v3.7.0.1
Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring - USD ($)
$ in Millions
Mar. 31, 2017
Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets measured on a recurring basis $ 718 $ 825
Fair value of liabilities measured on a recurring basis 1,978 2,039
Other Assets | Interest Rate Caps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets measured on a recurring basis 7 10
Other Assets | Equity Securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets measured on a recurring basis 118 123
Other Assets | Fixed Income Securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets measured on a recurring basis 439 576
Other Assets | Interest Rate Swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets measured on a recurring basis 91 71
Other Assets | Cross Currency Swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets measured on a recurring basis 63 45
Other Liabilities | Interest Rate Swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of liabilities measured on a recurring basis 296 236
Other Liabilities | Cross Currency Swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of liabilities measured on a recurring basis 1,682 1,803
Level 1    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets measured on a recurring basis [1] 118 133
Level 1 | Other Assets | Equity Securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets measured on a recurring basis [1] 118 123
Level 1 | Other Assets | Fixed Income Securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets measured on a recurring basis [1]   10
Level 2    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets measured on a recurring basis [2] 600 692
Fair value of liabilities measured on a recurring basis [2] 1,978 2,039
Level 2 | Other Assets | Interest Rate Caps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets measured on a recurring basis [2] 7 10
Level 2 | Other Assets | Fixed Income Securities    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets measured on a recurring basis [2] 439 566
Level 2 | Other Assets | Interest Rate Swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets measured on a recurring basis [2] 91 71
Level 2 | Other Assets | Cross Currency Swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of assets measured on a recurring basis [2] 63 45
Level 2 | Other Liabilities | Interest Rate Swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of liabilities measured on a recurring basis [2] 296 236
Level 2 | Other Liabilities | Cross Currency Swaps    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair value of liabilities measured on a recurring basis [2] $ 1,682 $ 1,803
[1] quoted prices in active markets for identical assets or liabilities
[2] observable inputs other than quoted prices in active markets for identical assets and liabilities