Segment Information - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Apr. 30, 2020	Apr. 30, 2019	Apr. 30, 2020	Apr. 30, 2019
Revenue from External Customer [Line Items]
Revenues	$ 3,002	$ 3,272	$ 5,863	$ 5,790
Small Business & Self-Employed
Revenue from External Customer [Line Items]
Revenues	982	887	3,001	2,628
Consumer
Revenue from External Customer [Line Items]
Revenues	1,827	2,150	2,426	2,701
Strategic Partner
Revenue from External Customer [Line Items]
Revenues	193	235	436	461
Online Ecosystem Subsegment | Small Business & Self-Employed
Revenue from External Customer [Line Items]
Revenues	560	439	1,591	1,204
Online Ecosystem Subsegment | Small Business & Self-Employed | QuickBooks
Revenue from External Customer [Line Items]
Revenues	353	260	989	708
Online Ecosystem Subsegment | Small Business & Self-Employed | Online Services
Revenue from External Customer [Line Items]
Revenues	207	179	602	496
Desktop Ecosystem Subsegment | Small Business & Self-Employed
Revenue from External Customer [Line Items]
Revenues	422	448	1,410	1,424
Desktop Ecosystem Subsegment | Small Business & Self-Employed | QuickBooks
Revenue from External Customer [Line Items]
Revenues	173	181	577	563
Desktop Ecosystem Subsegment | Small Business & Self-Employed | Desktop Services And Supplies
Revenue from External Customer [Line Items]
Revenues	249	267	833	861
Desktop Ecosystem Subsegment | Small Business & Self-Employed | QuickBooks Packaged Software
Revenue from External Customer [Line Items]
Revenues	$ 36	$ 53	$ 97	$ 119