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Investment Securities - Additional Information (Details) | 12 Months Ended
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Dec. 31, 2019 USD ($) Security | Dec. 31, 2018 USD ($) Security | Dec. 31, 2017 USD ($)
Investments Debt And Equity Securities [Abstract] |  |  |
Proceeds from sale of securities | $ 6,143,000 | $ 44,591,000 | $ 0
Gross gains recognized on sale of securities | $ 7,000 | $ 5,000 |
Number of investment securities pledged as collateral | Security | 1 | 1 |
Fair value of securities pledged to secure local agency deposit | $ 627,000 | $ 697,000 |

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- Definition Amount of realized gain (loss) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 9 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=118939692&loc=d3e27357-111563 + Details
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