CONDENSED CONSOLIDATED STATEMENT OF CASH FLOWS (Unaudited) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 326,239	$ 201,827
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation, depletion and amortization	458,995	469,022
Deferred income tax expense	181,439	107,235
(Gain) loss on sale of assets	2,735	(4,601)
Exploration expense	6,454	807
Unrealized (gain) loss on derivative instruments	(44,766)	0
Amortization of debt issuance costs	3,378	2,767
Stock-based compensation and other	13,304	36,684
Changes in assets and liabilities:
Accounts receivable, net	30,418	(6,321)
Income taxes	(23,430)	(3,639)
Inventories	3,737	(6,665)
Other current assets	(147)	(1,547)
Accounts payable and accrued liabilities	(9,712)	(19,837)
Other assets and liabilities	607	228
Stock-based compensation tax benefit	(6,001)	(9,284)
Net cash provided by operating activities	943,250	766,676
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(964,741)	(843,400)
Acquisitions	(15,826)	(128)
Proceeds from sale of assets	3,913	15,174
Restricted cash	28,094	0
Investment in equity method investments	(28,784)	(8,624)
Net cash used in investing activities	(977,344)	(836,978)
CASH FLOWS FROM FINANCING ACTIVITIES
Borrowings from debt	1,802,000	585,000
Repayments of debt	(1,337,000)	(510,000)
Treasury stock repurchases	(119,767)	0
Dividends paid	(25,018)	(16,830)
Stock-based compensation tax benefit	6,001	9,284
Capitalized debt issuance costs	(5,626)	0
Other	91	44
Net cash provided by financing activities	320,681	67,498
Net increase (decrease) in cash and cash equivalents	286,587	(2,804)
Cash and cash equivalents, beginning of period	23,400	30,736
Cash and cash equivalents, end of period	$ 309,987	$ 27,932