Note 12 - Convertible Notes - Related Parties - Convertible Notes Payable to Related Parties (Details) (Parentheticals)	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Director, Harold Aubrey de Lavenu [Member]
Interest Rate	5.00%	5.00%
Conversion Rights	548,980	548,980
Maturing Dates	Mar. 31, 2019	Mar. 31, 2019
Director, Alex Tarrabain [Member]
Interest Rate	5.00%	5.00%
Conversion Rights	30,000	30,000
Maturing Dates	Mar. 31, 2019	Mar. 31, 2019
Convertible Debt Payable to Related Party [Member]
Conversion Rights	1,586,676
Convertible Debt Payable to Related Party [Member] \| Bill Chaaban, President of Cen Biotech [Member]
Interest Rate	12.00%	12.00%
Conversion Rights	867,576	867,576
Maturing Dates	Aug. 17, 2020	Aug. 17, 2020
Convertible Debt Payable to Related Party [Member] \| Joseph Byrne [Member]
Interest Rate	12.00%	12.00%
Conversion Rights	140,120	140,120
Maturing Dates	Aug. 17, 2020	Aug. 17, 2020

The number of equity instruments that the holder of the debt instrument would receive if the debt was converted to equity.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

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