Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Cash flows from operating activities:
Net income	$ 977,341	$ 764,219	$ 739,385
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation, depletion, amortization and accretion	1,368,311	965,437	694,698
Property impairments	616,888	220,508	122,274
Non-cash (gain) loss on derivatives, net	(174,409)	130,196	(199,737)
Stock-based compensation	54,353	39,890	29,057
Provision for deferred income taxes	584,677	442,621	405,294
Excess tax benefit from stock-based compensation	0	0	(15,618)
Dry hole costs	23,679	9,350	767
Gain on sale of assets, net	(600)	(88)	(136,047)
Loss on extinguishment of debt	24,517	0	0
Other, net	7,637	2,037	5,007
Changes in assets and liabilities:
Accounts receivable	(129,634)	(166,138)	(91,791)
Inventories	(65,919)	(7,697)	(7,165)
Prepaid expenses and other	(57,489)	(11,537)	14,381
Accounts payable trade	85,540	107,250	(8,487)
Revenues and royalties payable	(18,022)	28,401	40,030
Accrued liabilities and other	58,880	44,260	40,309
Other noncurrent assets and liabilities	(35)	(5,414)	(292)
Net cash provided by operating activities	3,355,715	2,563,295	1,632,065
Cash flows from investing activities:
Exploration and development	(4,604,468)	(3,660,773)	(3,493,652)
Purchase of producing crude oil and natural gas properties	(48,917)	(16,604)	(570,985)
Purchase of other property and equipment	(63,402)	(62,054)	(53,468)
Proceeds from sale of assets and other	129,388	28,420	214,735
Net cash used in investing activities	(4,587,399)	(3,711,011)	(3,903,370)
Cash flows from financing activities:
Credit facility borrowings	1,695,000	970,000	2,119,000
Repayment of credit facility	(1,805,000)	(1,290,000)	(1,882,000)
Proceeds from issuance of Senior Notes	1,681,834	1,479,375	1,999,000
Redemption of Senior Notes	(300,000)	0	0
Premium on redemption of Senior Notes	(17,497)	0	0
Proceeds from other debt	0	0	22,000
Repayment of other debt	(2,013)	(1,951)	(1,579)
Debt issuance costs	(8,026)	(2,265)	(7,373)
Repurchase of equity grants	(16,583)	(14,690)	(11,236)
Excess tax benefit from stock-based compensation	0	0	15,618
Exercise of stock options	0	0	60
Net cash provided by financing activities	1,227,715	1,140,469	2,253,490
Effect of exchange rate on cash and cash equivalents	(132)
Net change in cash and cash equivalents	(4,101)	(7,247)	(17,815)
Cash and cash equivalents at beginning of period	28,482	35,729	53,544
Cash and cash equivalents at end of period	$ 24,381	$ 28,482	$ 35,729