Annual report pursuant to Section 13 and 15(d)

DERIVATIVE INSTRUMENTS (Details)

v3.6.0.2
DERIVATIVE INSTRUMENTS (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
DERIVATIVE INSTRUMENTS [Abstract]      
Feedstock and natural gas usage to operating expenses 62.20% 69.30% 78.00%
Derivative [Line Items]      
Unrealized gain (loss) $ 119 $ 381 $ (376)
Interest expense reclassified from other comprehensive income (loss) 0 0 378
Unrealized loss associated with the swap recognized in the Statement of Income     378
Interest Rate Swaps [Member]      
Derivative [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 $ 1,750    
Derivative, variable interest rate 5.83%    
Interest expense reclassified from other comprehensive income (loss) $ 0 0 378
Fair value of derivative liability 58 177  
Not Designated as Hedging Instrument [Member] | Commodity Financial Instruments [Member]      
Derivative [Line Items]      
Realized gain (loss) 0 (180) (452)
Unrealized gain (loss) 0 180 (132)
Net loss $ 0 $ 0 $ (584)