Regulatory Assets and Liabilities (Narrative) (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended
Sep. 30, 2014
Public Utilities, General Disclosures [Line Items]
Regulatory assets past expenditures not earning return	$ 182
Period for which expenditures are expected to be recovered	2 years
Virginia Electric and Power Company
Public Utilities, General Disclosures [Line Items]
Regulatory assets past expenditures not earning return	147
Dominion Gas Holdings, LLC
Public Utilities, General Disclosures [Line Items]
Regulatory assets past expenditures not earning return	$ 24

Remaining balance of regulatory assets for which no return on investment during recovery is provided. In some cases, a regulator may permit an enterprise to include a cost that would be charged to expense by an unregulated enterprise as an allowable cost over a period of time by amortizing that cost for rate-making purposes, but the regulator does not include the unrecovered amount in the rate base.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 980

-SubTopic 340

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6499975&loc=d3e44250-110382

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 980

-SubTopic 340

-Section 55

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6591318&loc=d3e44360-110383

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