Accumulated Other Comprehensive Income (Loss) - Changes in Accumulated Other Comprehensive Income (Loss) (Parenthetical) (Detail) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | ||
|---|---|---|---|---|
Jun. 30, 2017 |
Jun. 30, 2016 |
Jun. 30, 2017 |
Jun. 30, 2016 |
|
| Amounts Reclassified Out Of Accumulated Other Comprehensive Income Loss [Abstract] | ||||
| Gain (loss) from net investment hedging, net of tax | $ (31) | $ 12 | $ (38) | $ (11) |
| Gain (loss) from net investment hedging, tax | $ (18) | $ 8 | $ (22) | $ (6) |