Commitments and Contingencies (Nuclear Operations) (Narrative) (Details) (USD $)	12 Months Ended			1 Months Ended		3 Months Ended			12 Months Ended				1 Months Ended
	Dec. 31, 2012	Dec. 31, 2012 Spent Nuclear Fuel	Dec. 31, 2011 Spent Nuclear Fuel	Sep. 30, 2012 Millstone	Sep. 30, 2012 Kewaunee	Dec. 31, 2012 Kewaunee Minimum	Dec. 31, 2012 Kewaunee Maximum	Feb. 01, 2013 Kewaunee Subsequent Event	Dec. 31, 2012 Nuclear Plant	Dec. 31, 2012 Virginia Electric and Power Company	Dec. 31, 2012 Virginia Electric and Power Company Spent Nuclear Fuel	Dec. 31, 2011 Virginia Electric and Power Company Spent Nuclear Fuel	Nov. 30, 2012 Virginia Electric and Power Company Surry and North Anna
Loss Contingencies [Line Items]
Minimum financial assurance	$ 3,300,000,000									$ 1,800,000,000
Liability protection under Price-Anderson Act									12,600,000,000
Amount of coverage purchased from commercial insurance pools	375,000,000
Amount that could be assessed for each licensed reactor	118,000,000
Amount that could be assessed for each licensed reactor per reactor	18,000,000
Coverage that exceeds NRC minimum requirement	1,060,000,000
Maximum assessment for premiums on insurance policy	89,000,000									48,000,000
Maximum assessment for insurance policy	33,000,000					33,000,000	30,000,000			20,000,000
Property insurance coverage								1,800,000,000
Payments for legal settlements				20,000,000	6,000,000								75,000,000
Receviables for spent nuclear fuel related costs		$ 36,000,000	$ 102,000,000								$ 26,000,000	$ 76,000,000