Commitments and Contingencies (Subsidiary Guarantees) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2016 USD ($)
Guarantor Obligations [Line Items]
Maximum Exposure	$ 5,818	[1]
Commodity transactions
Guarantor Obligations [Line Items]
Maximum Exposure	2,074	[2]
Nuclear obligations
Guarantor Obligations [Line Items]
Maximum Exposure	169	[3]
Nuclear obligations | Cove Point
Guarantor Obligations [Line Items]
Maximum Exposure	1,900	[4]
Solar
Guarantor Obligations [Line Items]
Maximum Exposure	1,130	[5]
Other
Guarantor Obligations [Line Items]
Maximum Exposure	545	[6]
Equity Funding Agreements | Affiliated Entity
Guarantor Obligations [Line Items]
Maximum Exposure	36
Equity Funding Agreements | Minimum | Affiliated Entity
Guarantor Obligations [Line Items]
Maximum annual future contributions	4
Equity Funding Agreements | Maximum | Affiliated Entity
Guarantor Obligations [Line Items]
Maximum annual future contributions	$ 19

[1] Excludes Dominion's guarantee for the construction of the new corporate office property discussed further within Lease Commitments above.

[2] Guarantees related to commodity commitments of certain subsidiaries. These guarantees were provided to counterparties in order to facilitate physical and financial transaction related commodities and services.

[3] Guarantees related to certain DEI subsidiaries' regarding all aspects of running a nuclear facility.

[4] Guarantees related to Cove Point, in support of terminal services, transportation and construction. Cove Point has two guarantees that have no maximum limit and, therefore, are not included in this amount.

[5] Includes guarantees to facilitate the development of solar projects. Also includes guarantees entered into by DEI on behalf of certain subsidiaries to facilitate the acquisition and development of solar projects.

[6] Guarantees related to other miscellaneous contractual obligations such as leases, environmental obligations, construction projects and insurance programs. Due to the uncertainty of worker’s compensation claims, the parental guarantee has no stated limit. Also included are guarantees related to certain DEI subsidiaries' obligations for equity capital contributions and energy generation associated with Fowler Ridge and NedPower. As of December 31, 2016, Dominion's maximum remaining cumulative exposure under these equity funding agreements is $36 million through 2019 and its maximum annual future contributions could range from approximately $4 million to $19 million.