Note 6 - Income Taxes (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	21.00%	35.00%
Deferred Income Tax Liabilities, Net, Total	$ 275
Deferred Tax Assets, Net of Valuation Allowance, Total		280
Deferred Tax Assets, Valuation Allowance, Total	582	475
Unrecognized Tax Benefits, Ending Balance	0	0
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued, Total	0	0
Liability for Uncertainty in Income Taxes, Current	$ 0	$ 0