Loans, net and allowance for loan losses - Information Concerning Nonaccrual Loans by Major Loan Classification (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Financing Receivable, Recorded Investment, Past Due
Nonaccrual loans, Total	$ 6,428	$ 8,117
Commercial
Financing Receivable, Recorded Investment, Past Due
Nonaccrual loans, Total	2,198	3,822
Real estate Commercial
Financing Receivable, Recorded Investment, Past Due
Nonaccrual loans, Total	3,311	3,262
Real estate Residential
Financing Receivable, Recorded Investment, Past Due
Nonaccrual loans, Total	825	922
Consumer
Financing Receivable, Recorded Investment, Past Due
Nonaccrual loans, Total	$ 94	$ 111