The number of units or percentage investment held by one or more members or limited partners of the LLC or LP.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 272
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055

+ Details

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- Definition

The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

+ References

No definition available.

+ Details

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- Definition

Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

+ References

No definition available.

+ Details

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- Definition

Cash received on stock transaction after deduction of issuance costs.

+ References

No definition available.

+ Details

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Balance Type:	debit
Period Type:	duration

- Definition

The number of shares issued or sold by the subsidiary or equity method investee per stock transaction.

+ References

No definition available.

+ Details

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- Definition

Per share amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction.

+ References

No definition available.

+ Details

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Balance Type:	na
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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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- Details

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Nature of Operations (Narrative) (Details) $ / shares in Units, $ in Millions		1 Months Ended		12 Months Ended
	Dec. 31, 2016	Sep. 30, 2015 shares	Oct. 31, 2014 USD ($) shares	Dec. 31, 2016 segment	Oct. 20, 2014 $ / shares
Subsidiary, Sale of Stock [Line Items]
Number of operating segments				3
Dominion Midstream Partners, LP \| Limited Partner
Subsidiary, Sale of Stock [Line Items]
Percentage of limited partner interests in Dominion Midstream Partners, LP	50.90%
Dominion Midstream Partners, LP \| Preferred Partner
Subsidiary, Sale of Stock [Line Items]
Percentage of limited partner interests in Dominion Midstream Partners, LP	37.50%
Dominion Midstream Partners, LP \| IPO
Subsidiary, Sale of Stock [Line Items]
Net proceeds received from sale of units \| $			$ 392
Dominion Midstream Partners, LP \| Iroquois \| Partnership Interest
Subsidiary, Sale of Stock [Line Items]
Common units included in initial public offering \| shares		8,600,000
Noncontrolling partnership percentage interest	25.93%			25.93%
Dominion Midstream Partners, LP \| IPO
Subsidiary, Sale of Stock [Line Items]
Common units included in initial public offering \| shares			20,125,000
Price per unit for units included in initial public offering \| $ / shares					$ 21
Virginia Electric and Power Company
Subsidiary, Sale of Stock [Line Items]
Number of operating segments				2
Dominion Gas Holdings, LLC
Subsidiary, Sale of Stock [Line Items]
Number of operating segments				1