Derivatives and Hedge Accounting Activities (Selected Information Related to Gains (Losses) on Cash Flow Hedges Included in AOCI) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]
AOCI After-Tax	$ (177)
Amounts Expected to be Reclassified to Earnings during the next 12 Months After-Tax	20
Commodity | Gas Energy Contract
Derivative Instruments, Gain (Loss) [Line Items]
AOCI After-Tax	(5)
Amounts Expected to be Reclassified to Earnings during the next 12 Months After-Tax	(5)
Maximum Term	25 months
Commodity | Electricity Energy Contract
Derivative Instruments, Gain (Loss) [Line Items]
AOCI After-Tax	89
Amounts Expected to be Reclassified to Earnings during the next 12 Months After-Tax	32
Maximum Term	21 months
Commodity | Other Energy Contract
Derivative Instruments, Gain (Loss) [Line Items]
AOCI After-Tax	0
Amounts Expected to be Reclassified to Earnings during the next 12 Months After-Tax	(1)
Maximum Term	14 months
Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
AOCI After-Tax	(261)
Amounts Expected to be Reclassified to Earnings during the next 12 Months After-Tax	(6)
Maximum Term	393 months
Dominion Gas Holdings, LLC
Derivative Instruments, Gain (Loss) [Line Items]
AOCI After-Tax	(24)
Amounts Expected to be Reclassified to Earnings during the next 12 Months After-Tax	0
Dominion Gas Holdings, LLC | Commodity | NGLs
Derivative Instruments, Gain (Loss) [Line Items]
AOCI After-Tax	(1)
Amounts Expected to be Reclassified to Earnings during the next 12 Months After-Tax	0
Maximum Term	12 months
Dominion Gas Holdings, LLC | Interest rate
Derivative Instruments, Gain (Loss) [Line Items]
AOCI After-Tax	(23)
Amounts Expected to be Reclassified to Earnings during the next 12 Months After-Tax	$ 0
Maximum Term	357 months