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, 2013	Mar. 31, 2012
U.S. statutory rate	35.00%	35.00%
Increases (reductions) resulting from:
State taxes, net of federal benefit	4.00%	4.00%
Investment and production tax credits	(1.50%)	(0.50%)
Valuation allowances	0.10%	(2.60%)
AFUDC - equity	(0.70%)	(0.70%)
Other, net	(0.40%)	(0.70%)
Effective tax rate	36.50%	34.50%
Virginia Electric and Power Company
U.S. statutory rate	35.00%	35.00%
Increases (reductions) resulting from:
State taxes, net of federal benefit	3.90%	3.90%
Investment and production tax credits	0.00%	0.00%
Valuation allowances	0.00%	0.00%
AFUDC - equity	(1.30%)	(0.90%)
Other, net	0.20%	(0.20%)
Effective tax rate	37.80%	37.80%