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Securities - Fair Values and Amortized Costs Securities (Details) - USD ($) $ in Thousands | Mar. 31, 2019 | Dec. 31, 2018
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Debt Securities, Available-for-sale [Line Items] |  |
Debt Securities, Available-for-Sale, Amortized Cost | $ 673,638 | $ 685,170
Debt Securities, Available-for-Sale, Gross Unrealized Gains | 5,962 | 3,514
Debt Securities, Available-for-Sale, Gross Unrealized Losses | (3,678) | (8,628)
Debt Securities, Available-for-Sale, Fair Value | 675,922 | 680,056
Marketable equity securities | 4,498 | 4,816
Total Securities | 680,420 | 684,872
U.S. Treasury securities |  |
Debt Securities, Available-for-sale [Line Items] |  |
Debt Securities, Available-for-Sale, Amortized Cost | 9,961 | 9,958
Debt Securities, Available-for-Sale, Gross Unrealized Gains | 0 | 0
Debt Securities, Available-for-Sale, Gross Unrealized Losses | (124) | (222)
Debt Securities, Available-for-Sale, Fair Value | 9,837 | 9,736
Obligations of U.S. government corporations and agencies |  |
Debt Securities, Available-for-sale [Line Items] |  |
Debt Securities, Available-for-Sale, Amortized Cost | 129,263 | 129,267
Debt Securities, Available-for-Sale, Gross Unrealized Gains | 373 | 68
Debt Securities, Available-for-Sale, Gross Unrealized Losses | (267) | (1,074)
Debt Securities, Available-for-Sale, Fair Value | 129,369 | 128,261
Collateralized mortgage obligations of U.S. government corporations and agencies |  |
Debt Securities, Available-for-sale [Line Items] |  |
Debt Securities, Available-for-Sale, Amortized Cost | 153,717 | 149,849
Debt Securities, Available-for-Sale, Gross Unrealized Gains | 1,608 | 795
Debt Securities, Available-for-Sale, Gross Unrealized Losses | (1,166) | (1,985)
Debt Securities, Available-for-Sale, Fair Value | 154,159 | 148,659
Residential mortgage-backed securities of U.S. government corporations and agencies |  |
Debt Securities, Available-for-sale [Line Items] |  |
Debt Securities, Available-for-Sale, Amortized Cost | 22,481 | 24,564
Debt Securities, Available-for-Sale, Gross Unrealized Gains | 229 | 203
Debt Securities, Available-for-Sale, Gross Unrealized Losses | (196) | (417)
Debt Securities, Available-for-Sale, Fair Value | 22,514 | 24,350
Commercial mortgage-backed securities of U.S. government corporations and agencies |  |
Debt Securities, Available-for-sale [Line Items] |  |
Debt Securities, Available-for-Sale, Amortized Cost | 239,196 | 251,660
Debt Securities, Available-for-Sale, Gross Unrealized Gains | 272 | 0
Debt Securities, Available-for-Sale, Gross Unrealized Losses | (1,914) | (4,876)
Debt Securities, Available-for-Sale, Fair Value | 237,554 | 246,784
Obligations of states and political subdivisions |  |
Debt Securities, Available-for-sale [Line Items] |  |
Debt Securities, Available-for-Sale, Amortized Cost | 119,020 | 119,872
Debt Securities, Available-for-Sale, Gross Unrealized Gains | 3,480 | 2,448
Debt Securities, Available-for-Sale, Gross Unrealized Losses | (11) | (54)
Debt Securities, Available-for-Sale, Fair Value | $ 122,489 | $ 122,266

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