Note 20 - Fair Value Disclosures - Fair Value of Financial Instruments (Details) - USD ($)	Sep. 30, 2021	Dec. 31, 2020
Reported Value Measurement [Member]
Cash and cash equivalents	$ 213,805	$ 1,908
Note receivable – CEN Biotech Ukraine, LLC – related party	44,859	44,859
Loans payable	1,986,670	527,379
Loans payable – related parties	2,701,452	1,363,354
Patent acquisition liability	354,900	1,380,000
Convertible notes payable	749,526	6,730,448
Convertible notes payable – related parties	1,036,434	2,558,681
Other receivables		113,999
Reported Value Measurement [Member] \| CEBA, Loan Payable [Member]
Loans payable	31,396
Reported Value Measurement [Member] \| CEN Biotech Ukraine [Member]
Advances to Subsidiary	1,299,328	1,179,328
Reported Value Measurement [Member] \| Emergence Global [Member]
Advances to Subsidiary		17,901
Estimate of Fair Value Measurement [Member]
Cash and cash equivalents	213,805	1,908
Note receivable – CEN Biotech Ukraine, LLC – related party	44,859	44,859
Loans payable	1,986,670	527,379
Loans payable – related parties	0	0
Patent acquisition liability	354,900	1,380,000
Convertible notes payable	1,962,985	7,766,663
Convertible notes payable – related parties	0	0
Other receivables		113,999
Estimate of Fair Value Measurement [Member] \| CEBA, Loan Payable [Member]
Loans payable	31,396
Estimate of Fair Value Measurement [Member] \| CEN Biotech Ukraine [Member]
Advances to Subsidiary	1,299,328	1,179,328
Estimate of Fair Value Measurement [Member] \| Emergence Global [Member]
Advances to Subsidiary		17,901
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents	0	0
Note receivable – CEN Biotech Ukraine, LLC – related party	0	0
Loans payable	0	0
Loans payable – related parties	0	0
Patent acquisition liability	354,900	0
Convertible notes payable	0	0
Convertible notes payable – related parties	0	0
Other receivables		0
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member] \| CEBA, Loan Payable [Member]
Loans payable	0
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member] \| CEN Biotech Ukraine [Member]
Advances to Subsidiary	0	0
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 1 [Member] \| Emergence Global [Member]
Advances to Subsidiary		0
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member]
Cash and cash equivalents	213,805	1,908
Note receivable – CEN Biotech Ukraine, LLC – related party	0	0
Loans payable	0	0
Loans payable – related parties	0	0
Patent acquisition liability	0	0
Convertible notes payable	0	0
Convertible notes payable – related parties	0	0
Other receivables		0
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member] \| CEBA, Loan Payable [Member]
Loans payable	0
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member] \| CEN Biotech Ukraine [Member]
Advances to Subsidiary	0	0
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 2 [Member] \| Emergence Global [Member]
Advances to Subsidiary		0
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member]
Cash and cash equivalents	0	0
Note receivable – CEN Biotech Ukraine, LLC – related party	44,859	44,859
Loans payable	1,986,670	527,379
Loans payable – related parties	0	0
Patent acquisition liability	0	1,380,000
Convertible notes payable	1,962,985	7,766,663
Convertible notes payable – related parties	0	0
Other receivables		113,999
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member] \| CEBA, Loan Payable [Member]
Loans payable	31,396
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member] \| CEN Biotech Ukraine [Member]
Advances to Subsidiary	$ 1,299,328	1,179,328
Estimate of Fair Value Measurement [Member] \| Fair Value, Inputs, Level 3 [Member] \| Emergence Global [Member]
Advances to Subsidiary		$ 17,901

Fair value portion of advances to subsidiary.

No definition available.

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Namespace Prefix:	cenb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value portion of convertible debt payable to related party.

+ References

No definition available.

+ Details

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Namespace Prefix:	cenb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Fair value portion of loans payable to related party.

+ References

No definition available.

+ Details

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Namespace Prefix:	cenb_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Fair value portion of notes receivable from related party.

+ References

No definition available.

+ Details

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Namespace Prefix:	cenb_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The fair value amount of patent acquisition liability.

+ References

No definition available.

+ Details

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Namespace Prefix:	cenb_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- Definition

Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Fair value portion of borrowing which can be exchanged for a specified number of another security at the option of the issuer or the holder, for example, but not limited to, the entity's common stock.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Fair value portion of contractual obligation to pay money on demand or on fixed or determinable dates.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-URI http://asc.fasb.org/subtopic&trid=2196772

+ Details

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- Details

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- Details

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