Securities (Details Textual) (Details) - USD ($)	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Debt Securities, Available-for-sale [Line Items]
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Period Increase (Decrease)	$ 0	$ 0	$ 0	$ 0
Debt Securities, Available-for-sale	435,861,000		435,861,000		$ 447,498,000
Other than Temporary Impairment, Credit Losses Recognized in Earnings, Credit Losses on Debt Securities Held	0	$ 0	0	$ 0
Securities (Textual) [Abstract]
Callable Securities in Investment Portfolio	6,300,000		6,300,000
Pledged Financial Instruments, Not Separately Reported, Securities	523,600,000		523,600,000		547,200,000
Trading	1,581,000		1,581,000		1,324,000
Investments in obligations of individual states, counties or municipalities which exceed 10% of equity	0		0		0
Equity Securities, FV-NI	$ 20,430,000		$ 20,430,000
Equity Securities [Member]
Debt Securities, Available-for-sale [Line Items]
Debt Securities, Available-for-sale					$ 20,584,000

Callable securities in investment portfolio.

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- Definition

Investments in obligations of individual states, counties or municipalities which exceed 10% of equity

+ References

No definition available.

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- Definition

Securities.

+ References

No definition available.

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- Definition

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
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (b)
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Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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-Publisher FASB
-Name Accounting Standards Codification
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- Definition

The cumulative amount of credit losses recognized in earnings related to debt securities held for which a portion of an other than temporary impairment (OTTI) was recognized in other comprehensive income (a component of shareholders' equity).

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Amount of increase (decrease) in the cumulative amount of credit losses recognized in earnings related to debt securities held for which a portion of an other than temporary impairment (OTTI) was recognized in other comprehensive income (loss).

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Sum of the carrying amounts as of the date of the latest financial statement presented of securities which are owned but transferred to another party to serve as collateral to partially or fully secure a debt obligation, repurchase agreement or other current or potential obligation, and for which the transferee is not permitted to sell or re-pledge them to an unrelated party.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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Amount of investment in debt security measured at fair value with change in fair value recognized in net income (trading) and investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI).

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