Share Repurchases (Schedule Of Company's Share Repurchases) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	9 Months Ended
Oct. 31, 2011	Oct. 31, 2010
Share Repurchases [Abstract]
Total Number of Shares Repurchased	92.4	209.3
Average Price Paid per Share	$ 53.61	$ 52.44
Total Investment	$ 4,957	$ 10,972

Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

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

-Publisher FASB

-Name Accounting Standards Codification

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-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 12

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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

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-Publisher AICPA

-Name Accounting Research Bulletin (ARB)

-Number 43

-Chapter 1

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-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

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Balance Type:	debit
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