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Allowance for Credit Losses on Loans - Additional Information (Detail) - Financial Asset Originated - USD ($) $ in Thousands | 3 Months Ended | 9 Months Ended
--- | --- | ---
Sep. 30, 2020 | Sep. 30, 2019 | Sep. 30, 2020 | Sep. 30, 2019
Loans and Leases Receivable Disclosure [Line Items] |  |  |  |
Interest lost on nonaccrual loans | $ 303 | $ 325 | $ 1,162 | $ 1,014
Interest income on nonaccrual loans | 187 | $ 151 | $ 321 | $ 297
Changes in California Unemployment and Gross Domestic Product |  |  |  |
Loans and Leases Receivable Disclosure [Line Items] |  |  |  |
Increase in allowance for credit loss | 9,556 |  |  |
Reserve for concentration risk | (1,472) |  |  |
Reserves on individually evaluated loans | $ (321) |  |  |

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- Definition Financing Receivable, Allowance For Credit Losses, Individually Evaluated For Impairment, Increase (Decrease) + References No definition available. + Details
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- Definition Financing Receivable, Allowance For Credit Losses, Reserve For Concentration Risk, Increase (Decrease) + References No definition available. + Details
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- Definition Amount of increase (decrease) in allowance for credit loss on financing receivable. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11B -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=118936363&loc=SL6953423-111524 Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 13 -URI http://asc.fasb.org/extlink&oid=119407570&loc=SL82919249-210447 + Details
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- Definition Amount of interest income on financing receivable on nonaccrual status. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 20 -Section 50 -Paragraph 16 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=119407570&loc=SL82919258-210447 + Details
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
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- Definition Reflects the amount of additional interest income that would have been recorded if impaired or nonperforming loans were instead current, in compliance with their original terms, and outstanding throughout the reporting period or since origination (if held for part of the period). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 40 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=118939409&loc=d3e18794-111554 + Details
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