Goodwill (details) - Not Subject to Amortization (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Nov. 01, 2013 Dominion [Member]
Intangible assets not subject to amortization
Intangible assets not subject to amortization	$ 217	$ 216
Intangible assets acquired, not subject to amortization			$ 1

Amount of assets, excluding financial assets and goodwill, that lack physical substance, having a projected indefinite period of benefit, acquired at the acquisition date.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6910749&loc=d3e4845-128472

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