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Investment Securities - Amortized Cost and Fair Value (Details) - USD ($) $ in Thousands | Dec. 31, 2018 | Dec. 31, 2017
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Debt Securities, Held-to-maturity [Abstract] |  |
Held to maturity, Amortized Cost | $ 157,206 | $ 151,032
Held-to-maturity, Fair Value | 153,894 | 151,032
Held-to-maturity, Gross Unrealized Gains | 210 | 619
Held-to-maturity, Gross Unrealized (Losses) | (3,522) | (619)
Debt Securities, Available-for-sale [Abstract] |  |
Available for Sale, Amortized Cost, Total | 465,910 | 334,285
Available-for-sale, at fair value | 462,464 | 332,467
Available-for-sale, Gross Unrealized Gains | 1,748 | 574
Available-for-sale, Gross Unrealized (Losses) | (5,194) | (2,392)
Total investment securities, Amortized Cost | 623,116 | 485,317
Total investment securities, Fair Value | 616,358 | 483,499
Total investment securities, Gross Unrealized Gains | 1,958 | 1,193
Total investment securities, Gross Unrealized (Losses) | (8,716) | (3,011)
MBS pass-through securities issued by FHLMC and FNMA |  |
Debt Securities, Held-to-maturity [Abstract] |  |
Held to maturity, Amortized Cost | 88,606 | 100,376
Held-to-maturity, Fair Value | 85,804 | 100,096
Held-to-maturity, Gross Unrealized Gains | 7 | 234
Held-to-maturity, Gross Unrealized (Losses) | (2,809) | (514)
Debt Securities, Available-for-sale [Abstract] |  |
Available for Sale, Amortized Cost, Total | 95,339 | 65,559
Available-for-sale, at fair value | 94,467 | 65,262
Available-for-sale, Gross Unrealized Gains | 358 | 126
Available-for-sale, Gross Unrealized (Losses) | (1,230) | (423)
SBA-backed securities |  |
Debt Securities, Held-to-maturity [Abstract] |  |
Held to maturity, Amortized Cost | 8,720 | 0
Held-to-maturity, Fair Value | 8,757 | 0
Held-to-maturity, Gross Unrealized Gains | 37 | 0
Held-to-maturity, Gross Unrealized (Losses) | 0 | 0
Debt Securities, Available-for-sale [Abstract] |  |
Available for Sale, Amortized Cost, Total | 50,722 | 25,979
Available-for-sale, at fair value | 50,781 | 25,982
Available-for-sale, Gross Unrealized Gains | 465 | 58
Available-for-sale, Gross Unrealized (Losses) | (406) | (55)
CMOs issued by FNMA |  |
Debt Securities, Held-to-maturity [Abstract] |  |
Held to maturity, Amortized Cost | 11,447 | 0
Held-to-maturity, Fair Value | 11,327 | 0
Held-to-maturity, Gross Unrealized Gains | 0 | 0
Held-to-maturity, Gross Unrealized (Losses) | (120) | 0
Debt Securities, Available-for-sale [Abstract] |  |
Available for Sale, Amortized Cost, Total | 28,275 | 35,340
Available-for-sale, at fair value | 28,079 | 35,125
Available-for-sale, Gross Unrealized Gains | 134 | 33
Available-for-sale, Gross Unrealized (Losses) | (330) | (248)
CMOs issued by FHLMC |  |
Debt Securities, Held-to-maturity [Abstract] |  |
Held to maturity, Amortized Cost | 33,583 | 31,010
Held-to-maturity, Fair Value | 33,021 | 30,938
Held-to-maturity, Gross Unrealized Gains | 8 | 2
Held-to-maturity, Gross Unrealized (Losses) | (570) | (74)
Debt Securities, Available-for-sale [Abstract] |  |
Available for Sale, Amortized Cost, Total | 145,979 | 70,514
Available-for-sale, at fair value | 144,836 | 69,889
Available-for-sale, Gross Unrealized Gains | 454 | 3
Available-for-sale, Gross Unrealized (Losses) | (1,597) | (628)
CMOs issued by GNMA |  |
Debt Securities, Held-to-maturity [Abstract] |  |
Held to maturity, Amortized Cost | 3,739 | 0
Held-to-maturity, Fair Value | 3,769 | 0
Held-to-maturity, Gross Unrealized Gains | 30 | 0
Held-to-maturity, Gross Unrealized (Losses) | 0 | 0
Debt Securities, Available-for-sale [Abstract] |  |
Available for Sale, Amortized Cost, Total | 11,294 | 17,953
Available-for-sale, at fair value | 11,021 | 17,785
Available-for-sale, Gross Unrealized Gains | 1 | 26
Available-for-sale, Gross Unrealized (Losses) | (274) | (194)
Debentures of government- sponsored agencies |  |
Debt Securities, Available-for-sale [Abstract] |  |
Available for Sale, Amortized Cost, Total | 52,956 | 12,940
Available-for-sale, at fair value | 53,018 | 12,938
Available-for-sale, Gross Unrealized Gains | 185 | 3
Available-for-sale, Gross Unrealized (Losses) | (123) | (5)
Privately issued CMOs |  |
Debt Securities, Available-for-sale [Abstract] |  |
Available for Sale, Amortized Cost, Total | 295 | 1,432
Available-for-sale, at fair value | 297 | 1,431
Available-for-sale, Gross Unrealized Gains | 2 | 1
Available-for-sale, Gross Unrealized (Losses) | 0 | (2)
Obligations of state and political subdivisions |  |
Debt Securities, Held-to-maturity [Abstract] |  |
Held to maturity, Amortized Cost | 11,111 | 19,646
Held-to-maturity, Fair Value | 11,216 | 19,998
Held-to-maturity, Gross Unrealized Gains | 128 | 383
Held-to-maturity, Gross Unrealized (Losses) | (23) | (31)
Debt Securities, Available-for-sale [Abstract] |  |
Available for Sale, Amortized Cost, Total | 79,046 | 98,027
Available-for-sale, at fair value | 77,960 | 97,491
Available-for-sale, Gross Unrealized Gains | 134 | 298
Available-for-sale, Gross Unrealized (Losses) | (1,220) | (834)
Corporate bonds |  |
Debt Securities, Available-for-sale [Abstract] |  |
Available for Sale, Amortized Cost, Total | 2,004 | 6,541
Available-for-sale, at fair value | 2,005 | 6,564
Available-for-sale, Gross Unrealized Gains | 15 | 26
Available-for-sale, Gross Unrealized (Losses) | $ (14) | $ (3)

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