Segment Information - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jan. 31, 2021	Jan. 31, 2020	Jan. 31, 2021	Jan. 31, 2020
Revenue from External Customer [Line Items]
Net revenue:	$ 1,576	$ 1,696	$ 2,899	$ 2,861
Small Business & Self-Employed
Revenue from External Customer [Line Items]
Net revenue:	1,078	973	2,259	2,019
Consumer
Revenue from External Customer [Line Items]
Net revenue:	147	499	266	599
ProConnect
Revenue from External Customer [Line Items]
Net revenue:	207	224	230	243
Credit Karma
Revenue from External Customer [Line Items]
Net revenue:	144	0	144	0
Online Ecosystem Subsegment | Small Business & Self-Employed
Revenue from External Customer [Line Items]
Net revenue:	644	530	1,265	1,031
Online Ecosystem Subsegment | Small Business & Self-Employed | QuickBooks
Revenue from External Customer [Line Items]
Net revenue:	404	330	796	636
Online Ecosystem Subsegment | Small Business & Self-Employed | Online Services
Revenue from External Customer [Line Items]
Net revenue:	240	200	469	395
Desktop Ecosystem Subsegment | Small Business & Self-Employed
Revenue from External Customer [Line Items]
Net revenue:	434	443	994	988
Desktop Ecosystem Subsegment | Small Business & Self-Employed | QuickBooks
Revenue from External Customer [Line Items]
Net revenue:	160	165	401	404
Desktop Ecosystem Subsegment | Small Business & Self-Employed | Desktop Services and Supplies
Revenue from External Customer [Line Items]
Net revenue:	274	278	593	584
Desktop Ecosystem Subsegment | Small Business & Self-Employed | QuickBooks Packaged Software
Revenue from External Customer [Line Items]
Net revenue:	$ 25	$ 34	$ 45	$ 61