Earnings per share - Schedule of Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Earnings per share
Net income, Basic	$ 9,968	$ 9,096	$ 28,951	$ 27,105
Average common shares outstanding - basic	7,169,809	7,198,125	7,171,382	7,204,399
Net income - basic	$ 1.39	$ 1.26	$ 4.04	$ 3.76
Net income, Diluted	$ 9,968	$ 9,096	$ 28,951	$ 27,105
Average common shares outstanding - diluted	7,213,147	7,233,189	7,214,966	7,239,463
Net income - diluted	$ 1.38	$ 1.26	$ 4.01	$ 3.74