Annual report pursuant to Section 13 and 15(d)

DERIVATIVES. (Details 1)

v3.8.0.1
DERIVATIVES. (Details 1) - Non Designated Derivative Instruments [Member] - Commodity Contracts [Member] - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Derivative Instruments, Gain (Loss) [Line Items]      
Realized Gains (Losses) $ (4,165) $ 1,386 $ (338)
Unrealized Gains (Losses) 2,088 (3,370) (204)
Cost of goods sold [Member]      
Derivative Instruments, Gain (Loss) [Line Items]      
Realized Gains (Losses) (4,165) 1,386 (338)
Unrealized Gains (Losses) $ 2,088 $ (3,370) $ (204)