Note 6 - Stockholders' Equity and Stock-based Compensation - Summary of Performance Option Activity (Details) - Performance Options [Member] - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Options balances, number of shares (in shares)	1,224,130
Options balances, weighted average exercise price (in dollars per share)	$ 5.51
Options balances, weighted average remaining life (Year)	8 years 4 months 6 days	8 years 6 months 10 days
Options granted, number of shares (in shares)	39,000
Options granted, weighted average exercise price (in dollars per share)	$ 8.44
Options exercised, number of shares (in shares)	(3,000)
Options exercised, weighted average exercise price (in dollars per share)	$ 2.92
Options canceled, number of shares (in shares)	(3,000)
Options canceled, weighted average exercise price (in dollars per share)	$ 2.92
Options expired, number of shares (in shares)	0
Options expired, weighted average exercise price (in dollars per share)	$ 0
Options balances, number of shares (in shares)	1,257,130	1,224,130
Options balances, weighted average exercise price (in dollars per share)	$ 5.61	$ 5.51
Options exercisable, number of shares (in shares)	440,628
Options exercisable, weighted average exercise price (in dollars per share)	$ 7.6
Options exercisable, weighted average remaining life (Year)	7 years 6 months