Note 17 - Fair Value Disclosures - Fair Value of Financial Instruments (Details) - USD ($)	Jun. 30, 2019	Dec. 31, 2018
Reported Value Measurement [Member]
Cash and cash equivalents	$ 15,972	$ 3,193
Other receivables	419,958	418,905
Note receivable - related party	44,859	44,859
Advances to CEN Biotech Ukraine, LLC - related party	995,328	875,328
Loans payable	10,119,178	10,107,205
Loans payable - related parties	1,362,318	1,360,806
Patent acquisition liability	1,010,000	1,010,000
Convertible notes payable	5,705,038	5,143,647
Convertible notes payable - related parties	2,558,681	2,538,681
Estimate of Fair Value Measurement [Member]
Cash and cash equivalents	15,972	3,193
Other receivables	419,958	418,905
Note receivable - related party	44,859	44,859
Advances to CEN Biotech Ukraine, LLC - related party	995,328	875,328
Loans payable	10,119,178	10,107,205
Loans payable - related parties
Patent acquisition liability	1,010,000	1,010,000
Convertible notes payable	6,240,408	5,534,810
Convertible notes payable - related parties
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents
Other receivables
Note receivable - related party
Advances to CEN Biotech Ukraine, LLC - related party
Loans payable
Loans payable - related parties
Patent acquisition liability
Convertible notes payable
Convertible notes payable - related parties
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 2 [Member]
Cash and cash equivalents	15,972	3,193
Other receivables
Note receivable - related party
Advances to CEN Biotech Ukraine, LLC - related party
Loans payable
Loans payable - related parties
Patent acquisition liability
Convertible notes payable
Convertible notes payable - related parties
Estimate of Fair Value Measurement [Member] | Fair Value, Inputs, Level 3 [Member]
Cash and cash equivalents
Other receivables	419,958	418,905
Note receivable - related party	44,859	44,859
Advances to CEN Biotech Ukraine, LLC - related party	995,328	875,328
Loans payable	10,119,178	10,107,205
Loans payable - related parties
Patent acquisition liability	1,010,000	1,010,000
Convertible notes payable	6,240,408	5,534,810
Convertible notes payable - related parties