Note 15 - Income Taxes - Reconciliation of Income Tax Expense (Benefit) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Loss before income taxes	$ (8,364)	$ (9,435)
Theoretical tax benefit at the statutory rate (21.0% in 2022, 21.0% in 2021)	(1,756)	(1,981)
Differences in jurisdictional tax rates	(252)	(354)
Valuation allowance	2,067	1,984
Non-deductible expenses	213	334
Other		17
Total income tax provision	272	0
Net loss	$ (8,636)	$ (9,435)