Share Repurchases (Details) - USD ($) shares in Millions, $ in Millions	3 Months Ended	9 Months Ended
Apr. 28, 2019	Apr. 29, 2018	Apr. 28, 2019	Apr. 29, 2018
Statement [Line Items]
Shares repurchased, value	$ 0	$ 0	$ 0	$ 86
March 2017 Program [Member]
Statement [Line Items]
Authorized amount for shares repurchase	1,500		1,500
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 1,296		$ 1,296
Treasury Stock [Member]
Statement [Line Items]
Treasury stock purchased, shares	0	0	0	2
Shares repurchased, value	$ 0	$ 0	$ 0	$ 86

Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
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-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 30
-Section 45
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-URI http://asc.fasb.org/extlink&oid=6405813&loc=d3e23239-112655

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

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Balance Type:	debit
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