Derivatives and Hedging - Additional Information (Detail) - USD ($) $ in Millions |
3 Months Ended | 6 Months Ended | |
|---|---|---|---|
Jun. 30, 2017 |
Jun. 30, 2017 |
Dec. 31, 2016 |
|
| Derivative [Line Items] | |||
| Derivative maximum risk of loss for credit protection | $ 17 | $ 17 | |
| Other General and Administration Expense [Member] | |||
| Derivative [Line Items] | |||
| Foreign currency translation gains (losses) | 25 | 29 | |
| Total Return Swaps [Member] | |||
| Derivative [Line Items] | |||
| Notional value | 588 | 588 | $ 572 |
| Total Return Swaps [Member] | Nonoperating Income (Expense) [Member] | |||
| Derivative [Line Items] | |||
| Amount of gains (losses) recognized in income on derivative instruments | (30) | (64) | |
| Interest Rate Swaps [Member] | |||
| Derivative [Line Items] | |||
| Notional value | 42 | ||
| Forward Foreign Currency Exchange Contracts [Member] | |||
| Derivative [Line Items] | |||
| Notional value | $ 1,200 | $ 1,200 | $ 107 |