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Employee Benefit Plans (Tables) | 3 Months Ended
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Mar. 31, 2017
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |
Net Periodic Benefit Cost | The components of Dominion's provision for net periodic benefit cost (credit) were as follows:
| Pension Benefits | Other Postretirement Benefits
| 2017 | 2016 | 2017 | 2016
(millions) |  |  |  |
Three Months Ended March 31, |  |  |  |
Service cost | $ | 35 |  | $ | 29 |  | $ | 7 |  | $ | 8 |
Interest cost | 86 |  | 77 |  | 16 |  | 17 |
Expected return on plan assets | (159 | ) | (139 | ) | (32 | ) | (29 | )
Amortization of prior service credit | — |  | — |  | (12 | ) | (7 | )
Amortization of net actuarial loss | 40 |  | 28 |  | 3 |  | 1 |
Settlements | 1 |  | — |  | — |  | — |
Net periodic benefit cost (credit) | $ | 3 |  | $ | (5 | ) | $ | (18 | ) | $ | (10 | )
Dominion Gas Holdings, LLC |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |
Net Periodic Benefit Cost | The components of Dominion Gas' provision for net periodic benefit credit for employees represented by collective bargaining units were as follows:
| Pension Benefits | Other Postretirement Benefits
| 2017 | 2016 | 2017 | 2016
(millions) |  |  |  |
Three Months Ended March 31, |  |  |  |
Service cost | $ | 4 |  | $ | 3 |  | $ | 1 |  | $ | 1 |
Interest cost | 7 |  | 8 |  | 3 |  | 3 |
Expected return on plan assets | (35 | ) | (33 | ) | (6 | ) | (5 | )
Amortization of net actuarial loss | 4 |  | 3 |  | 1 |  | — |
Net periodic benefit credit | $ | (20 | ) | $ | (19 | ) | $ | (1 | ) | $ | (1 | )

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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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- Definition Tabular disclosure of the components of net benefit costs for pension plans and/or other employee benefit plans including service cost, interest cost, expected return on plan assets, gain (loss), prior service cost or credit, transition asset or obligation, and gain (loss) recognized due to settlements or curtailments. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h) -URI http://asc.fasb.org/extlink&oid=58740216&loc=d3e1928-114920 + Details
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- Details
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