Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	Preferred Stock [Member]	Common Stock	Capital Surplus [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Deferred Benefits for Directors [Member]
Beginning Balance at Dec. 31, 2021	$ 2,693,166	$ 144,484	$ 141,834	$ 1,635,642	$ 977,765	$ (199,759)	$ (5,120)	$ (1,680)
Beginning Balance, shares at Dec. 31, 2021			62,307,245
Net income	44,124				44,124
Other comprehensive income (loss)	(106,192)						(106,192)
Comprehensive income (loss)	(62,068)
Common dividends declared	(20,538)				(20,538)
Preferred dividends declared	(2,531)				(2,531)
Stock issued for dividend reinvestment					(505)	505
Stock issued for dividend reinvestment, shares			14,531
Treasury shares acquired	(62,323)					(62,323)
Treasury shares acquired, shares			(1,724,571)
Stock options exercised	373			(192)		565
Stock options exercised, shares			16,209
Stock compensation expense	1,241			1,241
Deferred benefits for directors- net	(4)			14				(18)
Ending Balance at Mar. 31, 2022	2,547,316	144,484	$ 141,834	1,636,705	998,315	(261,012)	(111,312)	(1,698)
Ending Balance, shares at Mar. 31, 2022			60,613,414
Beginning Balance at Dec. 31, 2022	2,426,662	144,484	$ 141,834	1,635,877	1,077,675	(308,964)	(262,416)	(1,828)
Beginning Balance, shares at Dec. 31, 2022			59,198,963
Net income	42,341				42,341
Other comprehensive income (loss)	28,017						28,017
Comprehensive income (loss)	70,358
Common dividends declared	(20,561)				(20,561)
Preferred dividends declared	(2,531)				(2,531)
Treasury shares acquired	(52)					(52)
Treasury shares acquired, shares			(1,394)
Stock options exercised	103			(34)		137
Stock options exercised, shares			4,441
Restricted stock granted				(1,372)		1,372
Restricted stock granted, shares			44,559
Stock compensation expense	1,585			1,585
Deferred benefits for directors- net	(107)			5				(112)
Ending Balance at Mar. 31, 2023	$ 2,475,457	$ 144,484	$ 141,834	$ 1,636,061	$ 1,096,924	$ (307,507)	$ (234,399)	$ (1,940)
Ending Balance, shares at Mar. 31, 2023			59,246,569