Property, Plant and Equipment (Share of Jointly-Owned Power Stations) (Details) $ in Millions	Dec. 31, 2016 USD ($)
Millstone Unit 3
Jointly Owned Utility Plant Interests [Line Items]
Ownership interest (percentage)	93.50%	[1]
Plant in service	$ 1,190	[1]
Accumulated depreciation	(349)	[1]
Nuclear fuel	469	[1]
Accumulated amortization of nuclear fuel	(366)	[1]
Plant under construction	$ 51	[1]
Virginia Electric and Power Company | Bath County Pumped Storage Station
Jointly Owned Utility Plant Interests [Line Items]
Ownership interest (percentage)	60.00%	[2]
Plant in service	$ 1,052	[2]
Accumulated depreciation	(585)	[2]
Nuclear fuel	0	[2]
Accumulated amortization of nuclear fuel	0	[2]
Plant under construction	$ 8	[2]
Virginia Electric and Power Company | North Anna
Jointly Owned Utility Plant Interests [Line Items]
Ownership interest (percentage)	88.40%	[2]
Plant in service	$ 2,520	[2]
Accumulated depreciation	(1,210)	[2]
Nuclear fuel	718	[2]
Accumulated amortization of nuclear fuel	(549)	[2]
Plant under construction	$ 69	[2]
Virginia Electric and Power Company | Clover Power Station
Jointly Owned Utility Plant Interests [Line Items]
Ownership interest (percentage)	50.00%	[2]
Plant in service	$ 586	[2]
Accumulated depreciation	(219)	[2]
Nuclear fuel	0	[2]
Accumulated amortization of nuclear fuel	0	[2]
Plant under construction	$ 4	[2]

[1] Unit jointly owned by Dominion.

[2] Units jointly owned by Virginia Power.