Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment [Member]	Cumulative Effect, Period of Adoption, Adjusted Balance [Member]	Common Stock [Member]	Common Stock [Member] Cumulative Effect, Period of Adoption, Adjusted Balance [Member]	Capital Surplus [Member]	Capital Surplus [Member] Cumulative Effect, Period of Adoption, Adjusted Balance [Member]	Retained Earnings [Member]	Retained Earnings [Member] Cumulative Effect, Period of Adoption, Adjustment [Member]	Retained Earnings [Member] Cumulative Effect, Period of Adoption, Adjusted Balance [Member]	Treasury Stock [Member]	Treasury Stock [Member] Cumulative Effect, Period of Adoption, Adjusted Balance [Member]	Deferred Compensation [Member]	Deferred Compensation [Member] Cumulative Effect, Period of Adoption, Adjusted Balance [Member]	Accumulated Other Total Comprehensive Earnings, net [Member]	Accumulated Other Total Comprehensive Earnings, net [Member] Cumulative Effect, Period of Adoption, Adjusted Balance [Member]
Cumulative effect of adopting ASC 326 on January 1, 2020, net of related income taxes		$ (466)							$ (466)
Beginning Balance at Dec. 31, 2019	$ 1,227,197		$ 1,226,731	$ 1,359	$ 1,359	$ 450,676	$ 450,676	$ 707,656		$ 707,190	$ (8,222)	$ (8,222)	$ 8,222	$ 8,222	$ 67,506	$ 67,506
Beginning Balance, Shares at Dec. 31, 2019				135,891,755	135,891,755
Treasury Stock, Beginning Balance, Shares at Dec. 31, 2019											(927,408)	(927,408)
NET EARNINGS	202,034							202,034
Stock option exercises	4,717			$ 3		4,714
Stock option exercises, Shares				295,093
Restricted stock grant, net	672					672
Restricted stock grant net, Shares				24,214
Cash dividends declared	(72,495)							(72,495)
Stock issued in acquisition	220,273			$ 63		220,210
Stock issued in acquisition, Shares				6,275,574
Change in unrealized gain (loss) in investment securities available-for-sale, net of related income taxes	102,889														102,889
Shares purchased in connection with directors’ deferred compensation plan, net											$ (904)		904
Shares purchased in connection with directors’ deferred compensation plan, net, Shares											(11,183)
Stock option expense	1,377					1,377
Shares repurchased and retired under stock repurchase authorization	(8,008)			$ (3)		(8,005)
Shares repurchased and retired under stock repurchase authorization, shares				(324,802)
Ending Balance at Dec. 31, 2020	1,678,190			$ 1,422		669,644		836,729			$ (9,126)		9,126		170,395
Ending Balance, Shares at Dec. 31, 2020				142,161,834
Treasury Stock, Ending Balance, Shares at Dec. 31, 2020											(938,591)
NET EARNINGS	227,562							227,562
Stock option exercises	5,905			$ 3		5,902
Stock option exercises, Shares				345,829
Restricted stock grant, net	9					9
Restricted stock grant net, Shares				24,453
Cash dividends declared	(82,616)							(82,616)
Change in unrealized gain (loss) in investment securities available-for-sale, net of related income taxes	(71,142)														(71,142)
Shares purchased in connection with directors’ deferred compensation plan, net											$ (964)		964
Shares purchased in connection with directors’ deferred compensation plan, net, Shares											1,694
Stock option expense	1,316					1,316
Ending Balance at Dec. 31, 2021	$ 1,759,224			$ 1,425		676,871		981,675			$ (10,090)		10,090		99,253
Ending Balance, Shares at Dec. 31, 2021				142,532,116
Treasury Stock, Ending Balance, Shares at Dec. 31, 2021	936,897										(936,897)
NET EARNINGS	$ 234,475							234,475
Stock option exercises	6,545			$ 4		6,541
Stock option exercises, Shares				355,692
Restricted stock grant, net	2,188					2,188
Restricted stock grant net, Shares				14,622
Cash dividends declared	(94,205)							(94,205)
Change in unrealized gain (loss) in investment securities available-for-sale, net of related income taxes	(634,481)														(634,481)
Shares purchased in connection with directors’ deferred compensation plan, net											$ (945)		945
Shares purchased in connection with directors’ deferred compensation plan, net, Shares											7,687
Stock option expense	1,440					1,440
Shares repurchased and retired under stock repurchase authorization	(9,449)			$ (2)		(9,447)
Shares repurchased and retired under stock repurchase authorization, shares				(244,559)
Ending Balance at Dec. 31, 2022	$ 1,265,737			$ 1,427		$ 677,593		$ 1,121,945			$ (11,035)		$ 11,035		$ (535,228)
Ending Balance, Shares at Dec. 31, 2022				142,657,871
Treasury Stock, Ending Balance, Shares at Dec. 31, 2022	929,210										(929,210)