CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss	$ (1,582,961)	$ (409,592)	$ (143,070)
Adjustments to reconcile net loss to net cash provided by operating activities:
Loss on extinguishment of debt	0	0	29,174
Depreciation, depletion and amortization	334,479	300,299	245,594
Impairments	1,397,424	791,809	132,224
Accretion of firm transportation obligation	942	1,301	1,674
Derivative contracts:
Net (gains) losses	(71,247)	(162,212)	20,852
Cash settlements, net	138,169	(7,424)	(1,042)
Deferred income tax benefit	(4,712)	(135,227)	(77,696)
(Gain) loss on sales of assets, net	(41,335)	(120,769)	266
Non-cash exploration expense	5,759	10,346	17,451
Non-cash interest expense	4,749	4,197	3,844
Share-based compensation (equity-classified)	4,540	3,627	5,781
Other, net	13	94	297
Changes in operating assets and liabilities:
Accounts receivable, net	137,854	(20,169)	(105,023)
Accounts payable and accrued expenses	(152,553)	27,362	129,670
Other assets and liabilities	(1,818)	(918)	1,516
Net cash provided by operating activities	169,303	282,724	261,512
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures – property and equipment	(364,844)	(774,139)	(504,203)
Acquisition, net	0	0	(358,239)
Receipts (payments) to settle working capital adjustments assumed in acquisition, net	0	33,712	(22,455)
Proceeds from sales of assets, net	85,189	313,933	(54)
Net cash used in investing activities	(279,655)	(426,494)	(884,951)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from revolving credit facility borrowings	233,000	412,000	297,000
Repayment of revolving credit facility borrowings	(98,000)	(583,000)	(91,000)
Proceeds from the issuance of preferred stock, net	0	313,330	0
Payments to induce conversion of preferred stock	0	(4,256)	0
Proceeds from the issuance of senior notes	0	0	775,000
Retirement of senior notes	0	0	(319,090)
Debt issuance costs paid	(744)	(151)	(25,634)
Dividends paid on preferred stock	(18,201)	(12,803)	(6,862)
Other, net	0	1,428	(151)
Net cash provided by financing activities	116,055	126,548	629,263
Net increase (decrease) in cash and cash equivalents	5,703	(17,222)	5,824
Cash and cash equivalents - beginning of period	6,252	23,474	17,650
Cash and cash equivalents - end of period	11,955	6,252	23,474
Cash paid for:
Cash paid for interest (net of amounts capitalized)	86,226	84,797	65,107
Cash paid for income taxes (net of refunds received)	(714)	3,612	0
Changes in accrued liabilities related to capital expenditures	(55,660)	24,715	6,356
Other assets acquired related to acquisition	0	0	99,213
Other liabilities assumed related to acquisition	0	0	96,271
Common stock transferred as consideration for acquisition	$ 0	$ 0	$ 42,300