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Loans and Allowance for Credit Losses - Commercial and Industrial Loans Narrative (Details) $ in Thousands | 1 Months Ended |  |
--- | --- | --- | ---
Oct. 31, 2020 | Dec. 31, 2020 USD ($) loan | Dec. 31, 2019 USD ($)
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |
Loans, at amortized cost |  | $ 2,088,556 | $ 1,843,286
Commercial | Commercial and industrial |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |
Loans, at amortized cost |  | $ 498,408 | $ 246,687
Small Business Administration Paycheck Protection Program |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |
Number of loans | loan |  | 1,800 |
Payment deferral period, before extension due to PPP forgiveness process delay | 6 months |  |
Payment deferral period, after extension due to PPP forgiveness process delay | 16 months |  |
Small Business Administration Paycheck Protection Program | Commercial | Commercial and industrial |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |
Loans, at amortized cost |  | $ 291,600 |
Unaccreted fess and costs |  | $ 5,400 |

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