Variable Interest Entities (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015 MW generator	Mar. 31, 2014
Virginia Electric and Power Company
Variable Interest Entities [Line Items]
Long term capacity contract non utility generators (generators)	5
Aggregate generation capacity from long-term power and capacity contracts (MW)	870
Remaining purchase commitments	$ 585
Payment for electric capacity	53	56
Payment for electric energy	37	54
Shared services purchased	83	28
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	$ 83	$ 26