Note 2 - Summary of Significant Accounting Policies - Noncash Stock-based Compensation Expense (Details) - USD ($) |
3 Months Ended | |
|---|---|---|
Mar. 31, 2023 |
Mar. 31, 2022 |
|
| Noncash stock compensation expense | $ 783,000 | $ 1,099,000 |
| Selling and Marketing Expense [Member] | ||
| Noncash stock compensation expense | 164,000 | 230,000 |
| Research and Development Expense [Member] | ||
| Noncash stock compensation expense | 89,000 | 189,000 |
| General and Administrative Expense [Member] | ||
| Noncash stock compensation expense | $ 530,000 | $ 680,000 |
| X | ||||||||||
- Definition Amount of expense for award under share-based payment arrangement. Excludes amount capitalized. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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| X | ||||||||||
- Details
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| X | ||||||||||
- Details
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| X | ||||||||||
- Details
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