Variable Interest Entities (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Payment for electric capacity	$ 109,000,000	$ 116,000,000	$ 344,000,000	$ 333,000,000
Shared Services Purchased	100,000,000	104,000,000	292,000,000	352,000,000
Option Price To Purchase Generating Facility At End Of Lease			898,000,000
Percentage Of Appraised Value In Excess Of Construction Cost Added To Purchase Price Of Generating Facility			51.00%
Amount Of Property Plant And Equipment Expected To Be Recorded From Consolidation	1,000,000,000
Amount Of Debt Expected To Be Recorded From Consolidation	900,000,000
Amount Of Non Controlling Interest Expected To Be Recorded From Consolidation	100,000,000
Virginia Power [Member]
Aggregate generation capacity from long-term power and capacity contracts (MW)			870
Contracts expiry date start range			2015
Contract expiry date end range			2021
Remaining purchase commitments			1,400,000,000
Payment for electric capacity	52,000,000	53,000,000	156,000,000	160,000,000
Payment for electric energy	$ 38,000,000	$ 46,000,000	$ 103,000,000	$ 120,000,000