Note 5 - Income Taxes (Details Textual) - USD ($) $ in Thousands |
6 Months Ended | |
|---|---|---|
Jun. 30, 2017 |
Jun. 30, 2016 |
|
| Current Income Tax Expense (Benefit) | $ 0 | $ 0 |
| Unrecognized Tax Benefits | 0 | |
| Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense | $ 0 | $ 0 |