Quarterly report pursuant to Section 13 or 15(d)

Nonrecourse Debt - Schedule of Outstanding Asset-Backed Nonrecourse Debt and Bank Loans (Detail)

v3.5.0.2
Nonrecourse Debt - Schedule of Outstanding Asset-Backed Nonrecourse Debt and Bank Loans (Detail) - USD ($)
$ in Millions
 9 Months Ended
Sep. 30, 2016
Dec. 31, 2015
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Debt issuance costs $ (14)  
Nonrecourse Asset-Backed Debt, Anticipated Balance at Maturity 0  
Value of Assets Pledged, Equity interest $ 41  
Minimum [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Nonrecourse Asset-Backed Debt, Interest Rate 2.26%  
Nonrecourse Asset-Backed Debt, Maturity Date 2017-12  
Maximum [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Nonrecourse Asset-Backed Debt, Interest Rate 7.45%  
Nonrecourse Asset-Backed Debt, Maturity Date 2032-12  
HASI Sustainable Yield Bond 2013-1 [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Nonrecourse Asset-Backed Debt, Interest Rate 2.79%  
Nonrecourse Asset-Backed Debt, Maturity Date 2019-12  
Nonrecourse Asset-Backed Debt, Anticipated Balance at Maturity $ 57  
ABS Loan Agreement [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Nonrecourse Asset-Backed Debt, Interest Rate 5.74%  
Nonrecourse Asset-Backed Debt, Maturity Date 2021-09  
Nonrecourse Asset-Backed Debt, Anticipated Balance at Maturity $ 17  
HASI Sustainable Yield Bond 2015-1 [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Nonrecourse Asset-Backed Debt, Interest Rate 4.28%  
Nonrecourse Asset-Backed Debt, Maturity Date 2034-10  
HASI SYB Loan Agreement 2015-1 [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Nonrecourse Asset-Backed Debt, Interest Rate 4.34%  
Nonrecourse Asset-Backed Debt, Maturity Date 2021-12  
HASI SYB Loan Agreement 2015-2 [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Nonrecourse Asset-Backed Debt, Interest Rate 4.92%  
Nonrecourse Asset-Backed Debt, Maturity Date 2023-12  
HASI SYB Loan Agreement 2015-3 [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Nonrecourse Asset-Backed Debt, Interest Rate 4.92%  
Nonrecourse Asset-Backed Debt, Maturity Date 2020-12  
Nonrecourse Asset-Backed Debt, Anticipated Balance at Maturity $ 132  
Asset-Backed Nonrecourse Debt Agreement [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Other nonrecourse debt 88 $ 101
Debt issuance costs (14) (16)
Outstanding Balance 610 664
Value of Assets Pledged, Equity interest $ 86 97
Description of Assets Pledged Financing receivables  
Asset-Backed Nonrecourse Debt Agreement [Member] | HASI Sustainable Yield Bond 2013-1 [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Outstanding Balance $ 77 83
Value of Assets Pledged, Equity interest $ 93 99
Description of Assets Pledged Financing receivables  
Asset-Backed Nonrecourse Debt Agreement [Member] | ABS Loan Agreement [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Outstanding Balance $ 92 102
Value of Assets Pledged, Equity interest $ 100 117
Description of Assets Pledged Equity interest in Strong Upwind Holdings I, LLC  
Asset-Backed Nonrecourse Debt Agreement [Member] | HASI Sustainable Yield Bond 2015-1 [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Outstanding Balance $ 98 100
Value of Assets Pledged, Equity interest $ 138 139
Description of Assets Pledged Financing receivables, real estate and real estate intangibles  
Asset-Backed Nonrecourse Debt Agreement [Member] | HASI SYB Loan Agreement 2015-1 [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Outstanding Balance $ 76 90
Value of Assets Pledged, Equity interest $ 100 117
Description of Assets Pledged Equity interest in Strong Upwind Holdings II and III, LLC, related interest rate swap  
Asset-Backed Nonrecourse Debt Agreement [Member] | HASI SYB Loan Agreement 2015-2 [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Outstanding Balance $ 41 42
Value of Assets Pledged, Equity interest $ 70 71
Description of Assets Pledged Equity interest in Buckeye Wind Energy Class B Holdings LLC, related interest rate swap  
Asset-Backed Nonrecourse Debt Agreement [Member] | HASI SYB Loan Agreement 2015-3 [Member]    
Financial Instruments Owned and Pledged as Collateral [Line Items]    
Outstanding Balance $ 152 162
Value of Assets Pledged, Equity interest $ 176 $ 175
Description of Assets Pledged Residential Solar Financing receivables