Note 3 - Available-for-sale Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
US Government Agencies Debt Securities [Member]
Amortized Cost	$ 19,476	$ 25,243
Unrealized Gains	10	1
Unrealized Losses		(12)
Fair Value	19,486	25,232
Amortized Cost	19,476	25,243
Unrealized Gains	10	1
Unrealized Losses		(12)
Fair Value	$ 19,486	$ 25,232

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.

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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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
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-Subparagraph (b)
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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-Section 50
-Paragraph 5
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Reference 3: http://www.xbrl.org/2003/role/presentationRef
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-Paragraph 1
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Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt and equity securities classified as available-for-sale.

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