Annual report pursuant to Section 13 and 15(d)

DERIVATIVE INSTRUMENTS (Details)

v3.3.1.900
DERIVATIVE INSTRUMENTS (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
DERIVATIVE INSTRUMENTS [Abstract]      
Feedstock and natural gas usage to operating expenses 69.30% 78.00% 80.60%
Derivatives, Fair Value [Line Items]      
Unrealized gain (loss) $ 381 $ (376) $ (57)
Interest expense reclassified from other comprehensive income (loss) 0 378 301
Unrealized loss associated with the swap recognized in the Statement of Income 378 378  
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 $ 2,750    
Derivative, variable interest rate 5.83%    
Cumulative loss $ 0 0 (563)
Deferred tax benefit 0 0 197
Net cumulative loss 0 0 (366)
Interest expense reclassified from other comprehensive income (loss) 0 378 301
Fair value of derivative liability 177 378  
Not Designated as Hedging Instrument [Member] | Commodity Financial Instruments [Member]      
Derivatives, Fair Value [Line Items]      
Realized gain (loss) (180) (452) 40
Unrealized gain (loss) 180 (132) (48)
Net loss 0 (584) $ (8)
Fair value of derivative liability $ 0 $ 180