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Investment Securities - Securities Sold, Pledged as Collateral and Transfers (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2018 | Dec. 31, 2017
Available-for-sale: |  |
Sales proceeds | $ 16,972 | $ 55,408
Gross realized gains | 27 | 46
Gross realized losses | 106 | 231
Securities transferred from available-for-sale to held-to-maturity | 27,422 | 128,965
Unrealized pre-tax loss from transfer of available-for-sale securities to held-to-maturity | 278 | 3,000
Amortization of net unrealized losses on securities transferred from available-for-sale to held-to-maturity | 516 | 426
Public Deposits |  |
Available-for-sale: |  |
Available-for-sale securities pledged as collateral | 125,696 | 107,829
Trust Deposits |  |
Available-for-sale: |  |
Available-for-sale securities pledged as collateral | 734 | 761
State of California |  |
Available-for-sale: |  |
Available-for-sale securities pledged as collateral | 126,430 | 108,590
Internal checking account |  |
Available-for-sale: |  |
Available-for-sale securities pledged as collateral | $ 2,000 | $ 2,026

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- Definition Amount of realized gain 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/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 9 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27357-111563 + Details
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- Definition Sum of the carrying amounts as of the date of the latest financial statement presented of securities which are owned but transferred to another party to serve as collateral to partially or fully secure a debt obligation, repurchase agreement or other current or potential obligation, and for which the transferee is not permitted to sell or re-pledge them to an unrelated party. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 30 -Section 50 -Paragraph 1A -Subparagraph (b)(1)(i) -URI http://asc.fasb.org/extlink&oid=109249958&loc=SL6224234-111729 + Details
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