Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Surplus [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Treasury Stock [Member]	Total
Beginning balance at Dec. 31, 2018	$ 5,134	$ 24,821	$ 42,525	$ (4,299)	$ (803)	$ 67,378
Beginning balance, shares at Dec. 31, 2018	5,092,048
Net income			1,413			1,413
Other comprehensive income				1,483		1,483
Cash dividends at $0.22 per share			(1,120)			(1,120)
Stock-based compensation		(19)				(19)
Forfeiture of restricted stock, Shares	(800)
Common stock issued for stock plans	$ 8	(8)
Common stock issued for stock plans, shares	7,500
Ending balance at Mar. 31, 2019	$ 5,142	24,832	42,818	(2,816)	(803)	69,173
Ending balance, shares at Mar. 31, 2019	5,098,748
Beginning balance at Dec. 31, 2018	$ 5,134	24,821	42,525	(4,299)	(803)	67,378
Beginning balance, shares at Dec. 31, 2018	5,092,048
Other comprehensive income				4,898
Ending balance at Dec. 31, 2019	$ 5,142	24,898	43,954	516	(803)	$ 73,707
Ending balance, shares at Dec. 31, 2019	5,099,729					5,099,729
Net income			1,038			$ 1,038
Other comprehensive income				3,900		3,900
Cash dividends at $0.22 per share			(1,122)			(1,122)
Stock-based compensation		(29)				(29)
Purchase of treasury stock					(186)	(186)
Purchase of treasury stock, shares	(15,400)
Common stock issued for stock plans	$ 9	(9)
Common stock issued for stock plans, shares	9,530
Ending balance at Mar. 31, 2020	$ 5,151	$ 24,918	$ 43,870	$ 4,416	$ (989)	$ 77,366
Ending balance, shares at Mar. 31, 2020	5,093,859					5,093,859