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, 2021	$ 4,439,555	$ 145,452	$ 642	$ 1,009,921	$ 2,956,966	$ 347,318	$ (20,744)
Net income	218,216				218,216
Other comprehensive income (loss)	(1,221,524)					(1,221,524)
Stock option exercises/stock unit conversions (13,626 shares QTD and 64,013 shares YTD in 2023 and 28,832 shares QTD and 144,262 shares YTD in 2022)	6,490				(4,777)		11,267
Stock compensation expense recognized in earnings	5,530			5,530
Purchase of treasury stock (289,149 shares QTD and 298,332 shares YTD in 2023 and 7,459 shares YTD in 2022)	(996)						(996)
Cash dividends – preferred stock (approximately $11.13 per share which is equivalent to approximately $0.28 per depository share QTD in 2023 and 2022, respectively and approximately $22.25 per share which is equivalent to approximately $0.56 per depository share YTD in 2023 and 2022, respectively )	(3,338)				(3,338)
Cash dividends – common stock ($0.87 per share QTD and $1.74 per share YTD in 2023 and $0.75 per share QTD and $1.50 per share YTD in 2022)	(96,958)				(96,958)
Total shareholders’ equity at end of period at Jun. 30, 2022	3,346,975	145,452	642	1,015,451	3,070,109	(874,206)	(10,473)
Total shareholders’ equity at beginning of period at Mar. 31, 2022	3,776,292	145,452	642	1,012,033	3,002,642	(371,790)	(12,687)
Net income	119,114				119,114
Other comprehensive income (loss)	(502,416)					(502,416)
Stock option exercises/stock unit conversions (13,626 shares QTD and 64,013 shares YTD in 2023 and 28,832 shares QTD and 144,262 shares YTD in 2022)	751				(1,463)		2,214
Stock compensation expense recognized in earnings	3,418			3,418
Cash dividends – preferred stock (approximately $11.13 per share which is equivalent to approximately $0.28 per depository share QTD in 2023 and 2022, respectively and approximately $22.25 per share which is equivalent to approximately $0.56 per depository share YTD in 2023 and 2022, respectively )	(1,669)				(1,669)
Cash dividends – common stock ($0.87 per share QTD and $1.74 per share YTD in 2023 and $0.75 per share QTD and $1.50 per share YTD in 2022)	(48,515)				(48,515)
Total shareholders’ equity at end of period at Jun. 30, 2022	3,346,975	145,452	642	1,015,451	3,070,109	(874,206)	(10,473)
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 (13,626 shares QTD and 64,013 shares YTD in 2023 and 28,832 shares QTD and 144,262 shares YTD in 2022)	2,446		1	1,463	(519)		1,501
Stock compensation expense recognized in earnings	9,535			9,535
Purchase of treasury stock (289,149 shares QTD and 298,332 shares YTD in 2023 and 7,459 shares YTD in 2022)	(29,124)						(29,124)
Cash dividends – preferred stock (approximately $11.13 per share which is equivalent to approximately $0.28 per depository share QTD in 2023 and 2022, respectively and approximately $22.25 per share which is equivalent to approximately $0.56 per depository share YTD in 2023 and 2022, respectively )	(3,338)				(3,338)
Cash dividends – common stock ($0.87 per share QTD and $1.74 per share YTD in 2023 and $0.75 per share QTD and $1.50 per share YTD in 2022)	(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 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 (13,626 shares QTD and 64,013 shares YTD in 2023 and 28,832 shares QTD and 144,262 shares YTD in 2022)	946				(491)		1,437
Stock compensation expense recognized in earnings	4,793			4,793
Purchase of treasury stock (289,149 shares QTD and 298,332 shares YTD in 2023 and 7,459 shares YTD in 2022)	(27,951)						(27,951)
Cash dividends – preferred stock (approximately $11.13 per share which is equivalent to approximately $0.28 per depository share QTD in 2023 and 2022, respectively and approximately $22.25 per share which is equivalent to approximately $0.56 per depository share YTD in 2023 and 2022, respectively )	(1,669)				(1,669)
Cash dividends – common stock ($0.87 per share QTD and $1.74 per share YTD in 2023 and $0.75 per share QTD and $1.50 per share YTD in 2022)	(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)