Note 5 - Fair Value - Quantitative Information About Level 3 Fair Value Measurements (Details) - USD ($)	9 Months Ended
Sep. 30, 2017	Dec. 31, 2016
Fair value	$ 23,722,953	$ 18,788,073
Impaired Loans Leases [Member]
Fair value	$ 18,177,320	12,823,121
Valuation technique	Appraisal of collateral
Impaired Loans Leases [Member] \| Minimum [Member]
Appraisal adjustments	(10.00%)
Impaired Loans Leases [Member] \| Maximum [Member]
Appraisal adjustments	50.00%
Other Securities [Member]
Fair value	$ 5,545,633	$ 5,964,952
Valuation technique	Appraisal of collateral
Other Securities [Member] \| Minimum [Member]
Appraisal adjustments	0.00%
Other Securities [Member] \| Maximum [Member]
Appraisal adjustments	35.00%

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.

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Percentage of adjustment to the observed price for a similar asset or liability when an identical transaction does not exist, used as an input to measure fair value.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)
-URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

Description of the inputs and valuation technique(s) used to measure fair value.

+ References

+ Details

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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

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Namespace Prefix:
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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: