Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Net income (loss)	$ 62,801	$ 96,327
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation, depletion and amortization	136,897	113,454
(Gain) loss on derivatives, net	97,310	(51,381)
Cash (paid) received for derivative settlements, net	(38,448)	1,258
Loss on extinguishment of debt	8,676	0
Stock-based compensation expense, net	10,724	3,596
Deferred income taxes	529	0
Non-cash interest expense, net	1,262	2,074
Other, net	3,975	2,767
Changes in components of working capital and other assets and liabilities-
Accounts receivable	2,437	(8,094)
Accounts payable	3,878	14,486
Accrued liabilities	(12,883)	5,650
Other assets and liabilities, net	(1,286)	(982)
Net cash provided by operating activities	275,872	179,155
Cash Flows From Investing Activities
Capital expenditures	(430,639)	(290,625)
Acquisitions of oil and gas properties	0	(16,533)
Deposit for pending acquisition of oil and gas properties	0	(75,000)
Proceeds from divestitures of oil and gas properties, net	345,789	18,201
Other, net	(1,096)	(2,479)
Net cash used in investing activities	(85,946)	(366,436)
Cash Flows From Financing Activities
Redemptions of senior notes	(330,435)	0
Redemption of preferred stock	(50,030)	0
Borrowings under credit agreement	1,126,856	919,097
Repayments of borrowings under credit agreement	(933,156)	(723,797)
Payments of debt issuance costs	(627)	(4,368)
Payment of Commitment Fees for Preferred Stock	0	(5,000)
Payments of dividends on preferred stock	(9,337)	0
Other, net	(638)	(617)
Net cash provided by (used in) financing activities	(197,367)	185,315
Net Decrease in Cash and Cash Equivalents	(7,441)	(1,966)
Cash and Cash Equivalents, Beginning of Period	9,540	4,194
Cash and Cash Equivalents, End of Period	$ 2,099	$ 2,228