Regulatory Assets and Liabilities (Regulatory Assets and Liabilities) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Regulatory Assets And Liabilities [Line Items]
Deferred cost of fuel used in electric generation	[1]	$ 111	$ 79
Deferred rate adjustment clause costs	[2]	90	124
Deferred nuclear refueling outage costs	[3]	75	44
Unrecovered gas costs	[4]	12	36
Other		63	64
Regulatory assets-current		351	347
Unrecognized pension and other postretirement benefit costs	[5]	1,015	1,050
Deferred rate adjustment clause costs	[2]	295	250
PJM transmission rates	[6]	192	0
Income taxes recoverable through future rates	[7]	126	133
Derivatives	[8]	110	101
Other		127	108
Regulatory assets-non-current		1,865	1,642
Total regulatory assets		2,216	1,989
PIPP, regulatory liabilities-current	[9]	46	71
Other		54	99
Regulatory liabilities-current	[10]	100	170
Provision for future cost of removal and AROs	[11]	1,120	1,072
Decommissioning trust	[12]	804	815
Deferred cost of fuel used in electric generation	[1]	97	6
Derivatives	[8]	79	0
Other		185	98
Regulatory liabilities-non-current		2,285	1,991
Total regulatory liabilities		$ 2,385	2,161
Maximum amortization period for deferred operation and maintenance costs		18 months
Virginia Electric and Power Company
Regulatory Assets And Liabilities [Line Items]
Deferred cost of fuel used in electric generation	[1]	$ 111	79
Deferred rate adjustment clause costs	[2]	80	117
Deferred nuclear refueling outage costs	[3]	75	44
Other		60	58
Regulatory assets-current		326	298
Deferred rate adjustment clause costs	[2]	213	179
PJM transmission rates	[6]	192	0
Income taxes recoverable through future rates	[7]	97	100
Derivatives	[8]	110	101
Other		55	59
Regulatory assets-non-current		667	439
Total regulatory assets		993	737
Other		35	90
Regulatory liabilities-current		35	90
Provision for future cost of removal	[11]	890	852
Decommissioning trust	[12]	804	815
Deferred cost of fuel used in electric generation	[1]	97	6
Derivatives	[8]	79	0
Other		59	10
Regulatory liabilities-non-current		1,929	1,683
Total regulatory liabilities		1,964	1,773
Dominion Gas Holdings, LLC
Regulatory Assets And Liabilities [Line Items]
Deferred rate adjustment clause costs	[2]	10	7
Unrecovered gas costs	[4]	11	29
Other		2	2
Regulatory assets-current		23	38
Unrecognized pension and other postretirement benefit costs	[5]	282	242
Deferred rate adjustment clause costs	[2]	82	71
Income taxes recoverable through future rates	[7]	20	24
Other		65	42
Regulatory assets-non-current		449	379
Total regulatory assets		472	417
PIPP, regulatory liabilities-current	[9]	46	71
Other		9	4
Regulatory liabilities-current		55	75
Provision for future cost of removal and AROs	[11]	170	172
Other		31	20
Regulatory liabilities-non-current		201	192
Total regulatory liabilities		$ 256	$ 267

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

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

[3] Legislation enacted in Virginia in April 2014 requires Virginia Power to defer operation and maintenance costs incurred in connection with the refueling of any nuclear-powered generating plant. These deferred costs will be amortized over the refueling cycle, not to exceed 18 months.

[4] Reflects unrecovered gas costs at regulated gas operations, which are recovered through filings with the applicable regulatory authority.

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

[6] Reflects amount related to the PJM transmission cost allocation matter. See Note 13 for more information.

[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] 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.

[9] Under PIPP, eligible customers can make reduced payments 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 rate adjustment clause according to East Ohio tariff provisions. See Note 13 for more information.

[10] Current regulatory liabilities are presented in other current liabilities in Dominion's Consolidated Balance Sheets.

[11] 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.

[12] 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 AROs.