Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional paid-in capital	Retained earnings	Treasury stock	Accumulated other comprehensive income (loss)
Balances at Dec. 31, 2018	$ 64,491	$ 9,888	$ 894	$ 58,911	$ (4,179)	$ (1,023)
Beginning balance (in shares) at Dec. 31, 2018		4,466,679
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	7,889			7,889
Other comprehensive income (loss)	2,186					2,186
Dividend reinvestment plan	27		21		6
Dividend reinvestment plan (in shares)		664
Cash dividends declared ($0.32 and $0.31 per share for the three months ended September 30, 2020 and 2019, respectively, and $0.96 and $0.93 per share for the nine months ended September 30, 2020 and 2019, respectively)	(4,155)			(4,155)
Stock based compensation expense	144		144
Exercise of stock options	44	$ 4	40
Exercise of stock options (in shares)		2,000
Purchase of treasury stock	(13)				(13)
Purchase of treasury stock (in shares)		(300)
Balances at Sep. 30, 2019	70,613	$ 9,892	1,099	62,645	(4,186)	1,163
Ending balance (in shares) at Sep. 30, 2019		4,469,043
Balances at Jun. 30, 2019	68,736	$ 9,890	1,020	61,292	(4,188)	722
Beginning balance (in shares) at Jun. 30, 2019		4,467,845
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	2,738			2,738
Other comprehensive income (loss)	441					441
Dividend reinvestment plan	7		5		2
Dividend reinvestment plan (in shares)		198
Cash dividends declared ($0.32 and $0.31 per share for the three months ended September 30, 2020 and 2019, respectively, and $0.96 and $0.93 per share for the nine months ended September 30, 2020 and 2019, respectively)	(1,385)			(1,385)
Stock based compensation expense	54		54
Exercise of stock options	22	$ 2	20
Exercise of stock options (in shares)		1,000
Balances at Sep. 30, 2019	70,613	$ 9,892	1,099	62,645	(4,186)	1,163
Ending balance (in shares) at Sep. 30, 2019		4,469,043
Balances at Dec. 31, 2019	71,843	$ 9,897	1,124	64,019	(4,183)	986
Beginning balance (in shares) at Dec. 31, 2019		4,471,977
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	9,011			9,011
Other comprehensive income (loss)	1,607					1,607
Dividend reinvestment plan	27		17		10
Dividend reinvestment plan (in shares)		1,144
Cash dividends declared ($0.32 and $0.31 per share for the three months ended September 30, 2020 and 2019, respectively, and $0.96 and $0.93 per share for the nine months ended September 30, 2020 and 2019, respectively)	(4,295)			(4,295)
Stock based compensation expense	209	$ 2	207
Stock based compensation expense (in shares)		1,185
Exercise of stock options	22	$ 2	20
Exercise of stock options (in shares)		1,000
Balances at Sep. 30, 2020	78,424	$ 9,901	1,368	68,735	(4,173)	2,593
Ending balance (in shares) at Sep. 30, 2020		4,475,306
Balances at Jun. 30, 2020	75,767	$ 9,901	1,306	66,020	(4,177)	2,717
Beginning balance (in shares) at Jun. 30, 2020		4,474,899
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	4,147			4,147
Other comprehensive income (loss)	(124)					(124)
Dividend reinvestment plan	8		4		4
Dividend reinvestment plan (in shares)		407
Cash dividends declared ($0.32 and $0.31 per share for the three months ended September 30, 2020 and 2019, respectively, and $0.96 and $0.93 per share for the nine months ended September 30, 2020 and 2019, respectively)	(1,432)			(1,432)
Stock based compensation expense	58	$ 0	58
Stock based compensation expense (in shares)		0
Balances at Sep. 30, 2020	$ 78,424	$ 9,901	$ 1,368	$ 68,735	$ (4,173)	$ 2,593
Ending balance (in shares) at Sep. 30, 2020		4,475,306