Note 8 - Stock-based Compensation - Share-based Payment Expense (Details) - USD ($) $ in Thousands |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2018 |
Jun. 30, 2017 |
Jun. 30, 2018 |
Jun. 30, 2017 |
|
| Share-based payment expense | $ 515 | $ 449 | $ 2,743 | $ 510 |
| Research and Development Expense [Member] | ||||
| Share-based payment expense | 152 | 73 | 518 | 124 |
| General and Administrative Expense [Member] | ||||
| Share-based payment expense | $ 363 | $ 376 | $ 2,225 | $ 386 |
| X | ||||||||||
- Definition Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees. Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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| X | ||||||||||
- Details
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| X | ||||||||||
- Details
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