XML 121 R111.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Goodwill and Intangible Assets (Goodwill) (Detail) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2017 | Dec. 31, 2016
Goodwill [Roll Forward] |  |  |
Goodwill, Beginning Balance | [1] | $ 6,399 | $ 3,294
Dominion Questar Combination |  | 6 |
Goodwill, Ending Balance | [1] | 6,405 | 6,399
Dominion Energy Gas Holdings, LLC |  |  |
Goodwill [Roll Forward] |  |  |
Goodwill, Beginning Balance | [1] | 542 | 542
No events affecting goodwill |  | 0 | 0
Goodwill, Ending Balance | [1] | 542 | 542
Dominion Questar Corporation |  |  |
Goodwill [Roll Forward] |  |  |
Dominion Questar Combination |  |  | 3,105
Operating Segments | Power Generation |  |  |
Goodwill [Roll Forward] |  |  |
Goodwill, Beginning Balance | [1] | 1,422 | 1,422
Goodwill, Ending Balance | [1] | 1,422 | 1,422
Operating Segments | Power Generation | Dominion Energy Gas Holdings, LLC |  |  |
Goodwill [Roll Forward] |  |  |
No events affecting goodwill |  | 0 | 0
Operating Segments | Gas Infrastructure |  |  |
Goodwill [Roll Forward] |  |  |
Goodwill, Beginning Balance | [1] | 4,051 | 946
Dominion Questar Combination |  | 6 |
Goodwill, Ending Balance | [1] | 4,057 | 4,051
Operating Segments | Gas Infrastructure | Dominion Energy Gas Holdings, LLC |  |  |
Goodwill [Roll Forward] |  |  |
Goodwill, Beginning Balance | [1] | 542 | 542
No events affecting goodwill |  | 0 | 0
Goodwill, Ending Balance | [1] | 542 | 542
Operating Segments | Power Delivery |  |  |
Goodwill [Roll Forward] |  |  |
Goodwill, Beginning Balance | [1] | 926 | 926
Goodwill, Ending Balance | [1] | 926 | 926
Operating Segments | Power Delivery | Dominion Energy Gas Holdings, LLC |  |  |
Goodwill [Roll Forward] |  |  |
No events affecting goodwill |  | 0 | 0
Operating Segments | Corporate and Other | Dominion Energy Gas Holdings, LLC |  |  |
Goodwill [Roll Forward] |  |  |
No events affecting goodwill | [2] | $ 0 | 0
Operating Segments | Dominion Questar Corporation | Gas Infrastructure |  |  |
Goodwill [Roll Forward] |  |  |
Dominion Questar Combination | [3] |  | $ 3,105
[1] | Goodwill amounts do not contain any accumulated impairment losses.
[2] | Goodwill recorded at the Corporate and Other segment is allocated to the primary operating segments for goodwill impairment testing purposes.
[3] | See Note 3.

X
- Definition Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975 + Details
Name: | us-gaap_Goodwill
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267 + Details
Name: | us-gaap_GoodwillAcquiredDuringPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of increase (decrease) of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267 + Details
Name: | us-gaap_GoodwillPeriodIncreaseDecrease
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
Name: | us-gaap_GoodwillRollForward
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | dei_LegalEntityAxis=d_DominionEnergyGasHoldingsLLCMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=d_DominionQuestarCorporationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConsolidationItemsAxis=us-gaap_OperatingSegmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=d_PowerGenerationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=d_GasInfrastructureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=d_PowerDeliveryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=us-gaap_CorporateAndOtherMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |