Note 10 - Liability Related to Sale of Future Royalties - Activity of Liability Related to Sale of Future Royalties (Details) - USD ($) $ in Thousands |
1 Months Ended | 12 Months Ended | 75 Months Ended | ||
|---|---|---|---|---|---|
Sep. 18, 2015 |
Sep. 30, 2015 |
Dec. 31, 2021 |
Dec. 31, 2020 |
Dec. 31, 2021 |
|
| Liability related to sale of future royalties — beginning balance | $ 88,471 | $ 0 | |||
| Proceeds from sale of future royalties | $ 61,200 | $ 61,200 | 0 | 61,184 | |
| Non-cash royalty revenue | (145) | (1,083) | |||
| Non-cash interest (income) expense recognized | (3,038) | $ (3,310) | 25,187 | ||
| Liability related to sale of future royalties as of December 31, 2021 | $ 85,288 | $ 85,288 | |||