Loans, net and allowance for loan losses - Changes in Allowance for Loan Losses Account by Major Classification of Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Allowance for loan losses:
Beginning Balance	$ 28,383	$ 27,344	$ 22,677
Charge-offs	(787)	(956)	(3,479)
Recoveries	325	245	746
Provisions (credits)	(449)	1,750	7,400
Ending balance	27,472	28,383	27,344
Commercial
Allowance for loan losses:
Beginning Balance	8,453	8,734	6,888
Charge-offs	(161)	(492)	(2,771)
Recoveries	40	89	525
Provisions (credits)	(2,720)	122	4,092
Ending balance	5,612	8,453	8,734
Commercial real estate
Allowance for loan losses:
Beginning Balance	15,928	14,559	11,496
Charge-offs	(284)	(252)	(144)
Recoveries	110	68	16
Provisions (credits)	2,161	1,553	3,191
Ending balance	17,915	15,928	14,559
Residential real estate
Allowance for loan losses:
Beginning Balance	3,209	3,129	3,226
Charge-offs	(31)	(24)	(247)
Recoveries	4	7	57
Provisions (credits)	(110)	97	93
Ending balance	3,072	3,209	3,129
Consumer
Allowance for loan losses:
Beginning Balance	793	922	1,067
Charge-offs	(311)	(188)	(317)
Recoveries	171	81	148
Provisions (credits)	220	(22)	24
Ending balance	$ 873	$ 793	$ 922