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Loans and Allowance for Credit Losses - Commercial and Industrial Loans Narrative (Details) $ in Thousands | 12 Months Ended |
--- | --- | ---
Dec. 31, 2021 USD ($) loan | Dec. 31, 2020 USD ($) | Jun. 30, 2021 USD ($) loan
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |
Loans, at amortized cost | $ 2,255,645 | $ 2,088,556 |
Commercial | Commercial and industrial |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |
Loans, at amortized cost | 301,602 | 498,408 |
Small Business Administration Paycheck Protection Program | Commercial | Commercial and industrial |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |
Number of loans | loan |  |  | 2,876
Loans, at amortized cost | 111,200 | 291,600 | $ 444,100
Unrecognized loan fees, net of costs | 2,500 | 5,400 |
Recognized loan fees, net of cost | $ 8,300 | $ 3,800 |
Small Business Administration Paycheck Protection Program | Commercial | Commercial and industrial | American River Bank ARB |  |  |
Financing Receivable, Allowance for Credit Loss [Line Items] |  |  |
Number of loans | loan | 13 |  |
Loans, at amortized cost | $ 2,800 |  |

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