Financial Instruments (Derivatives Not Designated As Hedges) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	May. 01, 2016	May. 03, 2015	May. 01, 2016	May. 03, 2015
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives	$ (5)	$ (1)	$ (4)	$ 36
Foreign Exchange Forward Contracts [Member] | Cost Of Products Sold [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives	1	2	0	2
Foreign Exchange Forward Contracts [Member] | Other expenses / (income) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives	2	(1)	1	(1)
Currency Swap [Member] | Other expenses / (income) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives	(21)	(10)	(9)	42
Commodity Derivative Contracts [Member] | Cost Of Products Sold [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives	9	6	0	(12)
Deferred Compensation Derivative Contracts [Member] | General and Administrative Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of Gain or (Loss) Recognized in Earnings on Derivatives	$ 4	$ 2	$ 4	$ 5