Note 4 - Securities - Sales of Securities (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Proceeds from sales of securities			$ 27,252	$ 34,389
Gross realized gains on sales of securities	$ 58	$ 96	128	215
Gross realized losses on sales of securities	(23)	(68)	(27)	(93)
Gain on investment securities, net	35	28	101	122
US Government Agencies Debt Securities [Member]
Proceeds from sales of securities	13,326	14,455	27,252	34,389
Gross realized gains on sales of securities		8		8
Gross realized losses on sales of securities		(4)		(4)
US States and Political Subdivisions Debt Securities [Member]
Gross realized gains on sales of securities	30	40	81	111
Residential Mortgage Backed Securities and Collateralized Mortgage Obligations [Member]
Gross realized gains on sales of securities	19	2	37	2
Gross realized losses on sales of securities	(23)	(64)	(24)	(64)
Corporate Debt Securities [Member]
Gross realized gains on sales of securities	9	33	10	76
Gross realized losses on sales of securities			(3)	(25)
Commercial Mortgage Backed Securities [Member]
Gross realized gains on sales of securities				4
Asset-backed Securities [Member]
Gross realized gains on sales of securities		$ 13		$ 14

This item represents the difference between the gross realized gains and losses realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities. Additionally, this item would include any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt and equity securities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 9
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27357-111563

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- Definition

This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

+ References

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- Definition

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+ References

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- Definition

The cash inflow associated with the sale of debt and equity securities classified as available-for-sale securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=82896770&loc=d3e26853-111562

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (a),(b)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3179-108585

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