Note 8 - Share-based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2023	Dec. 31, 2022
Balance, number of shares (in shares)	2,182,708
Balance, weighted average exercise price (in dollars per share)	$ 4.04
Balance, weighted average remaining contractual term (Year)	7 years 3 months 18 days	7 years 6 months
Balance, aggregate intrinsic value	$ 1,189	$ 343
Stock options granted, number of shares (in shares)	543,513
Stock options granted, weighted average exercise price (in dollars per share)	$ 1.69
Stock options exercised, number of shares (in shares)	(199)
Stock options exercised, weighted average exercise price (in dollars per share)	$ 1.49
Stock options forfeited, number of shares (in shares)	(119,941)
Stock options forfeited, weighted average exercise price (in dollars per share)	$ 2.36
Balance, number of shares (in shares)	2,606,081	2,182,708
Balance, weighted average exercise price (in dollars per share)	$ 3.63	$ 4.04
Exercisable, number of shares (in shares)	1,443,515
Exercisable, weighted average exercise price (in dollars per share)	$ 4.83
Exercisable, weighted average remaining contractual term (Year)	6 years
Exercisable, aggregate intrinsic value	$ 315