Note 6 - Stock-Based Compensation - Stock-Based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Total stock-based compensation expense	$ 1,912	$ 5,681
Total stock-based compensation expense	1,912	5,681
Service-based Options [Member]
Total stock-based compensation expense	2,692	4,107
Total stock-based compensation expense	2,692	4,107
Market-based Options [Member]
Total stock-based compensation expense	(907)	1,469
Total stock-based compensation expense	(907)	1,469
Restricted Stock Units (RSUs) [Member]
Total stock-based compensation expense	31	0
Total stock-based compensation expense	31	0
Employee Stock Purchase Plan Award [Member]
Total stock-based compensation expense	96	105
Total stock-based compensation expense	96	105
Cost of Product Revenue [Member]
Total stock-based compensation expense	44	0
Total stock-based compensation expense	44	0
Research and Development [Member]
Total stock-based compensation expense	1,758	2,762
Total stock-based compensation expense	1,758	2,762
Selling, General and Administrative [Member]
Total stock-based compensation expense	110	2,919
Total stock-based compensation expense	$ 110	$ 2,919