Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurements - Summary of Fair Value and Carrying Value of Financial Assets and Liabilities (Detail)

v3.2.0.727
Fair Value Measurements - Summary of Fair Value and Carrying Value of Financial Assets and Liabilities (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($)
$ in Millions
Jun. 30, 2015
Dec. 31, 2014
Fair Value [Member] | Other Nonrecourse Debt [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities $ 119  
Fair Value [Member] | Level 3 [Member] | Credit Facility [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities 420 $ 316
Fair Value [Member] | Level 3 [Member] | Other Nonrecourse Debt [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities   127
Fair Value [Member] | Level 3 [Member] | Asset-Backed Nonrecourse Notes [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities 197 208
Fair Value [Member] | Level 3 [Member] | Financing Receivable [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets 726 598
Fair Value [Member] | Level 3 [Member] | Financing Receivables Held-for-Sale [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets 85 62
Fair Value [Member] | Level 3 [Member] | Investments Available-for-Sale [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets 28 27
Carrying Value [Member] | Other Nonrecourse Debt [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities 108  
Carrying Value [Member] | Level 3 [Member] | Credit Facility [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities 420 316
Carrying Value [Member] | Level 3 [Member] | Other Nonrecourse Debt [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities   113
Carrying Value [Member] | Level 3 [Member] | Asset-Backed Nonrecourse Notes [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities 198 208
Carrying Value [Member] | Level 3 [Member] | Financing Receivable [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets 689 553
Carrying Value [Member] | Level 3 [Member] | Financing Receivables Held-for-Sale [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets 85 62
Carrying Value [Member] | Level 3 [Member] | Investments Available-for-Sale [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets $ 28 $ 27