Note 5 - Stock-based Compensation (Details Textual) - Share-Based Payment Arrangement, Nonemployee [Member] - shares shares in Thousands	3 Months Ended
Mar. 31, 2023	Mar. 31, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award, Shares Issued in Period (in shares)	240
Restricted Stock [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award, Shares Issued in Period (in shares)	28	10

Number of shares issued under share-based payment arrangement.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

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