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Note 3 - Investment Securities Available for Sale (Details) - Gross Unrealized Losses and Fair Value - USD ($) $ in Thousands | Dec. 31, 2015 | Dec. 31, 2014
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Note 3 - Investment Securities Available for Sale (Details) - Gross Unrealized Losses and Fair Value [Line Items] |  |
Less than Twelve Months, Fair Value | $ 13,811 | $ 2,406
Less than Twelve Months, Gross Unrealized Losses | (152) | (10)
Twelve Months or Greater, Fair Value | 26,951 | 50,740
Twelve Months or Greater, Gross Unrealized Losses | (566) | (1,227)
Total, Fair Value | 40,762 | 53,146
Total, Gross Unrealized Losses | (718) | (1,237)
US Government Agencies Debt Securities [Member] |  |
Note 3 - Investment Securities Available for Sale (Details) - Gross Unrealized Losses and Fair Value [Line Items] |  |
Less than Twelve Months, Fair Value | 3,818 | 0
Less than Twelve Months, Gross Unrealized Losses | (57) | 0
Twelve Months or Greater, Fair Value | 10,872 | 15,734
Twelve Months or Greater, Gross Unrealized Losses | (214) | (450)
Total, Fair Value | 14,690 | 15,734
Total, Gross Unrealized Losses | (271) | (450)
US States and Political Subdivisions Debt Securities [Member] | Tax-exempt [Member] |  |
Note 3 - Investment Securities Available for Sale (Details) - Gross Unrealized Losses and Fair Value [Line Items] |  |
Less than Twelve Months, Fair Value | 1,268 | 2,406
Less than Twelve Months, Gross Unrealized Losses | (9) | (10)
Twelve Months or Greater, Fair Value | 9,394 | 18,232
Twelve Months or Greater, Gross Unrealized Losses | (166) | (543)
Total, Fair Value | 10,662 | 20,638
Total, Gross Unrealized Losses | (175) | (553)
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] |  |
Note 3 - Investment Securities Available for Sale (Details) - Gross Unrealized Losses and Fair Value [Line Items] |  |
Less than Twelve Months, Fair Value | 8,725 | 0
Less than Twelve Months, Gross Unrealized Losses | (86) | 0
Twelve Months or Greater, Fair Value | 6,685 | 16,774
Twelve Months or Greater, Gross Unrealized Losses | (186) | (234)
Total, Fair Value | 15,410 | 16,774
Total, Gross Unrealized Losses | $ (272) | $ (234)

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