FAIR VALUE MEASUREMENTS (Derivative Financial Instruments) (Details) (Cashless Collar Contract [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Feb. 07, 2013 bbl	Jan. 08, 2013 bbl	Dec. 07, 2012 bbl	Nov. 09, 2012 bbl	Oct. 04, 2012 bbl	Sep. 11, 2012 bbl	Aug. 03, 2012 bbl	May 03, 2012 bbl	Apr. 10, 2012 bbl	Mar. 07, 2012 bbl	Mar. 05, 2012 bbl	Feb. 07, 2012 bbl	Dec. 28, 2012 Cap $143.50 [Member] bbl	Dec. 28, 2012 Cap $154.00 [Member] bbl	Dec. 28, 2012 Cap $144.50 [Member] bbl	Dec. 28, 2012 Cap $153.50 [Member] bbl	Dec. 28, 2012 Cap $117.80 [Member] bbl	Dec. 28, 2012 Cap $116.25 [Member] bbl	Mar. 31, 2013 Trade Date, March 5, 2012 [Member]	Mar. 31, 2013 Trade Date, February 7, 2012 [Member]	Mar. 31, 2013 Trade Date, December 28, 2012 [Member] Cap $143.50 [Member]	Mar. 31, 2013 Trade Date, December 28, 2012 [Member] Cap $154.00 [Member]	Mar. 31, 2013 Trade Date, December 28, 2012 [Member] Cap $144.50 [Member]	Mar. 31, 2013 Trade Date, December 28, 2012 [Member] Cap $153.50 [Member]	Mar. 31, 2013 Trade Date, December 28, 2012 [Member] Cap $117.80 [Member]	Mar. 31, 2013 Trade Date, December 28, 2012 [Member] Cap $116.25 [Member]	Mar. 31, 2013 Trade Date, February 7, 2013 [Member]	Mar. 31, 2013 Trade Date, April 10, 2012 [Member]	Mar. 31, 2013 Trade Date September 11, 2012 [Member]	Mar. 31, 2013 Trade Date December 7, 2012 [Member]	Mar. 31, 2013 Trade Date March 7, 2012 [Member]	Mar. 31, 2013 Trade Date May 3, 2012 [Member]	Mar. 31, 2013 Trade Date August 3, 2012 [Member]	Mar. 31, 2013 Trade Date October 4, 2012 [Member]	Mar. 31, 2013 Trade Date November 9, 2012 [Member]	Mar. 31, 2013 Trade Date January 8, 2013 [Member]
Derivative [Line Items]
Barrels of oil per Month		148,810	148,810	148,810	148,810	148,810	148,810	148,810	148,810	148,810	148,810	50,000	50,000	50,000	50,000	48,810	48,810	148,810	148,810
Floor		75.00	75.00	75.00	75.00	75.00	75.00	75.00	75.00	75.00	75.00	75.00	75.00	75.00	75.00	75.00	75.00	75.00	75.00
Cap		134.70	129.00	124.70	130.00	127.50	137.50	130.00	141.25	146.75	125.75	153.50	143.50	143.50	154.00	144.50	153.50	117.80	116.25
Assets, Fair Value	$ 9																			$ 0	$ 0	$ 0	$ 0	$ 0	$ 0			$ 9
Liabilities, Fair Value	$ 816																									$ 205	$ 221		$ 4	$ 6	$ 106	$ 74	$ 3	$ 43	$ 66	$ 41	$ 47