CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (loss)	$ (292,151)	$ (98,196)	$ 43,881
Adjustments to reconcile net income (loss) to cash provided by operating activities:
Depreciation, depletion and amortization	145,614	162,262	154,356
Impairment of property and equipment	7,593	41,917	12,027
Abandonments and impairments	3,536	6,509	20,647
(Gain) loss on sales of assets and impairment of inventory, net	(118,786)	3,018	(9,138)
Deferred income tax expense (benefit)	(32,400)	(55,218)	24,460
Non-cash employee compensation	(6,019)	(2,674)	1,397
(Gain) loss on commodity derivatives	20,289	(12,519)	(4,789)
Cash settlements of commodity derivatives	(7,394)	12,519	7,099
Loss on change in fair value of common stock warrants	229,980	0	0
Accretion of asset retirement obligations	4,364	3,945	3,662
Amortization of debt issue costs and original issue discount	7,106	3,246	3,030
Gain on early extinguishment of long-term debt	(3,967)	0	0
Amortization of deferred revenue from volumetric production payment	(1,479)	(6,822)	(7,708)
Paid in-kind interest expense	27,196	0	0
Impairment of investment and other	8,751	1,542	0
Changes in operating working capital:
Accounts receivable	(2,577)	30,817	5,255
Accounts payable	10,657	(35,860)	4,561
Other	10,414	(2,327)	(619)
Net cash provided by operating activities	10,727	52,159	258,121
CASH FLOWS FROM INVESTING ACTIVITIES
Additions to property and equipment	(111,541)	(179,827)	(422,473)
Termination of volumetric production payment	0	(13,703)	0
Proceeds from sales of assets	423,905	71,460	104,529
(Increase) decrease in equipment inventory	1,414	1,733	(1,886)
Proceeds from volumetric production payment and other	(551)	2,942	833
Net cash provided by (used in) investing activities	313,227	(117,395)	(318,997)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from long-term debt	343,237	45,000	102,139
Net repayments of Senior Notes	(95,001)	0	0
Repayments of long-term debt	(160,000)	0	(40,000)
Payment of debt issuance costs	(11,048)	0	0
Proceeds from sale of common stock	147,340	0	0
Proceeds from issuance of common stock warrants	16,763	0	0
Proceeds from exercise of stock options	0	0	130
Net cash provided by financing activities	241,291	45,000	62,269
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	565,245	(20,236)	1,393
CASH AND CASH EQUIVALENTS
Beginning of period	7,780	28,016	26,623
End of period	573,025	7,780	28,016
SUPPLEMENTAL DISCLOSURES
Cash paid for interest, net of amounts capitalized	49,451	51,293	47,817
Cash paid for income taxes	$ 135	$ 0	$ 1,600