Investments (Investments under Equity Method of Accounting) (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Schedule of Equity Method Investments [Line Items]
Investment Balance	$ 1,075	$ 916	[1]
Dominion Gas Holdings, LLC
Schedule of Equity Method Investments [Line Items]
Investment Balance	112	105
Dominion Gas Holdings, LLC | Iroquois
Schedule of Equity Method Investments [Line Items]
Ownership%	24.72%
Investment Balance	$ 112	$ 105

[1] Dominion’s Consolidated Balance Sheet at December 31, 2013 has been derived from the audited Consolidated Financial Statements at that date.