Business Combinations (Details)	3 Months Ended
	Jan. 31, 2018 USD ($) business	Apr. 30, 2018 USD ($)	Jul. 31, 2017 USD ($)
Business Acquisition [Line Items]
Goodwill		$ 1,613,000,000	$ 1,295,000,000
Exactor, Inc, TSheets, Inc and Applatix Inc.
Business Acquisition [Line Items]
Consideration transferred	$ 412,000,000
Fair value of equity awards	$ 27,000,000
Future service period	3 years
Number of businesses acquired | business	3
Tangible and identifiable intangible assets acquired and liabilities assumed	$ 385,000,000
Net tangible assets	$ 5,000,000
Weighted average life of identified intangible assets	4 years
Identified intangible assets	$ 62,000,000
Goodwill	318,000,000
Expected goodwill expected to be tax deductible	0
Exactor, Inc, TSheets, Inc and Applatix Inc. | Technology-Based Intangible Assets
Business Acquisition [Line Items]
Identified intangible assets	38,000,000
Exactor, Inc, TSheets, Inc and Applatix Inc. | Customer Lists
Business Acquisition [Line Items]
Identified intangible assets	17,000,000
Exactor, Inc, TSheets, Inc and Applatix Inc. | Noncompete Agreements
Business Acquisition [Line Items]
Identified intangible assets	$ 7,000,000