Investments (Investments Under Equity Method of Accounting) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011
Schedule of Equity Method Investments [Line Items]
Investment Balance	$ 558		$ 553
Commitment to invest in clean power and technology	50
Fowler I Holdings LLC
Schedule of Equity Method Investments [Line Items]
Ownership%	50.00%
Investment Balance	158		166
Description	Wind-powered merchant generation facility
NedPower Mount Storm LLC
Schedule of Equity Method Investments [Line Items]
Ownership%	50.00%
Investment Balance	137		146
Description	Wind-powered merchant generation facility
Elwood Energy LLC
Schedule of Equity Method Investments [Line Items]
Ownership%	50.00%
Investment Balance	117		108
Description	Natural gas-fired merchant generation peaking facility
Iroquois Gas Transmission System, LP
Schedule of Equity Method Investments [Line Items]
Ownership%	24.72%
Investment Balance	102		104
Description	Gas transmission system
Blue Racer Midstream LLC
Schedule of Equity Method Investments [Line Items]
Ownership%	50.00%
Investment Balance	39		0
Description	Midstream gas and related services
Other
Schedule of Equity Method Investments [Line Items]
Investment Balance	$ 5	[1]	$ 29	[1]

[1] Dominion has a $50 million commitment to invest in clean power and technology businesses through 2018.