Depreciation and Amortization (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	6 Months Ended
Feb. 29, 2012	Feb. 28, 2011	Feb. 29, 2012	Feb. 28, 2011
Notes to Financial Statements [Abstract]
Depreciation expense	$ 204	$ 200	$ 406	$ 408
Intangible asset amortization	61	46	121	98
System development costs amortization	18	10	33	23
Total depreciation and amortization expense	$ 283	$ 256	$ 560	$ 529

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by (used in) operations using the indirect method.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 142

-Paragraph 45

-Subparagraph a(2)

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- Definition

The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 28

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

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 12

-Paragraph 5

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- Definition

The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets.

+ References

No definition available.

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- Definition

For each income statement presented, the amount charged to expense for amortization of internally developed software costs.

+ References

No definition available.

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- Details

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