Description of Business and Summary of Significant Accounting Policies - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 31, 2017	Jul. 31, 2016	Jul. 31, 2015	Aug. 01, 2016
Property, Plant and Equipment [Line Items]
Product revenue recognition period (in years)	3 years
Advertising expense	$ 480	$ 394	$ 372
Business Combination Measurement Period (in years)	1 year
Acquired Intangible Assets, Useful Life (in years)	6 years	6 years
Excess tax benefits for provision for income taxes	$ 72
Net Cash Provided by Operating Activities	1,599	$ 1,460	1,589
Net cash used in financing activities	1,632	1,999	1,422
Net cumulative effect of change in accounting principal		2
Deferred tax assets	$ 132	139
Accounting Standards Update 2016-09 | New Accounting Pronouncement, Early Adoption, Effect
Property, Plant and Equipment [Line Items]
Net Cash Provided by Operating Activities		59	85
Net cash used in financing activities		59	$ 85
Deferred tax assets				$ 2
Additional Paid-In Capital
Property, Plant and Equipment [Line Items]
Net cumulative effect of change in accounting principal		6
Additional Paid-In Capital | Accounting Standards Update 2016-09 | New Accounting Pronouncement, Early Adoption, Effect
Property, Plant and Equipment [Line Items]
Net cumulative effect of change in accounting principal				6
Retained Earnings
Property, Plant and Equipment [Line Items]
Net cumulative effect of change in accounting principal		$ (4)
Retained Earnings | Accounting Standards Update 2016-09 | New Accounting Pronouncement, Early Adoption, Effect
Property, Plant and Equipment [Line Items]
Net cumulative effect of change in accounting principal				$ (4)
Minimum
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life (in years)	2 years
Acquired Intangible Assets, Useful Life (in years)	2 years
Maximum
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life (in years)	30 years
Acquired Intangible Assets, Useful Life (in years)	9 years
Software Development | Minimum
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life (in years)	3 years
Software Development | Maximum
Property, Plant and Equipment [Line Items]
Property and Equipment, Useful Life (in years)	5 years