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Note 6 - Investment Securities Available for Sale - Gross Unrealized Losses and Fair Value (Details) - USD ($)	Sep. 30, 2016	Dec. 31, 2015
US Government Agencies Debt Securities [Member]
Less than Twelve Months, Fair Value	$ 2,000,000	$ 3,818,000
Less than Twelve Months, Gross Unrealized Losses	0	(57,000)
Twelve Months or Greater, Fair Value	1,465,000	10,872,000
Twelve Months or Greater, Gross Unrealized Losses	(12,000)	(214,000)
Total, Fair Value	3,465,000	14,690,000
Total, Gross Unrealized Losses	(12,000)	(271,000)
US States and Political Subdivisions Debt Securities [Member] | Tax Exempt [Member]
Less than Twelve Months, Fair Value	608,000	1,268,000
Less than Twelve Months, Gross Unrealized Losses	0	(9,000)
Twelve Months or Greater, Fair Value	0	9,394,000
Twelve Months or Greater, Gross Unrealized Losses	(5,000)	(166,000)
Total, Fair Value	608,000	10,662,000
Total, Gross Unrealized Losses	(5,000)	(175,000)
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Less than Twelve Months, Fair Value	0	8,725,000
Less than Twelve Months, Gross Unrealized Losses	0	(86,000)
Twelve Months or Greater, Fair Value	4,709,000	6,685,000
Twelve Months or Greater, Gross Unrealized Losses	(44,000)	(186,000)
Total, Fair Value	4,709,000	15,410,000
Total, Gross Unrealized Losses	(44,000)	(272,000)
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Less than Twelve Months, Fair Value	75,000
Less than Twelve Months, Gross Unrealized Losses	0
Twelve Months or Greater, Fair Value	0
Twelve Months or Greater, Gross Unrealized Losses	0
Total, Fair Value	75,000
Total, Gross Unrealized Losses	0
Less than Twelve Months, Fair Value	2,683,000	13,811,000
Less than Twelve Months, Gross Unrealized Losses	0	(152,000)
Twelve Months or Greater, Fair Value	6,174,000	26,951,000
Twelve Months or Greater, Gross Unrealized Losses	(61,000)	(566,000)
Total, Fair Value	8,857,000	40,762,000
Total, Gross Unrealized Losses	$ (61,000)	$ (718,000)

X

- Definition

Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale that have been in a continuous loss position for twelve months or longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27290-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27337-111563

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X

- Definition

Amount of accumulated unrealized loss on investments in debt and equity securities classified as available-for-sale in a continuous loss position.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27337-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27290-111563

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- Definition

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27290-111563

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(2)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27290-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27337-111563

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- Definition

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27337-111563

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-Publisher FASB
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-Topic 320
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-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27290-111563

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+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27290-111563

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-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27337-111563

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