Derivatives and Hedge Accounting Activities (Schedule of Offsetting Liabilities) (Details) - USD ($) $ in Millions		Jun. 30, 2017		Dec. 31, 2016
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities		$ 148		$ 153
Gross Amounts Offset in the Consolidated Balance Sheet		0		0
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet		148		153
Total derivatives, not subject to a master netting or similar arrangement		2		2
Gross Amounts of Recognized Liabilities, Total		150		155
Derivative Liabilities		150	[1]	155	[2]
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		66		67
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		0		27
Net Amounts		82		59
Virginia Electric and Power Company
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities		64		23
Gross Amounts Offset in the Consolidated Balance Sheet		0		0
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet		64		23
Total derivatives, not subject to a master netting or similar arrangement		10		8
Gross Amounts of Recognized Liabilities, Total		74		31
Derivative Liabilities	[2]	74		31
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		0		2
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		0		0
Net Amounts		64		21
Dominion Energy Gas Holdings, LLC
Offsetting Liabilities [Line Items]
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet		5		11
Derivative Liabilities		5		11
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		5		0
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		0		0
Net Amounts		0		11
Commodity | Over-the-counter
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities		17		23
Gross Amounts Offset in the Consolidated Balance Sheet		0		0
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet		17		23
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		8		14
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		0		0
Net Amounts		9		9
Commodity | Over-the-counter | Virginia Electric and Power Company
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities		0		2
Gross Amounts Offset in the Consolidated Balance Sheet		0		0
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet		0		2
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		0		2
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		0		0
Net Amounts		0		0
Commodity | Over-the-counter | Dominion Energy Gas Holdings, LLC
Offsetting Liabilities [Line Items]
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet		0		5
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		0		0
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		0		0
Net Amounts		0		5
Commodity | Exchange
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities		42		71
Gross Amounts Offset in the Consolidated Balance Sheet		0		0
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet		42		71
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		42		44
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		0		27
Net Amounts		0		0
Interest rate | Over-the-counter
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities		84		53
Gross Amounts Offset in the Consolidated Balance Sheet		0		0
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet		84		53
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		11		9
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		0		0
Net Amounts		73		44
Interest rate | Over-the-counter | Virginia Electric and Power Company
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities		64		21
Gross Amounts Offset in the Consolidated Balance Sheet		0		0
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet		64		21
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		0		0
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		0		0
Net Amounts		64		21
Foreign currency | Over-the-counter
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities		5		6
Gross Amounts Offset in the Consolidated Balance Sheet		0		0
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet		5		6
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		5		0
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		0		0
Net Amounts		0		6
Foreign currency | Over-the-counter | Dominion Energy Gas Holdings, LLC
Offsetting Liabilities [Line Items]
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet		5		6
Gross Amounts Not Offset in the Consolidated Balance Sheet, Financial Instruments		5		0
Gross Amounts Not Offset in the Consolidated Balance Sheet, Cash Collateral		0		0
Net Amounts		$ 0		$ 6

[1] Noncurrent derivative liabilities are presented in other deferred credits and other liabilities in Dominion Energy’s Consolidated Balance Sheets.

[2] Noncurrent derivative liabilities are presented in other deferred credits and other liabilities in Virginia Power’s Consolidated Balance Sheets.