Segment Information (Details) $ in Millions	3 Months Ended								12 Months Ended
	Jul. 31, 2020 USD ($)	Apr. 30, 2020 USD ($)	Jan. 31, 2020 USD ($)	Oct. 31, 2019 USD ($)	Jul. 31, 2019 USD ($)	Apr. 30, 2019 USD ($)	Jan. 31, 2019 USD ($)	Oct. 31, 2018 USD ($)	Jul. 31, 2020 USD ($) segment	Jul. 31, 2019 USD ($)	Jul. 31, 2018 USD ($)
Segment Information (Textuals)
Number of reportable segments | segment									3
Net revenue:
Total net revenue	$ 1,816	$ 3,002	$ 1,696	$ 1,165	$ 994	$ 3,272	$ 1,502	$ 1,016	$ 7,679	$ 6,784	$ 6,025
Operating income:
Total segment operating income	$ 483	$ 1,413	$ 270	$ 10	$ (153)	$ 1,784	$ 233	$ (10)	2,176	1,854	1,560
Unallocated corporate items:
Amortization of acquired technology									(22)	(20)	(15)
Amortization of other acquired intangible assets									(6)	(6)	(6)
QuickBooks Online Accounting
Net revenue:
Total net revenue									1,354	980	695
Online Services
Net revenue:
Total net revenue									828	683	511
Total Online Ecosystem
Net revenue:
Total net revenue									2,182	1,663	1,206
QuickBooks Desktop Accounting
Net revenue:
Total net revenue									755	732	716
Desktop Services and Supplies
Net revenue:
Total net revenue									1,113	1,138	1,139
Total Desktop Ecosystem
Net revenue:
Total net revenue									1,868	1,870	1,855
QuickBooks Desktop Packaged Software Products
Net revenue:
Total net revenue									147	167	166
Small Business & Self-Employed
Net revenue:
Total net revenue									4,050	3,533	3,061
Consumer
Net revenue:
Total net revenue									3,136	2,775	2,508
Strategic Partner
Net revenue:
Total net revenue									493	476	456
Operating Segments
Operating income:
Total segment operating income									4,186	3,609	3,197
Operating Segments | Small Business & Self-Employed
Operating income:
Total segment operating income									1,911	1,549	1,326
Operating Segments | Consumer
Operating income:
Total segment operating income									1,942	1,742	1,587
Operating Segments | Strategic Partner
Operating income:
Total segment operating income									333	318	284
Segment Reconciling Items
Unallocated corporate items:
Share-based compensation expense									(435)	(401)	(382)
Other common expenses									(1,547)	(1,328)	(1,234)
Amortization of acquired technology									(22)	(20)	(15)
Amortization of other acquired intangible assets									(6)	(6)	(6)
Total unallocated corporate items									$ (2,010)	$ (1,755)	$ (1,637)
International | Maximum
Segment Information (Textuals)
International total net revenue, as a percentage of total									5.00%	5.00%	5.00%