Note 6 - Allowance for Loan Losses and Credit Quality Information (Details Textual) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Loans and Leases Receivable, Nonperforming, Nonaccrual of Interest	$ 2,678	$ 3,144	$ 3,300
Impaired Financing Receivable, Related Allowance	794	1,073
Loan Receivable for Which Value of Collateral Sufficient to Repay	400	400	700
Impaired Financing Receivable, Interest Income, Accrual Method, Total	175	194
Financing Receivable, Modifications, Recorded Investment	2,476	3,044	3,300
Loans and Leases Receivable, Impaired, Troubled Debt, Interest Income	300	400	600
Loans and Leases Receivable, Impaired, Commitment to Lend	$ 900	800
Loan to Value Ratio	75.00%
Allowance for Credit Losses, Change in Method of Calculating Impairment	$ 600	$ 900
Percentage Reserves For Loan Losses On Troubled Debt Restructurings	7.20%	9.80%
Loans and Leases Receivable, Allowance, Ending Balance	$ 8,686	$ 9,311	9,903	$ 9,709
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Carrying Amount, Net	200
Provision for Loan and Lease Losses, Total	(649)	(523)	(645)
Impaired Loans with Sufficient Collateral to Repay Loan [Member]
Impaired Financing Receivable, Interest Income, Accrual Method, Total	300	300	600
Impaired Financing Receivable, Interest Income, Cash Basis Method, Total	100	100	400
Trouble Debt Restructurings [Member]
Impaired Financing Receivable, Interest Income, Cash Basis Method, Total	200	200	400
Acquired Loans [Member]
Provision for Loan and Lease Losses, Total	0
Nonperforming Financial Instruments [Member]
Impaired Financing Receivable, Related Allowance	700	$ 900	$ 800
Nonperforming Financial Instruments [Member] \| Classified [Member]
Financing Receivable, Modifications, Recorded Investment	1,200
Performing Financial Instruments [Member] \| Classified [Member]
Financing Receivable, Modifications, Recorded Investment	$ 400

Loan receivable for which value of collateral sufficient to repay.

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- Definition

Represents the loan to value ratio.

+ References

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- Definition

Percentage reserves for loan losses on troubled debt restructurings.

+ References

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Amount of allowance for credit losses related to receivables which had been measured under a general allowance for credit losses methodology that are now identified as troubled debt restructurings.

+ References

No definition available.

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The recorded balance, net of any applicable reductions (for example, unamortized accretable yield and allowance for loan losses). This relates to loans not accounted for debt securities with evidence of deterioration of credit quality since origination that were acquired by completion of a transfer for which it is probable, at acquisition, that the investor will be unable to collect all contractually required payments receivable.

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- Definition

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

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Amount of interest income recognized that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

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Amount of interest income recognized on a cash-basis method of accounting that the financing receivables (with related allowance for credit losses and without a related allowance for credit losses) were impaired.

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Amount of allowance for credit losses related to recorded investment.

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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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- Definition

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 carrying amount of loans deemed to be questionable as to collection on which no interest is continuing to be recognized.

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The gross interest income that would have been recorded in the period on troubled debt restructurings, if the loans had been current in accordance with their original terms and had been outstanding throughout the period or since origination, if held for part of the period.

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Amount of expense related to estimated loss from loan and lease transactions.

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