Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017
Operating activities - cash provided by (used in):
Net income for the period	$ 45,502	$ 81,611
Adjustments to reconcile net income to cash provided by operating activities:
Depletion, depreciation and amortization	151,954	111,516
Unrealized loss (gain) on commodity derivatives	72,557	(4,133)
Deferred gain on sale of liquids gathering system	(7,915)	(7,915)
Stock compensation	11,547	34,182
Non-cash reorganization items, net		(451,099)
Amortization of deferred financing costs	8,333	4,781
Other	(1,046)	(1,014)
Net changes in operating assets and liabilities:
Accounts receivable	12,057	(91)
Other current assets	4,829	9,356
Other non-current assets	368	173
Accounts payable	(14,396)	38,619
Accrued liabilities	(6,439)	89,481
Production taxes payable	21,192	19,006
Interest payable	17,414	231,553
Other long-term obligations	(8,118)	(2,455)
Income taxes payable/receivable	6,844	(4,787)
Net cash provided by operating activities	314,683	148,784
Investing Activities - cash provided by (used in):
Oil and gas property expenditures	(339,918)	(386,754)
Change in capital cost accrual and accounts payable	(31,703)	20,437
Proceeds from sale of oil and gas properties	65,811
Inventory	(7,572)	(5,477)
Proceeds from sale of capital assets	2,872
Purchase of capital assets	(4,612)	(2,203)
Net cash used in investing activities	(315,122)	(373,997)
Financing activities - cash provided by (used in):
Borrowings under Credit Agreement	632,000	479,000
Payments under Credit Agreement	(632,000)	(459,000)
Borrowings under Term Loan		975,000
Extinguishment of long-term debt - (chapter 11)		(2,459,000)
Proceeds from issuance of Senior Notes		1,200,000
Deferred financing costs	(638)	(72,913)
Shares issued, net of transaction costs		573,774
Repurchased shares/net share settlements	(2,061)	(9,581)
Net cash (used in) provided by financing activities	(2,699)	227,280
(Decrease) increase in cash during the period	(3,138)	2,067
Cash, cash equivalents, and restricted cash, beginning of period	18,269	405,049
Cash, cash equivalents and restricted cash, end of period	$ 15,131	$ 407,116