Regulatory Assets and Liabilities (Regulatory Assets and Liabilities) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Regulatory Assets And Liabilities [Line Items]
Unrecovered gas costs	$ 59	[1]	$ 48	[1]
Deferred rate adjustment clause costs	55	[2]	113	[2]
Virginia sales taxes	37	[3]	32	[3]
Plant retirement, regulatory assets-current	25	[4]	27	[4]
Deferred cost of fuel used in electric generation	0	[5]	249	[5]
Derivatives, regulatory assets-current	0	[6]	45	[6]
Other	27		27
Regulatory assets-current	203		541
Unrecognized pension and other postretirement benefit costs	1,210	[7]	887	[7]
Deferred rate adjustment clause costs	173	[7]	107	[7]
Income taxes recoverable through future rates	140	[8]	121	[8]
Derivatives, regulatory assets-non-current	105	[6]	49	[6]
Other postretirement benefit costs	21	[9]	26	[9]
Plant retirement, regulatory assets-non-current	11	[4]	25	[4]
Deferred cost of fuel used in electric generation	0	[5]	122	[5]
Other	57		45
Regulatory assets-non-current	1,717		1,382
Total regulatory assets	1,920		1,923
PIPP, regulatory liabilities-current	100	[10]	58	[10]
Provision for rate proceedings	8	[11]	150	[11]
Other, regulatory assets-non-current	28		35
Regulatory liabilities-current	136		243
Provision for future cost of removal and AROs	985	[12]	901	[12]
Decommissioning trust	501	[13]	399	[13]
Other	28		24
Regulatory liabilities-non-current	1,514		1,324
Total regulatory liabilities	1,650		1,567
Virginia Electric and Power Company
Regulatory Assets And Liabilities [Line Items]
Deferred rate adjustment clause costs	51		113
Virginia sales taxes	37	[3]	32	[3]
Plant retirement, regulatory assets-current	25	[4]	27	[4]
Deferred cost of fuel used in electric generation	0		249
Derivatives, regulatory assets-current	0	[6]	45	[6]
Other	6		13
Regulatory assets-current	119		479
Deferred rate adjustment clause costs	127	[2]	70	[2]
Income taxes recoverable through future rates	110	[8]	100	[8]
Derivatives, regulatory assets-non-current	105	[6]	49	[6]
Plant retirement, regulatory assets-non-current	11	[6]	25	[6]
Deferred cost of fuel used in electric generation	0	[5]	122	[5]
Other	43		33
Regulatory assets-non-current	396		399
Total regulatory assets	515		878
Provision for rate proceedings	7	[11]	150	[11]
Other, regulatory assets-non-current	25		28
Regulatory liabilities-current	32		178
Provision for future cost of removal	763	[12]	687	[12]
Decommissioning trust	501	[13]	399	[13]
Other	21		9
Regulatory liabilities-non-current	1,285		1,095
Total regulatory liabilities	$ 1,317		$ 1,273

[1] Amounts to be recovered through an annual surcharge to reimburse Virginia Power for incremental sales taxes being incurred due to the repeal of the public service company sales tax exemption in Virginia.

[2] Reflects deferrals under the electric transmission FERC formula rate and the deferral of costs associated with certain current and prospective rider projects. See Note 13 for more information.

[3] Primarily reflects deferred fuel expenses for the Virginia jurisdiction of Virginia Power's generation operations. See Note 13 for more information.

[4] As discussed under Derivative Instruments in Note 2, for jurisdictions subject to cost-based rate regulation, changes in the fair value of derivative instruments result in the recognition of regulatory assets or regulatory liabilities as they are expected to be recovered from or refunded to customers.

[5] Reflects unrecovered gas costs at Dominion's regulated gas operations, which are recovered through quarterly or annual filings with the applicable regulatory authority.

[6] Reflects costs anticipated to be recovered in base rates for certain coal units expected to be retired.

[7] Amounts to be recovered through future rates to pay income taxes that become payable when rate revenue is provided to recover AFUDC-equity and depreciation of property, plant and equipment for which deferred income taxes were not recognized for ratemaking purposes, including amounts attributable to tax rate changes.

[8] Primarily reflects costs recognized in excess of amounts included in regulated rates charged by Dominion's regulated gas operations before rates were updated to reflect a change in accounting method for other postretirement benefit costs.

[9] Under PIPP, eligible customers can receive energy assistance based on their ability to pay. The difference between the customer's total bill and the PIPP plan amount is deferred and collected or returned annually under the PIPP rider according to East Ohio tariff provisions. See Note 13 for more information regarding PIPP.

[10] Represents unrecognized pension and other postretirement benefit costs expected to be recovered through future rates generally over the expected remaining service period of plan participants by certain of Dominion's rate-regulated subsidiaries.

[11] Reflects a reserve associated with the Biennial Review Order. See Note 13 for more information.

[12] Rates charged to customers by the Companies' regulated businesses include a provision for the cost of future activities to remove assets that are expected to be incurred at the time of retirement.

[13] Primarily reflects a regulatory liability representing amounts collected from Virginia jurisdictional customers and placed in external trusts (including income, losses and changes in fair value thereon) for the future decommissioning of Virginia Power's utility nuclear generation stations, in excess of the related ARO.