Segment Information - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Oct. 31, 2019	Oct. 31, 2018
Revenue from External Customer [Line Items]
Revenues	$ 1,165	$ 1,016
Small Business & Self-Employed
Revenue from External Customer [Line Items]
Revenues	1,046	908
Consumer
Revenue from External Customer [Line Items]
Revenues	100	90
Strategic Partner
Revenue from External Customer [Line Items]
Revenues	19	18
Online Ecosystem Subsegment | Small Business & Self-Employed
Revenue from External Customer [Line Items]
Revenues	501	371
Online Ecosystem Subsegment | Small Business & Self-Employed | QuickBooks
Revenue from External Customer [Line Items]
Revenues	306	217
Online Ecosystem Subsegment | Small Business & Self-Employed | Online Services
Revenue from External Customer [Line Items]
Revenues	195	154
Desktop Ecosystem Subsegment | Small Business & Self-Employed
Revenue from External Customer [Line Items]
Revenues	545	537
Desktop Ecosystem Subsegment | Small Business & Self-Employed | QuickBooks
Revenue from External Customer [Line Items]
Revenues	239	228
Desktop Ecosystem Subsegment | Small Business & Self-Employed | Desktop Services And Supplies
Revenue from External Customer [Line Items]
Revenues	306	309
Desktop Ecosystem Subsegment | Small Business & Self-Employed | QuickBooks Packaged Software
Revenue from External Customer [Line Items]
Revenues	$ 27	$ 29