Note 5 - Loans (Details Textual) - USD ($)	3 Months Ended	12 Months Ended
Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Unamortized Loan Commitment and Origination Fees and Unamortized Discounts or Premiums	$ 2,800,000		$ 2,900,000
Loans and Leases Receivable, Impaired, Interest Lost on Nonaccrual Loans	104,000	$ 84,000
Impaired Financing Receivable, Recorded Investment	$ 16,757,000		18,794,000
Percentage of Collateral Coverage to Loan Balance to Consider Restructured Loan to Performing and Accrual Status	100.00%
Financing Receivable, Modifications, Number of Contracts	118
Financing Receivable, Recorded Investment, Nonaccrual Status	$ 9,997,000		11,386,000
Financing Receivable, Modifications, Recorded Investment	$ 11,300,000		$ 12,100,000
Troubled Debt Restructurings Percentage of Gross Portfolio Loans	1.40%		1.50%
Doubtful Grade Remaining Outstanding Period, Minimum	180 days
Loans and Leases Receivable, Allowance	$ 11,641,000		$ 11,544,000
Percentage of Allowance for Loan and Lease Losses out of Net Loans	1.44%		1.44%
Fair Value Disclosure, Off-balance Sheet Risks, Amount, Asset	$ 217,800,000		$ 229,400,000
Reserve for Unfunded Commitments Included in Other Liabilities	$ 695,000		$ 695,000
Percentage of Loan Portfolio Secured by Real Estate	75.00%
Percentage of Unallocated Allowance Amount out of Allowance for Loan and Lease Losses	4.00%		4.00%
Maximum Loan to Value, Percentage	80.00%
Loans and Leases Receivable, Impaired, Commitment to Lend	$ 0		$ 0
Commercial Portfolio Segment [Member]
Impaired Financing Receivable, Recorded Investment	3,275,000		3,525,000
Financing Receivable, Recorded Investment, Nonaccrual Status	$ 2,534,000		2,749,000
Commercial Portfolio Segment [Member] \| Line of Credit [Member]
Financing Receivable, Modifications, Number of Contracts	1
Financing Receivable, Recorded Investment, Nonaccrual Status	$ 231,000
Performing Financial Instruments [Member]
Impaired Financing Receivable, Recorded Investment	$ 6,800,000		$ 7,100,000
Financing Receivable, Modifications, Number of Contracts	110

Period that a loan classified as Doubtful will remain outstanding.

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- Definition

The maximum loan to value percentage.

+ References

No definition available.

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- Definition

Percentage of the allowance for loan and lease losses as a percentage of total gross loans.

+ References

No definition available.

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The percentage of collateral coverage to loan balance, to consider restructured loan to performing and accrual status.

+ References

No definition available.

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- Definition

The percentage of the gross loan portfolio that is secured by real estate.

+ References

No definition available.

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- Definition

The percentage of unallocated allowance amount out of allowance for loan and lease losses.

+ References

No definition available.

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Amount of the reserve for unfunded commitments.

+ References

No definition available.

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- Definition

Percentage of gross portfolio loans that are classified as loans modified under a troubled debt restructuring.

+ References

No definition available.

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- Definition

The fair value of financial assets, which are not recognized in the financial statements (off-balance sheet) because they fail to meet some other criterion for recognition.

+ References

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-Publisher FASB
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- Definition

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

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The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings.

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- Definition

Recorded investment in financing receivables that are on nonaccrual status as of the balance sheet date.

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- Definition

Amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

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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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Reflects the unfunded portion of contractual agreements to lend funds to borrowers for loans whose terms have been modified by troubled debt restructuring.

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Reflects the amount of additional interest income that would have been recorded if impaired or nonperforming loans were instead current, in compliance with their original terms, and outstanding throughout the reporting period or since origination (if held for part of the period).

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Amount of deferred fees paid by borrowers and unamortized costs incurred to originate loans and leases, unamortized loan commitments and loan syndication fees, and premiums over or discounts from face amounts of loans that are being amortized into income as an adjustment to yield. Excludes amounts for loans and leases covered under loss sharing agreements.

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