Note 14 - Income Taxes - Differences Between the Expected Federal Tax Benefit and Actual Tax Provision (Details)	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Expected federal tax benefit	(21.00%)	(21.00%)	(34.00%)
Permanent items	0.60%	0.90%
Net operating loss utilized or expired	0.00%	0.00%
Increase in valuation allowance and others	20.40%	20.10%
Effective tax rate	0.00%	0.00%

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

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

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Percentage of the difference between reported income tax expense (benefit) and expected income tax expense (benefit) computed by applying the domestic federal statutory income tax rates to pretax income (loss) from continuing operations attributable to deductions. Including, but not limited to, extraterritorial income exclusion deduction, qualified production activity deduction, dividend deduction, deduction for dividend paid to employee stock ownership plan, Medicare prescription drug benefit subsidy deduction, and other deductions.

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