Commitments and Contingencies (Lease Commitments) (Narrative) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Loss Contingencies [Line Items]
Rental expense	$ 92	$ 101	$ 112
Virginia Electric and Power Company
Loss Contingencies [Line Items]
Rental expense	43	42	48
Dominion Gas Holdings, LLC
Loss Contingencies [Line Items]
Rental expense	$ 35	$ 15	$ 15