Commitments and Contingencies (Lease Commitments) (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Loss Contingencies [Line Items]
Rental expense	$ 99	$ 92	$ 101
Virginia Electric and Power Company
Loss Contingencies [Line Items]
Rental expense	51	43	42
Dominion Gas Holdings, LLC
Loss Contingencies [Line Items]
Rental expense	$ 37	$ 35	$ 15

Amount of rent expense incurred for leased assets, including but not limited to, furniture and equipment, that is not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

No definition available.

Name:	us-gaap_LeaseAndRentalExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration