Accumulated Other Comprehensive Income (Loss) (Components Of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Apr. 30, 2017	May 01, 2016	Apr. 30, 2017	May 01, 2016	Jul. 31, 2016
Beginning Balance				$ (104)
Other comprehensive income (loss), after tax		$ (5)	$ 79	(13)	$ 26
Ending Balance		(118)		(118)
Accumulated Translation Adjustment [Member]
Beginning Balance	[1]			(124)
Other Comprehensive Income (Loss) Before Reclassifications Net Of Tax				(29)
Other Comprehensive Income Reclassifications Current Period Net of Tax				0
Other comprehensive income (loss), after tax				(29)
Ending Balance	[1]	(153)		(153)
Other comprehensive income tax		(6)		(6)		$ (6)
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Beginning Balance	[2]			(41)
Other Comprehensive Income (Loss) Before Reclassifications Net Of Tax				21
Other Comprehensive Income Reclassifications Current Period Net of Tax				6
Other comprehensive income (loss), after tax				27
Ending Balance	[2]	(14)		(14)
Other comprehensive income tax		9		9		23
Accumulated Defined Benefit Plans Adjustment [Member]
Beginning Balance	[3]			61
Other Comprehensive Income (Loss) Before Reclassifications Net Of Tax				0
Other Comprehensive Income Reclassifications Current Period Net of Tax				(12)
Other comprehensive income (loss), after tax				(12)
Ending Balance	[3]	49		49
Other comprehensive income tax		(29)		(29)		$ (35)
Accumulated Other Comprehensive Income (Loss) [Member]
Beginning Balance				(104)
Other Comprehensive Income (Loss) Before Reclassifications Net Of Tax				(8)
Other Comprehensive Income Reclassifications Current Period Net of Tax				(6)
Other comprehensive income (loss), after tax				(14)	$ 24
Ending Balance		$ (118)		$ (118)

[1] Included a tax expense of $6 as of April 30, 2017, and July 31, 2016.

[2] Included a tax benefit of $9 as of April 30, 2017, and $23 as of July 31, 2016.

[3] Included a tax expense of $29 as of April 30, 2017, and $35 as of July 31, 2016.