Note 7 - Share-based Compensation - Summary of Stock Option Activity (Details) - Employee and Nonemployee Stock Option [Member] $ / shares in Units, $ in Thousands	9 Months Ended
	Sep. 30, 2023 USD ($) $ / shares shares
Outstanding, shares under options (in shares) | shares	92,075
Outstanding, weighted average exercise price (in dollars per share) | $ / shares	$ 39.98
Granted, shares under options (in shares) | shares	12,153
Granted (in dollars per share) | $ / shares	$ 131.13
Exercised, shares under options (in shares) | shares	(25,740)
Granted, weighted average exercise price (in dollars per share) | $ / shares	$ 30.67
Outstanding, shares under options (in shares) | shares	78,488
Outstanding, weighted average exercise price (in dollars per share) | $ / shares	$ 57.14
Outstanding, weighted average remaining contractual life (Year)	5 years 9 months 21 days
Outstanding, aggregate intrinsic value | $	$ 8,214
Exercisable, shares under options (in shares) | shares	66,335
Exercisable, weighted average exercise price (in dollars per share) | $ / shares	$ 43.59
Exercisable, weighted average remaining contractual life (Year)	5 years 8 months 23 days
Exercisable, aggregate intrinsic value | $	$ 7,818
Vested and expected to vest, shares under options (in shares) | shares	78,488
Vested and expected to vest, weighted average exercise price (in dollars per share) | $ / shares	$ 57.14
Vested and expected to vest, weighted average remaining contractual life (Year)	5 years 9 months 21 days
Vested and expected to vest, aggregate intrinsic value | $	$ 8,214