Regulatory Matters (Narrative) (Details) (USD $)	1 Months Ended						12 Months Ended
	May 31, 2012	Mar. 31, 2010	Apr. 30, 2008	Mar. 31, 2015	Feb. 28, 2015	Apr. 30, 2015 kV	Dec. 31, 2014	Dec. 31, 2018	Dec. 31, 2017
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
Virginia Electric and Power Company | Virginia Regulation
Regulatory Matters [Line Items]
Percentage ROE for combined test periods				10.13%
Jurisdictional projected fuel expenses					1,600,000,000
Approved decrease amount					512,000,000
Virginia Electric and Power Company | Virginia Regulation | Subsequent Event | Surry Switching Station Transmission Line
Regulatory Matters [Line Items]
Kilo Volt Line						500
Virginia Electric and Power Company | Virginia Regulation | Deferred Fuel Costs
Regulatory Matters [Line Items]
Percentage of deferred fuel costs written off							50.00%
Virginia Electric and Power Company | Virginia Regulation | Deferred Fuel Costs | Electric fuel and other energy-related purchases
Regulatory Matters [Line Items]
Write off of deferred fuel balances							85,000,000
Write off of deferred fuel balances, net of tax							52,000,000
Virginia Electric and Power Company | Virginia Regulation | Rider S
Regulatory Matters [Line Items]
Approved revenue requirement				245,000,000
Virginia Electric and Power Company | Virginia Regulation | Rider BW | Subsequent Event
Regulatory Matters [Line Items]
Approved revenue requirement						111,000,000
Virginia Electric and Power Company | Virginia Regulation | Rider R
Regulatory Matters [Line Items]
Approved revenue requirement				84,000,000
Virginia Electric and Power Company | Virginia Regulation | Riders C1A and C2A | Subsequent Event
Regulatory Matters [Line Items]
Approved decrease amount						7,000,000
Approved revenue requirement						37,000,000
Number of new energy efficiency programs						2
Term of energy efficiency programs						3 years
Combined cost cap of new energy efficiency programs						20,000,000
Virginia Electric and Power Company | Virginia Regulation | Rider B
Regulatory Matters [Line Items]
Approved revenue requirement				9,000,000
Number of power stations converted to biomass				3
East Ohio | Ohio Regulation | PIR Program
Regulatory Matters [Line Items]
Extension period of PIR program				5 years
Total annual investment				200,000,000
Percentage of capital investment increases				3.00%
Gross plant investment					155,000,000
Cumulative gross plant investment					829,000,000
Revenue requirement					108,000,000
East Ohio | Ohio Regulation | PIR Program | Scenario, Forecast
Regulatory Matters [Line Items]
Amount of investment increase								20,000,000	20,000,000
East Ohio | Ohio Regulation | AMR Program
Regulatory Matters [Line Items]
Projected revenue requirement					$ 8,000,000