Quarterly report pursuant to Section 13 or 15(d)

Nonrecourse Debt - Additional Information (Detail)

v3.2.0.727
Nonrecourse Debt - Additional Information (Detail) - USD ($)
$ in Thousands
1 Months Ended 6 Months Ended
Oct. 31, 2014
Dec. 31, 2013
Jun. 30, 2015
Dec. 31, 2014
Debt Instrument [Line Items]        
Nonrecourse Asset-Backed Loan Agreement     $ 197,694 $ 208,246
Cost on issuance of Notes     $ 11,000  
Joint Ventures [Member]        
Debt Instrument [Line Items]        
Ownership percentage     50.00%  
Asset-Backed Nonrecourse Notes [Member]        
Debt Instrument [Line Items]        
Nonrecourse Asset-Backed Loan Agreement   $ 100,000    
Nonrecourse Asset-Backed Loan Agreement, interest rate   2.79%    
Nonrecourse Asset-Backed Loan Agreement, maturity period     2019-12  
Outstanding Notes     $ 89,000 92,000
Amount of financing receivables pledged for Asset-Backed Notes     $ 103,000 104,000
Anticipated debt balance at maturity   $ 57,000    
Prepayment penalty, maturity date     2018-12  
Make whole payment discount rate   0.50%    
Asset-Backed Nonrecourse Loan Agreement [Member]        
Debt Instrument [Line Items]        
Nonrecourse Asset-Backed Loan Agreement $ 115,000      
Nonrecourse Asset-Backed Loan Agreement, interest rate 5.74%      
Nonrecourse Asset-Backed Loan Agreement, maturity period     2021-09  
Percentage of minimum principal payment amount     Minimum principal payment amount equal to one-half percent (0.5%) of the principal amount of the loan plus additional principal payments based on available cash flow and a target debt balance.  
Repayment of remaining debt balance in 2021 $ 17,000      
Default interest rate on debt in an event of default 7.74%      
Cost on issuance of Notes $ 2,000      
Asset-Backed Nonrecourse Loan Agreement [Member] | Ha Wind LLC [Member]        
Debt Instrument [Line Items]        
Ownership percentage 100.00%      
Asset-Backed Nonrecourse Loan Agreement [Member] | Joint Ventures [Member]        
Debt Instrument [Line Items]        
Ownership percentage 50.00%      
Other Nonrecourse Debt [Member]        
Debt Instrument [Line Items]        
Amount of financing receivables pledged for Asset-Backed Notes     $ 104,000 $ 108,000