Note 6 - Stockholders' Equity and Stock-based Compensation - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Total stock-based compensation expense	$ 5,189	$ 2,052	$ 10,870	$ 3,811
Time-based Options [Member]
Total stock-based compensation expense	3,579	1,315	7,686	2,478
Performance-based Options [Member]
Total stock-based compensation expense	0	14	0	22
Market-based Options [Member]
Total stock-based compensation expense	1,535	683	3,004	1,190
Employee Stock Purchase Plan Award [Member]
Total stock-based compensation expense	75	40	180	121
Research and Development Expense [Member]
Total stock-based compensation expense	2,335	1,001	5,097	1,950
General and Administrative Expense [Member]
Total stock-based compensation expense	$ 2,854	$ 1,051	$ 5,773	$ 1,861