Background and Basis of Presentation (Details)	Sep. 30, 2012
Number Of Vies Consolidated In Financial Statements	5

The number of variable interest entities (VIE's) consolidated in the financials.

No definition available.

Name:	cehe_NumberOfViesConsolidatedInFinancialStatements
Namespace Prefix:	cehe_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant