Note 4 - Property, Plant and Improvements - Property and Improvements Not Placed in Service (Details) - USD ($)	Dec. 31, 2016	Dec. 31, 2015
Net leasehold improvements	$ 1,270,115	$ 8,292,111
Property and Improvements Not Placed in Service [Member]
Leasehold improvements	6,105,711	6,130,644
Accumulated impairment	4,835,596
Net Leasehold Improvements	1,270,115
Land		1,064,651
Construction in progress		1,096,816
Net leasehold improvements	$ 1,270,115	$ 8,292,111

Amount of structure or a modification to a structure under construction, net of accumulated impairment.

No definition available.

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Period Type:	instant

- Definition

The accumulated impairment of leasehold improvements.

+ References

No definition available.

+ Details

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

- Definition

The amount of leasehold improvements, net of accumulated impairment.

+ References

No definition available.

+ Details

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

- Definition

Amount of structure or a modification to a structure under construction. Includes recently completed structures or modifications to structures that have not been placed into service.

+ References

+ Details

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

- Definition

Amount before accumulated depletion of real estate held for productive use, excluding land held for sale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 4
-Subparagraph (e)
-URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6812-107765

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.13)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Period Type:	instant

- Definition

Amount before accumulated depreciation of additions or improvements to assets held under a lease arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6391035&loc=d3e2868-110229

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 4
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=28358313&loc=d3e6812-107765

+ Details

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Period Type:	instant

- Details

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