Note 6 - Income Taxes (Details Textual) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Effective Income Tax Rate Reconciliation, Percent, Total	(0.10%)	(0.00%)	(1.80%)	(12.80%)
Income Tax Expense (Benefit), Total	$ 823	$ 0	$ (19,524)	$ (238,929)
Unrecognized Tax Benefits, Ending Balance	0		0
Approximation [Member]
Income Tax Expense (Benefit), Total	$ (1,000)	$ (0)	$ (19,000)	$ (239,000)