Commitments and contingencies (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Total commitments to extend credit	$ 126,356	$ 150,974
Standby letters of Credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Total commitments to extend credit	4,680	4,934
Undisbursed credit lines
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Total commitments to extend credit	103,125	107,130
Commitments to extend or originate credit
Fair Value, Off-balance Sheet Risks, Disclosure Information [Line Items]
Total commitments to extend credit	$ 18,551	$ 38,910