Note 12 - Convertible Notes - Related Party - Convertible Notes Payable to Related Party (Details) (Parentheticals)	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016
Conversion Rights	4,718,113
Convertible Debt Payable to Related Party [Member]
Conversion Rights	1,591,696
Bill Chaaban, President of Cen Biotech [Member] \| Convertible Debt Payable to Related Party [Member]
Interest Rate	12.00%	12.00%
Conversion Rights	871,576	871,576
Maturity Date	Dec. 31, 2018	Dec. 31, 2018
Director, Harold Aubrey de Lavenu [Member] \| Convertible Debt Payable to Related Party [Member]
Interest Rate	5.00%	5.00%
Conversion Rights	550,000	550,000
Maturing Dates Range	Between May 2018 and Feb 2019	Between May 2018 and Feb 2019
Director, Alex Tarrabain [Member] \| Convertible Debt Payable to Related Party [Member]
Interest Rate	5.00%	5.00%
Conversion Rights	30,000	30,000
Maturity Date	Oct. 26, 201	Oct. 26, 201
Joseph Byrne [Member] \| Convertible Debt Payable to Related Party [Member]
Interest Rate	12.00%	12.00%
Conversion Rights	140,120	140,120
Maturity Date	Aug. 17, 2018	Aug. 17, 2018

The maturity various date range of a debt instrument.

No definition available.

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(5))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21506-112644

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21475-112644

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21521-112644

+ Details

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Balance Type:	na
Period Type:	duration

- Definition

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

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

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

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Details

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- Details

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- Details

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- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=cenb_DirectorAlexTarrabainMember
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- Details

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