Note 18 - Fair Value Measurements (Details Textual) - USD ($)	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Available-for-sale Securities	$ 196,806,000	$ 188,476,000
Real Estate Owned, Valuation Allowance, Provision	$ 137,000	311,000	$ 47,000
Real Estate Owned [Member]
Fair Value Input, Selling Costs	8.00%
Real Estate Owned [Member] \| Minimum [Member]
Fair Value Inputs, Discount Rate	0.00%
Real Estate Owned [Member] \| Maximum [Member]
Fair Value Inputs, Discount Rate	25.00%
Impaired Loans Receivable [Member]
Fair Value Input, Selling Costs	8.00%
Fair Value, Inputs, Level 3 [Member]
Available-for-sale Securities	$ 0	0
Fair Value, Inputs, Level 3 [Member] \| Fair Value, Measurements, Recurring [Member]
Available-for-sale Securities	$ 0	$ 0

The selling costs rate used as an input to measure fair value.

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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=75030427&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=82897076&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=82896770&loc=d3e26610-111562

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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

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

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- Definition

Amount of expense recognized in the income statement for a decrease in valuation of real estate owned (REO).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03.10(4))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

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