Accumulated Other Comprehensive Income (Loss) (Components Of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jan. 27, 2019	Jan. 28, 2018	Jan. 27, 2019	Jan. 28, 2018	Jul. 29, 2018	Jul. 30, 2017
Beginning Balance				$ (118)
Other comprehensive income (loss), after tax		$ 13	$ 63	(34)	$ 31
Ending Balance		(143)		(143)
Accumulated Other Comprehensive Income Foreign Currency Translation Tax (Benefit) Expense		4	6	4	6	$ 6	$ 6
Accumulated Other Comprehensive Income Cashflow Hedges Tax (Benefit) Expense		(1)	(8)	(1)	(8)	(4)	(12)
Accumulated Other Comprehensive Income Unamortized Pension And Post Retirement Tax (Benefit) Expense		12	25	12	25	25	$ 30
Accumulated Translation Adjustment [Member]
Beginning Balance	[1]			(154)	(84)
Other Comprehensive Income (Loss) Before Reclassifications Net Of Tax				(23)	35
Other Comprehensive Income Reclassifications Current Period Net of Tax				0	0
Other comprehensive income (loss), after tax				(23)	35
Ending Balance	[1]	(175)	(49)	(175)	(49)
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Beginning Balance	[2]			(4)	(22)
Other Comprehensive Income (Loss) Before Reclassifications Net Of Tax				(1)	7
Other Comprehensive Income Reclassifications Current Period Net of Tax				1	1
Other comprehensive income (loss), after tax				0	8
Ending Balance	[2]	(7)	(14)	(7)	(14)
Accumulated Defined Benefit Plans Adjustment [Member]
Beginning Balance	[3]			40	53
Other Comprehensive Income (Loss) Before Reclassifications Net Of Tax				0	(2)
Other Comprehensive Income Reclassifications Current Period Net of Tax				(11)	(9)
Other comprehensive income (loss), after tax				(11)	(11)
Ending Balance	[3]	39	42	39	42
Accumulated Other Comprehensive Income (Loss) [Member]
Beginning Balance				(118)	(53)
Other Comprehensive Income (Loss) Before Reclassifications Net Of Tax				(24)	40
Other Comprehensive Income Reclassifications Current Period Net of Tax				(10)	(8)
Other comprehensive income (loss), after tax		13	64	(34)	32
Ending Balance		$ (143)	$ (21)	$ (143)	$ (21)
Accounting Standards Update 2018-02 [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	[4]					0
Accounting Standards Update 2018-02 [Member] | Accumulated Translation Adjustment [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	[5]					2
Accounting Standards Update 2018-02 [Member] | Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	[5]					(3)
Accounting Standards Update 2018-02 [Member] | Accumulated Defined Benefit Plans Adjustment [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	[5]					10
Accounting Standards Update 2018-02 [Member] | Accumulated Other Comprehensive Income (Loss) [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	[4],[5]					$ 9

[1] Included a tax expense of $4 as of January 27, 2019, and $6 as of July 29, 2018, January 28, 2018, and July 30, 2017.

[2] Included a tax benefit of $1 as of January 27, 2019, $4 as of July 29, 2018, $8 as of January 28, 2018, and $12 as of July 30, 2017.

[3] Included a tax expense of $12 as of January 27, 2019, $25 as of July 29, 2018, and January 28, 2018, and $30 as of July 30, 2017.

[4] See Note 2 for additional detail.

[5] Reflects the adoption of the FASB guidance on stranded tax effects. See Note 2 for additional information.