Loans and allowance for credit losses - Financial Effect of TDRs (Details)
$ in Thousands |
12 Months Ended |
|
Dec. 31, 2020
USD ($)
loan
|
Dec. 31, 2019
USD ($)
loan
|
Dec. 31, 2018
USD ($)
loan
|
| Financing Receivable, Troubled Debt Restructuring [Line Items] |
|
|
|
| Number of loans | loan |
18
|
12
|
9
|
| Pre-modification outstanding recorded investment |
$ 9,516
|
$ 7,657
|
$ 1,340
|
| Post-modification outstanding recorded investment |
9,516
|
7,658
|
1,340
|
| Charge offs and specific reserves |
$ 0
|
$ 115
|
$ 0
|
| Commercial and industrial |
|
|
|
| Financing Receivable, Troubled Debt Restructuring [Line Items] |
|
|
|
| Number of loans | loan |
5
|
3
|
2
|
| Pre-modification outstanding recorded investment |
$ 2,257
|
$ 3,204
|
$ 887
|
| Post-modification outstanding recorded investment |
2,257
|
3,204
|
887
|
| Charge offs and specific reserves |
$ 0
|
$ 0
|
$ 0
|
| Construction |
|
|
|
| Financing Receivable, Troubled Debt Restructuring [Line Items] |
|
|
|
| Number of loans | loan |
|
2
|
|
| Pre-modification outstanding recorded investment |
|
$ 1,085
|
|
| Post-modification outstanding recorded investment |
|
1,085
|
|
| Charge offs and specific reserves |
|
$ 0
|
|
| Commercial real estate: | Owner occupied |
|
|
|
| Financing Receivable, Troubled Debt Restructuring [Line Items] |
|
|
|
| Number of loans | loan |
7
|
2
|
1
|
| Pre-modification outstanding recorded investment |
$ 2,794
|
$ 1,494
|
$ 143
|
| Post-modification outstanding recorded investment |
2,794
|
1,495
|
143
|
| Charge offs and specific reserves |
$ 0
|
$ 0
|
$ 0
|
| Commercial real estate: | Non-owner occupied |
|
|
|
| Financing Receivable, Troubled Debt Restructuring [Line Items] |
|
|
|
| Number of loans | loan |
2
|
1
|
|
| Pre-modification outstanding recorded investment |
$ 3,752
|
$ 1,366
|
|
| Post-modification outstanding recorded investment |
3,752
|
1,366
|
|
| Charge offs and specific reserves |
$ 0
|
$ 106
|
|
| Residential real estate | 1-to-4 family mortgage |
|
|
|
| Financing Receivable, Troubled Debt Restructuring [Line Items] |
|
|
|
| Number of loans | loan |
3
|
2
|
1
|
| Pre-modification outstanding recorded investment |
$ 618
|
$ 175
|
$ 249
|
| Post-modification outstanding recorded investment |
618
|
175
|
249
|
| Charge offs and specific reserves |
$ 0
|
$ 0
|
$ 0
|
| Residential line of credit |
|
|
|
| Financing Receivable, Troubled Debt Restructuring [Line Items] |
|
|
|
| Number of loans | loan |
1
|
2
|
|
| Pre-modification outstanding recorded investment |
$ 95
|
$ 333
|
|
| Post-modification outstanding recorded investment |
95
|
333
|
|
| Charge offs and specific reserves |
$ 0
|
$ 9
|
|
| Consumer and other |
|
|
|
| Financing Receivable, Troubled Debt Restructuring [Line Items] |
|
|
|
| Number of loans | loan |
|
|
5
|
| Pre-modification outstanding recorded investment |
|
|
$ 61
|
| Post-modification outstanding recorded investment |
|
|
61
|
| Charge offs and specific reserves |
|
|
$ 0
|