Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities
Net income	$ 233,946	$ 469
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, Depletion, Amortization and Accretion	455,559	381,385
Property impairments	33,784	51,372
Non-cash gain on derivatives, net	(5,978)	(45,155)
Stock-based compensation	10,916	11,438
Provision for deferred income taxes	71,536	6,021
Dry hole costs	1	157
(Gain) loss on sale of assets, net	(41)	3,638
Other, net	3,397	3,099
Changes in assets and liabilities:
Accounts receivable	38,268	(22,053)
Inventories	(9,763)	13,297
Other current assets	(6,343)	(3,111)
Accounts payable trade	48,307	61,745
Revenues and royalties payable	18,541	20,543
Accrued liabilities and other	(5,848)	(12,338)
Other noncurrent assets and liabilities	(91)	(306)
Net cash provided by operating activities	886,191	470,201
Cash flows from investing activities
Exploration and development	(618,200)	(388,596)
Purchase of producing crude oil and natural gas properties	(2,647)	(137)
Purchase of other property and equipment	(7,421)	(6,336)
Proceeds from sale of assets	57	5,798
Net cash used in investing activities	(628,211)	(389,271)
Cash flows from financing activities
Credit facility borrowings	370,000	256,000
Repayment of credit facility	(558,000)	(326,000)
Repayment of other debt	(566)	(548)
Debt issuance costs	(312)	0
Repurchase of restricted stock for tax withholdings	(14,846)	(9,837)
Net cash used in financing activities	(203,724)	(80,385)
Effect of Exchange Rate on Cash and Cash Equivalents	(13)	0
Net change in cash and cash equivalents	54,243	545
Cash and cash equivalents at beginning of period	43,902	16,643
Cash and cash equivalents at end of period	$ 98,145	$ 17,188