Income Taxes (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Operating Loss Carryforwards [Line Items]
Deferred tax liabilities classified as current representing cumulative adjustments from tax accounting method changes	$ 17
Operating loss carryforward		195	51
Unrecognized tax benefits that would impact effective tax rate	126	167	184
Change in unrecognized tax benefits	29	1	(51)
Decrease of unrecognized tax benefits	2	4	0
Federal
Operating Loss Carryforwards [Line Items]
Operating loss carryforward	1,200
Investment tax credit	58
Tax credits	45
Payment after conclusion of audit	46
Federal | Scenario, Forecast
Operating Loss Carryforwards [Line Items]
Decrease of unrecognized tax benefits	115
Earnings increase as a result of tax settlement	65
State
Operating Loss Carryforwards [Line Items]
Operating loss carryforward	1,500
Carryforwards valuation allowance	763
General Business | State
Operating Loss Carryforwards [Line Items]
Tax credits	133
Investment Credit That Expires In 2014 | State
Operating Loss Carryforwards [Line Items]
Tax credits	7
Fairless | State
Operating Loss Carryforwards [Line Items]
Reduction of valuation allowance		20
Virginia Electric and Power Company
Operating Loss Carryforwards [Line Items]
Unrecognized tax benefits that would impact effective tax rate	8	13	20
Change in unrecognized tax benefits	(4)	(1)	(6)
Decrease of unrecognized tax benefits	2	4	0
Virginia Electric and Power Company | Federal
Operating Loss Carryforwards [Line Items]
Operating loss carryforward	282
Tax credits	5
Virginia Electric and Power Company | Federal | Scenario, Forecast
Operating Loss Carryforwards [Line Items]
Decrease of unrecognized tax benefits	25
Earnings increase as a result of tax settlement	7
Virginia Electric and Power Company | State
Operating Loss Carryforwards [Line Items]
Operating loss carryforward	$ 2