Variable Interest Entities (Narrative) (Details) (USD $)	12 Months Ended			1 Months Ended	110 Months Ended		12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Aug. 31, 2013 Juniper	Aug. 31, 2013 Juniper	Oct. 31, 2011 Juniper	Dec. 31, 2013 Virginia Electric and Power Company MW	Dec. 31, 2012 Virginia Electric and Power Company	Dec. 31, 2011 Virginia Electric and Power Company
Variable Interest Entity [Line Items]
Aggregate generation capacity from long-term power and capacity contracts (MW)							870
Contracts exprity date start range							2015
Contracts exprity date end range							2021
Remaining purchase commitments							$ 900,000,000
Payment for electric capacity							217,000,000	214,000,000	211,000,000
Payment for electric energy							98,000,000	83,000,000	125,000,000
Shared services purchased							331,000,000	328,000,000	389,000,000
Annual lease payments					53,000,000
Fair value of property plant and equipment						957,000,000
Amount of debt expected to be recorded from consolidation						896,000,000
Amount of non-controlling interest expected to be recorded from consolidation						61,000,000
Acquisition of Juniper noncontrolling interest in Fairless	$ 923,000,000	$ 0	$ 0	$ 923,000,000