Note 15 - Fair Value of Financial Instruments - Estimated Fair Value and Related Carrying or Notional Amounts of Company's Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Assets:
Investment securities available-for-sale	$ 156,642	$ 153,871
Investment securities held-to-maturity	24,687	25,949
Reported Value Measurement [Member]
Assets:
Cash and cash equivalents	34,473	27,124
Investment securities available-for-sale	156,642	153,871
Investment securities held-to-maturity	25,300	26,279
Federal Home Loan Bank stock	1,413	1,609
Loans, net of allowance for loan losses	353,805	346,121
Other assets – derivatives	889	443
Federal funds sold		15,000
Liabilities:
Deposits	525,273	517,079
Short-term borrowings	10,298	15,594
Long-term debt	10,000	10,000
Deposits	525,273	517,079
Estimate of Fair Value Measurement [Member]
Assets:
Cash and cash equivalents	34,473	27,124
Investment securities available-for-sale	156,642	153,871
Investment securities held-to-maturity	24,687	25,949
Federal Home Loan Bank stock	1,413	1,609
Loans, net of allowance for loan losses	346,658	342,248
Other assets – derivatives	889	443
Federal funds sold		15,000
Liabilities:
Deposits	522,767	515,645
Short-term borrowings	10,298	15,594
Long-term debt	9,998	9,998
Deposits	522,767	515,645
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member]
Assets:
Cash and cash equivalents	34,473	27,124
Investment securities available-for-sale
Investment securities held-to-maturity
Federal Home Loan Bank stock
Loans, net of allowance for loan losses
Other assets – derivatives
Federal funds sold
Liabilities:
Deposits
Short-term borrowings
Long-term debt
Deposits
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member]
Assets:
Cash and cash equivalents
Investment securities available-for-sale	156,642	153,871
Investment securities held-to-maturity	24,687	25,949
Federal Home Loan Bank stock
Loans, net of allowance for loan losses
Other assets – derivatives	889	443
Federal funds sold		15,000
Liabilities:
Deposits	522,767	515,645
Short-term borrowings	10,298	15,594
Long-term debt	9,998	9,998
Deposits	522,767	515,645
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member]
Assets:
Cash and cash equivalents
Investment securities available-for-sale
Investment securities held-to-maturity
Federal Home Loan Bank stock	1,413	1,609
Loans, net of allowance for loan losses	346,648	342,248
Other assets – derivatives
Federal funds sold
Liabilities:
Deposits
Short-term borrowings
Long-term debt
Deposits

Fair value portion of federal funds sold.

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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-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563

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- Definition

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

No definition available.

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- Definition

Fair value portion of deposit liabilities held by the entity, including, but not limited to, foreign and domestic, interest and noninterest bearing, demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits.

+ References

No definition available.

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 20
-Section 55
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226008-175313

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=109250915&loc=d3e13433-108611

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-Topic 210
-SubTopic 20
-Section 50
-Paragraph 3
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312

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- References

No definition available.

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- References

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- Definition

Fair value of investment in debt security measured at amortized cost (held-to-maturity).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27232-111563

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- Definition

Fair value portion of investments in Federal Home Loan Bank (FHLBank) stock.

+ References

No definition available.

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- Definition

Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-URI http://asc.fasb.org/subtopic&trid=2196772

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- Definition

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

+ References

No definition available.

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- Definition

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents the amount of short-term debt existing as of the balance sheet date.

+ References

No definition available.

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