Condensed Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Statement of Other Comprehensive Income [Abstract]
Net income	$ 1,107	$ 454	$ 3,557	$ 2,749
Other comprehensive income (loss), net of reclassification adjustments and income taxes	(4)	73	(24)	(35)
Comprehensive income	$ 1,103	$ 527	$ 3,533	$ 2,714

The change in equity [net assets] of a business enterprise during a period from transactions and other events and circumstances from non-owner sources which are attributable to the reporting entity. It includes all changes in equity during a period except those resulting from investments by owners and distributions to owners, but excludes any and all transactions which are directly or indirectly attributable to that ownership interest in subsidiary equity which is not attributable to the parent.

+ References+ Details

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

+ References

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

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Reference 4: http://www.xbrl.org/2003/role/presentationRef

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Reference 7: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

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-Number 210

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Reference 8: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Net Income

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-Name Emerging Issues Task Force (EITF)

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Reference 14: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

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-Name Accounting Research Bulletin (ARB)

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Reference 16: http://www.xbrl.org/2003/role/presentationRef

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+ Details

- Definition

Net of tax amount of other comprehensive income (loss) attributable to the parent entity.

+ References

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

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-Topic 810

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+ Details