Loans and allowance for loan losses - Information about TDRs (Details) - USD ($) |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2020 |
Sep. 30, 2019 |
Sep. 30, 2020 |
Sep. 30, 2019 |
|
| Information About Tdrs Identified During Period Line Items [Line Items] | ||||
| Number of Loans | 0 | 0 | ||
| Commercial real estate | ||||
| Information About Tdrs Identified During Period Line Items [Line Items] | ||||
| Number of Loans | 1,000 | 1,000 | ||
| Pre-Modification Recorded Investment | $ 311,000 | $ 515,000 | ||
| Post-Modification Recorded Investment | $ 311,000 | $ 515,000 | ||
| Commercial real estate | Owner Occupied [Member] | ||||
| Information About Tdrs Identified During Period Line Items [Line Items] | ||||
| Number of Loans | 1,000 | |||
| Pre-Modification Recorded Investment | $ 311,000 | |||
| Post-Modification Recorded Investment | $ 311,000 | |||
| Commercial real estate | Non-Owner Occupied [Member] | ||||
| Information About Tdrs Identified During Period Line Items [Line Items] | ||||
| Number of Loans | 1,000 | |||
| Pre-Modification Recorded Investment | $ 515,000 | |||
| Post-Modification Recorded Investment | $ 515,000 | |||