Industry Segments (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2015 segment	Mar. 31, 2014
Industry Segments
Number of operating segments	3us-gaap_NumberOfReportableSegments
Segment Information
Net sales	$ 3,089us-gaap_SalesRevenueNet	$ 4,968us-gaap_SalesRevenueNet
Pretax operating profit (loss)	(234)	1,931
Income taxes	19us-gaap_IncomeTaxExpenseBenefit	(794)us-gaap_IncomeTaxExpenseBenefit
Discontinued operations, net	(3)	255
Less: Income from continuing operations attributable to noncontrolling interest		(2)
Net income	(218)us-gaap_NetIncomeLoss	1,390us-gaap_NetIncomeLoss
Pre-tax impairment of oil and gas properties	310us-gaap_ImpairmentOfOilAndGasProperties
Other charges	14
Operating segments \| Oil and Gas
Segment Information
Net sales	2,009	3,602
Pretax operating profit (loss)	(266)	1,719
Net income	(266)	1,719
Operating segments \| Chemical
Segment Information
Net sales	1,000	1,220
Pretax operating profit (loss)	139	136
Net income	139	136
Operating segments \| Midstream and Marketing
Segment Information
Net sales	197	340
Pretax operating profit (loss)	(15)	164
Less: Income from continuing operations attributable to noncontrolling interest		(2)
Net income	(15)	162
Corporate and Eliminations
Segment Information
Net sales	(117)	(194)
Pretax operating profit (loss)	(92)	(88)
Income taxes	19	(794)
Discontinued operations, net	(3)	255
Net income	$ (76)	$ (627)

Represents the total corporate significant items affecting earnings before taxes.

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This element represents the income or loss from continuing operations before income taxes, and after income or loss from equity method investments.

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The expense recorded to reduce the value of oil and gas assets consisting of proved properties and unproved properties as the estimate of future successful production from these properties is reduced.

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Amount of income (loss) from a disposal group, net of income tax before extraordinary items allocable to noncontrolling interests. Includes, net of tax, income (loss) from operations during the phase-out period, gain (loss) on disposal, provision (or any reversals of earlier provisions) for loss on disposal, and adjustments of a prior period gain (loss) on disposal.

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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Amount of Net Income (Loss) attributable to noncontrolling interest.

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Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements.

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Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

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