DERIVATIVE INSTRUMENTS (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Commodity derivatives:
Realized losses (gains)	$ 4,460	$ (9,649)
Unrealized losses	8,391	35,161
Interest rate derivatives:
Realized gains	0	(3,082)
Unrealized losses	0	3,150
Realized and unrealized losses on derivative instruments, net	$ 12,851	$ 25,580