Securities Available for Sale - Amortized costs and fair values of debt and equity securities available for sale (Details 2) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Fair Value	$ 410,911
Amortized Cost	421,948
Mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	135,845
Amortized Cost	140,427
Accounting Standards Update 2016-01
Debt Securities, Available-for-sale [Line Items]
Fair Value	410,911	$ 405,153
Amortized Cost	421,948	408,093
Gross Unrealized Gains	288	2,073
Gross Unrealized Losses	11,325	5,013
Accounting Standards Update 2016-01 \| U.S. government agency securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	26,254	26,209
Amortized Cost	27,133	26,586
Gross Unrealized Gains	0	0
Gross Unrealized Losses	879	377
Accounting Standards Update 2016-01 \| State, county and municipals
Debt Securities, Available-for-sale [Line Items]
Fair Value	164,822	184,044
Amortized Cost	169,431	186,128
Gross Unrealized Gains	38	180
Gross Unrealized Losses	4,647	2,264
Accounting Standards Update 2016-01 \| Mortgage-backed securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	135,845	155,532
Amortized Cost	140,427	157,705
Gross Unrealized Gains	85	160
Gross Unrealized Losses	4,667	2,333
Accounting Standards Update 2016-01 \| Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Fair Value	83,990	36,797
Amortized Cost	84,957	36,387
Gross Unrealized Gains	165	449
Gross Unrealized Losses	$ 1,132	39
Accounting Standards Update 2016-01 \| Equity Securities
Debt Securities, Available-for-sale [Line Items]
Fair Value		2,571
Amortized Cost		1,287
Gross Unrealized Gains		1,284
Gross Unrealized Losses		$ 0

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (b)
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Amount, before tax, of unrealized loss in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

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Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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-Section 50
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Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
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-Section 45
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