Consolidated Statements of Changes In Stockholders' Equity - USD ($) $ in Thousands		Total	Common Stock	Additional Paid-In Capital	Retained Earnings	Unallocated ESOP Shares	Accumulated Other Comprehensive Loss	Treasury Stock
Stockholders' equity, beginning balance at Dec. 31, 2017		$ 249,603	$ 18,481	$ 290,219	$ 28,818	$ (200)	$ (8,514)	$ (79,201)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income		8,531			8,531
Other Comprehensive Income (Loss)		(2,440)					(2,440)
Cash Dividends Paid	[1]	(3,485)			(3,485)
Stock Options Exercised, Net		610		307				303
Shares Issued Under the Employee Stock Purchase Plan		116		76				40
Shares Issued for Dividend Reinvestment Plans		431		289				142
Stock-Based Compensation Expense		89		89
Purchases of Treasury Stock		(619)						(619)
Stockholders' equity, ending balance at Mar. 31, 2018		252,734	18,481	290,980	34,093	(200)	(11,285)	(79,335)
Stockholders' equity, beginning balance at Dec. 31, 2018		269,584	19,035	314,533	29,257	(100)	(13,810)	(79,331)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income		8,734			8,734
Other Comprehensive Income (Loss)		2,243					2,243
Cash Dividends Paid		(3,760)			(3,760)
Stock Options Exercised, Net		535		249				286
Shares Issued Under the Employee Stock Purchase Plan		117		76				41
Shares Issued for Dividend Reinvestment Plans		453		309				144
Stock-Based Compensation Expense		95		95
Purchases of Treasury Stock		(1,392)						(1,392)
Stockholders' equity, ending balance at Mar. 31, 2019		$ 276,609	$ 19,035	$ 315,262	$ 34,231	$ (100)	$ (11,567)	$ (80,252)

[1] Cash dividends paid per share have been adjusted for the September 27, 2018 3% stock dividend.