Consolidated Statements of Changes In Stockholders' Equity - USD ($) $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Cumulative Effect, Period of Adoption, Adjusted Balance	Common Stock	Common Stock Cumulative Effect, Period of Adoption, Adjusted Balance	Additional Paid-In Capital	Additional Paid-In Capital Cumulative Effect, Period of Adoption, Adjusted Balance	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	Retained Earnings Cumulative Effect, Period of Adoption, Adjusted Balance	Accumulated Other Comprehensive Loss	Accumulated Other Comprehensive Loss Cumulative Effect, Period of Adoption, Adjusted Balance	Treasury Stock	Treasury Stock Cumulative Effect, Period of Adoption, Adjusted Balance
Stockholders' equity, beginning balance at Dec. 31, 2019	$ 301,728			$ 19,606		$ 335,355		$ 33,218			$ (6,357)		$ (80,094)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	8,127							8,127
Other Comprehensive Income	3,945										3,945
Cash Dividends Paid	(3,904)							(3,904)
Stock Options Exercised, Net	343					199							144
Shares Issued Under the Employee Stock Purchase Plan	121					84							37
Shares Issued for Dividend Reinvestment Plans	442					280							162
Stock-Based Compensation Expense	103					103
Purchases of Treasury Stock	(1,507)												(1,507)
Stockholders' equity, ending balance at Mar. 31, 2020	309,398			19,606		336,021		37,441			(2,412)		(81,258)
Stockholders' equity, beginning balance at Dec. 31, 2020	334,392	$ 120	$ 334,512	20,194	$ 20,194	353,662	$ 353,662	41,899	$ 120	$ 42,019	(816)	$ (816)	(80,547)	$ (80,547)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	13,280							13,280
Other Comprehensive Income	(2,280)										(2,280)
Cash Dividends Paid	(4,036)							(4,036)
Stock Options Exercised, Net	156					94							62
Shares Issued Under the Directors' Stock	98					70							28
Shares Issued Under the Employee Stock Purchase Plan	124					86							38
Shares Issued for Dividend Reinvestment Plans	455					342							113
Stock-Based Compensation Expense	104					104
Stockholders' equity, ending balance at Mar. 31, 2021	$ 342,413			$ 20,194		$ 354,358		$ 51,263			$ (3,096)		$ (80,306)