Quarterly report pursuant to Section 13 or 15(d)

DERIVATIVE INSTRUMENTS (Details)

v3.4.0.3
DERIVATIVE INSTRUMENTS (Details) - USD ($)
$ in Thousands
3 Months Ended
Mar. 31, 2016
Mar. 31, 2015
Dec. 31, 2015
DERIVATIVE INSTRUMENTS [Abstract]      
Feedstock and natural gas usage to operating expenses 64.00% 68.00%  
Monthly feedstock requirements hedged, Maximum 40.00%    
Derivatives, Fair Value [Line Items]      
Unrealized gain $ 30 $ 242  
Realized and unrealized gains/(losses) as a percentage of cost of sales and processing 0.00% 0.00%  
Unrealized loss $ (6) $ 10  
Realized loss 36 53  
Interest Rate Swaps [Member]      
Derivatives, Fair Value [Line Items]      
Term loan in pay fixed, receive variable interest rate swap 10,000    
Term loan secured by plant, pipeline and equipment 14,000    
Notional amount $ 2,500   $ 2,750
Derivative, variable interest rate 5.83%    
Fair value of interest rate swap - liability $ 147   $ 177
Not Designated as Hedging Instrument [Member] | Commodity Financial Instruments [Member]      
Derivatives, Fair Value [Line Items]      
Unrealized gain 0 180  
Realized loss 0 (180)  
Net gain (loss) $ 0 $ 0