Note 13 - Share-based Compensation - Share-based Compensation Expense (Details) - USD ($) $ in Thousands |
3 Months Ended | |
|---|---|---|
Mar. 31, 2019 |
Mar. 31, 2018 |
|
| Total share-based compensation | $ 130 | $ 153 |
| Research and Development Expense [Member] | ||
| Total share-based compensation | 58 | 22 |
| General and Administrative Expense [Member] | ||
| Total share-based compensation | $ 72 | $ 131 |
| X | ||||||||||
- Definition Amount of expense for award under share-based payment arrangement. Excludes amount capitalized. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
|
| X | ||||||||||
- Details
|
| X | ||||||||||
- Details
|