Commitments and Contingencies (Subsidiary Guarantees) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012
Guarantor Obligations [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	$ 4,206
Value	915	[1]
Debt
Guarantor Obligations [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	363	[2]
Value	363	[1],[2]
Commodity transactions
Guarantor Obligations [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	2,939	[3]
Value	377	[1],[3]
Nuclear obligations
Guarantor Obligations [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	231	[4]
Value	77	[1],[4]
Other
Guarantor Obligations [Line Items]
Guarantor Obligations, Maximum Exposure, Undiscounted	673	[5]
Value	98	[1],[5]
Millstone | Nuclear obligations
Guarantor Obligations [Line Items]
Stated Limit	150
Kewaunee | Nuclear obligations
Guarantor Obligations [Line Items]
Stated Limit	$ 60

[1] Represents the estimated portion of the guarantee's stated limit that is utilized as of December 31, 2012 based upon prevailing economic conditions and fact patterns specific to each guarantee arrangement. For those guarantees related to obligations that are recorded as liabilities by Dominion's subsidiaries, the value includes the recorded amount.

[2] Guarantees of debt of certain DEI subsidiaries. In the event of default by the subsidiaries, Dominion would be obligated to repay such amounts.

[3] Guarantees related to energy trading and marketing activities and other commodity commitments of certain subsidiaries, including subsidiaries of Virginia Power and DEI. These guarantees were provided to counterparties in order to facilitate physical and financial transactions in gas, oil, electricity, pipeline capacity, transportation and related commodities and services. If any of these subsidiaries fail to perform or pay under the contracts and the counterparties seek performance or payment, Dominion would be obligated to satisfy such obligation. Dominion and its subsidiaries receive similar guarantees as collateral for credit extended to others. The value provided includes certain guarantees that do not have stated limits.

[4] Guarantees related to certain DEI subsidiaries' potential retrospective premiums that could be assessed if there is a nuclear incident under Dominion's nuclear insurance programs and guarantees for a DEI subsidiary's and Virginia Power's commitment to buy nuclear fuel. Excludes Dominion's agreement to provide up to $150 million and $60 million to two DEI subsidiaries to pay the operating expenses of Millstone and Kewaunee, respectively, in the event of a prolonged outage, as part of satisfying certain NRC requirements concerned with ensuring adequate funding for the operations of nuclear power stations. The agreement for Kewaunee also provides for funds through the completion of decommissioning.

[5] Guarantees related to other miscellaneous contractual obligations such as leases, environmental obligations and construction projects. Also includes guarantees related to certain DEI subsidiaries' obligations for equity capital contributions and energy generation associated with Fowler Ridge and NedPower.