Share Repurchases (Schedule Of Company's Share Repurchases) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended
Apr. 30, 2013	Apr. 30, 2012
Equity, Class of Treasury Stock [Line Items]
Total Number of Shares Repurchased	30.8	26.3
Average Price Paid per Share	$ 72.87	$ 60.43
Total Share Repurchase	$ 2,246	$ 1,589

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

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