Commitments and Contingencies (Subsidiary Guarantees) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013
Stated Limit	$ 4,252
Value	863	[1]
Subsidiary Debt
Stated Limit	363	[2]
Value	363	[1],[2]
Commodity Transactions
Stated Limit	3,019	[3]
Value	341	[1],[3]
Nuclear Obligations
Stated Limit	232	[4]
Value	51	[1],[4]
Other
Stated Limit	638	[5]
Value	108	[1],[5]
Millstone Power Station | Nuclear Obligations
Stated Limit	150
Kewaunee Power Station | Nuclear Obligations
Stated Limit	$ 60

[1] Represents the estimated portion of the guarantee's stated limit that is utilized as of March 31, 2013 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.