Calculation of earnings per share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Earnings Per Share [Abstract]
Net income	$ 15,874	$ 16,473	$ 11,940
Less: Undistributed earnings allocated to participating securities	(276)	(248)	(165)
Net income allocated to common shareholders	15,598	16,225	11,775
Weighted average common shares issued	5,770	5,710	5,674
Less: Unvested restricted stock awards	(100)	(86)	(78)
Weighted average common shares outstanding used to calculate basic earnings per common share	5,670	5,624	5,596
Add: Dilutive effect of performance based restricted stock awards and stock options	26	48	16
Weighted average common shares outstanding used to calculate diluted earnings per common share	$ 5,696	$ 5,672	$ 5,612
Earnings per common share (basic)	$ 2.75	$ 2.88	$ 2.11
Earnings per common share (diluted)	$ 2.74	$ 2.86	$ 2.10