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, 2015	Mar. 31, 2014
Operating Loss Carryforwards [Line Items]
U.S. statutory rate	35.00%	35.00%
Increases (reductions) resulting from:
State taxes, net of federal benefit	2.90%	2.70%
Investment tax credits	(0.80%)	(3.60%)
Production tax credits	(0.80%)	(0.60%)
Other, net	(0.60%)	(0.80%)
Effective tax rate	35.70%	32.70%
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%	3.80%
Investment tax credits	0.00%	0.00%
Production tax credits	(0.40%)	(0.80%)
Other, net	(0.70%)	(0.20%)
Effective tax rate	37.70%	37.80%
Dominion Gas Holdings, LLC
Operating Loss Carryforwards [Line Items]
U.S. statutory rate	35.00%	35.00%
Increases (reductions) resulting from:
State taxes, net of federal benefit	4.00%	3.40%
Investment tax credits	0.00%	0.00%
Production tax credits	0.00%	0.00%
Other, net	(0.10%)	0.30%
Effective tax rate	38.90%	38.70%