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Loans and Allowance for Credit Losses on Loans - Outstanding and Aging Analysis (Details) | 3 Months Ended |  |  |
--- | --- | --- | --- | ---
Mar. 31, 2022 USD ($) branch | Mar. 31, 2021 USD ($) | Dec. 31, 2021 USD ($) loan | Aug. 06, 2021 USD ($) | Jun. 30, 2021 USD ($)
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | $ 2,201,854,000 |  | $ 2,255,645,000 |  |
Loans past due more than 90 days still accruing | 0 |  |  |  |
Financing receivable, nonaccrual, earning interest on cash basis | 0 |  | 0 |  |
Financing receivable, nonaccrual, interest income | $ 0 | $ 0 |  |  |
Financing receivable, number of loans placed on nonaccrual status | branch | 1 |  |  |  |
Financing receivable, nonaccrual, amortized cost | $ 16,000 | $ 0 |  |  |
Financing receivable, accrued interest, writeoff | 1,000 |  |  |  |
Commercial loans | Commercial and industrial |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 248,625,000 |  | 301,602,000 |  |
Loans past due more than 90 days still accruing |  |  | 229,000 |  |
Commercial loans | Commercial and industrial | SBA PPP |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 40,600,000 |  | $ 111,200,000 |  | $ 444,100,000
Number of loans | loan |  |  | 2 |  |
Commercial loans | Commercial and industrial | American River Bank (ARB) | SBA PPP |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost |  |  |  | $ 18,600,000 |
Commercial real estate loans | Commercial owner-occupied |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 391,924,000 |  | $ 392,345,000 |  |
Commercial real estate loans | Commercial investor-owned |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 1,176,918,000 |  | 1,189,021,000 |  |
Commercial real estate loans | Construction |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 131,015,000 |  | 119,840,000 |  |
Residential loans | Home equity |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 88,092,000 |  | 88,746,000 |  |
Residential loans | Other residential |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 114,277,000 |  | 114,558,000 |  |
Consumer loans | Installment and other consumer loans |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 51,003,000 |  | 49,533,000 |  |
Financial asset, other than financial asset acquired with credit deterioration |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 2,201,854,000 |  | 2,255,645,000 |  |
Non-accrual | 7,678,000 |  | 8,376,000 |  |
Non-accrual loans with no allowance | 7,678,000 |  | 8,376,000 |  |
Financial asset, other than financial asset acquired with credit deterioration | Total past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 2,643,000 |  | 2,314,000 |  |
Financial asset, other than financial asset acquired with credit deterioration | 30-59 days past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 2,130,000 |  | 1,536,000 |  |
Financial asset, other than financial asset acquired with credit deterioration | 60-89 days past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 443,000 |  | 461,000 |  |
Financial asset, other than financial asset acquired with credit deterioration | 90 days or more past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 70,000 |  | 317,000 |  |
Financial asset, other than financial asset acquired with credit deterioration | Current |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 2,199,211,000 |  | 2,253,331,000 |  |
Financial asset, other than financial asset acquired with credit deterioration | Commercial loans | Commercial and industrial |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 248,625,000 |  | 301,602,000 |  |
Non-accrual | 0 |  | 0 |  |
Non-accrual loans with no allowance | 0 |  | 0 |  |
Financial asset, other than financial asset acquired with credit deterioration | Commercial loans | Commercial and industrial | Total past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 776,000 |  | 625,000 |  |
Financial asset, other than financial asset acquired with credit deterioration | Commercial loans | Commercial and industrial | 30-59 days past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 435,000 |  | 2,000 |  |
Financial asset, other than financial asset acquired with credit deterioration | Commercial loans | Commercial and industrial | 60-89 days past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 341,000 |  | 394,000 |  |
Financial asset, other than financial asset acquired with credit deterioration | Commercial loans | Commercial and industrial | 90 days or more past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 0 |  | 229,000 |  |
Financial asset, other than financial asset acquired with credit deterioration | Commercial loans | Commercial and industrial | Current |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 247,849,000 |  | 300,977,000 |  |
Financial asset, other than financial asset acquired with credit deterioration | Commercial real estate loans | Commercial owner-occupied |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 391,924,000 |  | 392,345,000 |  |
Non-accrual | 7,272,000 |  | 7,269,000 |  |
Non-accrual loans with no allowance | 7,272,000 |  | 7,269,000 |  |
Financial asset, other than financial asset acquired with credit deterioration | Commercial real estate loans | Commercial owner-occupied | Total past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 324,000 |  | 0 |  |
Financial asset, other than financial asset acquired with credit deterioration | Commercial real estate loans | Commercial owner-occupied | 30-59 days past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 324,000 |  | 0 |  |
Financial asset, other than financial asset acquired with credit deterioration | Commercial real estate loans | Commercial owner-occupied | 60-89 days past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 0 |  | 0 |  |
Financial asset, other than financial asset acquired with credit deterioration | Commercial real estate loans | Commercial owner-occupied | 90 days or more past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 0 |  | 0 |  |
Financial asset, other than financial asset acquired with credit deterioration | Commercial real estate loans | Commercial owner-occupied | Current |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 391,600,000 |  | 392,345,000 |  |
Financial asset, other than financial asset acquired with credit deterioration | Commercial real estate loans | Commercial investor-owned |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 1,176,918,000 |  | 1,189,021,000 |  |
Non-accrual | 0 |  | 694,000 |  |
Non-accrual loans with no allowance | 0 |  | 694,000 |  |
