Note 9 - Stockholders' Equity - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands |
3 Months Ended | |
|---|---|---|
Mar. 31, 2021 |
Mar. 31, 2020 |
|
| Stock-based compensation expense | $ 679 | $ 956 |
| Cost of Sales [Member] | ||
| Stock-based compensation expense | 31 | 22 |
| Research and Development Expense [Member] | ||
| Stock-based compensation expense | 42 | 105 |
| General and Administrative Expense [Member] | ||
| Stock-based compensation expense | $ 606 | $ 829 |
| 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
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| X | ||||||||||
- Details
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| X | ||||||||||
- Details
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| X | ||||||||||
- Details
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