Derivatives and Hedge Accounting Activities (Schedule of Offsetting Liabilities) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Offsetting Liabilities [Line Items]
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	$ 754	$ 782
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Total derivatives, not subject to a master netting or similar arrangement	11	12
Derivative Liabilities	765	794
Derivative, Collateral, Right to Reclaim Securities	389	348
Derivative, Collateral, Right to Reclaim Cash	38	196
Net Amounts	327	238
Interest rate | Over-the-counter
Offsetting Liabilities [Line Items]
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	307	202
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Derivative, Collateral, Right to Reclaim Securities	18	16
Derivative, Collateral, Right to Reclaim Cash	0	0
Net Amounts	289	186
Commodity | Over-the-counter
Offsetting Liabilities [Line Items]
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	83	87
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Derivative, Collateral, Right to Reclaim Securities	45	34
Derivative, Collateral, Right to Reclaim Cash	0	1
Net Amounts	38	52
Commodity | Exchange
Offsetting Liabilities [Line Items]
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	364	493
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Derivative, Collateral, Right to Reclaim Securities	326	298
Derivative, Collateral, Right to Reclaim Cash	38	195
Net Amounts	0	0
Virginia Electric and Power Company
Offsetting Liabilities [Line Items]
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	133	80
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Total derivatives, not subject to a master netting or similar arrangement	6	7
Derivative Liabilities	139	87
Derivative, Collateral, Right to Reclaim Securities	4	4
Derivative, Collateral, Right to Reclaim Cash	0	0
Net Amounts	129	76
Virginia Electric and Power Company | Interest rate | Over-the-counter
Offsetting Liabilities [Line Items]
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	128	72
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Derivative, Collateral, Right to Reclaim Securities	0	0
Derivative, Collateral, Right to Reclaim Cash	0	0
Net Amounts	128	72
Virginia Electric and Power Company | Commodity | Over-the-counter
Offsetting Liabilities [Line Items]
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	5	8
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Derivative, Collateral, Right to Reclaim Securities	4	4
Derivative, Collateral, Right to Reclaim Cash	0	0
Net Amounts	1	4
Dominion Gas Holdings, LLC
Offsetting Liabilities [Line Items]
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	16	9
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Derivative, Collateral, Right to Reclaim Securities	3	0
Derivative, Collateral, Right to Reclaim Cash	0	0
Net Amounts	13	9
Dominion Gas Holdings, LLC | Interest rate | Over-the-counter
Offsetting Liabilities [Line Items]
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	13	9
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Derivative, Collateral, Right to Reclaim Securities	0	0
Derivative, Collateral, Right to Reclaim Cash	0	0
Net Amounts	13	9
Dominion Gas Holdings, LLC | Commodity | Over-the-counter
Offsetting Liabilities [Line Items]
Net Amounts of Liabilities Presented in the Consolidated Balance Sheet	3	0
Gross Amounts Offset in the Consolidated Balance Sheet	0	0
Derivative, Collateral, Right to Reclaim Securities	3	0
Derivative, Collateral, Right to Reclaim Cash	0	0
Net Amounts	$ 0	$ 0