Note 11 - Equity Incentive Plan - Stock Options (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2023
Outstanding, shares (in shares)	1,530,703	1,530,703
Outstanding, Weighted Average Exercise (in dollars per share)	$ 34.93	$ 34.93
Granted, shares (in shares)	339,145
Granted, Weighted Average Exercise Price (in dollars per share)	$ 29.68
Exercised, shares (in shares)	(637)
Exercised, Weighted Average Exercise Price (in dollars per share)	$ 10.87
Exercised, Aggregate Intrinsic Value	$ 13
Forfeited and canceled, shares (in shares)	(11,212)
Forfeited and canceled, Weighted Average Exercise Price (in dollars per share)	$ 39.77
Outstanding, shares (in shares)	1,857,999
Outstanding, Weighted Average Exercise Price (in dollars per share)	$ 33.95
Outstanding, Weighted Average Remaining Contractual Term (Year)	8 years 2 months 12 days
Outstanding, Aggregate Intrinsic Value	$ 632
Vested, shares (in shares)		915,798
Vested, Weighted Average Exercise Price (in dollars per share)	$ 37.08
Vested, Weighted Average Remaining Contractual Term (Year)	7 years 4 months 24 days
Vested, Aggregate Intrinsic Value	$ 82
Vested and expected to vest, shares (in shares)		1,857,999
Vested and expected to vest, Weighted Average Exercise Price (in dollars per share)	$ 33.95
Vested and expected to vest, Weighted Average Remaining Contractual Term (Year)	8 years 2 months 12 days
Vested and expected to vest, Aggregate Intrinsic Value	$ 632