Segment Information (Details) $ in Millions	3 Months Ended								12 Months Ended
	Jul. 31, 2017 USD ($)	Apr. 30, 2017 USD ($)	Jan. 31, 2017 USD ($)	Oct. 31, 2016 USD ($)	Jul. 31, 2016 USD ($)	Apr. 30, 2016 USD ($)	Jan. 31, 2016 USD ($)	Oct. 31, 2015 USD ($)	Jul. 31, 2017 USD ($) segment	Jul. 31, 2016 USD ($)	Jul. 31, 2015 USD ($)
Segment Information (Textuals)
Number of Reportable Segments | segment									3
Net revenue:
Total net revenue	$ 842	$ 2,541	$ 1,016	$ 778	$ 754	$ 2,304	$ 923	$ 713	$ 5,177	$ 4,694	$ 4,192
Operating income from continuing operations:
Total segment operating income	$ (10)	$ 1,444	$ 22	$ (61)	$ (56)	$ 1,285	$ 42	$ (29)	1,395	1,242	738
Unallocated corporate items:
Amortization of acquired technology									(12)	(22)	(30)
Amortization of other acquired intangible assets									(2)	(12)	(12)
Goodwill and intangible asset impairment charges									0	0	(148)
Small Business
Net revenue:
Total net revenue									2,597	2,293	2,108
Consumer Tax
Net revenue:
Total net revenue									2,143	1,973	1,800
ProConnect
Net revenue:
Total net revenue									437	428	284
Operating Segments
Operating income from continuing operations:
Total segment operating income									2,730	2,451	1,952
Operating Segments | Small Business
Operating income from continuing operations:
Total segment operating income									1,075	894	709
Operating Segments | Consumer Tax
Operating income from continuing operations:
Total segment operating income									1,392	1,289	1,134
Operating Segments | ProConnect
Operating income from continuing operations:
Total segment operating income									263	268	109
Segment Reconciling Items
Unallocated corporate items:
Share-based compensation expense									(326)	(278)	(242)
Other common expenses									(995)	(897)	(782)
Amortization of acquired technology									(12)	(22)	(30)
Amortization of other acquired intangible assets									(2)	(12)	(12)
Goodwill and intangible asset impairment charges									0	0	(148)
Total unallocated corporate items									$ (1,335)	$ (1,209)	$ (1,214)
International | Maximum
Segment Information (Textuals)
International total net revenue, as a percentage of total									5.00%	5.00%	5.00%