Quarterly report pursuant to Section 13 or 15(d)

Investment Fund (Details)

v3.7.0.1
Investment Fund (Details) - USD ($)
$ in Thousands
Mar. 31, 2017
Dec. 31, 2016
Cash    
Variable Interest Entity [Line Items]    
Variable interest entity, carrying amount, assets $ 664 $ 1,157
Restricted cash    
Variable Interest Entity [Line Items]    
Variable interest entity, carrying amount, assets 1,554 1,554
Accounts receivable    
Variable Interest Entity [Line Items]    
Variable interest entity, carrying amount, assets 0 80
Costs and estimated earnings in excess of billings    
Variable Interest Entity [Line Items]    
Variable interest entity, carrying amount, assets 52 50
Prepaid expenses and other current assets    
Variable Interest Entity [Line Items]    
Variable interest entity, carrying amount, assets 0 50
Project assets, net    
Variable Interest Entity [Line Items]    
Variable interest entity, carrying amount, assets 33,370 33,734
Other assets    
Variable Interest Entity [Line Items]    
Variable interest entity, carrying amount, assets 0 77
Accrued liabilities    
Variable Interest Entity [Line Items]    
Variable interest entity, consolidated, carrying amount, liabilities $ 117 $ 165