Income Taxes (Reconciliation of Income Taxes at the U.S. Statutory Federal Rate as Compared to the Income Tax Expense Recorded in Our Consolidated Statements of Income) (Details)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Operating Loss Carryforwards [Line Items]
U.S. statutory rate	35.00%	35.00%
Increases (reductions) resulting from:
State taxes, net of federal benefit	2.70%	4.00%
Investment and production tax credits	(4.20%)	(1.50%)
AFUDC - equity	(0.30%)	(0.70%)
Other, net	(0.50%)	(0.30%)
Effective tax rate	32.70%	36.50%
Virginia Electric and Power Company
Operating Loss Carryforwards [Line Items]
U.S. statutory rate	35.00%	35.00%
Increases (reductions) resulting from:
State taxes, net of federal benefit	3.80%	3.90%
Investment and production tax credits	(0.80%)	0.00%
AFUDC - equity	(0.30%)	(1.30%)
Other, net	0.10%	0.20%
Effective tax rate	37.80%	37.80%