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 loss	$ (203,806)	$ (971,410)	$ (183,176)
Adjustments to reconcile net loss to net cash provided by operating activities
Depreciation, depletion and amortization	92,948	244,750	89,218
Exploration expense	30,853	95,849	6,433
Pension benefit costs		259	56
Stock-based compensation	6,216	4,635	256
Impairment of proved oil and gas properties	17,665	691,334	34,855
Accretion of asset retirement obligations	391	1,623	791
Gain on reduction of pension obligations			(2,208)
(Gain) loss on derivative instruments	52,338	(56,021)	(20,791)
Net cash receipts (payments) on settled derivatives	38,696	37,074	564
Net cash payments on option premiums			(385)
(Gain) loss on sale of assets	6,936	(4,737)	(960)
Gain on sale of business		(400)	(353)
(Gain) loss on early extinguishment of debt	(14,489)	59,392
Deferred income taxes	540	(72,761)	71,667
Interest not paid in cash		1,232	15,721
Amortization of deferred financing costs	1,962	1,991	1,744
Amortization of debt discount	1,362	1,886	2,308
Changes in operating assets and liabilities:
Accounts receivable	(20,563)	20,437	(33,605)
Other assets	(1,795)	445	(1,188)
Accounts payable and accrued liabilities	(2,849)	24,721	29,517
Accrued liabilities - affiliate			(1,951)
Net cash provided by operating activities	6,405	80,299	8,513
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures for oil and gas properties	(167,355)	(475,659)	(731,013)
Capital expenditures for other property and equipment	(1,164)	(1,748)	(3,637)
Proceeds from sale of assets	79,201	40,139	15,460
Acquisition of business, net of cash acquired			754
Net cash used in investing activities	(89,318)	(437,268)	(718,436)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from issuance of long-term debt		538,466
Debt issuance costs	30	(13,362)	(1,232)
Repayments of long-term debt	(24,045)	(485,317)	(213)
Capital contributions			124,667
Proceeds from issuance of common stock	124,361	440,000	550,025
Equity issuance costs	(548)	(5,930)	(5,316)
Employee tax withholding for settlement of equity compensation awards	(61)
Net cash provided by financing activities	99,737	473,857	667,931
Net increase (decrease) in cash and cash equivalents	16,824	116,888	(41,992)
Cash and cash equivalents at beginning of period	184,405	67,517	109,509
Cash and cash equivalents at end of period	201,229	184,405	67,517
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash paid for interest	48,483	39,808	26,020
Cash paid for income taxes		505
SUPPLEMENTAL DISCLOSURE OF NON-CASH ACTIVITIES
Asset retirement obligations incurred, including changes in estimate	1,014	3,435	7,554
Additions of other property through debt financing		888	945
Additions to oil and natural gas properties - changes in accounts payable, accrued liabilities, and accrued capital expenditures	$ 8,583	(142,665)	126,656
Assets held for sale		(35,289)	20,673
Interest paid-in-kind		$ 14,786	$ 22,461