Summary of Significant Accounting Policies (Schedule Of Unbilled Revenues Within Restricted Receivables) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Summary Of Significant Accounting Policies [Abstract]
Unbilled revenues within restricted receivables of variable interest entities and receivables	$ 674	$ 751

Unbilled Revenues Within Restricted Receivables Of Variable Interest Entities And Receivables

No definition available.

Name:	duk_UnbilledRevenuesWithinRestrictedReceivablesOfVariableInterestEntitiesAndReceivables
Namespace Prefix:	duk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant