Annual report pursuant to Section 13 and 15(d)

Nonrecourse Debt - Additional Information (Detail)

v3.6.0.2
Nonrecourse Debt - Additional Information (Detail) - USD ($)
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Debt Instrument [Line Items]          
Nonrecourse Asset-Backed Debt, Aggregate Principal Amount $ 692,091,000 $ 663,791,000 $ 692,091,000 $ 663,791,000  
Ineffectiveness recorded on designated hedges 0 0      
Interest expense     45,241,000 $ 26,385,000 $ 16,655,000
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