CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Common Shares	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock
Beginning balance at Dec. 31, 2021	$ 845,025	$ 686,282	$ 207,076	$ (11,619)	$ (36,714)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	74,443		74,443
Other comprehensive loss, net of tax	(123,304)			(123,304)
Cash dividends declared	(31,686)		(31,686)
Reissuance of treasury stock for common share awards	0	(4,944)			4,944
Reissuance of treasury stock for deferred compensation plan for Boards of Directors	78				78
Repurchase of treasury stock in connection with employee incentive program and compensation plan for Boards of Directors	(1,671)				(1,671)
Common shares repurchased under share repurchase program then in effect	(7,155)				(7,155)
Common shares issued under dividend reinvestment plan	921	921
Common shares issued under compensation plan for Boards of Directors	378	64			314
Common shares issued under employee stock purchase plan	549	95			454
Stock-based compensation	2,933	2,933
Ending balance at Sep. 30, 2022	760,511	685,351	249,833	(134,923)	(39,750)
Beginning balance at Jun. 30, 2022	786,824	684,416	234,608	(93,359)	(38,841)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	25,978		25,978
Other comprehensive loss, net of tax	(41,564)			(41,564)
Cash dividends declared	(10,753)		(10,753)
Reissuance of treasury stock for common share awards	0	(219)			219
Repurchase of treasury stock in connection with employee incentive program and compensation plan for Boards of Directors	(235)				(235)
Common shares repurchased under share repurchase program then in effect	(1,168)				(1,168)
Common shares issued under dividend reinvestment plan	320	320
Common shares issued under compensation plan for Boards of Directors	126	20			106
Common shares issued under employee stock purchase plan	203	34			169
Stock-based compensation	780	780
Ending balance at Sep. 30, 2022	760,511	685,351	249,833	(134,923)	(39,750)
Beginning balance at Dec. 31, 2022	785,328	686,450	265,936	(127,136)	(39,922)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	79,538		79,538
Other comprehensive loss excluding pension termination settlement, net of tax	(18,518)			(18,518)
Other comprehensive loss, net of tax	(16,660)
Pension termination settlement, net of tax	1,858			1,858
Cash dividends declared	(37,940)		(37,940)
Reissuance of treasury stock for common share awards	0	(5,724)			5,724
Reissuance of treasury stock for deferred compensation plan for Boards of Directors	115				115
Repurchase of treasury stock in connection with employee incentive program and compensation plan for Boards of Directors	(1,445)				(1,445)
Common shares issued under dividend reinvestment plan	1,036	1,036
Common shares issued under compensation plan for Boards of Directors	410	25			385
Common shares issued under employee stock purchase plan	675	61			614
Stock-based compensation	4,233	4,233
Issuance of common shares related to merger with Limestone Bancorp, Inc.	177,929	177,929
Ending balance at Sep. 30, 2023	993,219	864,010	307,534	(143,796)	(34,529)
Beginning balance at Jun. 30, 2023	998,907	862,960	289,445	(118,920)	(34,578)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	31,882		31,882
Other comprehensive loss excluding pension termination settlement, net of tax	(26,734)			(26,734)
Other comprehensive loss, net of tax	(24,876)
Pension termination settlement, net of tax	1,858			1,858
Cash dividends declared	(13,793)		(13,793)
Reissuance of treasury stock for common share awards	0	(314)			314
Repurchase of treasury stock in connection with employee incentive program and compensation plan for Boards of Directors	(391)				(391)
Common shares issued under dividend reinvestment plan	284	284
Common shares issued under compensation plan for Boards of Directors	139	6			133
Common shares issued under employee stock purchase plan	(7)				(7)
Stock-based compensation	1,074	1,074
Ending balance at Sep. 30, 2023	$ 993,219	$ 864,010	$ 307,534	$ (143,796)	$ (34,529)