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Goodwill and Other Intangible Assets (Core Deposit Intangibles) (Details) - Core Deposit Intangibles - USD ($) | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2018 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items] |  |  |  |
Impairment write-offs/write downs on the remaining core deposit intangibles |  | $ 0 | $ 0 | $ 0
Gross balance |  | 86,099,000 | 86,099,000 |
Accumulated amortization |  | (76,088,000) | (71,570,000) |
Net carrying balance |  | $ 10,011,000 | $ 14,529,000 |
Desert Community Bank |  |  |  |
Finite-Lived Intangible Assets [Line Items] |  |  |  |
Impairment write-offs/write downs on the remaining core deposit intangibles | $ 1,000,000.0 |  |  |

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- Definition Accumulated amount of amortization of assets, excluding financial assets and goodwill, lacking physical substance with a finite life. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=66006027&loc=d3e16323-109275 + Details
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