Note 2 - Investment Securities (Details Textual)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Available-for-sale Securities	$ 192,606,119	$ 248,294,725
US Government Agencies Debt Securities [Member]
Available-for-sale Securities Pledged as Collateral	32,600,000	11,800,000
Held-to-maturity Securities Pledged as Collateral	510,000	508,000
Available-for-sale Securities	$ 16,995,000	31,385,000
US States and Political Subdivisions Debt Securities [Member]
Number of Investment Securities	49
Available-for-sale Securities	$ 53,682,000	$ 56,831,000
Municipal General Obligation Bonds [Member]
Available-for-sale Securities	30,956,000
Municipal General Obligation Bonds [Member] \| WASHINGTON
Available-for-sale Securities	3,305,000
Municipal General Obligation Bonds [Member] \| Insurance Policy Assured Guaranty Municipal Corp [Member] \| King County, Washington [Member] \| WASHINGTON
Available-for-sale Debt Securities, Amortized Cost Basis	2,400,000
Available-for-sale Securities	2,400,000
Municipal Revenue Bonds [Member]
Available-for-sale Securities	22,726,000
Municipal Revenue Bonds [Member] \| Dormitory Authority of the State of New York [Member] \| NEW YORK
Available-for-sale Debt Securities, Amortized Cost Basis	2,900,000
Available-for-sale Securities	$ 2,900,000
Percent of State Income Tax Used to Secure Debt	25.00%

The number of investment securities held by the entity.

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- Definition

The percent of state personal income tax used to secure the debt.

+ References

No definition available.

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- Definition

This item represents the cost of debt securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27161-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.2)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 25
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=65884222&loc=d3e22054-111558

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27232-111563

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=66010992&loc=d3e26610-111562

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- Definition

The fair value of available-for-sale securities that serve as collateral for borrowings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=66008989&loc=d3e5086-111524

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- Definition

The carrying amount of held-to-maturity securities that serve as collateral for borrowings.

+ References

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