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Employee Benefit Plans (Tables) | 12 Months Ended
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Dec. 31, 2017
Retirement Benefits [Abstract] |
Change in Benefit Obligation, Plan Assets and Funded Status of Defined Benefit Pension Plans | The change in benefit obligation, plan assets and the funded status of the defined benefit pension plans in the United States, United Kingdom, Norway, Germany and the Netherlands and defined postretirement plans in the United States, using a measurement date of December 31, 2017 and 2016, is as follows (in millions):
|  | Pension benefits |  |  | Postretirement benefits |
At year end |  | 2017 |  |  | 2016 |  |  | 2017 |  |  | 2016 |
Benefit obligation at beginning of year |  | $ | 622 |  |  | $ | 703 |  |  | $ | 92 |  |  | $ | 90 |
Service cost |  |  | 1 |  |  |  | 5 |  |  |  | — |  |  |  | — |
Interest cost |  |  | 20 |  |  |  | 25 |  |  |  | 3 |  |  |  | 3 |
Actuarial loss (gain) |  |  | 6 |  |  |  | 42 |  |  |  | (17 | ) |  |  | (29 | )
Benefits paid |  |  | (31 | ) |  |  | (30 | ) |  |  | (14 | ) |  |  | (16 | )
Participants contributions |  |  | — |  |  |  | — |  |  |  | 2 |  |  |  | 2 |
Exchange rate loss (gain) |  |  | 30 |  |  |  | (37 | ) |  |  | — |  |  |  | — |
Acquisitions (disposals) |  |  | — |  |  |  | 2 |  |  |  | — |  |  |  | — |
Curtailments |  |  | — |  |  |  | (17 | ) |  |  | (4 | ) |  |  | — |
Settlements |  |  | (15 | ) |  |  | (71 | ) |  |  | — |  |  |  | — |
Other |  |  | — |  |  |  | — |  |  |  | — |  |  |  | 42 |
Benefit obligation at end of year |  | $ | 633 |  |  | $ | 622 |  |  | $ | 62 |  |  | $ | 92 |
Fair value of plan assets at beginning of year |  | $ | 543 |  |  | $ | 601 |  |  | $ | — |  |  | $ | — |
Actual return |  |  | 57 |  |  |  | 60 |  |  |  | — |  |  |  | — |
Benefits paid |  |  | (31 | ) |  |  | (30 | ) |  |  | (14 | ) |  |  | (16 | )
Company contributions |  |  | 11 |  |  |  | 16 |  |  |  | 12 |  |  |  | 14 |
Participants contributions |  |  | — |  |  |  | — |  |  |  | 2 |  |  |  | 2 |
Exchange rate gain (loss) |  |  | 24 |  |  |  | (34 | ) |  |  | — |  |  |  | — |
Settlements |  |  | (15 | ) |  |  | (71 | ) |  |  | — |  |  |  | — |
Acquisitions (disposals) |  |  | — |  |  |  | 1 |  |  |  | — |  |  |  | — |
Other |  |  | (1 | ) |  |  | — |  |  |  | — |  |  |  | — |
Fair value of plan assets at end of year |  | $ | 588 |  |  | $ | 543 |  |  | $ | — |  |  | $ | — |
Funded status |  | $ | (45 | ) |  | $ | (79 | ) |  | $ | (62 | ) |  | $ | (92 | )
Accumulated benefit obligation at end of year |  | $ | 630 |  |  | $ | 617 |  |  |  |  |  |  |  |  |
Assumption Rates Used for Benefit Obligations | The assumption rates used for benefit obligations are as follows:
|  | Years Ended December 31,
|  | 2017 |  | 2016
Discount rate: |  |  |  |
United States plan |  | 3.00% - 3.60% |  | 3.10% - 4.00%
International plans |  | 1.80% - 2.40% |  | 1.80% - 2.80%
Salary increase: |  |  |  |
United States plan |  | N/A |  | N/A
International plans |  | 1.80% - 3.30% |  | 1.80% - 3.50%
Assumption Rates Used for Net Periodic Benefit Costs | The assumption rates used for net periodic benefit costs are as follows:
|  | Years Ended December 31, |
|  | 2017 |  |  | 2016 |  |  | 2015 |
Discount rate: |  |  |  |  |  |  |  |  |  |  |  |
United States plan |  |  | 3.10% - 4.00% |  |  |  | 3.20% - 4.20% |  |  |  | 3.70% - 4.20% |
International plans |  |  | 1.80% - 2.80% |  |  |  | 2.20% - 3.70% |  |  |  | 2.20% - 3.70% |
Salary increase: |  |  |  |  |  |  |  |  |  |  |  |
United States plan |  |  | N/A |  |  |  | N/A |  |  |  | N/A |
International plans |  |  | 1.80% - 3.50% |  |  |  | 2.00% - 4.20% |  |  |  | 2.00% - 4.20% |
Expected return on assets: |  |  |  |  |  |  |  |  |  |  |  |
United States plan |  |  | 5.60% |  |  |  | 5.60% |  |  |  | 5.50% |
International plans |  |  | 1.80% - 3.00% |  |  |  | 1.80% - 3.00% |  |  |  | 2.30% - 5.12% |
Plan's Assets Carried at Fair Value | The following table sets forth by level, within the fair value hierarchy, the Plan’s assets carried at fair value (in millions):
|  | Fair Value Measurements |
|  | Total |  |  | Level 1 |  |  | Level 2 |  |  | Level 3 |
December 31, 2016: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity securities |  | $ | 181 |  |  | $ | — |  |  | $ | 181 |  |  | $ | — |
Bonds |  |  | 262 |  |  |  | — |  |  |  | 262 |  |  |  | — |
Other (insurance contracts) |  |  | 100 |  |  |  | — |  |  |  | 47 |  |  |  | 53 |
Total Fair Value Measurements |  | $ | 543 |  |  | $ | — |  |  | $ | 490 |  |  | $ | 53 |
December 31, 2017: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Equity securities |  | $ | 161 |  |  | $ | — |  |  | $ | 161 |  |  | $ | — |
Bonds |  |  | 284 |  |  |  | — |  |  |  | 284 |  |  |  | — |
Other (insurance contracts) |  |  | 143 |  |  |  | — |  |  |  | 82 |  |  |  | 61 |
Total Fair Value Measurements |  | $ | 588 |  |  | $ | — |  |  | $ | 527 |  |  | $ | 61 |
Summary of Changes in Fair Value of Plan's Level Three Assets | The following table sets forth a summary of changes in the fair value of the Plan’s Level 3 assets (in millions):
|  | Level 3 Plan Assets |
Balance at December 31, 2015 |  | $ | 99 |
Actual return on plan assets still held at reporting date |  |  | 5 |
Purchases, sales and settlements |  |  | (50 | )
Currency translation adjustments |  |  | (1 | )
Balance at December 31, 2016 |  | $ | 53 |
Actual return on plan assets still held at reporting date |  |  | 2 |
Purchases, sales and settlements |  |  | (1 | )
Currency translation adjustments |  |  | 7 |
Balance at December 31, 2017 |  | $ | 61 |

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