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)	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
Operating Loss Carryforwards [Line Items]
U.S. statutory rate	35.00%	35.00%
Increases (reductions) resulting from:
State taxes, net of federal benefit	1.90%	4.10%
Investment and production tax credits	(1.50%)	(0.50%)
Valuation allowances	0.00%	(1.80%)
AFUDC - equity	(0.80%)	(0.70%)
Other, net	(0.50%)	(1.10%)
Effective tax rate	34.10%	35.00%
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	2.60%	3.90%
Investment and production tax credits	0.00%	0.00%
Valuation allowances	0.00%	0.00%
AFUDC - equity	(1.40%)	(1.10%)
Other, net	0.20%	0.10%
Effective tax rate	36.40%	37.90%