Acquisitions and Dispositions (Narrative) (Details) $ / shares in Units, a in Thousands, $ in Millions			1 Months Ended						3 Months Ended	6 Months Ended		24 Months Ended
		Apr. 01, 2015 USD ($) $ / shares shares	Jun. 30, 2015 USD ($) Project MW	Apr. 30, 2015 USD ($) Project MW	Mar. 31, 2015 USD ($) a Field	Jan. 31, 2015 USD ($) mi	Mar. 31, 2014 USD ($)	Dec. 31, 2013 USD ($) a Field	Dec. 31, 2015 USD ($) MW	Jun. 30, 2015 USD ($)	Jun. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Expected cost of projects			$ 66							$ 66
Percentage ownership in total units			70.90%							70.90%
Goodwill			$ 3,294							$ 3,294		$ 3,044	[1]
Proceeds from assignments of Marcellus acreage										28	$ 0
Electric Retail Energy Marketing Business
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Proceeds from assignments of Marcellus acreage							$ 187
Gain on sale							100
After tax gain on sale							57
Write off of goodwill							$ 31
Scenario, Forecast
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Percentage of equity interests acquired									100.00%
Acquisition price									$ 65
Expected generation capacity of facilities (mw) | MW									20
Dominion Gas Holdings, LLC
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Goodwill			542							542		542	[2]
Dominion Gas Holdings, LLC | Marcellus Acreage
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Acres of Marcellus Shale development rights conveyed | a					11			79
Number of natural gas storage fields | Field					1			1
Amount per agreement					$ 27			$ 200
Duration of conveyance of rights								9 years
Cash proceeds from sale of assets												98
Deferred revenue												$ 85
Gain on sale of assets					27
After tax gain on sale of assets					$ 16
Dominion Gas Holdings, LLC | Marcellus Acreage | Amended Agreement to Extend Conveyance of Development Rights
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Acres of Marcellus Shale development rights conveyed | a					9
Duration of conveyance of rights					2 years
Deferred revenue			$ 38							$ 38
Deferred revenue recognized from conveyance of rights					$ 43
Deferred revenue recognized from conveyance of rights, after tax					$ 27
Four Brothers
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Percentage of equity interests acquired			50.00%							50.00%
Acquisition price			$ 64
Acquisition price in cash			$ 2
Number of solar development projects | Project			4
Expected cost of projects			$ 730							$ 730
Expected generation capacity of facilities (mw) | MW			320
Percentage ownership in total units			50.00%							50.00%
Net property, plant and equipment acquired			$ 89							$ 89
Non-controlling interest			25							25
Acquired equity			$ 64							$ 64
Four Brothers | Federal | Investment Tax Credits
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Percentage of expected federal investment tax credits on projects to be claimed			99.00%							99.00%
Four Brothers | Obligation to Contribute Capital to Fund Construction of Projects | Four Brothers
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Amount obligated to contribute to fund construction of projects			$ 445							$ 445
Four Brothers | Other Current Liabilities
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Liabilities incurred			$ 62
EC&R NA Solar PV, LLC
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Acquisition price	[3]			$ 66
Number of solar development projects | Project				1
Expected cost of projects	[4]			$ 66
Expected generation capacity of facilities (mw) | MW				20
Acquisition of CGT
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Percentage of equity interests acquired						100.00%
Acquisition price						$ 497
Net property, plant and equipment acquired						$ 277
Length of natural gas pipeline | mi						1,500
Goodwill						$ 250
Goodwill expected to be deductible for income tax purposes						225
Regulatory liabilities assumed						$ 38
Acquisition of CGT | Affiliated Entity | Dominion Midstream Partners, LP
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Acquisition price		$ 501
Percentage of equity interests in DCGT contributed in Dominion Midstream		100.00%
Acquisition of CGT | Affiliated Entity | Dominion Midstream Partners, LP | Partnership Interest
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Consideration received, common units of Dominion Midstream | shares		5,112,139
Consideration received, value of common units of Dominion Midstream		$ 200
Number of trading days used to determine weighted average trading price		10 days
Price per unit | $ / shares		$ 39.12
Acquisition of CGT | Affiliated Entity | Dominion Midstream Partners, LP | Senior unsecured promissory note payable
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Liabilities incurred		$ 301
Term of senior unsecured promissory note payable		2 years
Annual interest rate for senior unsecured promissory note payable		0.60%

[1] Dominion’s Consolidated Balance Sheet at December 31, 2014 has been derived from the audited Consolidated Financial Statements at that date.

[2] Dominion Gas’ Consolidated Balance Sheet at December 31, 2014 has been derived from the audited Consolidated Financial Statements at that date.

[3] The purchase price was primarily allocated to Property, Plant and Equipment.

[4] Includes acquisition cost.