Note 3 - Summary of Significant Accounting Policies (Details Textual) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)	Jun. 30, 2021 $ / shares
Number of Operating Segments	1
Cash and cash equivalents	$ 24,228	$ 34,946
Impairment, Long-Lived Asset, Held-for-Use	$ 0	$ 0
Common Stock [Member]
Shares Issued, Price Per Share | $ / shares			$ 5