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, 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	[1]	(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)
Stockholders' equity, beginning balance at Dec. 31, 2019		301,728	19,606	335,355	33,218	0	(6,357)	(80,094)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income		8,127			8,127
Other Comprehensive Income (Loss)		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	$ 0	$ (2,412)	$ (81,258)

[1] Cash dividends paid per share have been adjusted for the September 27, 2019 3% stock dividend.