Note 6 - Liabilities Related to Sale of Future Royalties - Deferred Revenue Activity (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Dec. 31, 2024
Current portion	$ (3,322)	$ (4,060)
Long-term portion	412	$ 1,698
HealthCare Royalty Partners III, L.P. [Member] | Royalty Arrangement [Member]
Total liability related to sale of future royalties, start of period	5,758
Non-cash royalty revenue paid to HCRP	(3,021)
Non-cash interest expense recognized	997
Total liability related to sale of future royalties, end of period	3,734
Current portion	(3,322)
Long-term portion	$ 412