Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Treasury Stock [Member]	Surplus [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]	Total
Balance at Dec. 31, 2016	$ 4,351	$ (1,730)	$ 68,973	$ 25,520	$ (2,274)	$ 94,840
Net income				2,441		2,441
Other comprehensive income (loss)					100	100
Restricted stock compensation expense	4		103			107
Exercise of stock options	7		(7)
Taxes on exercise of stock options			(135)			(135)
Tax benefit for stock option exercises			110			110
Cash dividends - common				(297)		(297)
Sale of treasury shares to 401(k)		54	31			85
Sale of treasury shares to deferred comp. plan		23	14			37
Balance at Mar. 31, 2017	4,362	(1,653)	69,089	27,664	(2,174)	97,288
Balance at Dec. 31, 2017	4,379	(1,429)	69,110	32,272	(2,390)	101,942
Net income				2,613		2,613
Other comprehensive income (loss)					(801)	(801)
Restricted stock compensation expense	4		92			96
Exercise of stock options	1		(1)
Taxes on exercise of stock options	(1)		(36)			(37)
Cash dividends - common				(300)		(300)
Sale of treasury shares to 401(k)		58	50			108
Sale of treasury shares to deferred comp. plan		26	23			49
Adoption impact - ASU 2018-02				471	(471)
Balance at Mar. 31, 2018	$ 4,383	$ (1,345)	$ 69,238	$ 35,056	$ (3,662)	$ 103,670