Note 3 - Contingencies and Uncertainties (Details Textual) $ in Millions	Feb. 02, 2016 USD ($)
Claim Against Attorney General of Canada [Member]
Litigation, Estimated Recovery	$ 15

Reflects the estimated amount of recovery from a litigation.

No definition available.

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