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Investment Securities - Amortized Cost and Fair Value (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
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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