Supplemental Cash Flow Information (Details) (USD $) In Millions	9 Months Ended
Sep. 30, 2011	Sep. 30, 2010
Net cash provided from operating activities:
Interest paid (net of amounts capitalized)	$ 197	$ 93
Income taxes paid to taxing authorities	2,183	1,426
Noncash investing and financing activities
Debt payments made on our behalf	18	106
Additions to property, plant and equipment	2,437	2,703
Change In capital accruals	(61)	(201)
Capital expenditures	$ 2,376	$ 2,502

Total expenditures for additions to long-lived assets other than financial instruments, long-term customer relationships of a financial institution, mortgage and other servicing rights, deferred policy acquisition costs, and deferred tax assets. This amount includes accruals.

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- Definition

The cash expense associated with the acquisition of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale; includes cash accruals to pay for construction of self-constructed asset.

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- Definition

Marathon and U.S. Steel separated on January 1, 2002. US Steel services long-term debt that is on Marathon's books. These are payments made by U.S. Steel related to debt service or redemption.

+ Details

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- Definition

Designated to encapsulate the entire footnote disclosure that gives information on the supplemental cash flow activities for noncash (or part noncash) transactions for the period. Noncash is defined as information about all investing and financing activities of an enterprise during a period that affect recognized assets or liabilities but that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

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- Definition

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.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 29

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 27

-Subparagraph f

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- Definition

The amount of cash paid during the current period for interest owed on money borrowed, net of interest capitalized.

+ References

+ Details

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- Definition

The net cash from (used in) all of the entity's operating activities, including those of discontinued operations, of the reporting entity. Operating activities include all transactions and events that are not defined as investing or financing activities. Operating activities generally involve producing and delivering goods and providing services. Cash flows from operating activities are generally the cash effects of transactions and other events that enter into the determination of net income.

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- Definition

The cash outflow associated with the acquisition of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale; includes cash outflows to pay for construction of self-constructed assets.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 15

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 17

-Subparagraph c

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