Earnings per common share (Details) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2020
Sep. 30, 2019
Sep. 30, 2020
Sep. 30, 2019
Numerator        
Net income - basic and diluted $ 2,269 $ 1,727 $ 5,502 $ 3,173
Denominator        
Weighted average shares outstanding - basic (in shares) 1,462 1,451 1,456 1,442
Dilutive effect of common stock options (in shares) 0 0    
Weighted average shares outstanding - diluted (in shares) 1,462 1,451 1,456 1,442
Earnings per share - basic (in dollars per share) $ 1.55 $ 1.19 $ 3.78 $ 2.20
Earnings per share - diluted (in dollars per share) $ 1.55 $ 1.19 $ 3.78 $ 2.20