Financial Instruments (Derivatives not Designated as Hedges) (Details) (USD $) In Millions	3 Months Ended		9 Months Ended
	May 01, 2011	May 02, 2010	May 01, 2011	May 02, 2010
Amount of Gain or (Loss) Recognized in Earnings on Derivatives	$ (53)	$ 1	$ (83)	$ (12)
Foreign Exchange Contracts [Member] | Other Expenses/Income [Member]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives	1	1		(3)
Foreign Exchange Contracts [Member] | Cost of Products Sold [Member]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives			(1)
Cross-currency Swap Contracts [Member] | Other Expenses/Income [Member]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives	(55)	(9)	(94)	(19)
Commodity Derivative Contracts [Member] | Cost of Products Sold [Member]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives	1	3	10
Equity Contracts [Member] | Administrative Expense [Member]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives		$ 6	$ 2	$ 10