Note 9 - Income Taxes (Details Textual) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%	21.00%
Unrecognized Tax Benefits, Ending Balance	$ 0	$ 0
Operating Loss Carryforwards, Total	27,500
Deferred Tax Assets, Valuation Allowance, Total	4,951	3,081
Income Tax Examination, Penalties and Interest Expense, Total	$ 0	$ 0
Domestic Tax Authority [Member] \| Internal Revenue Service (IRS) [Member]
Open Tax Year	2016 2017 2018 2019
State and Local Jurisdiction [Member]
Open Tax Year	2015 2016 2017 2018 2019

Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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The sum of the amounts of estimated penalties and interest recognized in the period arising from income tax examinations.

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Tax year that remains open to examination under enacted tax laws, in CCYY format.

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Amount of operating loss carryforward, before tax effects, available to reduce future taxable income under enacted tax laws.

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Amount of unrecognized tax benefits.

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