Note 8 - Stock-based Compensation - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2024	Dec. 31, 2023	Sep. 30, 2023
Outstanding, options (in shares)	7,876
Outstanding, weighted average exercise price (in dollars per share)	$ 3.81
Outstanding, weighted average remaining contractual term (Year)	6 years 4 months 9 days	8 years 18 days
Outstanding, aggregate intrinsic value	$ 1,795	$ 11
Granted, options (in shares)	5,753
Granted, weighted average exercise price (in dollars per share)	$ 1.57
Granted, weighted average remaining contractual term (Year)	7 years 1 month 17 days
Exercised, options (in shares)	0
Exercised, weighted average exercise price (in dollars per share)	$ 0
Forfeited/canceled, options (in shares)	(4)
Forfeited/canceled, weighted average exercise price (in dollars per share)	$ 3.26
Outstanding, options (in shares)	13,625	7,876
Outstanding, weighted average exercise price (in dollars per share)	$ 2.87	$ 3.81
Vested, options (in shares)	5,780
Vested, weighted average exercise price (in dollars per share)	$ 3.82
Vested, weighted average remaining contractual term (Year)	5 years 4 months 17 days
Vested, aggregate intrinsic value	$ 99		$ 34,000