Goodwill and Intangible Assets (Goodwill) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015
Goodwill [Roll Forward]
Goodwill, Beginning Balance	[1]	$ 3,294	$ 3,044
Goodwill, Ending Balance	[1]	6,399	3,294
DCG
Goodwill [Roll Forward]
Acquisition			250
Dominion Questar Corporation
Goodwill [Roll Forward]
Acquisition		3,105
Operating Segments | Dominion Generation
Goodwill [Roll Forward]
Goodwill, Beginning Balance	[1]	1,422	1,422	[2]
Goodwill, Ending Balance	[1]	1,422	1,422
Operating Segments | Dominion Generation | DCG
Goodwill [Roll Forward]
Acquisition			0
Operating Segments | Dominion Generation | Dominion Questar Corporation
Goodwill [Roll Forward]
Acquisition		0
Operating Segments | Dominion Energy
Goodwill [Roll Forward]
Goodwill, Beginning Balance	[1]	946	696	[2]
Goodwill, Ending Balance	[1]	4,051	946
Operating Segments | Dominion Energy | DCG
Goodwill [Roll Forward]
Acquisition	[3]		250
Operating Segments | Dominion Energy | Dominion Questar Corporation
Goodwill [Roll Forward]
Acquisition	[3]	3,105
Operating Segments | DVP
Goodwill [Roll Forward]
Goodwill, Beginning Balance	[1]	926	926
Goodwill, Ending Balance	[1]	926	926
Operating Segments | DVP | DCG
Goodwill [Roll Forward]
Acquisition			0
Operating Segments | DVP | Dominion Questar Corporation
Goodwill [Roll Forward]
Acquisition		0
Operating Segments | Corporate and Other
Goodwill [Roll Forward]
Goodwill, Beginning Balance	[1],[4]	0	0
Goodwill, Ending Balance	[1],[4]	0	0
Operating Segments | Corporate and Other | DCG
Goodwill [Roll Forward]
Acquisition	[4]		0
Operating Segments | Corporate and Other | Dominion Questar Corporation
Goodwill [Roll Forward]
Acquisition	[4]	0
Dominion Gas Holdings, LLC
Goodwill [Roll Forward]
Goodwill, Beginning Balance	[1]	542	542
No events affecting goodwill		0	0
Goodwill, Ending Balance	[1]	542	542
Dominion Gas Holdings, LLC | Operating Segments | Dominion Generation
Goodwill [Roll Forward]
Goodwill, Beginning Balance	[1]	0	0
No events affecting goodwill		0	0
Goodwill, Ending Balance	[1]	0	0
Dominion Gas Holdings, LLC | Operating Segments | Dominion Energy
Goodwill [Roll Forward]
Goodwill, Beginning Balance	[1]	542	542
No events affecting goodwill		0	0
Goodwill, Ending Balance	[1]	542	542
Dominion Gas Holdings, LLC | Operating Segments | DVP
Goodwill [Roll Forward]
Goodwill, Beginning Balance	[1]	0	0
No events affecting goodwill		0	0
Goodwill, Ending Balance	[1]	0	0
Dominion Gas Holdings, LLC | Operating Segments | Corporate and Other
Goodwill [Roll Forward]
Goodwill, Beginning Balance	[1],[4]	0	0
No events affecting goodwill	[4]	0	0
Goodwill, Ending Balance	[1],[4]	$ 0	$ 0

[1] Goodwill amounts do not contain any accumulated impairment losses.

[2] Recast to reflect nonregulated retail energy marketing operations in the Dominion Energy segment.

[3] See Note 3 for discussion of Dominion's acquisitions.

[4] Goodwill recorded at the Corporate and Other segment is allocated to the primary operating segments for goodwill impairment testing purposes.