Fair Value Measurements (Net Change in the Assets and Liabilities Measured at Fair Value on a Recurring Basis and Included in the Level 3 Fair Value Category) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Total realized and unrealized gains (losses):
Included in earnings	$ (10)	$ (10)	$ 100	$ 2
The amount of gains (losses) for the period included in earnings attributable to the change in unrealized gains (losses) relating to assets/liabilities still held at the reporting date	0	(4)	1	(11)
Level 3 | Commodity Transactions | Fair Value, Measurements, Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	8	9	(16)	25
Total realized and unrealized gains (losses):
Included in earnings	(10)	(10)	100	2
Included in other comprehensive income (loss)	(1)	26	3	36
Included in regulatory assets/liabilities	(3)	(22)	14	(27)
Settlements	9	(1)	(99)	(26)
Transfers out of Level 3	0	0	1	(8)
Ending balance	3	2	3	2
The amount of gains (losses) for the period included in earnings attributable to the change in unrealized gains (losses) relating to assets/liabilities still held at the reporting date	0	(4)	1	(11)
Level 3 | Virginia Electric and Power Company | Commodity Transactions | Fair Value, Measurements, Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	10	(3)	(7)	2
Total realized and unrealized gains (losses):
Included in earnings	(9)	(7)	111	(4)
Included in regulatory assets/liabilities	(3)	(22)	14	(27)
Settlements	9	7	(111)	4
Ending balance	7	(25)	7	(25)
Level 3 | Dominion Gas Holdings, LLC | Commodity Transactions | Fair Value, Measurements, Recurring
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	(2)	(1)	(6)	(12)
Total realized and unrealized gains (losses):
Included in earnings	(2)	3	(7)	2
Included in other comprehensive income (loss)	(1)	24	3	35
Settlements	2	(3)	7	(2)
Ending balance	$ (3)	$ 23	$ (3)	$ 23