Income Taxes - Reconciliation of Unrecognized Tax Benefits (Detail) - USD ($) $ in Millions |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|
| Income Tax Disclosure [Abstract] | |||
| Balance as of January 1, | $ 177 | $ 146 | $ 149 |
| Translation differences | (4) | 4 | 1 |
| Decreases from activities which are held for sale | 0 | 0 | (7) |
| Increases from tax positions taken during prior periods | 7 | 19 | 1 |
| Decreases from tax positions taken during prior periods | (17) | 0 | (3) |
| Increases from tax positions taken during current period | 7 | 10 | 9 |
| Decreases relating to settlements with the tax authorities | (5) | (2) | (4) |
| Balance as of December 31, | $ 165 | $ 177 | $ 146 |