Consolidated Statements Of Changes In Shareholders' Equity - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, Adjusted Balance	Common Stock [Member]	Common Stock [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	Capital Surplus[Member]	Capital Surplus[Member] Cumulative Effect, Period of Adoption, Adjusted Balance	Retained Earnings [Member]	Retained Earnings [Member] Cumulative Effect, Period of Adoption, Adjustment	Retained Earnings [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	Treasury Stock, Common [Member]	Treasury Stock, Common [Member] Cumulative Effect, Period of Adoption, Adjusted Balance	Accumulated Other Comprehensive Income (Loss) [Member]	Accumulated Other Comprehensive Income (Loss) [Member] Cumulative Effect, Period of Adoption, Adjusted Balance
Beginning balance at Dec. 31, 2018	$ 600,764			$ 47,619		$ 169,555		$ 485,967			$ (87,895)		$ (14,482)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income Available to Common Shareholders	89,352							89,352
Other comprehensive income	20,322												20,322
Cash dividends declared	(36,066)							(36,066)
Stock-based compensation expense, net	2,516					2,516
Restricted Awards Granted	$ 0					(1,657)					1,657
Exercise of stock options	11,721
Exercise of stock options	$ 526					(105)					631
Purchase of treasury shares	(19,431)										(19,431)
Ending balance at Dec. 31, 2019	657,983	$ (2,335)	$ 655,648	47,619	$ 47,619	170,309	$ 170,309	539,253	$ (2,335)	$ 536,918	(105,038)	$ (105,038)	5,840	$ 5,840
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income Available to Common Shareholders	89,595							89,595
Other comprehensive income	25,393												25,393
Cash dividends declared	(36,525)							(36,525)
Stock-based compensation expense, net	3,253					3,253
Restricted Awards Granted	$ 0					(2,146)					2,146
Exercise of stock options	4,921
Exercise of stock options	$ 223					(112)					335
Purchase of treasury shares	(36,481)										(36,481)
Ending balance at Dec. 31, 2020	$ 701,106			47,619		171,304		589,988			(139,038)		31,233
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible List]	Accounting Standards Update 2016-13 [Member]
Net Income Available to Common Shareholders	$ 88,080							88,080
Other comprehensive income	(16,973)												(16,973)
Cash dividends declared	(36,242)							(36,242)
Stock-based compensation expense, net	3,121					3,121
Restricted Awards Granted	$ 0					(1,860)					1,860
Exercise of stock options	14,603
Exercise of stock options	$ 691					(1,623)					2,314
Purchase of treasury shares	(58,678)										(58,678)
Ending balance at Dec. 31, 2021	$ 681,105			$ 47,619		$ 170,942		$ 641,826			$ (193,542)		$ 14,260