Note 11 - Net Loss Per Share - Summary of Antidilutive Securities (Details) - shares	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Potentially dilutive securities excluded from denominator of the diluted earnings per share computation (in shares)	22,738,219	14,490,693	19,526,614	12,818,877
Share-Based Payment Arrangement, Option [Member]
Potentially dilutive securities excluded from denominator of the diluted earnings per share computation (in shares)	18,469,856	13,873,456	16,452,951	12,388,584
Restricted Stock Units (RSUs) [Member]
Potentially dilutive securities excluded from denominator of the diluted earnings per share computation (in shares)	3,672,594	389,638	2,445,397	200,277
Warrant [Member] | Common Stock [Member]
Potentially dilutive securities excluded from denominator of the diluted earnings per share computation (in shares)	227,434	227,599	227,434	230,016
Employee Stock Purchase Plan [Member]
Potentially dilutive securities excluded from denominator of the diluted earnings per share computation (in shares)	368,335	0	400,832	0