Accumulated Other Comprehensive Income (Schedule of Changes in AOCI by Component Net of Tax) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	$ (317)		$ (483)		$ (324)	[1]	$ (877)
Other comprehensive income before reclassifications: gains (losses)	(56)		(51)		(192)		290
Amounts reclassified from AOCI: (gains) losses	(44)	[2]	(2)	[2]	99	[2]	51	[2]
Total other comprehensive income (loss)	(100)		(53)		(93)		341
Ending balance	(417)		(536)		(417)		(536)
Dominion Gas Holdings, LLC
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(75)		(55)		(58)	[3],[4]	(140)
Other comprehensive income before reclassifications: gains (losses)	(7)		(21)		(33)		58
Amounts reclassified from AOCI: (gains) losses	5	[2]	4	[2]	14	[2]	10	[2]
Total other comprehensive income (loss)	(2)		(17)		(19)		68
Ending balance	(77)	[3]	(72)		(77)	[3]	(72)
Deferred gains and losses on derivatives-hedging activities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(353)		(31)		(288)		(122)
Other comprehensive income before reclassifications: gains (losses)	(58)		(77)		(267)		(45)
Amounts reclassified from AOCI: (gains) losses	(31)	[2]	(6)	[2]	113	[2]	53	[2]
Total other comprehensive income (loss)	(89)		(83)		(154)		8
Ending balance	(442)		(114)		(442)		(114)
Deferred gains and losses on derivatives-hedging activities | Dominion Gas Holdings, LLC
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(16)		22		3		(47)
Other comprehensive income before reclassifications: gains (losses)	(7)		(21)		(33)		45
Amounts reclassified from AOCI: (gains) losses	4	[2]	3	[2]	11	[2]	6	[2]
Total other comprehensive income (loss)	(3)		(18)		(22)		51
Ending balance	(19)		4		(19)		4
Unrealized gains and losses on investment securities
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	534		371		474		326
Other comprehensive income before reclassifications: gains (losses)	2		38		80		119
Amounts reclassified from AOCI: (gains) losses	(21)	[2]	(10)	[2]	(39)	[2]	(46)	[2]
Total other comprehensive income (loss)	(19)		28		41		73
Ending balance	515		399		515		399
Unrecognized pension and other postretirement benefit costs
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(493)		(823)		(510)		(1,081)
Other comprehensive income before reclassifications: gains (losses)	0		(12)		0		216
Amounts reclassified from AOCI: (gains) losses	8	[2]	14	[2]	25	[2]	44	[2]
Total other comprehensive income (loss)	8		2		25		260
Ending balance	(485)		(821)		(485)		(821)
Unrecognized pension and other postretirement benefit costs | Dominion Gas Holdings, LLC
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(59)		(77)		(61)		(93)
Other comprehensive income before reclassifications: gains (losses)	0		0		0		13
Amounts reclassified from AOCI: (gains) losses	1	[2]	1	[2]	3	[2]	4	[2]
Total other comprehensive income (loss)	1		1		3		17
Ending balance	(58)		(76)		(58)		(76)
Other comprehensive income (loss) from equity method investee
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning balance	(5)		0		0		0
Other comprehensive income before reclassifications: gains (losses)	0		0		(5)		0
Amounts reclassified from AOCI: (gains) losses	0	[2]	0	[2]	0	[2]	0	[2]
Total other comprehensive income (loss)	0		0		(5)		0
Ending balance	$ (5)		$ 0		$ (5)		$ 0

[1] Dominion’s Consolidated Balance Sheet at December 31, 2013 has been derived from the audited Consolidated Financial Statements at that date.

[2] See table below for details about these reclassifications.

[3] See Note 17 for amounts attributable to related parties.

[4] Dominion Gas’ Consolidated Balance Sheet at December 31, 2013 has been derived from the audited Consolidated Financial Statements at that date.