Annual report pursuant to Section 13 and 15(d)

Joint Venture and Investment Activities (Details)

v3.6.0.2
Joint Venture and Investment Activities (Details) - USD ($)
 1 Months Ended
Aug. 02, 2016
Jul. 31, 2016
Dec. 31, 2016
May 19, 2016
Dec. 31, 2015
Dec. 28, 2015
Schedule of Equity Method Investments [Line Items]            
Equity interest in joint venture (percent)     43.00%     50.00%
Warrant exercise price per share (in dollars per share)   $ 4.00     $ 4.00  
Warrants exercised for investment in joint venture   $ 2,700,000.0        
Investments in joint venture     $ 13,500,000      
Offshore Investors            
Schedule of Equity Method Investments [Line Items]            
Investment by other party to joint venture           $ 3,000,000
Ultra Emissions Technology Ltd.            
Schedule of Equity Method Investments [Line Items]            
Warrants exercised for investment in joint venture $ 2,000,000          
TTcogen, LLC            
Schedule of Equity Method Investments [Line Items]            
Equity interest in joint venture (percent)       50.00%    
Warrant            
Schedule of Equity Method Investments [Line Items]            
Warrants exercised (shares)   675,000        
Warrant | Ultra Emissions Technology Ltd.            
Schedule of Equity Method Investments [Line Items]            
Warrants exercised (shares) 2,000,000          
Warrant exercise price per share (in dollars per share) $ 1.00          
Co-venturer            
Schedule of Equity Method Investments [Line Items]            
Investments in joint venture     $ 6,500,000      
Co-venturer | TTcogen, LLC            
Schedule of Equity Method Investments [Line Items]            
Equity interest in joint venture (percent)       50.00%