Note 6 - Stockholders' Equity and Stock-based Compensation - Summary of Time-based Option Activity (Details) - Time-based Options [Member] - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Options balances, number of shares (in shares)	4,730,394
Options balances, weighted average exercise price (in dollars per share)	$ 12.95
Options balances, weighted average remaining life (Year)	7 years 25 days	6 years 1 month 28 days
Options granted, number of shares (in shares)	2,390,386
Options granted, weighted average exercise price (in dollars per share)	$ 4.7
Options exercised, number of shares (in shares)	(301,254)
Options exercised, weighted average exercise price (in dollars per share)	$ 3.89
Options canceled, number of shares (in shares)	(262,994)
Options canceled, weighted average exercise price (in dollars per share)	$ 6.06
Options expired, number of shares (in shares)	(414,626)
Options expired, weighted average exercise price (in dollars per share)	$ 13.01
Options balances, number of shares (in shares)	6,141,906	4,730,394
Options balances, weighted average exercise price (in dollars per share)	$ 10.48	$ 12.95
Options exercisable, number of shares (in shares)	3,390,035
Options exercisable, weighted average exercise price (in dollars per share)	$ 14.47
Options exercisable, weighted average remaining life (Year)	5 years 3 months 10 days