Consolidated Statements Of Cash Flows (USD $) In Millions	6 Months Ended
Jun. 30, 2011	Jun. 30, 2010
Operating activities:
Net income	$ 1,331	$ 116
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	434	489
Pension and other postretirement benefits, net	62	71
Deferred income taxes	34	121
Net gain on disposal of assets	(5)	(3)
Equity method investments, net	(6)	(26)
Changes in the fair value of derivative instruments	(92)	(28)
Changes in:
Current receivables	(746)	(256)
Inventories	(613)	(238)
Current accounts payable and accrued liabilities	628	34
Receivables from / payables to related parties	(59)	13
All other, net	(16)	2
Net cash provided by operating activities	952	295
Investing activities:
Additions to property, plant and equipment	(517)	(634)
Acquisitions	(74)
Disposal of assets	133	7
Investments in related party debt securities - purchases	(10,326)	(6,023)
Investments in related party debt securities - redemptions	12,730	6,476
Investments - loans and advances	(42)	(17)
Investments - repayments of loans	35	21
All other, net	5	(2)
Net cash provided by (used in) investing activities	1,944	(172)
Financing activities:
Long-term debt payable to Marathon Oil and subsidiaries - borrowings	7,748	5,533
Long-term debt payable to Marathon Oil and subsidiaries - repayments	(11,366)	(5,125)
Long-term debt - borrowings	2,989
Long-term debt - repayments	(6)	(5)
Debt issuance costs	(58)
Distributions to Marathon Oil	(699)	(500)
Net cash used in financing activities	(1,392)	(97)
Net increase in cash and cash equivalents	1,504	26
Cash and cash equivalents at beginning of period	118	128
Cash and cash equivalents at end of period	$ 1,622	$ 154

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Includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Entity may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months. Compensating balance arrangements that do not legally restrict the withdrawal or usage of cash amounts may be reported as Cash and Cash Equivalents, while legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or company statements of intention with regard to particular deposits are not generally reported as cash and cash equivalents. Includes cash and cash equivalents associated with the entity's continuing operations. Excludes cash and cash equivalents associated with the disposal group (and discontinued operation).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.1)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 1
-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 7
-Footnote 1
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3044-108585

Reference 5: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 8, 9
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 6: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6361293&loc=d3e6676-107765

Reference 7: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Cash
-URI http://asc.fasb.org/extlink&oid=6506951

Reference 8: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 7, 26
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 9: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Cash Equivalents
-URI http://asc.fasb.org/extlink&oid=6507016