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)

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Fair Value Measurements - Summary of Fair Value and Carrying Value of Financial Assets and Liabilities (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($)
$ in Millions
Sep. 30, 2017
Dec. 31, 2016
Fair Value [Member] | Level 3 [Member] | Credit Facilities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities $ 175 $ 283
Fair Value [Member] | Level 3 [Member] | Non-recourse Debt [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities 1,103 718
Fair Value [Member] | Level 3 [Member] | Financing Receivable [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets 1,044 1,017
Fair Value [Member] | Level 3 [Member] | Investments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets 131 58
Fair Value [Member] | Level 3 [Member] | Securitization Residual Assets [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets 35 19
Fair Value [Member] | Fair Value, Inputs, Level 2 [Member] | Convertible Debt [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities 156  
Fair Value [Member] | Fair Value, Inputs, Level 2 [Member] | Derivative Liabilities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities 1  
Fair Value [Member] | Fair Value, Inputs, Level 2 [Member] | Derivative Assets [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets   1
Carrying Value [Member] | Level 3 [Member] | Credit Facilities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities 175 283
Carrying Value [Member] | Level 3 [Member] | Non-recourse Debt [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities 1,097 709
Carrying Value [Member] | Level 3 [Member] | Financing Receivable [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets 1,062 1,042
Carrying Value [Member] | Level 3 [Member] | Investments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets 131 58
Carrying Value [Member] | Level 3 [Member] | Securitization Residual Assets [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets 35 19
Carrying Value [Member] | Fair Value, Inputs, Level 2 [Member] | Convertible Debt [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities 151  
Carrying Value [Member] | Fair Value, Inputs, Level 2 [Member] | Derivative Liabilities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Liabilities $ 1  
Carrying Value [Member] | Fair Value, Inputs, Level 2 [Member] | Derivative Assets [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Assets   $ 1