Note 2 - Summary of Significant Accounting Policies (Details Textual) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2022 USD ($)	Mar. 31, 2021 USD ($)	Dec. 31, 2021	May 31, 2018 USD ($)
Number of Operating Segments	2		2
Number of Reportable Segments	3		2
Inventory Write-down	$ 123	$ 39
Deferred Grant Proceeds	236
City of Rochester and State of New York [Member]
Contingent Liability, Repayment of State and Local Grant Funds Received	87			$ 550
Covenant, Future Amount Receivable	$ 285