Segment Information (Details) $ in Millions	3 Months Ended								12 Months Ended
	Jul. 31, 2019 USD ($)	Apr. 30, 2019 USD ($)	Jan. 31, 2019 USD ($)	Oct. 31, 2018 USD ($)	Jul. 31, 2018 USD ($)	Apr. 30, 2018 USD ($)	Jan. 31, 2018 USD ($)	Oct. 31, 2017 USD ($)	Jul. 31, 2019 USD ($) segment	Jul. 31, 2018 USD ($)	Jul. 31, 2017 USD ($)
Segment Information (Textuals)
Number of reportable segments | segment									3
Net revenue:
Total net revenue	$ 994	$ 3,272	$ 1,502	$ 1,016	$ 864	$ 2,912	$ 1,339	$ 910	$ 6,784	$ 6,025	$ 5,196
Operating income:
Total segment operating income	$ (153)	$ 1,784	$ 233	$ (10)	$ (200)	$ 1,601	$ 194	$ (35)	1,854	1,560	1,418
Unallocated corporate items:
Amortization of acquired technology									(20)	(15)	(12)
Amortization of other acquired intangible assets									(6)	(6)	(2)
QuickBooks Online Accounting
Net revenue:
Total net revenue									980	695	448
Online Services
Net revenue:
Total net revenue									683	511	410
Total Online Ecosystem
Net revenue:
Total net revenue									1,663	1,206	858
QuickBooks Desktop Accounting
Net revenue:
Total net revenue									732	716	599
Desktop Services and Supplies
Net revenue:
Total net revenue									1,138	1,139	1,117
Total Desktop Ecosystem
Net revenue:
Total net revenue									1,870	1,855	1,716
QuickBooks Desktop Packaged Software Products
Net revenue:
Total net revenue									167	166	190
Small Business & Self-Employed
Net revenue:
Total net revenue									3,533	3,061	2,574
Consumer
Net revenue:
Total net revenue									2,775	2,508	2,182
Strategic Partner
Net revenue:
Total net revenue									476	456	440
Operating Segments
Operating income:
Total segment operating income									3,609	3,197	2,753
Operating Segments | Small Business & Self-Employed
Operating income:
Total segment operating income									1,549	1,326	1,111
Operating Segments | Consumer
Operating income:
Total segment operating income									1,742	1,587	1,376
Operating Segments | Strategic Partner
Operating income:
Total segment operating income									318	284	266
Segment Reconciling Items
Unallocated corporate items:
Share-based compensation expense									(401)	(382)	(326)
Other common expenses									(1,328)	(1,234)	(995)
Amortization of acquired technology									(20)	(15)	(12)
Amortization of other acquired intangible assets									(6)	(6)	(2)
Total unallocated corporate items									$ (1,755)	$ (1,637)	$ (1,335)
International | Maximum
Segment Information (Textuals)
International total net revenue, as a percentage of total									5.00%	5.00%	5.00%