| **Consolidated Statements of Changes in Shareholder's Equity - USD ($) $ in Millions** | Total   | Common stock | Additional paid-in capital | Retained earnings | Accumulated other comprehensive income/(loss) | Noncontrolling interests |
|----------------------------------------------------------------------------------------|---------|--------------|----------------------------|-------------------|-----------------------------------------------|--------------------------|
| Balance at Dec. 31, 2017                                                               | $ 3,264 | $ 745        | $ 2                        | $ 2,969           | $ (592)                                       | $ 140                    |
| **Increase (Decrease) in Shareholder's Equity [Roll Forward]**                         |    |         |                       |              |                                          |                     |
| Profit of consolidated companies                                                       | 95      |         |                       | 91                |                                          | 4                        |
| Foreign currency translation, net of tax                                               | 71      |         |                       |              | 65                                            | 6                        |
| Derivative financial instruments, net of tax                                           | (6)     |         |                       |              | (6)                                           |                     |
| Balance at Mar. 31, 2018                                                               | 3,424   | 745          | 2                          | 3,060             | (533)                                         | 150                      |
| Balance at Dec. 31, 2018                                                               | 2,849   | 745          | 2                          | 2,874             | (925)                                         | 153                      |
| **Increase (Decrease) in Shareholder's Equity [Roll Forward]**                         |    |         |                       |              |                                          |                     |
| Profit of consolidated companies                                                       | 104     |         |                       | 98                |                                          | 6                        |
| Foreign currency translation, net of tax                                               | 15      |         |                       |              | 13                                            | 2                        |
| Derivative financial instruments, net of tax                                           | (14)    |         |                       |              | (14)                                          |                     |
| Adjustment to adopt new accounting guidance | Accounting Standards Update 2018-02      | 0       |         |                       | (97)              | 97                                            |                     |
| Balance at Mar. 31, 2019                                                               | $ 2,954 | $ 745        | $ 2                        | $ 2,875           | $ (829)                                       | $ 161                    |

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.
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Represents the quantification of the effect of adopting the new accounting standard or change in accounting principle expected by the entity to have a significant effect on the entity's financial statements.
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Amount, after tax and reclassification, of gain (loss) from derivative instrument designated and qualifying as cash flow hedge included in assessment of hedge effectiveness, attributable to parent.
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| - Definition
Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.
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The consolidated profit or loss for the period, net of income taxes, including the portion attributable to the noncontrolling interest.
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Amount of stockholders' equity (deficit), net of receivables from officers, directors, owners, and affiliates of the entity, attributable to both the parent and noncontrolling interests. Amount excludes temporary equity. Alternate caption for the concept is permanent equity.
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