SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Property and Equipment and Goodwill) (Details) (USD $)	12 Months Ended							3 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Minimum	Dec. 31, 2013 Maximum	Dec. 31, 2012 United States	Dec. 31, 2012 South Africa	Dec. 31, 2013 Texas Panhandle Area	Dec. 31, 2013 Texas Panhandle Area	Dec. 31, 2012 Italy
Property, Plant and Equipment
General and administrative costs (including stock-based compensation) capitalized to oil and gas properties related to its continuing operations	$ 34,000,000	$ 37,800,000	$ 46,400,000
Interest costs capitalized to unproved oil and gas properties of its continuing operations	1,967,000	7,223,000	10,259,000
Impairment of unproved properties							66,900,000
Discount factor used in full cost ceiling test (as a percent)	10.00%
Ceiling test write-down of oil and natural gas properties	57,636,000	992,404,000	0			957,587,000				34,817,000
Gain on asset dispositions, net	202,023,000	0	0					193,000,000	193,000,000
Proceeds reducing capitalized costs for previous sale of oil and natural gas properties (as a percent)	100.00%
Furniture and fixtures, leasehold improvements, computer hardware and software, and other equipment - useful lives (in years)				3 years	15 years
Goodwill
Goodwill allocated to the Panhandle divestiture									$ 105,000,000
Reserve percentage threshold for determining whether a significant alteration of the relationship between capitalized costs and reserves occurs upon a sale of reserves	25.00%