Regulatory Matters (Narrative) (Details) (Virginia Electric and Power Company, USD $)	1 Months Ended	9 Months Ended		1 Months Ended
	Mar. 31, 2010	Sep. 30, 2012	Sep. 30, 2012 Minimum	Sep. 30, 2012 Virginia Regulation	Aug. 31, 2012 Virginia Regulation Rider T1	Aug. 31, 2012 Virginia Regulation Riders C1A And C2A DSM_Programs	Aug. 31, 2012 Virginia Regulation Riders C1A And C2A Air Conditioner Cycling Program	Aug. 31, 2012 Virginia Regulation Riders C1A And C2A Low Income Program	Aug. 31, 2012 Virginia Regulation Bremo Power Station MW	Sep. 30, 2012 North Carolina Regulation	Aug. 31, 2012 North Carolina Regulation
Regulatory Matters [Line Items]
Authorized ROE		11.40%
Incentive for 4 electric transmission enhancement projects		1.50%
Incentive for 7 electric transmission enhancement projects		1.25%
Costs claimed to be unjust and excluded from transmission formula rate	$ 223,000,000
Potential settlement required annual payment for 10 Years		250,000
Liability due to change in estimate of future billing adjustments			33,000,000
Proposed annual fuel revenue decrease				389,000,000							27,000,000
Proposed decrease revenue requirement					100,000,000
Number of demand side management programs approved						2
Period for demand side management programs							5 years	2 years
Capacity preserved from converting units from coal to natural gas									227
Proposed non fuel revenue increase										$ 24,000,000	$ 53,000,000