Note 1 - Description of Business and Summary of Significant Accounting Policies - Potentially Dilutive Shares Excluded From Calculation of Diluted Net Loss Per Share (Details) - shares	3 Months Ended
Mar. 31, 2023	Mar. 31, 2022
Share-Based Payment Arrangement, Option [Member]
Potentially dilutive securities (in shares)	1,216,055	991,588
Restricted Stock Units (RSUs) [Member]
Potentially dilutive securities (in shares)	25,555	22,898

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 260
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482662/260-10-50-1

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration