Investment Securities - Amortized Cost and Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Held to maturity, Amortized Cost	$ 172,272	$ 44,438
Held to maturity, Fair Value	172,421	45,097
Held-to-maturity, Gross Unrealized Gains	828	820
Held-to-maturity, Gross Unrealized Losses	(679)	(161)
Available-for-sale, Amortized Cost	242,650	378,254
Available-for-sale, Fair Value	241,684	372,580
Available-for-sale, Gross Unrealized Gains	831	575
Available-for-sale, Gross Unrealized Losses	(1,797)	(6,249)
Total investment securities, Amortized Cost	414,922	422,692
Total investment securities, Fair Value	414,105	417,677
Total investment securities, Gross Unrealized Gains	1,659	1,395
Total investment securities, Gross Unrealized Losses	(2,476)	(6,410)
MBS pass-through securities issued by FHLMC and FNMA
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available-for-sale, Amortized Cost	93,676	193,998
Available-for-sale, Fair Value	93,719	190,566
Available-for-sale, Gross Unrealized Gains	328	145
Available-for-sale, Gross Unrealized Losses	(285)	(3,577)
CMOs issued by FNMA
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available-for-sale, Amortized Cost	12,897	13,790
Available-for-sale, Fair Value	12,874	13,772
Available-for-sale, Gross Unrealized Gains	84	91
Available-for-sale, Gross Unrealized Losses	(107)	(109)
CMOs issued by FHLMC
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available-for-sale, Amortized Cost	10,237	43,452
Available-for-sale, Fair Value	10,260	42,758
Available-for-sale, Gross Unrealized Gains	25	37
Available-for-sale, Gross Unrealized Losses	(2)	(731)
CMOs issued by GNMA
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available-for-sale, Amortized Cost	6,181	6,844
Available-for-sale, Fair Value	6,268	6,945
Available-for-sale, Gross Unrealized Gains	87	102
Available-for-sale, Gross Unrealized Losses	0	(1)
Debentures of government sponsored agencies
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available-for-sale, Amortized Cost	35,488	35,486
Available-for-sale, Fair Value	35,386	35,403
Available-for-sale, Gross Unrealized Gains	2	7
Available-for-sale, Gross Unrealized Losses	(104)	(90)
Privately issued CMOs
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available-for-sale, Amortized Cost	305	419
Available-for-sale, Fair Value	305	419
Available-for-sale, Gross Unrealized Gains	0	1
Available-for-sale, Gross Unrealized Losses	0	(1)
Obligations of state and political subdivisions
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available-for-sale, Amortized Cost	78,905	79,306
Available-for-sale, Fair Value	77,843	77,701
Available-for-sale, Gross Unrealized Gains	237	135
Available-for-sale, Gross Unrealized Losses	(1,299)	(1,740)
Corporate bonds
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available-for-sale, Amortized Cost	4,961	4,959
Available-for-sale, Fair Value	5,029	5,016
Available-for-sale, Gross Unrealized Gains	68	57
Available-for-sale, Gross Unrealized Losses	0	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	27,741	30,856
Held to maturity, Fair Value	28,407	31,544
Held-to-maturity, Gross Unrealized Gains	669	694
Held-to-maturity, Gross Unrealized Losses	(3)	(6)
Corporate bonds
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Held to maturity, Amortized Cost	3,514	3,519
Held to maturity, Fair Value	3,511	3,518
Held-to-maturity, Gross Unrealized Gains	0	0
Held-to-maturity, Gross Unrealized Losses	(3)	(1)
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	109,357	10,063
Held to maturity, Fair Value	108,843	10,035
Held-to-maturity, Gross Unrealized Gains	109	126
Held-to-maturity, Gross Unrealized Losses	(623)	(154)
CMOs issued by FHLMC
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Held to maturity, Amortized Cost	31,660	0
Held to maturity, Fair Value	31,660	0
Held-to-maturity, Gross Unrealized Gains	50	0
Held-to-maturity, Gross Unrealized Losses	$ (50)	$ 0

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Fair Value of Available-for-sale Securities and Held-to-maturity Securities.

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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Amount of accumulated unrealized gain on investments in debt securities classified as held-to-maturity.

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