Goodwill and Acquired Intangible Assets - Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
Jul. 31, 2018	Jul. 31, 2017	Jul. 31, 2016
Goodwill [Roll Forward]
Goodwill, beginning	$ 1,295	$ 1,282
Goodwill Acquired/ Adjusted	316	13
Goodwill, ending	1,611	1,295
Small Business & Self-Employed
Goodwill [Roll Forward]
Goodwill, beginning	1,180	1,168
Goodwill Acquired/ Adjusted	316	12
Goodwill, ending	1,496	1,180
Goodwill net of accumulated impairment losses			$ 114
Consumer
Goodwill [Roll Forward]
Goodwill, beginning	23	23
Goodwill Acquired/ Adjusted	0	0
Goodwill, ending	23	23
Strategic Partner
Goodwill [Roll Forward]
Goodwill, beginning	92	91
Goodwill Acquired/ Adjusted	0	1
Goodwill, ending	$ 92	$ 92

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=77989000&loc=SL49117168-202975

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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-Section 45
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- Definition

Amount of accumulated impairment loss for an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 350
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (h)
-URI http://asc.fasb.org/extlink&oid=108376223&loc=d3e13816-109267

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-Publisher FASB
-Name Accounting Standards Codification
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Amount of increase (decrease) of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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