Note 10 - Stock-based Compensation - Share-based Payment Expense (Details) - USD ($) $ in Thousands |
3 Months Ended | |
|---|---|---|
Mar. 31, 2020 |
Mar. 31, 2019 |
|
| Share-based payment expense | $ 4,401 | $ 662 |
| Research and Development Expense [Member] | ||
| Share-based payment expense | 800 | 118 |
| General and Administrative Expense [Member] | ||
| Share-based payment expense | $ 3,601 | $ 544 |
| 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
|