Commitments and Contingencies (Guarantees, Surety Bonds and Letters of Credit) (Details) $ in Millions	6 Months Ended
	Jun. 30, 2017 USD ($)
Guarantor Obligations [Line Items]
Maximum Exposure	$ 5,658	[1]
Nuclear Obligations
Guarantor Obligations [Line Items]
Maximum Exposure	227	[2]
Commodity Transactions
Guarantor Obligations [Line Items]
Maximum Exposure	1,934	[3]
Cove Point
Guarantor Obligations [Line Items]
Maximum Exposure	1,900	[4]
Financial Guarantee | Equity Method Investees
Guarantor Obligations [Line Items]
Maximum Exposure	48
Financial Guarantee | Affiliate
Guarantor Obligations [Line Items]
Maximum Exposure	26
Financial Guarantee | Affiliate | Minimum
Guarantor Obligations [Line Items]
Maximum annual future contributions	4
Financial Guarantee | Affiliate | Maximum
Guarantor Obligations [Line Items]
Maximum annual future contributions	19
Solar
Guarantor Obligations [Line Items]
Maximum Exposure	1,054	[5]
Other
Guarantor Obligations [Line Items]
Maximum Exposure	543	[6]
Surety Bond
Guarantor Obligations [Line Items]
Maximum Exposure	140
Surety Bond | Virginia Electric and Power Company
Guarantor Obligations [Line Items]
Maximum Exposure	63
Surety Bond | Dominion Energy Gas Holdings, LLC
Guarantor Obligations [Line Items]
Maximum Exposure	22
Letters of Credit by Financial Institutions
Guarantor Obligations [Line Items]
Maximum Exposure	$ 72

[1] Excludes Dominion Energy's guarantee for the construction of a new corporate office property as discussed in Note 22 to the Consolidated Financial Statements in the Companies' Annual Report on Form 10-K for the year ended December 31, 2016.

[2] Guarantees related to certain DGI subsidiaries regarding all aspects of running a nuclear facility.

[3] 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.

[4] Guarantees related to Cove Point, in support of terminal services, transportation and construction.

[5] Includes guarantees to facilitate the development of solar projects. Also includes guarantees entered into by DGI 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 workers’ compensation claims, the parental guarantee has no stated limit. Also included are guarantees related to certain DGI subsidiaries' obligations for equity capital contributions and energy generation associated with Fowler Ridge and NedPower. As of June 30, 2017, Dominion Energy's maximum remaining cumulative exposure under these equity funding agreements is $26 million through 2019 and its maximum annual future contributions could range from approximately $4 million to $19 million.