Recent Accounting Pronouncements (Narrative) (Details) - USD ($) $ in Millions		Jul. 29, 2019	Jul. 29, 2018
Accounting Standards Update 2014-09 [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	[1]		$ 8
Accounting Standards Update 2014-09 [Member] | Earnings Retained In The Business [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption			8
Accounting Standards Update 2014-09 [Member] | Accrued Liabilities [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption			(10)
Accounting Standards Update 2014-09 [Member] | Accounts Payable [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption			(1)
Accounting Standards Update 2014-09 [Member] | Other Liabilities [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption			2
Accounting Standards Update 2014-09 [Member] | Other Assets [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption			1
Accounting Standards Update 2018-02 [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption	[1]		0
Accounting Standards Update 2018-02 [Member] | Earnings Retained In The Business [Member]
Cumulative Effect of New Accounting Principle in Period of Adoption			$ 9
Accounting Standards Update 2016-02 [Member]
Derecognize Asset and Liability due to New Accounting Pronouncement		$ 20
Accounting Standards Update 2016-02 [Member] | Minimum [Member]
Operating Lease, Right-of-Use Asset		245
Operating Lease, Liability		240
Accounting Standards Update 2016-02 [Member] | Maximum [Member]
Operating Lease, Right-of-Use Asset		260
Operating Lease, Liability		$ 255

[1] See Note 2 for additional detail.