Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Surplus [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Beginning balance at Dec. 31, 2017	$ 626	$ 47,431	$ 70,426	$ (77)	$ (2,667)	$ 115,739
Beginning balance, shares at Dec. 31, 2017	6,256,063			2,608
Net income			10,352			10,352
Other comprehensive income (loss)					(5,825)	(5,825)
Cash dividends declared			(4,133)			(4,133)
Compensation expense related to restricted stock		154				154
Acquisition of treasury stock				$ (179)		(179)
Acquisition of treasury stock, shares				5,446
Stock options exercised	$ 2	325		$ 68		395
Stock options exercised, shares	18,450			2,325
Compensation expense related to stock options		177				177
Ending balance, shares at Sep. 30, 2018	6,274,513			5,729
Ending balance at Sep. 30, 2018	$ 628	48,087	76,645	$ (188)	(8,492)	116,680
Beginning balance at Jun. 30, 2018	$ 627	47,815	74,315	$ (188)	(7,036)	115,533
Beginning balance, shares at Jun. 30, 2018	6,266,388			5,729
Net income			3,710			3,710
Other comprehensive income (loss)					(1,456)	(1,456)
Cash dividends declared			(1,380)			(1,380)
Compensation expense related to restricted stock		52				52
Acquisition of treasury stock
Stock options exercised	$ 1	161				162
Stock options exercised, shares	8,125
Compensation expense related to stock options		59				59
Ending balance, shares at Sep. 30, 2018	6,274,513			5,729
Ending balance at Sep. 30, 2018	$ 628	48,087	76,645	$ (188)	(8,492)	116,680
Beginning balance at Dec. 31, 2018	$ 630	48,322	78,434	$ (81)	(5,020)	122,285
Beginning balance, shares at Dec. 31, 2018	6,295,113			2,470
Net income			10,619			10,619
Other comprehensive income (loss)					6,163	6,163
Cash dividends declared			(4,531)			(4,531)
Compensation expense related to restricted stock		217				217
Acquisition of treasury stock				$ (374)		(374)
Acquisition of treasury stock, shares				11,337
Stock options exercised	$ 2	357				$ 359
Stock options exercised, shares	19,575					19,575
Compensation expense related to stock options		156				$ 156
Ending balance, shares at Sep. 30, 2019	6,314,688			13,807
Ending balance at Sep. 30, 2019	$ 632	49,052	84,522	$ (455)	1,143	134,894
Beginning balance at Jun. 30, 2019	$ 630	48,741	82,127	$ (455)	440	131,483
Beginning balance, shares at Jun. 30, 2019	6,304,413			13,807
Net income			3,907			3,907
Other comprehensive income (loss)					703	703
Cash dividends declared			(1,512)			(1,512)
Compensation expense related to restricted stock		72				72
Acquisition of treasury stock
Stock options exercised	$ 2	187				189
Stock options exercised, shares	10,275
Compensation expense related to stock options		52				52
Ending balance, shares at Sep. 30, 2019	6,314,688			13,807
Ending balance at Sep. 30, 2019	$ 632	$ 49,052	$ 84,522	$ (455)	$ 1,143	$ 134,894