Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss	$ (157,541)	$ (150,153)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation, depletion and amortization	170,245	51,967
Exploration expense	7,118	5,091
Pension benefit costs	76	69
Stock-based compensation	3,394	87
Impairment of proved oil and gas properties		4,605
Accretion of asset retirement obligations	1,197	575
Gain on reduction of pension obligation		(2,208)
Gain on derivative instruments	(31,527)	(1,098)
Net cash received (paid) on settled derivatives	23,754	(1,647)
Net cash paid for option premium		(385)
Gain on sale of assets	(5,183)	(1,585)
Loss on early extinguishment of debt	59,392
Deferred income taxes	(52,447)	83,997
Interest not paid in cash	1,232	2,166
Amortization of deferred financing costs	1,481	1,314
Amortization of debt discount	1,529	1,711
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable	23,126	(37,187)
Other assets	(619)	(1,213)
Accounts payable and accrued liabilities	15,491	21,270
Accrued liabilities-related parties		(1,951)
Net cash provided by (used in) operating activities	60,718	(24,575)
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures on oil and natural gas properties	(410,527)	(495,950)
Additions to other property and equipment	(1,327)	(2,986)
Acquisition of business, net of cash acquired		754
Proceeds from the sale of assets	37,287
Net cash used in investing activities	(374,567)	(498,182)
CASH FLOWS FROM FINANCING ACTIVITIES
Repayments of long-term debt	(485,158)	(166)
Proceeds from issuance of long-term debt	538,466
Debt issuance costs	(13,232)	(1,232)
Capital contributions		124,667
Proceeds from issuance of common stock, net of underwriting fees	440,000	550,025
Equity issuance costs	(5,875)	(5,303)
Net cash provided by financing activities	474,201	667,991
Net increase in cash and cash equivalents	160,352	145,234
Cash and cash equivalents at beginning of period	67,517	109,509
Cash and cash equivalents at end of period	227,869	254,743
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid for interest	39,125	25,865
Cash paid for income taxes	284
SUPPLEMENTAL DISCLOSURE OF NON-CASH ACTIVITIES:
Asset retirement obligations incurred, including changes in estimate	495	420
Additions of other property through debt financing	888	823
Oil and natural gas properties - changes in accounts payable, accrued liabilities, and accrued capital expenditures	(120,751)	114,639
Interest paid-in-kind	$ 14,786	$ 22,461