Crude Oil and Natural Gas Property Information - Schedule of Results of Operations from Crude Oil and Natural Gas Producing Activities (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Oil and Gas Exploration and Production Industries Disclosures [Abstract]
Crude oil and natural gas sales	$ 4,203,022	$ 3,573,431	$ 2,349,500
Production expenses	(352,472)	(282,197)	(195,440)
Production taxes and other expenses (1)	(349,760)us-gaap_ResultsOfOperationsExpenseOther	(298,787)us-gaap_ResultsOfOperationsExpenseOther	(198,505)us-gaap_ResultsOfOperationsExpenseOther
Exploration Expense	(50,067)us-gaap_ExplorationExpense	(34,947)us-gaap_ExplorationExpense	(23,507)us-gaap_ExplorationExpense
Depreciation, depletion, amortization and accretion	(1,338,351)	(953,796)	(683,207)
Property impairments	(616,888)	(220,508)	(122,274)
Income taxes	(559,311)	(659,783)	(428,095)
Results from crude oil and natural gas producing activities	$ 936,173	$ 1,123,413	$ 698,472

Exploration expenses (including prospecting) related to oil and gas producing entities and would be included in operating expenses of that entity. Costs incurred in identifying areas that may warrant examination and in examining specific areas that are considered to have prospects of containing oil and gas reserves, including costs of drilling exploratory wells and exploratory-type stratigraphic test wells. Exploration costs may be incurred both before acquiring the related property (sometimes referred to in part as prospecting costs) and after acquiring the property. Principal types of exploration costs, which include depreciation and applicable operating costs of support equipment and facilities and other costs of exploration activities, are: (i) Costs of topographical, geographical and geophysical studies, rights of access to properties to conduct those studies, and salaries and other expenses of geologists, geophysical crews, and others conducting those studies. Collectively, these are sometimes referred to as geological and geophysical or "G&G" costs. (ii) Costs of carrying and retaining undeveloped properties, such as delay rentals, ad valorem taxes on properties, legal costs for title defense, and the maintenance of land and lease records. (iii) Dry hole contributions and bottom hole contributions. (iv) Costs of drilling and equipping exploratory wells. (v) Costs of drilling exploratory-type stratigraphic test wells.

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Depreciation, depletion and amortization, and valuation provisions (impairments) related to oil and gas producing activities.

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Other costs for oil and gas producing activities.

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Costs related to the impairment of oil and gas properties.

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Income tax expense for oil and gas producing activities.

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The results of operations for oil and gas producing activities, excluding corporate overhead and interest costs.

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Production (lifting) costs from oil and gas producing activities, including but not limited to lease operating expense, production and ad valorem taxes, and transportation expense.

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Total revenues from oil and gas producing activities.

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