Fair value - Carrying amounts and estimated fair value of the company's (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Financial assets
Investment securities available for sale, at fair value	$ 94,699	$ 40,844
Loans held for sale	5,100	34,400
Fair Value, Inputs, Level 1 [Member] | Reported Value Measurement [Member]
Financial assets
Cash	13,444	12,709
Fair Value, Inputs, Level 1 [Member] | Estimate of Fair Value Measurement [Member]
Financial assets
Cash	13,444	12,709
Fair Value, Inputs, Level 2 [Member] | Reported Value Measurement [Member]
Financial assets
Cash equivalents	80,545	30,742
Investment securities available for sale, at fair value	92,949	40,594
Federal Home Loan Bank stock	353	484
Loans held for sale	5,141	34,421
Accrued interest receivable	3,245	4,943
Interest rate lock commitments	471	1,552
Financial liabilities
Deposits	664,048	588,382
Trust preferred securities	8,764	8,764
Other borrowings	5,660	47,157
Accrued interest payable	68	194
Forward sales commitment	651	3,105
Fair Value, Inputs, Level 2 [Member] | Estimate of Fair Value Measurement [Member]
Financial assets
Cash equivalents	80,545	30,742
Investment securities available for sale, at fair value	92,949	40,594
Federal Home Loan Bank stock	353	484
Loans held for sale	5,141	34,421
Accrued interest receivable	3,245	4,943
Interest rate lock commitments	471	1,552
Financial liabilities
Deposits	663,898	589,017
Trust preferred securities	9,554	9,697
Other borrowings	5,660	47,157
Accrued interest payable	68	194
Forward sales commitment	651	3,105
Fair Value, Inputs, Level 3 [Member] | Reported Value Measurement [Member]
Financial assets
Investment securities available for sale, at fair value	1,750	250
Loans	526,457	561,003
Other real estate owned		336
Bank owned life insurance	12,494	7,806
Fair Value, Inputs, Level 3 [Member] | Estimate of Fair Value Measurement [Member]
Financial assets
Investment securities available for sale, at fair value	1,750	250
Loans	526,668	562,362
Other real estate owned		336
Bank owned life insurance	$ 12,494	$ 7,806