	$ (1,348,294)	$ 0
Net income	339,771				339,771
Other comprehensive income (loss)	43,267					43,267
Stock option exercises/stock unit conversions (38,452 shares QTD and 122,628 shares YTD in 2024 and 13,626 shares QTD and 64,013 shares YTD in 2023)	2,446		1	1,463	(519)		1,501
Stock compensation expense recognized in earnings	9,535			9,535
Purchase of treasury stock (301,094 shares QTD and 319,287 shares YTD in 2024 and 289,149 shares QTD and 298,332 shares YTD in 2023)	(29,124)						(29,124)
Cash dividends – preferred stock (approximately $11.13 per share which is equivalent to approximately $0.28 per depository share QTD and $22.25 per share which is equivalent to approximately $0.56 per depository share YTD in both 2024 and 2023, respectively.)	(3,338)				(3,338)
Cash dividends – common stock ($0.92 per share QTD and $1.84 per share YTD in 2024 and $0.87 per share QTD and $1.74 per share YTD in 2023)	(113,043)				(113,043)
Total shareholders’ equity at end of period at Jun. 30, 2023	3,386,742	145,452	644	1,040,754	3,532,542	(1,305,027)	(27,623)
Total shareholders’ equity at beginning of period at Dec. 31, 2022	3,137,228	145,452	643	1,029,756	3,309,671	(1,348,294)	0
Total shareholders’ equity at end of period at Dec. 31, 2023	3,716,447	145,452	644	1,055,809	3,657,688	(1,119,219)	(23,927)
Total shareholders’ equity at beginning of period at Mar. 31, 2023	3,467,801	145,452	644	1,035,961	3,428,991	(1,142,138)	(1,109)
Net income	162,118				162,118
Other comprehensive income (loss)	(162,889)					(162,889)
Stock option exercises/stock unit conversions (38,452 shares QTD and 122,628 shares YTD in 2024 and 13,626 shares QTD and 64,013 shares YTD in 2023)	946				(491)		1,437
Stock compensation expense recognized in earnings	4,793			4,793
Purchase of treasury stock (301,094 shares QTD and 319,287 shares YTD in 2024 and 289,149 shares QTD and 298,332 shares YTD in 2023)	(27,951)						(27,951)
Cash dividends – preferred stock (approximately $11.13 per share which is equivalent to approximately $0.28 per depository share QTD and $22.25 per share which is equivalent to approximately $0.56 per depository share YTD in both 2024 and 2023, respectively.)	(1,669)				(1,669)
Cash dividends – common stock ($0.92 per share QTD and $1.84 per share YTD in 2024 and $0.87 per share QTD and $1.74 per share YTD in 2023)	(56,407)				(56,407)
Total shareholders’ equity at end of period at Jun. 30, 2023	3,386,742	145,452	644	1,040,754	3,532,542	(1,305,027)	(27,623)
Total shareholders’ equity at beginning of period at Dec. 31, 2023	3,716,447	145,452	644	1,055,809	3,657,688	(1,119,219)	(23,927)
Net income	281,189				281,189
Other comprehensive income (loss)	(190,125)					(190,125)
Stock option exercises/stock unit conversions (38,452 shares QTD and 122,628 shares YTD in 2024 and 13,626 shares QTD and 64,013 shares YTD in 2023)	5,209				(5,919)		11,128
Stock compensation expense recognized in earnings	8,261			8,261
Purchase of treasury stock (301,094 shares QTD and 319,287 shares YTD in 2024 and 289,149 shares QTD and 298,332 shares YTD in 2023)	(32,226)						(32,226)
Cash dividends – preferred stock (approximately $11.13 per share which is equivalent to approximately $0.28 per depository share QTD and $22.25 per share which is equivalent to approximately $0.56 per depository share YTD in both 2024 and 2023, respectively.)	(3,338)				(3,338)
Cash dividends – common stock ($0.92 per share QTD and $1.84 per share YTD in 2024 and $0.87 per share QTD and $1.74 per share YTD in 2023)	(119,612)				(119,612)
Total shareholders’ equity at end of period at Jun. 30, 2024	3,665,805	145,452	644	1,064,070	3,810,008	(1,309,344)	(45,025)
Total shareholders’ equity at beginning of period at Mar. 31, 2024	3,638,180	145,452	644	1,059,547	3,726,559	(1,276,283)	(17,739)
Net income	145,499				145,499
Other comprehensive income (loss)	(33,061)					(33,061)
Stock option exercises/stock unit conversions (38,452 shares QTD and 122,628 shares YTD in 2024 and 13,626 shares QTD and 64,013 shares YTD in 2023)	2,294				(573)		2,867
Stock compensation expense recognized in earnings	4,523			4,523
Purchase of treasury stock (301,094 shares QTD and 319,287 shares YTD in 2024 and 289,149 shares QTD and 298,332 shares YTD in 2023)	(30,153)						(30,153)
Cash dividends – preferred stock (approximately $11.13 per share which is equivalent to approximately $0.28 per depository share QTD and $22.25 per share which is equivalent to approximately $0.56 per depository share YTD in both 2024 and 2023, respectively.)	(1,669)				(1,669)
Cash dividends – common stock ($0.92 per share QTD and $1.84 per share YTD in 2024 and $0.87 per share QTD and $1.74 per share YTD in 2023)	(59,808)				(59,808)
Total shareholders’ equity at end of period at Jun. 30, 2024	$ 3,665,805	$ 145,452	$ 644	$ 1,064,070	$ 3,810,008	$ (1,309,344)	$ (45,025)