Regulatory Matters (Narrative) (Details)	1 Months Ended												3 Months Ended	6 Months Ended
	Jul. 31, 2015 USD ($)	Jun. 30, 2015 USD ($)	May. 31, 2015 USD ($)	Apr. 30, 2015 kV	Oct. 31, 2014 USD ($)	Apr. 30, 2014	Dec. 31, 2012	May. 31, 2012 USD ($)	Mar. 31, 2010 USD ($)	Aug. 31, 2009 kV	Apr. 30, 2008	Apr. 30, 2007 kV	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) Power_Station	Dec. 31, 2014 USD ($)	Jun. 30, 2014 USD ($)
Regulatory Matters [Line Items]
Charge associated with North Anna and offshore wind legislation														$ 0		$ 287,000,000
Virginia Electric and Power Company
Regulatory Matters [Line Items]
ROE (percentage)											11.40%
Costs claimed to be unjust and excluded from transmission formula rate									$ 223,000,000
Potential settlement required annual payment for 10 Years								$ 250,000
Period for annual settlement payment								10 years
Facility operating capacity (kV) | kV										500		500
Charge associated with North Anna and offshore wind legislation														$ 0		$ 287,000,000
Virginia Electric and Power Company | Virginia Regulation | North Anna Power Station
Regulatory Matters [Line Items]
Percentage of costs previously deferred						70.00%
Virginia Electric and Power Company | Virginia Regulation | North Anna Power Station | Other Operations and Maintenance Expense | Virginia legislation
Regulatory Matters [Line Items]
Charge associated with North Anna and offshore wind legislation													$ 287,000,000		$ 87,000,000
Amount of expense, after tax													$ 191,000,000		$ 57,000,000
Virginia Electric and Power Company | Virginia Regulation | Surry to Skiffes Creek Transmission Line
Regulatory Matters [Line Items]
Capacity of kV overhead transmission line | kV				500
Virginia Electric and Power Company | Virginia Regulation | Rider T1
Regulatory Matters [Line Items]
Projected revenue requirement			$ 668,000,000
Proposed revenue requirement, amount of increase (decrease)			130,000,000
Revised revenue requirement			$ 96,000,000
Percentage reduction of rate impact on residential customers			50.00%
Duration of rate impact			1 year
Virginia Electric and Power Company | Virginia Regulation | Rider S
Regulatory Matters [Line Items]
Projected revenue requirement		$ 250,000,000
Proposed revenue requirement, amount of increase (decrease)		5,000,000
Virginia Electric and Power Company | Virginia Regulation | Rider W
Regulatory Matters [Line Items]
Projected revenue requirement		118,000,000
Proposed revenue requirement, amount of increase (decrease)		(17,000,000)
Virginia Electric and Power Company | Virginia Regulation | Rider R
Regulatory Matters [Line Items]
Projected revenue requirement		74,000,000
Proposed revenue requirement, amount of increase (decrease)		(10,000,000)
Virginia Electric and Power Company | Virginia Regulation | Rider B
Regulatory Matters [Line Items]
Projected revenue requirement		30,000,000
Proposed revenue requirement, amount of increase (decrease)		$ 21,000,000
Number of power stations converted to biomass | Power_Station														3
Virginia Electric and Power Company | Virginia Regulation | Rider U
Regulatory Matters [Line Items]
Projected revenue requirement					$ 28,000,000
Revised revenue requirement			$ 24,000,000
Virginia Electric and Power Company | North Carolina Regulation
Regulatory Matters [Line Items]
ROE (percentage)							10.20%
Virginia Electric and Power Company | North Carolina Regulation | Subsequent Event
Regulatory Matters [Line Items]
ROE (percentage)	10.20%
East Ohio | Ohio Regulation | Subsequent Event | PIPP Rider
Regulatory Matters [Line Items]
Over-recovery of accumulated arrearages	$ 57,000,000
Deferred program costs	35,000,000
East Ohio | Ohio Regulation | Subsequent Event | UEX Rider
Regulatory Matters [Line Items]
Accumulated bad debt expense	14,000,000
Recovery of prospective net bad debt expense	$ 20,000,000