Other real estate owned - Summary of Other Real Estate Owned (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Other Real Estate [Roll Forward]
Balance at beginning of period	$ 12,111	$ 18,939	$ 12,643
Transfers from loans	5,262	2,746	5,487
Transfers to premises and equipment	0	(841)	4,290
Proceeds from sale of other real estate owned	(9,396)	(6,937)	(3,860)
Gain on sale of other real estate owned	3,248	354	1,058
Loans provided for sales of other real estate owned	(704)	(305)	(166)
Write-downs and partial liquidations	(744)	(1,845)	(513)
Balance at end of period	$ 9,777	$ 12,111	$ 18,939