Note 5 - Fair Value Measurements and Fair Values of Financial Instruments (Details) - Valuation Techniques and the Unobservable Inputs Used in Determining Fair Value - USD ($)	6 Months Ended	12 Months Ended
Jun. 30, 2015	Dec. 31, 2014
Impaired loans:
Impaired loans	$ 3,880,000	$ 3,241,000
Valuation allowance	600,000	769,000
Residential Portfolio Segment [Member]
Foreclosed assets held for sale - real estate:
Foreclosed assets held for sale	487,000
Commercial Portfolio Segment [Member] \| Commercial and Industrial [Member]
Impaired loans:
Impaired loans	75,000	150,000
Valuation allowance	75,000	82,000
Commercial Portfolio Segment [Member] \| Loans Secured by Farmland [Member]
Impaired loans:
Impaired loans	564,000	545,000
Valuation allowance	98,000	102,000
Servicing Rights Asset [Member] \| Income Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair value	$ 1,209,000	$ 1,281,000
Discount rate	10.00%	12.00%
Weighted-average PSA	173.00%	156.00%
Servicing fees of loan balances	0.25%	0.25%
Servicing fees of payments are late	4.00%	4.00%
Late fees assessed	5.00%	5.00%
Miscellaneous fees per account per month	$ 1.94	$ 1.94
Monthly servicing cost per account	6.00	6.00
Additional monthly servicing cost per loan on loans more than 30 days delinquent	$ 24.00	$ 24.00
Of loans more than 30 days delinquent	1.50%	1.50%
Annual increase in servicing costs	3.00%	3.00%
Impaired loans:
Discount rate	10.00%	12.00%
Foreclosed assets held for sale - real estate:
Discount rate	10.00%	12.00%
Impaired Loans [Member]
Impaired loans:
Fair value	$ 3,280,000	$ 2,472,000
Impaired loans	3,880,000	3,241,000
Valuation allowance	600,000	769,000
Foreclosed assets held for sale - real estate:
Fair value	3,280,000	2,472,000
Impaired Loans [Member] \| Commercial Portfolio Segment [Member] \| Market Approach Valuation Technique [Member] \| Real Estate Loan [Member]
Impaired loans:
Fair value	242,000	0
Impaired loans	322,000	16,000
Valuation allowance	80,000	16,000
Foreclosed assets held for sale - real estate:
Fair value	242,000	0
Impaired Loans [Member] \| Commercial Portfolio Segment [Member] \| Market Approach Valuation Technique [Member] \| Commercial and Industrial [Member]
Impaired loans:
Fair value	0	68,000
Impaired loans	75,000	150,000
Valuation allowance	75,000	82,000
Foreclosed assets held for sale - real estate:
Fair value	0	68,000
Impaired Loans [Member] \| Commercial Portfolio Segment [Member] \| Market Approach Valuation Technique [Member] \| Construction Loans [Member]
Impaired loans:
Fair value	1,604,000	1,604,000
Impaired loans	1,815,000	1,815,000
Valuation allowance	211,000	211,000
Foreclosed assets held for sale - real estate:
Fair value	1,604,000	1,604,000
Impaired Loans [Member] \| Commercial Portfolio Segment [Member] \| Market Approach Valuation Technique [Member] \| Loans Secured by Farmland [Member]
Impaired loans:
Fair value	466,000	443,000
Impaired loans	564,000	545,000
Valuation allowance	98,000	102,000
Foreclosed assets held for sale - real estate:
Fair value	466,000	443,000
Foreclosed Assets Held-for-Sale [Member]
Impaired loans:
Fair value	1,223,000	1,189,000
Foreclosed assets held for sale - real estate:
Fair value	1,223,000	1,189,000
Foreclosed assets held for sale	1,223,000	1,189,000
Valuation allowance	0	0
Foreclosed Assets Held-for-Sale [Member] \| Market Approach Valuation Technique [Member] \| Land [Member]
Impaired loans:
Fair value	736,000	724,000
Foreclosed assets held for sale - real estate:
Fair value	736,000	724,000
Foreclosed assets held for sale	736,000	724,000
Valuation allowance	0	0
Foreclosed Assets Held-for-Sale [Member] \| Residential Portfolio Segment [Member] \| Market Approach Valuation Technique [Member]
Impaired loans:
Fair value	487,000	306,000
Foreclosed assets held for sale - real estate:
Fair value	487,000	306,000
Foreclosed assets held for sale	487,000	306,000
Valuation allowance	0	0
Foreclosed Assets Held-for-Sale [Member] \| Commercial Portfolio Segment [Member] \| Market Approach Valuation Technique [Member]
Impaired loans:
Fair value		159,000
Foreclosed assets held for sale - real estate:
Fair value		159,000
Foreclosed assets held for sale		159,000
Valuation allowance		0
Senior Lien [Member] \| Residential Portfolio Segment [Member] \| Real Estate Loan [Member]
Impaired loans:
Impaired loans	1,104,000	715,000
Valuation allowance	136,000	358,000
Senior Lien [Member] \| Impaired Loans [Member] \| Residential Portfolio Segment [Member] \| Market Approach Valuation Technique [Member] \| Real Estate Loan [Member]
Impaired loans:
Fair value	968,000	357,000
Impaired loans	1,104,000	715,000
Valuation allowance	136,000	358,000
Foreclosed assets held for sale - real estate:
Fair value	$ 968,000	$ 357,000
Weighted Average [Member] \| Impaired Loans [Member] \| Commercial Portfolio Segment [Member] \| Market Approach Valuation Technique [Member] \| Real Estate Loan [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate	40.00%	42.00%
Impaired loans:
Discount rate	40.00%	42.00%
Foreclosed assets held for sale - real estate:
Discount rate	40.00%	42.00%
Weighted Average [Member] \| Impaired Loans [Member] \| Commercial Portfolio Segment [Member] \| Market Approach Valuation Technique [Member] \| Commercial and Industrial [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate	45.00%	21.00%
Impaired loans:
Discount rate	45.00%	21.00%
Foreclosed assets held for sale - real estate:
Discount rate	45.00%	21.00%
Weighted Average [Member] \| Impaired Loans [Member] \| Commercial Portfolio Segment [Member] \| Market Approach Valuation Technique [Member] \| Construction Loans [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate	30.00%	30.00%
Impaired loans:
Discount rate	30.00%	30.00%
Foreclosed assets held for sale - real estate:
Discount rate	30.00%	30.00%
Weighted Average [Member] \| Impaired Loans [Member] \| Commercial Portfolio Segment [Member] \| Market Approach Valuation Technique [Member] \| Loans Secured by Farmland [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate	40.00%	40.00%
Impaired loans:
Discount rate	40.00%	40.00%
Foreclosed assets held for sale - real estate:
Discount rate	40.00%	40.00%
Weighted Average [Member] \| Foreclosed Assets Held-for-Sale [Member] \| Market Approach Valuation Technique [Member] \| Land [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate	26.00%	29.00%
Impaired loans:
Discount rate	26.00%	29.00%
Foreclosed assets held for sale - real estate:
Discount rate	26.00%	29.00%
Weighted Average [Member] \| Foreclosed Assets Held-for-Sale [Member] \| Residential Portfolio Segment [Member] \| Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate	27.00%	42.00%
Impaired loans:
Discount rate	27.00%	42.00%
Foreclosed assets held for sale - real estate:
Discount rate	27.00%	42.00%
Weighted Average [Member] \| Foreclosed Assets Held-for-Sale [Member] \| Commercial Portfolio Segment [Member] \| Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate		23.00%
Impaired loans:
Discount rate		23.00%
Foreclosed assets held for sale - real estate:
Discount rate		23.00%
Weighted Average [Member] \| Senior Lien [Member] \| Impaired Loans [Member] \| Residential Portfolio Segment [Member] \| Market Approach Valuation Technique [Member] \| Real Estate Loan [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Discount rate	34.00%	36.00%
Impaired loans:
Discount rate	34.00%	36.00%
Foreclosed assets held for sale - real estate:
Discount rate	34.00%	36.00%

