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				7,138		7,138
Other comprehensive income (loss)					264	264
Restricted stock compensation expense	13		308			321
Exercise of stock options	9		(9)
Taxes on exercise of stock options			(189)			(189)
Cash dividends - common				(895)		(895)
Sale of treasury shares to 401(k)		151	62			213
Sale of treasury shares to deferred comp. plan		77	115			192
Balance at Sep. 30, 2017	4,373	(1,502)	69,260	31,763	(2,010)	101,884
Balance at Dec. 31, 2017	4,379	(1,429)	69,110	32,272	(2,390)	101,942
Net income				7,682		7,682
Other comprehensive income (loss)					(1,116)	(1,116)
Restricted stock compensation expense	10		260			270
Exercise of stock options	8		(8)
Taxes on exercise of stock options	(4)		(262)			(266)
Cash dividends - common				(902)		(902)
Sale of treasury shares to 401(k)		159	145			304
Sale of treasury shares to deferred comp. plan		74	71			145
Adoption impact - ASU 2018-02				471	(471)
Balance at Sep. 30, 2018	$ 4,393	$ (1,196)	$ 69,316	$ 39,523	$ (3,977)	$ 108,059