CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
CASH FLOWS FROM OPERATING ACTIVITIES:
Net loss	$ (22,931)	$ (56,577)
Adjustments to reconcile net loss to net cash provided by (used for) operating activities:
Deferred income taxes	359	4,446
Gain on sale of oil and gas properties		(740)
Exploratory lease impairments		7,753
Impairment of oil and gas properties		22,718
Depreciation, depletion and amortization	29,905	38,836
Gain on derivative financial instruments	(7,860)	(656)
Cash settlements of derivative financial instruments	505	998
Gain on extinguishment of debt		(33,380)
Amortization of debt discount, premium and issuance costs	5,435	1,281
Interest paid in-kind	9,240
Stock-based compensation	1,265	1,330
(Increase) decrease in accounts receivable	(2,048)	4,287
Decrease in other current assets	362	109
Decrease in accounts payable and accrued expenses	(11,025)	(21,444)
Net cash provided by (used for) operating activities	3,207	(31,039)
CASH FLOWS FROM INVESTING ACTIVITIES:
Capital expenditures	(38,401)	(14,185)
Proceeds from sales of oil and gas properties		868
Net cash used for investing activities	(38,401)	(13,317)
CASH FLOWS FROM FINANCING ACTIVITIES:
Common stock warrants exercised	1
Debt and equity issuance costs		(15)
Tax withholdings related to equity awards	(271)	(312)
Net cash used for financing activities	(270)	(327)
Net decrease in cash and cash equivalents	(35,464)	(44,683)
Cash and cash equivalents, beginning of period	65,904	134,006
Cash and cash equivalents, end of period	$ 30,440	$ 89,323