Note 18 - Income Taxes - Reconciliation of Beginning and Ending Balance of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Unrecognized benefit—beginning of period | $ 2,162 | $ 1,939 | $ 1,667 |
| Gross decreases—prior period tax positions | |||
| Gross increases—current period tax positions | 203 | 223 | 272 |
| Unrecognized benefit—end of period | $ 2,365 | $ 2,162 | $ 1,939 |