Calculation of earnings per share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Note 8 Earnings Per Share
Net income	$ 3,568	$ 4,526
Less: Undistributed earnings allocated to participating securities	(60)	(64)
Net income allocated to common stock	3,508	4,462
Weighted-average common shares issued	2,867	2,845
Less: Unvested restricted stock awards	(49)	(40)
Weighted average common shares outstanding used to calculate basic earnings per common share	2,818	2,805
Add: Dilutive effect of stock options and restricted stock units	29	10
Weighted-average common shares outstanding used to calculate diluted earnings per common share	$ 2,847	$ 2,815
Earnings per common share (basic)	$ 1.24	$ 1.59
Earnings per common share (diluted)	$ 1.23	$ 1.59