FAIR VALUE MEASUREMENTS (Change in Fair Value at Level 3) (Details) - Commodity Contract [Member] - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Change in Fair Value Measurement Categorized in Level 3 [Roll Forward]
Balance at beginning of period	$ 1,905	$ 2,689	$ 1,521	$ (23,365)
Purchases	0	0	0	0
Settlements	(1,238)	(9,020)	(12,549)	(5,353)
Unrealized loss included in earnings	(852)	19,377	10,843	41,764
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Balance at end of period	$ (185)	$ 13,046	$ (185)	$ 13,046