Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Cumulative Effect, Period of Adoption, Adjustment [Member] Retained Earnings [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member]	Common Stock Outstanding [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI, Accumulated Gain (Loss), Debt Securities, Available-for-sale, Parent [Member]	Total
Balance at Dec. 31, 2018			$ 21,248	$ 73,960	$ 208,164	$ (7,705)	$ 295,667
Cash dividends declared					(5,843)		(5,843)
Issuance of shares of common stock pursuant to dividend reinvestment plan			183	4,368			4,551
Issuance of shares of common stock pursuant to exercise of stock options			17	289			306
Share based compensation expense			0	99			99
Net change in fair value of available-for-sale securities during the year, net of taxes						2,498	2,498
Net earnings for the quarter					8,290		8,290
Balance (Accounting Standards Update 2016-02 [Member]) at Mar. 31, 2019	$ (27)	$ (27)
Balance at Mar. 31, 2019			21,448	78,716	210,584	(5,207)	305,541
Balance at Dec. 31, 2019			21,586	82,249	232,456	693	336,984
Cash dividends declared					(6,476)		(6,476)
Issuance of shares of common stock pursuant to dividend reinvestment plan			183	4,825			5,008
Issuance of shares of common stock pursuant to exercise of stock options			14	225			239
Share based compensation expense				108			108
Net change in fair value of available-for-sale securities during the year, net of taxes						4,103	4,103
Net earnings for the quarter					9,031		9,031
Balance at Mar. 31, 2020			$ 21,783	$ 87,407	$ 235,011	$ 4,796	$ 348,997