Schedule of Assets and Liabilities Related to Asset-backed Debt Arrangements (Detail) - USD ($) $ in Millions |
Jun. 30, 2017 |
Dec. 31, 2016 |
|---|---|---|
| Accounts Receivable, net | ||
| Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items] | ||
| Assets | $ 6,472 | $ 3,383 |
| Prepaid Expenses and Other | ||
| Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items] | ||
| Assets | 396 | 236 |
| Other Assets | ||
| Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items] | ||
| Assets | 3,071 | 2,383 |
| Accounts Payable and Accrued Liabilities | ||
| Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items] | ||
| Liabilities | 4 | 4 |
| Long-term Debt | ||
| Assets and Associated Liabilities of Transfers Accounted for as Secured Borrowings [Line Items] | ||
| Liabilities | $ 7,869 | $ 4,988 |