Annual report pursuant to Section 13 and 15(d)

Related Party Transactions - Additional Information (Detail)

v3.3.1.900
Related Party Transactions - Additional Information (Detail)
1 Months Ended 12 Months Ended
Dec. 01, 2014
USD ($)
Apr. 21, 2014
shares
Apr. 09, 2013
shares
Aug. 31, 2015
USD ($)
Aug. 31, 2014
USD ($)
Jun. 30, 2014
USD ($)
Apr. 30, 2014
USD ($)
Feb. 28, 2014
USD ($)
Dec. 31, 2015
USD ($)
Agreement
shares
Dec. 31, 2014
USD ($)
shares
Dec. 31, 2013
USD ($)
shares
Oct. 31, 2015
USD ($)
Apr. 30, 2015
USD ($)
Related Party Transaction [Line Items]                          
Notes payable, current                 $ 10,360,000 $ 360,000      
Guaranteed borrowing capacity                         $ 5,000,000
Line of credit facility, maximum borrowing amount         $ 25,000,000             $ 30,000,000 $ 25,000,000
Debt instrument maturity date         Aug. 20, 2017                
Accrued interest                 300,000        
Interest Expenses                 1,100,000        
Proceeds from issuance of common stock $ 8,600,000               $ 8,960,000 $ 8,614,000 $ 4,950,000    
Common stock, issued | shares                 159,645,000 129,714,000      
Promissory Notes | Energy Source                          
Related Party Transaction [Line Items]                          
Notes payable, current       $ 10,000,000                  
Debt instrument maturity date       Jul. 20, 2016                  
RVL One Limited Liability Company                          
Related Party Transaction [Line Items]                          
Number of separate investment agreements | Agreement                 4        
Proceeds from issuance of convertible preferred stock                 $ 26,000,000        
Proceeds from issuance of common stock                     $ 192,000    
Common stock, issued | shares                     75,000    
Related party transaction costs incurred                     $ 33,000    
RVL One Limited Liability Company | Series G Redeemable Convertible Preferred Stock                          
Related Party Transaction [Line Items]                          
Proceeds from issuance of convertible preferred stock                 $ 12,500,000        
RVL One Limited Liability Company | RVL Note                          
Related Party Transaction [Line Items]                          
Debt instrument amount             $ 10,800,000            
Debt instrument maturity date                 Apr. 01, 2015        
Interest rate of debt             9.00%            
Debt instrument converted in to equity           $ 10,800,000              
Aston Capital Limited Liability Company                          
Related Party Transaction [Line Items]                          
Loans Receivable, Commercial, Trade Financing                     $ 9,900,000    
Monthly payment for underlying lease                 $ 26,537        
Related party transaction costs incurred                 300,000 $ 700,000      
Aston Capital Limited Liability Company | Promissory Notes                          
Related Party Transaction [Line Items]                          
Debt instrument amount                 $ 2,700,000        
Debt instrument maturity date                 Apr. 01, 2017        
Aston Capital Limited Liability Company | February Note                          
Related Party Transaction [Line Items]                          
Debt instrument amount           1,900,000 $ 1,000,000 $ 3,500,000          
Debt instrument maturity date                 Apr. 01, 2015        
Interest rate of debt               9.00%          
Debt instrument converted in to equity           $ 1,600,000              
Aston Capital Limited Liability Company | Restricted Stock                          
Related Party Transaction [Line Items]                          
Restricted common stock agreed to be issued for services | shares     500,000                    
Restricted common stock agreed to be issued for services, vesting period     3 years                    
Restricted common stock agreed to be issued for services, vesting date     Sep. 25, 2013                    
Number of shares authorized for grant | shares   300,000                      
Stock awards vesting periods   3 years