Investment Securities - Amortized Cost and Fair Value (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Held to maturity, Amortized Cost	$ 63,246	$ 69,637
Held to maturity, Fair Value	64,848	71,054
Held-to-maturity, Gross Unrealized Gains	1,624	1,459
Held-to-maturity, Gross Unrealized Losses	(22)	(42)
Available-for-sale, Amortized Cost	333,044	417,410
Available-for-sale, Fair Value	336,234	417,787
Available-for-sale, Gross Unrealized Gains	3,397	1,883
Available-for-sale, Gross Unrealized Losses	(207)	(1,506)
Total investment securities, Amortized Cost	396,290	487,047
Total investment securities, Fair Value	401,082	488,841
Total investment securities, Gross Unrealized Gains	5,021	3,342
Total investment securities, Gross Unrealized Losses	(229)	(1,548)
Mortgage-backed Securities, Issued by FHLMC and FNMA
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available-for-sale, Amortized Cost	128,434	138,222
Available-for-sale, Fair Value	129,983	138,462
Available-for-sale, Gross Unrealized Gains	1,613	694
Available-for-sale, Gross Unrealized Losses	(64)	(454)
CMOs issued by FNMA
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available-for-sale, Amortized Cost	17,190	18,266
Available-for-sale, Fair Value	17,290	18,219
Available-for-sale, Gross Unrealized Gains	147	97
Available-for-sale, Gross Unrealized Losses	(47)	(144)
CMOs issued by FHLMC
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available-for-sale, Amortized Cost	23,287	22,889
Available-for-sale, Fair Value	23,471	22,932
Available-for-sale, Gross Unrealized Gains	196	82
Available-for-sale, Gross Unrealized Losses	(12)	(39)
CMOs issued by GNMA
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available-for-sale, Amortized Cost	9,394	10,326
Available-for-sale, Fair Value	9,562	10,480
Available-for-sale, Gross Unrealized Gains	172	169
Available-for-sale, Gross Unrealized Losses	(4)	(15)
Debentures of government sponsored agencies
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available-for-sale, Amortized Cost	87,592	161,690
Available-for-sale, Fair Value	87,623	160,892
Available-for-sale, Gross Unrealized Gains	93	28
Available-for-sale, Gross Unrealized Losses	(62)	(826)
Privately-issued CMOs
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available-for-sale, Amortized Cost	3,785	3,960
Available-for-sale, Fair Value	3,971	4,150
Available-for-sale, Gross Unrealized Gains	187	190
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]
Available-for-sale, Amortized Cost	58,412	57,110
Available-for-sale, Fair Value	59,373	57,673
Available-for-sale, Gross Unrealized Gains	964	580
Available-for-sale, Gross Unrealized Losses	(3)	(17)
Corporate bonds
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Available-for-sale, Amortized Cost	4,950	4,947
Available-for-sale, Fair Value	4,961	4,979
Available-for-sale, Gross Unrealized Gains	25	43
Available-for-sale, Gross Unrealized Losses	(14)	(11)
Obligations of state and political subdivisions
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Held to maturity, Amortized Cost	40,254	42,919
Held to maturity, Fair Value	41,580	44,146
Held-to-maturity, Gross Unrealized Gains	1,338	1,246
Held-to-maturity, Gross Unrealized Losses	(12)	(19)
Corporate bonds
Schedule of Available-for-sale Securities and Held-to-maturity Securities [Line Items]
Held to maturity, Amortized Cost	11,544	15,072
Held to maturity, Fair Value	11,560	15,098
Held-to-maturity, Gross Unrealized Gains	19	42
Held-to-maturity, Gross Unrealized Losses	(3)	(16)
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	11,448	11,646
Held to maturity, Fair Value	11,708	11,810
Held-to-maturity, Gross Unrealized Gains	267	171
Held-to-maturity, Gross Unrealized Losses	$ (7)	$ (7)

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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 gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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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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