Computation of Basic and Diluted Earnings Per Common Share (Detail) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Mar. 31, 2012	Mar. 26, 2011	Mar. 31, 2012	Mar. 26, 2011
Numerator:
Net income	$ 11,622	$ 5,987	$ 24,686	$ 11,991
Denominator:
Weighted-average shares outstanding	933,582	923,196	932,265	921,245
Effect of dilutive securities	11,311	12,748	10,920	13,304
Weighted-average diluted shares	944,893	935,944	943,185	934,549
Basic earnings per common share	$ 12.45	$ 6.49	$ 26.48	$ 13.02
Diluted earnings per common share	$ 12.30	$ 6.40	$ 26.17	$ 12.83

The amount of net income (loss) for the period per each share of common stock or unit outstanding during the reporting period.

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+ Details

- Definition

The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

+ References+ Details

- Definition

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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-Glossary Other Comprehensive Income

-URI http://asc.fasb.org/extlink&oid=6519514

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

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-Glossary Net Income

-URI http://asc.fasb.org/extlink&oid=6518256

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-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 51

-Paragraph A7

-Appendix A

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+ Details

- Definition

The sum of dilutive potential common shares or units used in the calculation of the diluted per-share or per-unit computation.

+ References+ Details

- Definition

The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

+ References+ Details

- Definition

Number of [basic] shares or units, after adjustment for contingently issuable shares or units and other shares or units not deemed outstanding, determined by relating the portion of time within a reporting period that common shares or units have been outstanding to the total time in that period.

+ References

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

-Publisher FASB

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-Glossary Weighted-Average Number of Common Shares Outstanding

-URI http://asc.fasb.org/extlink&oid=6528421

+ Details