Consolidated Statement of Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]
Balance at Dec. 31, 2018	$ 104,348	$ 2,280	$ 20,041	$ 91,635	$ (7,132)	$ (2,476)
Balance (in shares) at Dec. 31, 2018		3,484,080
Net income	9,612			9,612
Other comprehensive income (loss), net of tax	7,672				7,672
Cash dividends declared	(3,460)			(3,460)
Stock issued in connection with dividend reinvestment and stock purchase plan	638	$ 12	626
Stock issued in connection with dividend reinvestment and stock purchase plan (in shares)		18,150
Stock issued for employee stock purchase plan	54	$ 1	53
Stock issued for employee stock purchase plan (in shares)		1,617
Stock issued for options exercised	$ 37	$ 2	35
Stock issued for options exercised (in shares)	8,775	3,709
Stock-based compensation expense	$ 84		84
Balance at Sep. 30, 2019	118,985	$ 2,295	20,839	97,787	540	(2,476)
Balance (in shares) at Sep. 30, 2019		3,507,556
Balance at Jun. 30, 2019	115,878	$ 2,291	20,607	95,852	(396)	(2,476)
Balance (in shares) at Jun. 30, 2019		3,501,446
Net income	3,090			3,090
Other comprehensive income (loss), net of tax	936				936
Cash dividends declared	(1,155)			(1,155)
Stock issued in connection with dividend reinvestment and stock purchase plan	205	$ 4	201
Stock issued in connection with dividend reinvestment and stock purchase plan (in shares)		5,860
Stock issued for options exercised	7		7
Stock issued for options exercised (in shares)		250
Stock-based compensation expense	24		24
Balance at Sep. 30, 2019	118,985	$ 2,295	20,839	97,787	540	(2,476)
Balance (in shares) at Sep. 30, 2019		3,507,556
Balance at Dec. 31, 2019	$ 120,717	$ 2,303	21,261	99,372	257	(2,476)
Balance (in shares) at Dec. 31, 2019	3,519,767	3,519,767
Balance at Jun. 30, 2020	$ 128,563	$ 2,317	21,876	101,127	5,719	(2,476)
Balance (in shares) at Jun. 30, 2020		3,542,261
Balance at Dec. 31, 2019	$ 120,717	$ 2,303	21,261	99,372	257	(2,476)
Balance (in shares) at Dec. 31, 2019	3,519,767	3,519,767
Net income	$ 7,932			7,932
Other comprehensive income (loss), net of tax	5,078				5,078
Cash dividends declared	(3,603)			(3,603)
Stock issued in connection with dividend reinvestment and stock purchase plan	678	$ 15	663
Stock issued in connection with dividend reinvestment and stock purchase plan (in shares)		24,791
Stock issued for employee stock purchase plan	75	$ 2	73
Stock issued for employee stock purchase plan (in shares)		2,923
Stock issued for options exercised	$ 37	$ 2	35
Stock issued for options exercised (in shares)	9,550	3,121
Stock-based compensation expense	$ 81		81
Balance at Sep. 30, 2020	$ 130,995	$ 2,322	22,113	103,701	5,335	(2,476)
Balance (in shares) at Sep. 30, 2020	3,550,602	3,550,602
Balance at Jun. 30, 2020	$ 128,563	$ 2,317	21,876	101,127	5,719	(2,476)
Balance (in shares) at Jun. 30, 2020		3,542,261
Net income	3,778			3,778
Other comprehensive income (loss), net of tax	(384)				(384)
Cash dividends declared	(1,204)			(1,204)
Stock issued in connection with dividend reinvestment and stock purchase plan	218	$ 5	213
Stock issued in connection with dividend reinvestment and stock purchase plan (in shares)		8,341
Stock-based compensation expense	24		24
Balance at Sep. 30, 2020	$ 130,995	$ 2,322	$ 22,113	$ 103,701	$ 5,335	$ (2,476)
Balance (in shares) at Sep. 30, 2020	3,550,602	3,550,602