Variable Interest Entities (Narrative) (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) MW generator	Jun. 30, 2014 USD ($)
Virginia Electric and Power Company
Variable Interest Entities [Line Items]
Long term capacity contract non utility generators (generators) | generator			5
Aggregate generation capacity from long-term power and capacity contracts (MW) | MW			870
Remaining purchase commitments			$ 530
Payment for electric capacity	$ 56	$ 55	108	$ 111
Payment for electric energy	23	33	60	87
Shared services purchased	83	106	$ 166	214
Virginia Electric and Power Company | Minimum
Variable Interest Entities [Line Items]
Contracts expiry date start range			2015
Virginia Electric and Power Company | Maximum
Variable Interest Entities [Line Items]
Contracts expiry date start range			2021
Dominion Gas Holdings, LLC
Variable Interest Entities [Line Items]
Shared services purchased	$ 30	$ 26	$ 58	$ 52