Note 14 - Subsequent Events (Details Textual) - USD ($) $ / shares in Units, $ in Thousands			3 Months Ended	6 Months Ended
	Jul. 21, 2023	Jul. 18, 2023	Jun. 30, 2023	Jun. 30, 2023	Jun. 30, 2022
Stock Issued During Period, Value, New Issues			$ 32	$ 64
Proceeds from Issuance of Common Stock				$ 2,784	$ 4,588
Subsequent Event [Member] \| Yulho Co, Ltd. [Member] \| Yulho License Agreement [Member]
Agreement, Period of Execution (Day)		75 days
Subsequent Event [Member] \| Yulho Offering [Member] \| Yulho Co, Ltd. [Member]
Stock Issued During Period, Shares, New Issues (in shares)		4,545,455
Shares Issued, Price Per Share (in dollars per share)		$ 1.10
Stock Issued During Period, Value, New Issues		$ 5,000
Subsequent Event [Member] \| July 2023 Public Offering [Member]
Stock Issued During Period, Shares, New Issues (in shares)	18,193,000
Shares Issued, Price Per Share (in dollars per share)	$ 1.10
Proceeds from Issuance of Common Stock	$ 18,500