Mergers and acquisitions - Purchased Credit-deteriorated Loans (Details) - USD ($)
$ in Thousands |
|
|
12 Months Ended |
Aug. 15, 2020 |
Feb. 14, 2020 |
Dec. 31, 2020 |
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
| Deterioration credit quality since origination, percentage |
27.90%
|
10.10%
|
|
| Allowance for credit loss, purchased with credit deterioration |
|
|
$ 25,500
|
| Franklin Financial Network, Inc. |
|
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
| Principal balance |
$ 693,999
|
|
|
| Allowance for credit losses at acquisition |
(24,831)
|
|
|
| Net premium attributable to other factors |
8,810
|
|
|
| Loans purchased credit-deteriorated fair value |
677,978
|
|
|
| Allowance for credit loss, purchased with credit deterioration |
52,822
|
|
|
| Increase in provision for credit losses from unfunded commitments acquired in business combination |
$ 10,499
|
|
|
| FNB Financial Corp. |
|
|
|
| Accounts, Notes, Loans and Financing Receivable [Line Items] |
|
|
|
| Principal balance |
|
$ 18,964
|
|
| Allowance for credit losses at acquisition |
|
(669)
|
|
| Net premium attributable to other factors |
|
63
|
|
| Loans purchased credit-deteriorated fair value |
|
18,358
|
|
| Allowance for credit loss, purchased with credit deterioration |
|
$ 2,885
|
|