Quarterly report pursuant to Section 13 or 15(d)

Nonrecourse Debt - Additional Information (Detail)

v3.5.0.2
Nonrecourse Debt - Additional Information (Detail) - USD ($)
9 Months Ended
Sep. 30, 2016
Dec. 31, 2015
Sep. 30, 2016
Debt Instrument [Line Items]      
Nonrecourse Asset-Backed Debt, Aggregate Principal Amount $ 610,267,000 $ 663,791,000 $ 610,267,000
Ineffectiveness recorded on designated hedges 0 0  
Reclassification out of Accumulated Other Comprehensive Income [Member]      
Debt Instrument [Line Items]      
Interest Expense 0 $ 0  
Asset-Backed Nonrecourse Debt Agreement [Member] | HASI Sustainable Yield Bond 2015-1A ("HASI SYB") [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
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
Nonrecourse Asset-Backed Debt, Interest Rate 5.00%   5.00%
Nonrecourse Asset-Backed Debt, Maturity Date     2034-10