Note 3 - Investment Securities - Held to Maturity Securities (Details) - USD ($) $ in Thousands |
Dec. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Held to maturity, amortized cost | $ 40,741 | $ 41,282 |
| Held to maturity, gross unrealized gains | 703 | 1,333 |
| Held to maturity, gross unrealized losses | (288) | (178) |
| Held to maturity, estimated market value | 41,156 | 42,437 |
| US States and Political Subdivisions Debt Securities [Member] | ||
| Held to maturity, amortized cost | 40,241 | 40,782 |
| Held to maturity, gross unrealized gains | 701 | 1,333 |
| Held to maturity, gross unrealized losses | (288) | (178) |
| Held to maturity, estimated market value | 40,654 | 41,937 |
| Corporate Debt Securities [Member] | ||
| Held to maturity, amortized cost | 500 | 500 |
| Held to maturity, gross unrealized gains | 2 | |
| Held to maturity, gross unrealized losses | ||
| Held to maturity, estimated market value | $ 502 | $ 500 |