Note 11 - Retirement Plans - Amounts Recognized in Accumulated Other Comprehensive Income (Details) - Supplemental Employee Retirement Plan [Member] - USD ($) $ in Thousands |
Dec. 31, 2016 |
Dec. 31, 2015 |
|---|---|---|
| Unrecognized net actuarial loss (gain) | $ 87 | $ (19) |
| Total | $ 87 | $ (19) |