Earnings per common share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Numerator
Net income - basic and diluted	$ 2,190	$ 3,294	$ 3,990	$ 7,191
Denominator
Weighted average shares outstanding - basic (in shares)	1,477	1,468	1,476	1,467
Weighted average shares outstanding - diluted (in shares)	1,477	1,468	1,476	1,467
Earnings per share - basic (in dollars per share)	$ 1.48	$ 2.24	$ 2.71	$ 4.90
Earnings per share - diluted (in dollars per share)	$ 1.48	$ 2.24	$ 2.70	$ 4.90