Note 15 - Equity Incentive Plans - Stock Option Activity (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Stock options outstanding (in shares)	425,646	222,700
Stock options, weighted average exercise price, outstanding (in dollars per share)	$ 5.17	$ 7.45
Stock options, outstanding, weighted average remaining contractual life (Year)	7 years 8 months 12 days	8 years 10 months 24 days	9 years 8 months 12 days
Stock options, granted (in shares)	459,281	226,746
Stock options, weighted average exercise price, granted (in dollars per share)	$ 1.91	$ 3.18
Stock options, exercised (in shares)	1,155	0
Stock options, weighted average exercise price, exercised (in dollars per share)	$ 1.28	$ 0
Stock options, expired (in shares)	0	0
Stock options, weighted average exercise price, expired (in dollars per share)		$ 0
Stock options, forfeited (in shares)	(92,827)	(23,800)
Stock options, weighted average exercise price, forfeited (in dollars per share)	$ 3.15	$ 0
Stock options, intrinsic value, outstanding	$ 0	$ 0
Options assumed (in shares)	108,875
Options assumed, weighted average exercise price (in dollars per share)	$ 2.96
Exercised (in shares)	(1,155)	0
Stock options, weighted average exercise price, outstanding (in shares)	899,820	425,646	222,700
Stock options, weighted average exercise price, outstanding (in dollars per share)	$ 3.12	$ 5.17	$ 7.45
Stock options, exercisable (in shares)	465,566
Stock options, weighted average exercise price, exercisable (in dollars per share)	$ 3.68
Stock options, aggregate intrinsic value, exercisable	$ 0
Stock options, exercisable, weighted average remaining contractual term (Year)	6 years 8 months 12 days