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Note 6 - Investment Securities Available for Sale (Details) - Gross Unrealized Losses and Fair Value - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Note 6 - Investment Securities Available for Sale (Details) - Gross Unrealized Losses and Fair Value [Line Items]
Less than Twelve Months, Fair Value	$ 17,673	$ 13,811
Less than Twelve Months, Gross Unrealized Losses	(139)	(152)
Twelve Months or Greater, Fair Value	15,713	26,951
Twelve Months or Greater, Gross Unrealized Losses	(229)	(566)
Total, Fair Value	33,386	40,762
Total, Gross Unrealized Losses	(368)	(718)
US Government Agencies Debt Securities [Member]
Note 6 - Investment Securities Available for Sale (Details) - Gross Unrealized Losses and Fair Value [Line Items]
Less than Twelve Months, Fair Value	4,565	3,818
Less than Twelve Months, Gross Unrealized Losses	(9)	(57)
Twelve Months or Greater, Fair Value	7,612	10,872
Twelve Months or Greater, Gross Unrealized Losses	(67)	(214)
Total, Fair Value	12,177	14,690
Total, Gross Unrealized Losses	(76)	(271)
US States and Political Subdivisions Debt Securities [Member]
Note 6 - Investment Securities Available for Sale (Details) - Gross Unrealized Losses and Fair Value [Line Items]
Less than Twelve Months, Fair Value	8,999
Less than Twelve Months, Gross Unrealized Losses	(122)
Twelve Months or Greater, Fair Value	1,426
Twelve Months or Greater, Gross Unrealized Losses	(52)
Total, Fair Value	10,425
Total, Gross Unrealized Losses	(174)
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Note 6 - Investment Securities Available for Sale (Details) - Gross Unrealized Losses and Fair Value [Line Items]
Less than Twelve Months, Fair Value	4,000	8,725
Less than Twelve Months, Gross Unrealized Losses	(7)	(86)
Twelve Months or Greater, Fair Value	6,675	6,685
Twelve Months or Greater, Gross Unrealized Losses	(110)	(186)
Total, Fair Value	10,675	15,410
Total, Gross Unrealized Losses	(117)	(272)
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Note 6 - Investment Securities Available for Sale (Details) - Gross Unrealized Losses and Fair Value [Line Items]
Less than Twelve Months, Fair Value	109
Less than Twelve Months, Gross Unrealized Losses	(1)
Total, Fair Value	109
Total, Gross Unrealized Losses	$ (1)
Tax-exempt [Member] | US States and Political Subdivisions Debt Securities [Member]
Note 6 - Investment Securities Available for Sale (Details) - Gross Unrealized Losses and Fair Value [Line Items]
Less than Twelve Months, Fair Value		1,268
Less than Twelve Months, Gross Unrealized Losses		(9)
Twelve Months or Greater, Fair Value		9,394
Twelve Months or Greater, Gross Unrealized Losses		(166)
Total, Fair Value		10,662
Total, Gross Unrealized Losses		$ (175)

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