Note 13 - Income Taxes (Details Textual) - USD ($) Pure in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Tax Expense (Benefit), Total	$ 0	$ 0	$ 0	$ 0
Effective Income Tax Rate Reconciliation, Percent, Total	0.00%	0.00%