Note 2 - Summary of Significant Accounting Policies (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Accounts Receivable, Allowance for Credit Loss, Ending Balance	$ 0	$ 0
Developed Technology Rights [Member] | Minimum [Member]
Finite-Lived Intangible Asset, Useful Life (Year)	1 year 109 days
Developed Technology Rights [Member] | Maximum [Member]
Finite-Lived Intangible Asset, Useful Life (Year)	11 years 273 days
Intellectual Property [Member]
Finite-Lived Intangible Asset, Useful Life (Year)	20 years