Commitments (Details Narrative) (USD $)	12 Months Ended
Sep. 30, 2012 Customers MMBTU
Commitments Details Narrative
Storage capacity maintained	736,000
Asset Management agreement	$ 2,100,000
Customers	14,700

The value of the amount of gas purchased in an asset management agreement with ConocoPhillips.

No definition available.

Name:	CNIG_AssetManagementAgreementValue
Namespace Prefix:	CNIG_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration