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v3.20.1

Nature of Operations (Narrative) (Detail) | Mar. 31, 2020 | Dec. 31, 2019
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White River Hub |  |
Subsidiary Sale Of Stock [Line Items] |  |
Percentage ownership in total units |  | 50.00%
White River Hub | Dominion Energy Gas Holdings, LLC |  |
Subsidiary Sale Of Stock [Line Items] |  |
Percentage ownership in total units | 50.00% |
Iroquois | Dominion Energy Gas Holdings, LLC |  |
Subsidiary Sale Of Stock [Line Items] |  |
Percentage ownership in total units | 50.00% |

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- Details
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