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Commitments and Contingencies (Summary of Contractual and Notional Amounts of Financial Instruments) (Details) - USD ($) $ in Thousands | Dec. 31, 2020 | Dec. 31, 2019
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Financial Instruments [Line Items] |  |
Contractual Amounts Of Financial Instrument | $ 728,721 | $ 739,860
Commitments to Extend Credit [Member] |  |
Financial Instruments [Line Items] |  |
Contractual Amounts Of Financial Instrument | 723,986 | 734,649
Standby Letters of Credit [Member] |  |
Financial Instruments [Line Items] |  |
Contractual Amounts Of Financial Instrument | $ 4,735 | $ 5,211

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