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Loans (Narrative) (Details) | 12 Months Ended
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Dec. 31, 2018 USD ($) business loan | Dec. 31, 2017 USD ($) loan | Dec. 31, 2016 USD ($) loan
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Number of loans modified as debt restructurings | loan | 0 | 3 | 0
Troubled debt restructuring, additional lending amount | $ 0 | $ 0 |
Number of loans that subsequently default after modification | loan | 0 | 0 | 0
Mortgage loans in process of foreclosure | $ 58,000 | $ 14,000 |
Threshold amount to individually evaluate loans for impairment | 250,000 |  |
Loans Acquired with Deteriorated Credit Quality |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Increase in allowance for loans that subsequently default after modification | 33,000 | 11,000 | $ 107,000
Loans Purchased |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Allowance for loan losses, reversal | $ 36,000 | $ 110,000 | $ 2,000
Bank and Branch Acquisitions |  |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |  |
Number of acquisitions | business | 2 |  |

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