Accumulated Other Comprehensive Income (Loss) (Components Of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Apr. 29, 2018	Apr. 30, 2017	Apr. 29, 2018	Apr. 30, 2017	Jul. 30, 2017	Jul. 31, 2016
Beginning Balance				$ (53)
Other comprehensive income (loss), after tax		$ (55)	$ (5)	(24)	$ (13)
Ending Balance		(76)		(76)
Accumulated Other Comprehensive Income Foreign Currency Translation Tax (Benefit) Expense		6	6	6	6	$ 6	$ 6
Accumulated Other Comprehensive Income Cashflow Hedges Tax (Benefit) Expense		(5)	(9)	(5)	(9)	(12)	(23)
Accumulated Other Comprehensive Income Unamortized Pension And Post Retirement Tax (Benefit) Expense		24	29	24	29	$ 30	$ 35
Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Beginning Balance	[1]			(84)	(124)
Other Comprehensive Income (Loss) Before Reclassifications Net Of Tax				(24)	(29)
Reclassification from AOCI, Current Period, Net of Tax				0	0
Other comprehensive income (loss), after tax				(24)	(29)
Ending Balance	[1]	(108)	(153)	(108)	(153)
Accumulated Net Gain (Loss) from Cash Flow Hedges Attributable to Parent [Member]
Beginning Balance	[2]			(22)	(41)
Other Comprehensive Income (Loss) Before Reclassifications Net Of Tax				15	21
Reclassification from AOCI, Current Period, Net of Tax				2	6
Other comprehensive income (loss), after tax				17	27
Ending Balance	[2]	(5)	(14)	(5)	(14)
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Beginning Balance	[3]			53	61
Other Comprehensive Income (Loss) Before Reclassifications Net Of Tax				(2)	0
Reclassification from AOCI, Current Period, Net of Tax				(14)	(12)
Other comprehensive income (loss), after tax				(16)	(12)
Ending Balance	[3]	37	49	37	49
AOCI Attributable to Parent [Member]
Beginning Balance				(53)	(104)
Other Comprehensive Income (Loss) Before Reclassifications Net Of Tax				(11)	(8)
Reclassification from AOCI, Current Period, Net of Tax				(12)	(6)
Other comprehensive income (loss), after tax				(23)	(14)
Ending Balance		$ (76)	$ (118)	$ (76)	$ (118)

[1] Included a tax expense of $6 as of April 29, 2018, July 30, 2017, April 30, 2017, and July 31, 2016.

[2] Included a tax benefit of $5 as of April 29, 2018, $12 as of July 30, 2017, $9 as of April 30, 2017, and $23 as of July 31, 2016.

[3] Included a tax expense of $24 as of April 29, 2018, $30 as of July 30, 2017, $29 as of April 30, 2017, and $35 as of July 31, 2016.