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Investment Securities Unrealized Gains (Losses) (Details) - USD ($) $ in Thousands | 3 Months Ended | 6 Months Ended
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Jun. 30, 2018 | Jun. 30, 2017 | Jun. 30, 2018 | Jun. 30, 2017
Investments, Debt and Equity Securities [Abstract] |  |  |  |
Net Gain on Equity Securities | $ 223 | $ 0 | $ 241 | $ 0
Less: Net gain (loss) recognized during the reporting period on equity securities sold during the period | 0 |  | 0 |
Unrealized net gain recognized during the reporting period on equity securities still held at the reporting date | $ 223 |  | $ 241 |

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