Note 7 - Income Taxes (Details Textual) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2021
Effective Income Tax Rate Reconciliation, Percent, Total	(0.20%)	0.00%	0.00%	3.00%
Deferred Income Tax Expense (Benefit), Total	$ 0	$ 0	$ 0	$ 1,400
Current Income Tax Expense (Benefit), Total	30	$ 0	0	$ 40
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	$ 0		$ 0
Forecast [Member]
Effective Income Tax Rate Reconciliation, Percent, Total					0.00%

Amount of current income tax expense (benefit) pertaining to taxable income (loss) from continuing operations.

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Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations.

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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The total amount of unrecognized tax benefits that, if recognized, would affect the effective tax rate.

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