Supplemental Cash Flow Information (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Decrease (increase) in current assets:
Receivables, net	$ 2,753us-gaap_IncreaseDecreaseInReceivables	$ (753)us-gaap_IncreaseDecreaseInReceivables	$ 437us-gaap_IncreaseDecreaseInReceivables
Inventories	(1,014)us-gaap_IncreaseDecreaseInInventories	(13)us-gaap_IncreaseDecreaseInInventories	(282)us-gaap_IncreaseDecreaseInInventories
Income taxes receivable	(23)	10	51
Prepaid expenses and other	(32)	2	(28)
Increase (decrease) in current liabilities:
Accounts payable	(3,149)	977	(113)
Accrued expenses	38	53	13
Taxes other than income taxes	(64)	337	(260)
Income taxes payable	(319)	309	(120)
Changes in current assets and current liabilities	(1,810)	922	(302)
Cash Flows Related to Interest and Income Taxes
Interest paid in excess of amount capitalized	392us-gaap_InterestPaidNet	361us-gaap_InterestPaidNet	302us-gaap_InterestPaidNet
Income taxes paid, net	$ 1,624us-gaap_IncomeTaxesPaidNet	$ 387us-gaap_IncomeTaxesPaidNet	$ 705us-gaap_IncomeTaxesPaidNet

The amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income, net of any cash received during the current period as refunds for the overpayment of taxes.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4297-108586

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The increase (decrease) during the reporting period in the aggregate amount of liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received that are used in an entity's business.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

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The increase (decrease) during the period in the amount due for taxes based on the reporting entity's earnings or attributable to the entity's income earning process (business presence) within a given jurisdiction.

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The increase (decrease) during the reporting period in the aggregate amount of expenses incurred but not yet paid.

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The increase (decrease) during the reporting period in income taxes receivable, which represents the amount due from tax authorities for refunds of overpayments or recoveries of income taxes paid.

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The increase (decrease) during the reporting period in the aggregate value of all inventory held by the reporting entity, associated with underlying transactions that are classified as operating activities.

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The increase (decrease) during the reporting period in other current operating assets less other current operating liabilities not separately disclosed in the statement of cash flows.

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The increase (decrease) during the reporting period in the value of prepaid expenses and other assets not separately disclosed in the statement of cash flows, for example, deferred expenses, intangible assets, or income taxes.

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The increase (decrease) during the period in the amount of cash payments due to taxing authorities for non-income-related taxes.

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The increase (decrease) during the reporting period in the total amount due within one year (or one operating cycle) from all parties, associated with underlying transactions that are classified as operating activities.

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The amount of cash paid for interest during the period net of cash paid for interest that is capitalized.

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