This item represents the entity's aggregate generation capacity from long-term power and capacity contracts.

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Costs incurred in purchasing electric capacity.

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Long Term Capacity Contract Non Utility Generators

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Long-term capacity contract expired number of nonutility generators.

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Shared Services Purchased

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No definition available.

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The aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities.

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Carrying amount as of the balance sheet date of obligations due all related parties. For classified balance sheets, represents the current portion of such liabilities (due within one year or within the normal operating cycle if longer).

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Percentage investment held by members or limited partners of limited liability company (LLC) or limited partnership (LP).

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Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt, classified as current. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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- Definition

Minimum amount to be expended to satisfy the terms of arrangements in which the entity has agreed to expend funds to procure goods or services, excluding long-term purchase commitments or unconditional purchase obligations.

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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.

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Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly).

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Variable Interest Entities (Narrative) (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($) MW Generators	Dec. 31, 2016 USD ($)
Virginia Electric and Power Company
Variable Interest Entity [Line Items]
Securities due within one year	$ 350	$ 850
Long term debt	11,321	10,496
Payables to affiliates	209	125
Dominion Energy Gas Holdings, LLC
Variable Interest Entity [Line Items]
Securities due within one year	449
Long term debt	3,609	3,570
Payables to affiliates	$ 65	62
Variable Interest Entity, Primary Beneficiary \| Partnership Interest \| Merchant Solar Projects
Variable Interest Entity [Line Items]
Initial membership interest percentage	67.00%
Variable Interest Entity, Primary Beneficiary \| Dominion Energy Midstream Partners, LP \| Partnership Interest \| Limited Partner
Variable Interest Entity [Line Items]
Percentage of limited partner interests in Dominion Midstream Partners, LP	60.90%
Variable Interest Entity, Primary Beneficiary \| Dominion Energy Midstream Partners, LP \| Partnership Interest \| Preferred Partner
Variable Interest Entity [Line Items]
Percentage of limited partner interests in Dominion Midstream Partners, LP	37.50%
Variable Interest Entity, Primary Beneficiary \| SBL Holdco
Variable Interest Entity [Line Items]
Securities due within one year	$ 31
Long term debt	$ 299
Variable Interest Entity, Not Primary Beneficiary \| Distribution \| Atlantic Coast Pipeline \| Pipelines \| Jointly Owned Natural Gas Pipeline
Variable Interest Entity [Line Items]
Initial membership interest percentage	48.00%
Variable Interest Entity, Not Primary Beneficiary \| Virginia Electric and Power Company \| DES
Variable Interest Entity [Line Items]
Shared services purchased	$ 335	340	$ 346
Payables to affiliates	107	36
Variable Interest Entity, Not Primary Beneficiary \| Dominion Energy Gas Holdings, LLC \| DES
Variable Interest Entity [Line Items]
Shared services purchased	126	126	123
Payables to affiliates	46	$ 14
Variable Interest Entity (VIE) or Potential VIE, Information Unavailability \| Virginia Electric and Power Company
Variable Interest Entity [Line Items]
Long term capacity contract non utility generators (generators) \| Generators		3
Number of expired non-utility generators \| Generators		2
Aggregate generation capacity from long-term power and capacity contracts (MW) \| MW		218
Remaining purchase commitments	150
Payment for electric capacity	50	$ 86	144
Payment for electric energy	$ 18	$ 24	$ 31