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Loans and Loans Held for Sale - Summary of Restructured Loans (Details) - USD ($) $ in Thousands | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2021 | Mar. 31, 2020 | Dec. 31, 2020
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Restructured loans | $ 6,865 | $ 1,897 |
Commercial real estate | Commercial |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Restructured loans | 0 | 0 |
Commercial and industrial | Commercial |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Restructured loans | 6,296 | 0 |
Commercial construction | Commercial |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Restructured loans | 0 | 1,806 |
Business banking | Commercial |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Restructured loans | 0 | 0 |
Consumer real estate | Consumer |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Restructured loans | 568 | 91 |
Other consumer | Consumer |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Restructured loans | 1 | $ 0 |
Total TDRs |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Restructured loans | 47,899 |  | $ 46,748
Total TDRs | Commercial real estate | Commercial |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Restructured loans | 15,762 |  | 16,668
Total TDRs | Commercial and industrial | Commercial |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Restructured loans | 19,001 |  | 16,975
Total TDRs | Commercial construction | Commercial |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Restructured loans | 3,245 |  | 3,267
Total TDRs | Business banking | Commercial |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Restructured loans | 1,868 |  | 1,933
Total TDRs | Consumer real estate | Consumer |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Restructured loans | 8,018 |  | 7,900
Total TDRs | Other consumer | Consumer |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Restructured loans | 5 |  | 5
Performing TDRs |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Restructured loans | 17,916 |  | 17,460
Performing TDRs | Commercial real estate | Commercial |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Restructured loans | 9 |  | 14
Performing TDRs | Commercial and industrial | Commercial |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Restructured loans | 7,576 |  | 7,090
Performing TDRs | Commercial construction | Commercial |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Restructured loans | 3,245 |  | 3,267
Performing TDRs | Business banking | Commercial |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Restructured loans | 1,471 |  | 1,503
Performing TDRs | Consumer real estate | Consumer |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Restructured loans | 5,611 |  | 5,581
Performing TDRs | Other consumer | Consumer |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Restructured loans | 5 |  | 5
Nonperforming TDRs |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Restructured loans | 29,983 |  | 29,288
Nonperforming TDRs | Commercial real estate | Commercial |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Restructured loans | 15,754 |  | 16,654
Nonperforming TDRs | Commercial and industrial | Commercial |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Restructured loans | 11,425 |  | 9,885
Nonperforming TDRs | Commercial construction | Commercial |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Restructured loans | 0 |  | 0
Nonperforming TDRs | Business banking | Commercial |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Restructured loans | 397 |  | 430
Nonperforming TDRs | Consumer real estate | Consumer |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Restructured loans | 2,407 |  | 2,319
Nonperforming TDRs | Other consumer | Consumer |  |  |
Financing Receivable, Troubled Debt Restructuring [Line Items] |  |  |
Restructured loans | $ 0 |  | $ 0

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