Variable Interest Entities (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Shared Services Purchased	$ 389,000,000	$ 465,000,000	$ 416,000,000
Annual Lease Payments	53,000,000
Option Price To Purchase Generating Facility At End Of Lease	923,000,000
Percent Of Original Project Cost Responsible For If Facility Is Sold And Proceeds Are Less Than Original Construction Cost	70.75%
Amount Of Property Plant And Equipment Expected To Be Recorded From Consolidation	957,000,000
Amount Of Debt Expected To Be Recorded From Consolidation	896,000,000
Amount Of Non Controlling Interest Expected To Be Recorded From Consolidation	61,000,000
Virginia Power [Member]
Aggregate generation capacity from long-term power and capacity contracts (MW)	870
Contracts Exprity Date Start Range	2015
Contracts Exprity Date End Range	2021
Remaining purchase commitments	1,300,000,000
Payment for electric capacity	211,000,000	213,000,000	210,000,000
Payment for electric energy	$ 125,000,000	$ 164,000,000	$ 117,000,000