Note 4 - Investment Securities - Amortized Cost and Fair Value of Held to Maturity Investment Securities (Details) - USD ($) $ in Thousands |
Dec. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Held-to-maturity Securities | $ 2,879 | $ 0 |
| Gross Unrealized Gains | ||
| Gross Unrealized Losses | (61) | |
| Fair Value | 2,818 | $ 0 |
| Collateralized Mortgage Backed Securities [Member] | ||
| Held-to-maturity Securities | 2,879 | |
| Gross Unrealized Gains | ||
| Gross Unrealized Losses | (61) | |
| Fair Value | $ 2,818 |