Note 3 - Revenue From Contracts With Customers - Changes in Contract Liabilities (Details) - USD ($) |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2022 |
Jun. 30, 2021 |
Jun. 30, 2022 |
Jun. 30, 2021 |
|
| Total deferred revenue, beginning of period | $ 800,000 | $ 700,000 | $ 700,000 | $ 700,000 |
| Deferred revenue related to milestones achieved | 0 | 0 | 100,000 | 0 |
| Deferred revenue related to milestones achieved, written off due to contract renegotiations | (100,000) | 0 | (100,000) | 0 |
| Total deferred revenue, end of period | $ 700,000 | $ 700,000 | $ 700,000 | $ 700,000 |
| X | ||||||||||
- Definition Amount of revenue deferred for which consideration to customer has not been performed related to milestone achieved. No definition available.
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| X | ||||||||||
- Definition Amount of obligation to transfer good or service to customer for which consideration has been received or is receivable. Reference 1: http://www.xbrl.org/2003/role/disclosureRef
|
| X | ||||||||||
- Definition Amount of increase (decrease) in revenue recognized for cumulative catch-up adjustment from contract modification which (increases) decreases obligation to transfer good or service to customer for which consideration from customer has been received or is due. Reference 1: http://www.xbrl.org/2003/role/exampleRef
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