Other Items - Net Interest And Other Financial Costs (Detail) - USD ($) $ in Millions |
3 Months Ended | |
|---|---|---|
Mar. 31, 2018 |
Mar. 31, 2017 |
|
| Other Income and Expenses [Abstract] | ||
| Interest income | $ (20) | $ (5) |
| Interest expense | 213 | 163 |
| Interest capitalized | (18) | (15) |
| Loss on extinguishment of debt | 4 | 0 |
| Other financial costs | 4 | 6 |
| Net interest and other financial costs | $ 183 | $ 149 |