Investments (Investments under Equity Method of Accounting) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Schedule of Equity Method Investments [Line Items]
Investment Balance	$ 1,085	$ 1,081	[1]
Dominion Gas Holdings, LLC
Schedule of Equity Method Investments [Line Items]
Investment Balance	103	107
Dominion Gas Holdings, LLC | Iroquois
Schedule of Equity Method Investments [Line Items]
Ownership%	24.72%
Investment Balance	$ 103	$ 107

[1] Dominion’s Consolidated Balance Sheet at December 31, 2014 has been derived from the audited Consolidated Financial Statements at that date.