CONDENSED CONSOLIDATED STATEMENT OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (loss)	$ (51,194)	$ 40,255
Adjustments to reconcile net income (loss) to cash provided by operating activities:
Depreciation, depletion and amortization	161,887	175,497
Deferred income tax expense (benefit)	(28,973)	15,081
(Gain) loss on sale of assets	(1,354)	(138)
Exploratory dry hole cost	0	162
(Gain) loss on derivative instruments	(18,994)	(34,123)
Net cash received (paid) in settlement of derivative instruments	0	37,685
Earnings of equity method investments	(2,009)	(1,421)
Amortization of debt issuance costs	1,191	1,267
Stock-based compensation	10,606	5,911
Changes in assets and liabilities:
Accounts receivable, net	19,358	49,615
Income taxes	233	8,979
Inventories	1,101	(61)
Other current assets	1,300	(192)
Accounts payable, accrued liabilities and interest payable	(31,292)	(29,629)
Other assets and liabilities	230	1,930
Stock-based compensation tax benefit	0	(3,437)
Net cash provided by operating activities	62,090	267,381
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(92,237)	(395,242)
Proceeds from sale of assets	49,828	3,081
Investment in equity method investments	(11,652)	(5,078)
Net cash used in investing activities	(54,061)	(397,239)
CASH FLOWS FROM FINANCING ACTIVITIES
Borrowings from debt	90,000	382,000
Repayments of debt	(503,000)	(257,000)
Sale of common stock, net	995,278	0
Dividends paid	(8,282)	(8,263)
Stock-based compensation tax benefit	0	3,437
Capitalized debt issuance costs	(3,223)	0
Other	0	2,678
Net cash provided by financing activities	570,773	122,852
Net increase (decrease) in cash and cash equivalents	578,802	(7,006)
Cash and cash equivalents, beginning of period	514	20,954
Cash and cash equivalents, end of period	579,316	13,948
Supplemental non-cash transactions:
Change in accrued capital costs	$ (549)	$ (91,644)