BASIS OF PRESENTATION (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Oil and Gas Properties
Discount rate for calculating present value of estimated future net revenues from proved reserves (as a percent)			10.00%
Impairment of oil and gas properties	$ 399,194	$ 967,287	$ 629,326	$ 1,570,886
Impairment of oil and gas properties, after tax	253,600		400,000
Receivables, net of allowance
Trade	54,188		54,188		$ 81,888
Oil and gas sales	166,866		166,866		136,537
Gas gathering, processing, and marketing	8,568		8,568		6,935
Other	12		12		38
Receivables, net	229,634		229,634		225,398
Accounts payable:
Trade	39,224		39,224		53,384
Gas gathering, processing, and marketing	16,340		16,340		13,431
Accounts payable	55,564		55,564		66,815
Accrued liabilities
Exploration and development	46,761		46,761		56,721
Taxes other than income	15,947		15,947		17,545
Other	157,446		157,446		173,242
Accrued liabilities	$ 220,154		$ 220,154		$ 247,508