Equity (Schedule of Reclassifications out of Accumulated Other Comprehensive Income) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Operating Revenue	$ 2,943	$ 3,050	$ 2,813	$ 3,630	$ 3,185	$ 3,432	$ 2,980	$ 3,523	$ 12,436		$ 13,120		$ 12,835
Purchased gas									1,355		1,331		1,177
Electric fuel and other energy-related purchases									3,400		3,885		3,645
Interest and related charges									1,193		877		816
Income from continuing operations including noncontrolling interests before income taxes									1,778		2,704		2,265
Income tax expense									(452)		(892)		(811)
Income from continuing operations including noncontrolling interests									1,326		1,812		1,454
Other income									250		265		223
Impairment									13		8		14
Deferred gains and losses on derivatives-hedging activities | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income from continuing operations including noncontrolling interests before income taxes									152		130
Income tax expense									(59)		(53)
Income from continuing operations including noncontrolling interests									93		77
Unrealized gains and losses on investment securities | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income from continuing operations including noncontrolling interests before income taxes									(87)		(90)
Income tax expense									33		35
Income from continuing operations including noncontrolling interests									(54)		(55)
Other income									(100)		(98)
Impairment									13		8
Unrecognized pension and other postretirement benefit costs | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income from continuing operations including noncontrolling interests before income taxes									57		94
Income tax expense									(24)		(39)
Income from continuing operations including noncontrolling interests									33		55
Prior-service costs (credits)									(12)		(8)
Actuarial losses									69		102
Commodity | Deferred gains and losses on derivatives-hedging activities | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Operating Revenue									130		58
Purchased gas									13		47
Electric fuel and other energy-related purchases									(7)		10
Interest rate | Deferred gains and losses on derivatives-hedging activities | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest and related charges									16		15
Dominion Gas Holdings, LLC
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Operating Revenue	510	391	428	569	533	388	430	586	1,898	[1]	1,937	[1]	1,677	[1]
Purchased gas									315	[1]	323	[1]	235	[1]
Interest and related charges									27	[1]	28	[1]	40	[1]
Income from continuing operations including noncontrolling interests before income taxes									846		762		747
Income tax expense									(334)		(301)		(288)
Other income									22		28		37
Dominion Gas Holdings, LLC | Deferred gains and losses on derivatives-hedging activities | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income from continuing operations including noncontrolling interests before income taxes									13		16
Income tax expense									(5)		(5)
Income from continuing operations including noncontrolling interests									8		11
Dominion Gas Holdings, LLC | Unrecognized pension and other postretirement benefit costs | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income from continuing operations including noncontrolling interests before income taxes									8		10
Income tax expense									(3)		(4)
Income from continuing operations including noncontrolling interests									5		6
Prior-service costs (credits)									1		1
Actuarial losses									7		9
Dominion Gas Holdings, LLC | Commodity | Deferred gains and losses on derivatives-hedging activities | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Operating Revenue									(2)		2
Purchased gas									14		14
Dominion Gas Holdings, LLC | Interest rate | Deferred gains and losses on derivatives-hedging activities | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest and related charges									1
Virginia Electric and Power Company
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Operating Revenue	1,814	2,053	1,729	1,983	1,745	2,059	1,710	1,781	7,579	[2]	7,295	[2]	7,226	[2]
Electric fuel and other energy-related purchases									2,406	[2]	2,304	[2]	2,368	[2]
Interest and related charges									411		369		385
Income from continuing operations including noncontrolling interests before income taxes									1,406		1,797		1,703
Income tax expense									(548)		(659)		(653)
Other income									93		86		96
Impairment									2		1		1
Virginia Electric and Power Company | Deferred gains and losses on derivatives-hedging activities | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income from continuing operations including noncontrolling interests before income taxes									(5)
Income tax expense									2
Income from continuing operations including noncontrolling interests									(3)
Virginia Electric and Power Company | Unrealized gains and losses on investment securities | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income from continuing operations including noncontrolling interests before income taxes									(10)		(5)
Income tax expense									4		2
Income from continuing operations including noncontrolling interests									(6)		(3)
Other income									(10)		(6)
Impairment											1
Virginia Electric and Power Company | Commodity | Deferred gains and losses on derivatives-hedging activities | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Electric fuel and other energy-related purchases									(5)
Virginia Electric and Power Company | Interest rate | Deferred gains and losses on derivatives-hedging activities | Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest and related charges									$ 0

[1] See Note 24 for amounts attributable to related parties.

[2] See Note 24 for amounts attributable to affiliates.