SUPPLEMENTAL INFORMATION - NATURAL GAS AND CRUDE OIL PROPERTIES Results of Operations for Natural Gas and Crude Oil Producing Activities (Unaudited) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Line Items]
Lease operating expenses	$ 14,244	$ 13,824	$ 12,639	$ 16,285	$ 11,050	$ 11,020	$ 11,961	$ 8,371	$ 56,992	$ 42,402	$ 33,817
Production taxes	5,237	5,476	3,837	3,893	2,950	8,724	7,551	6,390	18,443	25,615	21,758
Transportation, gathering and processing expenses	$ 3,567	$ 3,938	$ 1,308	$ 1,338	$ 1,331	$ 1,208	$ 818	$ 1,235	10,151	4,592	5,152
Results of Operations for Crude Oil and Natural Gas Producing Activities
Results of Operations for Oil and Gas Producing Activities, by Geographic Area [Line Items]
Natural gas, NGL and crude oil sales									378,713	495,562	379,796
Commodity price risk management									203,183	309,219	(23,905)
Total Revenues from Oil and Gas Producing Activities									581,896	804,781	355,891
Lease operating expenses									56,992	43,682	40,339
Production taxes									18,443	27,194	25,474
Transportation, gathering and processing expenses									10,151	8,128	10,435
Exploration Expense									1,102	948	7,071
Impairment of Oil and Gas Properties									161,620	167,280	53,827
Depreciation, Depletion and Amortization									298,760	201,656	124,202
Accretion of Asset Retirement Obligations									6,293	3,455	4,747
(Gain) loss on Sale of Properties and Equipment									(385)	(75,972)	3,722
Total Expense from Oil and Gas Producing Activities									552,976	376,371	269,817
Results of Operations of Natural Gas and Crude Oil Producing Activities, Income before Income Taxes									28,920	428,410	86,074
Provision for Income Taxes									(10,394)	(166,930)	(31,109)
Results of operations for natural gas and crude oil producing activities, excluding corporate overhead and interest costs									$ 18,526	$ 261,480	$ 54,965