Quarterly report pursuant to Section 13 or 15(d)

Nonrecourse Debt - Additional Information (Detail)

v3.7.0.1
Nonrecourse Debt - Additional Information (Detail) - USD ($)
 6 Months Ended
Jun. 30, 2017
Dec. 31, 2016
Jun. 30, 2017
Jan. 31, 2017
Debt Instrument [Line Items]        
Nonrecourse Asset-Backed Debt, Aggregate Principal Amount $ 921,780,000 $ 692,091,000 $ 921,780,000  
Ineffectiveness recorded on designated hedges 0 0    
SunPower Corporation [Member] | Residential Solar Loan [Member]        
Debt Instrument [Line Items]        
Outstanding Balance $ 5,000,000   5,000,000  
Payment of principal and interest on loan     $ 1,000,000  
HASI Sustainable Yield Bond 2015-1A [Member]        
Debt Instrument [Line Items]        
Nonrecourse Asset-Backed Debt, Interest Rate 4.28%   4.28%  
Nonrecourse Asset-Backed Debt, Maturity Date     2034-10  
HASI Sustainable Yield Bond 2015-1B [Member]        
Debt Instrument [Line Items]        
Nonrecourse Asset-Backed Debt, Interest Rate 5.41%   5.41%  
Nonrecourse Asset-Backed Debt, Maturity Date     2034-10  
Asset-Backed Nonrecourse Debt Agreement [Member]        
Debt Instrument [Line Items]        
Outstanding Balance $ 922,000,000 692,000,000 $ 922,000,000  
Asset-Backed Nonrecourse Debt Agreement [Member] | HASI Sustainable Yield Bond 2015-1A [Member]        
Debt Instrument [Line Items]        
Nonrecourse Asset-Backed Debt, Aggregate Principal Amount $ 101,000,000   $ 101,000,000  
Nonrecourse Asset-Backed Debt, Interest Rate 4.28%   4.28%  
Nonrecourse Asset-Backed Debt, Maturity Date     2034-10  
Outstanding Balance $ 96,000,000 $ 97,000,000 $ 96,000,000  
Asset-Backed Nonrecourse Debt Agreement [Member] | HASI Sustainable Yield Bond 2015-1B [Member]        
Debt Instrument [Line Items]        
Nonrecourse Asset-Backed Debt, Aggregate Principal Amount $ 18,000,000   $ 18,000,000 $ 14,000,000
Nonrecourse Asset-Backed Debt, Interest Rate 5.00%   5.00%  
Nonrecourse Asset-Backed Debt, Maturity Date     2034-10  
Outstanding Balance $ 14,000,000   $ 14,000,000