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Loans and Loans Held for Sale - Restructured Loans During Periods Presented (Details) $ in Thousands | 3 Months Ended
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Mar. 31, 2017 USD ($) contract | Mar. 31, 2016 USD ($) contract
Financing Receivable, Modifications [Line Items] |  |  |  |  |
Number of Loans | contract |  | 7 |  | 16 |
Pre-Modification Outstanding Recorded Investment | [1] | $ 442 |  | $ 2,646 |
Post-Modification Outstanding Recorded Investment | [1] | 438 |  | 2,614 |
Total Difference in Recorded Investment |  | $ (4) |  | $ (32) |
Principal deferral |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |
Number of Loans | contract |  | 0 |  | 0 |
Pre-Modification Outstanding Recorded Investment | [1] | $ 0 |  | $ 0 |
Post-Modification Outstanding Recorded Investment | [1] | 0 |  | 0 |
Total Difference in Recorded Investment |  | $ 0 |  | $ 0 |
Chapter 7 bankruptcy |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |
Number of Loans | contract | [2] | 6 |  | 9 |
Pre-Modification Outstanding Recorded Investment | [1],[2] | $ 269 |  | $ 1,175 |
Post-Modification Outstanding Recorded Investment | [1],[2] | 266 |  | 1,164 |
Total Difference in Recorded Investment | [2] | $ (3) |  | $ (11) |
Maturity date extension |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |
Number of Loans | contract |  | 0 |  | 6 |
Pre-Modification Outstanding Recorded Investment | [1] | $ 0 |  | $ 1,341 |
Post-Modification Outstanding Recorded Investment | [1] | 0 |  | 1,320 |
Total Difference in Recorded Investment |  | $ 0 |  | $ (21) |
Maturity date extension and interest rate reduction |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |
Number of Loans | contract |  | 1 |  | 1 |
Pre-Modification Outstanding Recorded Investment | [1] | $ 173 |  | $ 130 |
Post-Modification Outstanding Recorded Investment | [1] | 172 |  | 130 |
Total Difference in Recorded Investment |  | $ (1) |  | $ 0 |
Commercial Real Estate | Chapter 7 bankruptcy |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |
Number of Loans | contract | [2] | 0 |  | 1 |
Pre-Modification Outstanding Recorded Investment | [1],[2] | $ 0 |  | $ 709 |
Post-Modification Outstanding Recorded Investment | [1],[2] | 0 |  | 702 |
Total Difference in Recorded Investment | [2] | $ 0 |  | $ (7) |
Commercial And Industrial | Maturity date extension |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |
Number of Loans | contract |  | 0 |  | 2 |
Pre-Modification Outstanding Recorded Investment | [1] | $ 0 |  | $ 625 |
Post-Modification Outstanding Recorded Investment | [1] | 0 |  | 605 |
Total Difference in Recorded Investment |  | $ 0 |  | $ (20) |
Commercial Construction | Maturity date extension |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |
Number of Loans | contract |  | 0 |  | 1 |
Pre-Modification Outstanding Recorded Investment | [1] | $ 0 |  | $ 33 |
Post-Modification Outstanding Recorded Investment | [1] | 0 |  | 33 |
Total Difference in Recorded Investment |  | $ 0 |  | $ 0 |
Residential Mortgage | Chapter 7 bankruptcy |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |
Number of Loans | contract |  | 0 | [1] | 3 | [2]
Pre-Modification Outstanding Recorded Investment | [1],[2] | $ 0 |  | $ 221 |
Post-Modification Outstanding Recorded Investment | [1],[2] | 0 |  | 219 |
Total Difference in Recorded Investment | [2] | $ 0 |  | $ (2) |
Residential Mortgage | Maturity date extension |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |
Number of Loans | contract |  | 0 |  | 1 |
Pre-Modification Outstanding Recorded Investment | [1] | $ 0 |  | $ 483 |
Post-Modification Outstanding Recorded Investment | [1] | 0 |  | 483 |
Total Difference in Recorded Investment |  | $ 0 |  | $ 0 |
Home Equity Loan | Chapter 7 bankruptcy |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |
Number of Loans | contract | [2] | 6 |  | 5 |
Pre-Modification Outstanding Recorded Investment | [1],[2] | $ 269 |  | $ 245 |
Post-Modification Outstanding Recorded Investment | [1],[2] | 266 |  | 243 |
Total Difference in Recorded Investment | [2] | $ (3) |  | $ (2) |
Home Equity Loan | Maturity date extension |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |
Number of Loans | contract |  | 0 |  | 2 |
Pre-Modification Outstanding Recorded Investment | [1] | $ 0 |  | $ 200 |
Post-Modification Outstanding Recorded Investment | [1] | 0 |  | 199 |
Total Difference in Recorded Investment |  | $ 0 |  | $ (1) |
Home Equity Loan | Maturity date extension and interest rate reduction |  |  |  |  |
Financing Receivable, Modifications [Line Items] |  |  |  |  |
Number of Loans | contract |  | 1 |  | 1 |
Pre-Modification Outstanding Recorded Investment | [1] | $ 173 |  | $ 130 |
Post-Modification Outstanding Recorded Investment | [1] | 172 |  | 130 |
Total Difference in Recorded Investment |  | $ (1) |  | $ 0 |
[1] | Excludes loans that were fully paid off or fully charged-off by period end. The pre-modification balance represents the balance outstanding prior to modification. The post-modification balance represents the outstanding balance at period end.
[2] | Chapter 7 bankruptcy loans where the debt has been legally discharged through the bankruptcy court and not reaffirmed.

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