Loans and Allowance for Loan Losses (Details Textual)	3 Months Ended
Mar. 31, 2018 USD ($) Contract Borrower	Mar. 31, 2017 USD ($) Loan	Dec. 31, 2017 USD ($)
Accounts Notes And Loans Receivable [Line Items]
Current Loans	$ 450,845,000		$ 486,305,000
Charge off amount recorded as loan discount	$ 1,213,000	$ 137,000
Period after which loans considered nonperforming	90 days
Number of loans modified as TDRs	7	0
Number of commercial loan borrowers \| Borrower	1
60-day or less term commercial loans
Accounts Notes And Loans Receivable [Line Items]
Current Loans			43,000,000
Financing receivables, maturity	First quarter of 2018
Charge off amount recorded as loan discount	$ 1,200,000
Reserve previously allocated to loans			$ 625,000

Financing receivables maturity period.

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- Definition

Minimum period after which loans to be considered non performing.

+ References

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- Definition

Number of commercial loan borrowers.

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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.

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Amount of direct write-downs of financing receivables charged against the allowance.

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- Definition

Number of financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
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Financing receivables that are current.

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- Definition

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

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