DIVESTITURES AND DISCONTINUED OPERATIONS Additional Information (Details) (USD $)	6 Months Ended		3 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 Permian Basin [Member]	Dec. 31, 2011 Permian Basin [Member]	Mar. 31, 2011 North Dakota [Member]
Significant Acquisitions and Disposals [Line Items]
Proceeds from Sale of Oil and Gas Property and Equipment	$ 187,340,000	$ 10,062,000	$ 189,200,000	$ 13,200,000	$ 9,500,000
Oil and gas assets sale price before adjustments			173,900,000
Proceeds to non-affiliated investor partners					$ 3,800,000