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Investment Securities - Amortized Cost and Fair Value (Details) - USD ($) $ in Thousands | Sep. 30, 2019 | Dec. 31, 2018
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Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Held to maturity, Amortized Cost | $ 142,213 | $ 157,206
Held to maturity, Fair Value | 145,118 | 153,894
Held-to-maturity, Gross Unrealized Gains | 3,130 | 210
Held-to-maturity, Gross Unrealized Losses | (225) | (3,522)
Total | 348,369 | 465,910
Available-for-sale, at fair value | 358,724 | 462,464
Available-for-sale, Gross Unrealized Gains | 10,557 | 1,748
Available-for-sale, Gross Unrealized Losses | (202) | (5,194)
Total investment securities, Amortized Cost | 490,582 | 623,116
Total investment securities, Fair Value | 503,842 | 616,358
Total investment securities, Gross Unrealized Gains | 13,687 | 1,958
Total investment securities, Gross Unrealized Losses | (427) | (8,716)
MBS pass-through securities issued by FHLMC and FNMA |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Held to maturity, Amortized Cost | 80,166 | 88,606
Held to maturity, Fair Value | 81,308 | 85,804
Held-to-maturity, Gross Unrealized Gains | 1,357 | 7
Held-to-maturity, Gross Unrealized Losses | (215) | (2,809)
Total | 62,654 | 95,339
Available-for-sale, at fair value | 64,290 | 94,467
Available-for-sale, Gross Unrealized Gains | 1,683 | 358
Available-for-sale, Gross Unrealized Losses | (47) | (1,230)
SBA-backed securities |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Held to maturity, Amortized Cost | 8,001 | 8,720
Held to maturity, Fair Value | 8,360 | 8,757
Held-to-maturity, Gross Unrealized Gains | 359 | 37
Held-to-maturity, Gross Unrealized Losses | 0 | 0
Total | 36,014 | 50,722
Available-for-sale, at fair value | 36,943 | 50,781
Available-for-sale, Gross Unrealized Gains | 990 | 465
Available-for-sale, Gross Unrealized Losses | (61) | (406)
CMOs issued by FNMA |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Held to maturity, Amortized Cost | 10,679 | 11,447
Held to maturity, Fair Value | 10,981 | 11,327
Held-to-maturity, Gross Unrealized Gains | 302 | 0
Held-to-maturity, Gross Unrealized Losses | 0 | (120)
Total | 24,168 | 28,275
Available-for-sale, at fair value | 24,560 | 28,079
Available-for-sale, Gross Unrealized Gains | 392 | 134
Available-for-sale, Gross Unrealized Losses | 0 | (330)
CMOs issued by FHLMC |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Held to maturity, Amortized Cost | 32,568 | 33,583
Held to maturity, Fair Value | 33,524 | 33,021
Held-to-maturity, Gross Unrealized Gains | 966 | 8
Held-to-maturity, Gross Unrealized Losses | (10) | (570)
Total | 138,731 | 145,979
Available-for-sale, at fair value | 144,067 | 144,836
Available-for-sale, Gross Unrealized Gains | 5,374 | 454
Available-for-sale, Gross Unrealized Losses | (38) | (1,597)
CMOs issued by GNMA |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Held to maturity, Amortized Cost | 3,757 | 3,739
Held to maturity, Fair Value | 3,810 | 3,769
Held-to-maturity, Gross Unrealized Gains | 53 | 30
Held-to-maturity, Gross Unrealized Losses | 0 | 0
Total | 12,621 | 11,294
Available-for-sale, at fair value | 12,686 | 11,021
Available-for-sale, Gross Unrealized Gains | 66 | 1
Available-for-sale, Gross Unrealized Losses | (1) | (274)
Debentures of government- sponsored agencies |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Total | 23,069 | 52,956
Available-for-sale, at fair value | 23,822 | 53,018
Available-for-sale, Gross Unrealized Gains | 753 | 185
Available-for-sale, Gross Unrealized Losses | 0 | (123)
Privately issued CMOs |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Total | 120 | 295
Available-for-sale, at fair value | 119 | 297
Available-for-sale, Gross Unrealized Gains | 0 | 2
Available-for-sale, Gross Unrealized Losses | (1) | 0
Obligations of state and political subdivisions |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Held to maturity, Amortized Cost | 7,042 | 11,111
Held to maturity, Fair Value | 7,135 | 11,216
Held-to-maturity, Gross Unrealized Gains | 93 | 128
Held-to-maturity, Gross Unrealized Losses | 0 | (23)
Total | 48,993 | 79,046
Available-for-sale, at fair value | 50,232 | 77,960
Available-for-sale, Gross Unrealized Gains | 1,292 | 134
Available-for-sale, Gross Unrealized Losses | (53) | (1,220)
Corporate bonds |  |
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items] |  |
Total | 1,999 | 2,004
Available-for-sale, at fair value | 2,005 | 2,005
Available-for-sale, Gross Unrealized Gains | 7 | 15
Available-for-sale, Gross Unrealized Losses | $ (1) | $ (14)

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