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Note 4 - Fair Value Disclosure Measurments - Assets Measured on a Recurring Basis (Details) - USD ($) $ in Thousands | Jun. 30, 2017 | Dec. 31, 2016
--- | --- | ---
Investment securities available for sale, at fair value | $ 104,951 | $ 114,376
US Government Agencies Debt Securities [Member] |  |
Investment securities available for sale, at fair value | 9,514 | 10,236
US States and Political Subdivisions Debt Securities [Member] |  |
Investment securities available for sale, at fair value | 77,635 | 81,223
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] |  |
Investment securities available for sale, at fair value | 17,512 | 20,069
Debt Securities [Member] |  |
Investment securities available for sale, at fair value | 104,661 | 113,237
Mortgage-backed Securities, Issued by Private Enterprises [Member] |  |
Investment securities available for sale, at fair value |  | 1,709
Equity Securities In Financial Institutions [Member] |  |
Investment securities available for sale, at fair value | 290 | 1,139
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member] |  |
Investment securities available for sale, at fair value | 104,951 | 114,376
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | US Government Agencies Debt Securities [Member] |  |
Investment securities available for sale, at fair value | 9,514 | 10,236
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | US States and Political Subdivisions Debt Securities [Member] |  |
Investment securities available for sale, at fair value | 77,635 | 81,223
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member] |  |
Investment securities available for sale, at fair value | 17,512 | 20,069
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Debt Securities [Member] |  |
Investment securities available for sale, at fair value | 104,661 | 113,237
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Mortgage-backed Securities, Issued by Private Enterprises [Member] |  |
Investment securities available for sale, at fair value |  | 1,709
Fair Value, Inputs, Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Equity Securities In Financial Institutions [Member] |  |
Investment securities available for sale, at fair value | $ 290 | $ 1,139

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