Financial asset, other than financial asset acquired with credit deterioration | Commercial real estate loans | Commercial investor-owned | Total past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 0 |  | 0 |  |
Financial asset, other than financial asset acquired with credit deterioration | Commercial real estate loans | Commercial investor-owned | 30-59 days past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 0 |  | 0 |  |
Financial asset, other than financial asset acquired with credit deterioration | Commercial real estate loans | Commercial investor-owned | 60-89 days past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 0 |  | 0 |  |
Financial asset, other than financial asset acquired with credit deterioration | Commercial real estate loans | Commercial investor-owned | 90 days or more past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost |  |  | 0 |  |
Financial asset, other than financial asset acquired with credit deterioration | Commercial real estate loans | Commercial investor-owned | Current |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 1,176,918,000 |  | 1,189,021,000 |  |
Financial asset, other than financial asset acquired with credit deterioration | Commercial real estate loans | Construction |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 131,015,000 |  | 119,840,000 |  |
Non-accrual | 0 |  | 0 |  |
Non-accrual loans with no allowance | 0 |  | 0 |  |
Financial asset, other than financial asset acquired with credit deterioration | Commercial real estate loans | Construction | Total past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 0 |  | 0 |  |
Financial asset, other than financial asset acquired with credit deterioration | Commercial real estate loans | Construction | 30-59 days past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 0 |  | 0 |  |
Financial asset, other than financial asset acquired with credit deterioration | Commercial real estate loans | Construction | 60-89 days past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 0 |  | 0 |  |
Financial asset, other than financial asset acquired with credit deterioration | Commercial real estate loans | Construction | 90 days or more past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 0 |  | 0 |  |
Financial asset, other than financial asset acquired with credit deterioration | Commercial real estate loans | Construction | Current |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 131,015,000 |  | 119,840,000 |  |
Financial asset, other than financial asset acquired with credit deterioration | Residential loans | Home equity |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 88,092,000 |  | 88,746,000 |  |
Non-accrual | 390,000 |  | 413,000 |  |
Non-accrual loans with no allowance | 390,000 |  | 413,000 |  |
Financial asset, other than financial asset acquired with credit deterioration | Residential loans | Home equity | Total past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 553,000 |  | 653,000 |  |
Financial asset, other than financial asset acquired with credit deterioration | Residential loans | Home equity | 30-59 days past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 399,000 |  | 498,000 |  |
Financial asset, other than financial asset acquired with credit deterioration | Residential loans | Home equity | 60-89 days past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 100,000 |  | 67,000 |  |
Financial asset, other than financial asset acquired with credit deterioration | Residential loans | Home equity | 90 days or more past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 54,000 |  | 88,000 |  |
Financial asset, other than financial asset acquired with credit deterioration | Residential loans | Home equity | Current |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 87,539,000 |  | 88,093,000 |  |
Financial asset, other than financial asset acquired with credit deterioration | Residential loans | Other residential |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 114,277,000 |  | 114,558,000 |  |
Non-accrual | 0 |  | 0 |  |
Non-accrual loans with no allowance | 0 |  | 0 |  |
Financial asset, other than financial asset acquired with credit deterioration | Residential loans | Other residential | Total past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 635,000 |  | 0 |  |
Financial asset, other than financial asset acquired with credit deterioration | Residential loans | Other residential | 30-59 days past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 635,000 |  | 0 |  |
Financial asset, other than financial asset acquired with credit deterioration | Residential loans | Other residential | 60-89 days past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 0 |  | 0 |  |
Financial asset, other than financial asset acquired with credit deterioration | Residential loans | Other residential | 90 days or more past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 0 |  | 0 |  |
Financial asset, other than financial asset acquired with credit deterioration | Residential loans | Other residential | Current |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 113,642,000 |  | 114,558,000 |  |
Financial asset, other than financial asset acquired with credit deterioration | Consumer loans | Installment and other consumer loans |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 51,003,000 |  | 49,533,000 |  |
Non-accrual | 16,000 |  | 0 |  |
Non-accrual loans with no allowance | 16,000 |  | 0 |  |
Financial asset, other than financial asset acquired with credit deterioration | Consumer loans | Installment and other consumer loans | Total past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 355,000 |  | 1,036,000 |  |
Financial asset, other than financial asset acquired with credit deterioration | Consumer loans | Installment and other consumer loans | 30-59 days past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 337,000 |  | 1,036,000 |  |
Financial asset, other than financial asset acquired with credit deterioration | Consumer loans | Installment and other consumer loans | 60-89 days past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 2,000 |  | 0 |  |
Financial asset, other than financial asset acquired with credit deterioration | Consumer loans | Installment and other consumer loans | 90 days or more past due |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | 16,000 |  | 0 |  |
Financial asset, other than financial asset acquired with credit deterioration | Consumer loans | Installment and other consumer loans | Current |  |  |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |  |  |
Loans at amortized cost | $ 50,648,000 |  | $ 48,497,000 |  |

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