CONDENSED CONSOLIDATED STATEMENT OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (loss)	$ (114,104)	$ 12,747
Adjustments to reconcile net income (loss) to cash provided by operating activities:
Depreciation, depletion and amortization	309,420	328,009
Deferred income tax expense (benefit)	(64,294)	7,160
(Gain) loss on sale of assets	(477)	(59)
Exploratory dry hole cost	18	178
(Gain) loss on derivative instruments	8,190	(27,304)
Net cash received (paid) in settlement of derivative instruments	11,305	88,730
Earnings on equity method investments	(1,935)	(2,933)
Amortization of debt issuance costs	2,692	2,337
Stock-based compensation and other	17,963	14,535
Changes in assets and liabilities:
Accounts receivable, net	2,118	99,897
Income taxes	516	(2,184)
Inventories	1,362	(6,397)
Other current assets	(1,858)	(2,953)
Accounts payable, accrued liabilities and interest payable	(24,318)	(65,023)
Other assets and liabilities	646	(2,663)
Stock-based compensation tax benefit	0	(5,486)
Net cash provided by operating activities	147,244	438,591
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(159,399)	(645,092)
Acquisitions	0	16,300
Proceeds from sale of assets	49,828	3,002
Investment in equity method investments	(18,171)	(10,114)
Net cash used in investing activities	(127,742)	(668,504)
CASH FLOWS FROM FINANCING ACTIVITIES
Borrowings from debt	90,000	642,000
Repayments of debt	(567,000)	(399,000)
Sale of common stock, net	995,279	0
Dividends paid	(17,582)	(16,537)
Stock-based compensation tax benefit	0	5,486
Capitalized debt issuance costs	(3,223)	(7,838)
Other	0	79
Net cash provided by financing activities	497,474	224,190
Net increase (decrease) in cash and cash equivalents	516,976	(5,723)
Cash and cash equivalents, beginning of period	514	20,954
Cash and cash equivalents, end of period	517,490	15,231
Supplemental non-cash transactions:
Change in accrued capital costs	$ 3,167	$ (134,875)