Note 6 - Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2021
Effective Income Tax Rate Reconciliation, Percent, Total	0.20%	3.80%
Deferred Income Tax Expense (Benefit), Total	$ 0	$ 700
Current Income Tax Expense (Benefit), Total	$ (40)	$ 20
Forecast [Member]
Effective Income Tax Rate Reconciliation, Percent, Total			(0.10%)