Note 4 - Summary of Significant Accounting Policies (Details Textual) $ / shares in Units, $ in Thousands		1 Months Ended		3 Months Ended		12 Months Ended
	Jan. 24, 2024 USD ($) $ / shares shares	Jul. 31, 2023 USD ($)	Jun. 30, 2023 USD ($)	Mar. 31, 2024 USD ($) $ / shares shares	Mar. 31, 2023 USD ($) shares	Dec. 31, 2023 USD ($) $ / shares	Nov. 01, 2017 USD ($)
Number of Reporting Units					1
Goodwill, Impairment Loss				$ 0	$ 484
Goodwill			$ 0	0		$ 0
Foreign Currency Transaction Gain, before Tax				200	$ 100
Liability for Contingent Milestone Payment, Noncurrent				$ 0		$ 15,000
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares				$ 0.001		$ 0.001
Number of Shares of Common Stock Potentially Issuable upon the Exercise of Stock Options and Warrants (in shares) | shares				300,000	30,000
Exchange and Termination Agreement with Deerfield Management Company, L.P. [Member]
Termination Agreement, Payable	$ 200
Stock Issued During Period, Shares, New Issues (in shares) | shares	33,793
Common Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares	$ 0.001
Deerfield Loan [Member] | Exchange and Termination Agreement [Member] | Deerfield Management, L.P. [Member]
Liability for Contingent Milestone Payment, Noncurrent							$ 15,000
Minimum [Member]
Property, Plant and Equipment, Useful Life (Year)				3 years
Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)				10 years
Executive [Member]
Severance Costs		$ 500	$ 200			$ 200
Severance Accrual						$ 300