Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash flows from operating activities
Net income (loss)	$ 476,410	$ (63,088)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation, Depletion, Amortization and Accretion	902,217	774,810
Property impairments	62,946	174,689
Non-cash (gain) loss on derivatives, net	11,465	(68,420)
Stock-based compensation	21,478	20,571
Provision (benefit) for deferred income taxes	146,768	(31,834)
Dry hole costs	1	157
(Gain) loss on sale of assets, net	(6,751)	2,859
Other, net	7,159	5,089
Changes in assets and liabilities:
Accounts receivable	(79,043)	(19,347)
Inventories	(17,904)	14,984
Other current assets	(8,138)	(2,225)
Accounts payable trade	103,710	105,441
Revenues and royalties payable	5,857	21,105
Accrued liabilities and other	17,550	(17,968)
Other noncurrent assets and liabilities	(3,732)	(251)
Net cash provided by operating activities	1,639,993	916,572
Cash flows from investing activities
Exploration and development	(1,334,681)	(877,115)
Purchase of producing crude oil and natural gas properties	(24,097)	(812)
Purchase of other property and equipment	(12,205)	(9,372)
Proceeds from sale of assets	27,380	7,979
Net cash used in investing activities	(1,343,603)	(879,320)
Cash flows from financing activities
Credit facility borrowings	803,000	540,000
Repayment of credit facility	(991,000)	(565,000)
Repayment of other debt	(1,134)	(1,099)
Debt issuance costs	(5,524)	0
Repurchase of restricted stock for tax withholdings	(15,619)	(10,620)
Net cash used in financing activities	(210,277)	(36,719)
Effect of Exchange Rate on Cash and Cash Equivalents	(26)	14
Net change in cash and cash equivalents	86,087	547
Cash and cash equivalents at beginning of period	43,902	16,643
Cash and cash equivalents at end of period	$ 129,989	$ 17,190