Note 3 - Earnings (Loss) Per Share (Details Textual) - $ / shares	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Weighted Average Number of Shares Outstanding, Basic, Total	150,832,451	147,865,246
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	13,390,677	43,343,224
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price	$ 0.25
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price	0.17
Class of Warrant or Right, Exercise Price of Warrants or Rights	0.25	$ 0.25
Debt Instrument, Convertible, Conversion Price	0.25
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercisable, Weighted Average Exercise Price	0.34
Class of Warrant or Right, Exercise Price of Warrants or Rights	0.60	$ 0.60
Debt Instrument, Convertible, Conversion Price	$ 0.50

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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