Note 8 - Convertible Notes Payable - Related Parties - Convertible Notes Payable to Related Parties (Details) (Parentheticals) - Convertible Debt Payable to Related Party [Member]	6 Months Ended	12 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Conversion Rights	1,587,167
Bill Chaaban, President of Cen Biotech [Member]
Interest Rate	12.00%	12.00%
Conversion Rights	867,576	867,576
Maturity Date	Aug. 17, 2020	Aug. 17, 2020
Director, Harold Aubrey de Lavenu [Member]
Interest Rate	5.00%	5.00%
Conversion Rights	548,980	548,980
Maturity Date	Mar. 31, 2019	Mar. 31, 2019
Joseph Byrne [Member]
Interest Rate	12.00%	12.00%
Conversion Rights	76,123	76,123
Maturity Date	Aug. 17, 2020	Aug. 17, 2020
Jeff Thomas [Member]
Interest Rate	5.00%	5.00%
Conversion Rights	48,000	48,000
Maturity Date	May 24, 2022	May 24, 2022
Director, Alex Tarrabain [Member]
Interest Rate		5.00%
Conversion Rights		30,000
Brother of Director Ameen Ferris [Member]
Interest Rate		5.00%
Conversion Rights		12,500