Asset Retirement Obligations (Changes to AROs) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015		Dec. 31, 2014
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
AROs, Beginning balance		$ 1,714	[1]	$ 1,578
Obligations incurred during the period		315	[2]	40
Obligations settled during the period		(106)		(82)
Revisions in estimated cash flows		88	[2]	102	[3]
Accretion		93		81
Other		(1)		(5)
AROs , Ending balance	[1]	2,103		1,714
Asset retirement obligations, non current		1,887		1,633
Current Liabilities
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset retirement obligation, current		216		81
Virginia Electric and Power Company
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
AROs, Beginning balance		855		689
Obligations incurred during the period		289	[2]	28
Obligations settled during the period		(39)		(1)
Revisions in estimated cash flows		92	[2]	108	[3]
Accretion		50		37
Other				(6)
AROs , Ending balance		1,247		855
Asset retirement obligation, current		143		7
Asset retirement obligations, non current		1,104		848
Dominion Gas Holdings, LLC
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
AROs, Beginning balance		147	[4]	137
Obligations incurred during the period		5		2
Obligations settled during the period		(6)		(8)
Revisions in estimated cash flows		(5)
Accretion		9		8
Other		(1)		8
AROs , Ending balance	[4]	149		147
Dominion Gas Holdings, LLC | Other Deferred Credits and Other Liabilities
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset retirement obligations, non current		$ 137		$ 140

[1] Includes $81 million and $216 million reported in other current liabilities at December 31, 2014, and 2015, respectively.

[2] Primarily reflects future ash pond and landfill closure costs at certain utility generation facilities. See Note 22 for further information.

[3] Relates primarily to a shift of the delayed planned date on which the DOE is expected to begin accepting spent nuclear fuel.

[4] Includes $140 million and $137 million reported in other deferred credits and other liabilities, with the remainder recorded in other current liabilities, at December 31, 2014 and 2015, respectively.