Investment Securities - Portfolio of Available-for-Sale Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale, Amortized Cost	$ 301,411	$ 312,584
Gross Unrealized Gains	1,318	1,961
Gross Unrealized Losses	8,759	5,354
Fair Value	293,970	309,191
Obligations of state and political subdivisions
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale, Amortized Cost	20,943	23,042
Gross Unrealized Gains	75	209
Gross Unrealized Losses	825	442
Fair Value	20,193	22,809
GSE mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale, Amortized Cost	55,926	58,620
Gross Unrealized Gains	561	825
Gross Unrealized Losses	976	321
Fair Value	55,511	59,124
Collateralized mortgage obligations: residential
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale, Amortized Cost	194,647	202,573
Gross Unrealized Gains	103	90
Gross Unrealized Losses	6,743	4,508
Fair Value	188,007	198,155
Collateralized mortgage obligations: commercial
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale, Amortized Cost	2,230	2,274
Gross Unrealized Gains	0	0
Gross Unrealized Losses	47	34
Fair Value	2,183	2,240
Mutual funds
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale, Amortized Cost	2,100	2,100
Gross Unrealized Gains	0	0
Gross Unrealized Losses	74	39
Fair Value	2,026	2,061
Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale, Amortized Cost	25,565	23,975
Gross Unrealized Gains	579	837
Gross Unrealized Losses	94	10
Fair Value	$ 26,050	$ 24,802

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

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 25
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=65884222&loc=d3e22054-111558

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27232-111563

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=66010992&loc=d3e26610-111562

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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
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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.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27161-111563

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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