The additional monthly servicing cost per loan for loans that are more than 30 days delinquent.

No definition available.

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- Definition

Annual increase in servicing costs expressed as a percentage.

+ References

No definition available.

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- References

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- Definition

Estimated miscellaneous servicing fees receivable per account per month.

+ References

No definition available.

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- Definition

Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

+ References

No definition available.

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- Definition

Expense for monthly servicing costs per account per month.

+ References

No definition available.

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- Definition

The percentage of loans that are more than 30 days delinquent.

+ References

No definition available.

+ Details

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- Definition

Servicing fees associated with payments that are late.

+ References

No definition available.

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- Definition

Servicing fees associated with loan balances.

+ References

No definition available.

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- Definition

Servicing fees associated with late fees assessed.

+ References

No definition available.

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- Definition

Rate at which loans or a loan portfolio are expected to prepay principal balances, used as an input to measure fair value. Calculated as weighted-average PSA.

+ References

No definition available.

+ Details

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- Definition

This element represents the aggregate of the assets reported on the balance sheet at period end measured at fair value on a nonrecurring basis by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.

+ References

No definition available.

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- Definition

This element represents the aggregate of the assets reported on the balance sheet at period end measured at fair value on a recurring basis by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.

+ References

No definition available.

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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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- Definition

Amount of allowance for credit losses related to recorded investment.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 15

-Subparagraph (a)(3)

-URI http://asc.fasb.org/extlink&oid=49124121&loc=d3e5212-111524

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- Definition

Amount of investment in impaired financing receivables for which there is a related allowance for credit losses.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 14A

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=49124121&loc=SL6953550-111524

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- Definition

Carrying amount as of the balance sheet date of land and buildings obtained through foreclosure proceedings or defeasance in full or partial satisfaction of a debt arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11

-URI http://asc.fasb.org/extlink&oid=49124121&loc=d3e5162-111524

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 28

-Article 12

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph c

-Subparagraph Schedule III

-Article 5

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For each period for which an income statement is required, disclosure of the changes in the allowance, including balances at end of period.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.10(4))

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