Note 8 - Stock-based Compensation - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2023	Dec. 31, 2022	Jun. 30, 2022
Outstanding (in shares)	5,378
Outstanding, weighted average exercise price per share (in dollars per share)	$ 3.89
Outstanding, weighted average remaining contractual term (Year)	8 years 6 months 3 days	8 years 2 months 26 days
Outstanding, aggregate intrinsic value	$ 1,814	$ 6,316
Granted (in shares)	2,613
Granted, weighted average exercise price per shar (in dollars per share)	$ 3.80
Granted, weighted average remaining contractual term (Year)	9 years 7 months 20 days
Exercised (in shares)	(12)
Exercised, weighted average exercise price per shar (in dollars per share)	$ 2.43
Forfeited/canceled (in shares)	(228)
Forfeited/cancelled, weighted average exercise price per shar (in dollars per share)	$ 4.75
Outstanding (in shares)	7,751	5,378
Outstanding, weighted average exercise price per share (in dollars per share)	$ 3.84	$ 3.89
Vested (in shares)	3,233
Vested, weighted average exercise price per share (in dollars per share)	$ 4.34
Vested, weighted average remaining contractual term (Year)	7 years 9 months
Vested, aggregate intrinsic value	$ 569		$ 47