Segment Information (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jan. 31, 2017 USD ($)	Jan. 31, 2016 USD ($)	Jan. 31, 2017 USD ($) segment	Jan. 31, 2016 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment			3
International total net revenue as a percentage of total (less than)	5.00%	5.00%	5.00%	5.00%
Financial results by reportable segment
Total net revenue	$ 1,016	$ 923	$ 1,794	$ 1,636
Total operating income (loss) from continuing operations	22	42	(39)	13
Unallocated corporate items:
Share-based compensation expense			170	137
Amortization of other acquired intangible assets	0	1	1	3
Operating Segments
Financial results by reportable segment
Total operating income (loss) from continuing operations	346	308	617	568
Corporate, Non-Segment
Financial results by reportable segment
Total operating income (loss) from continuing operations	(324)	(266)	(656)	(555)
Unallocated corporate items:
Share-based compensation expense	(81)	(65)	(170)	(132)
Other common expenses	(240)	(194)	(479)	(408)
Corporate, Non-Segment | Technology-Based Intangible Assets
Unallocated corporate items:
Amortization of other acquired intangible assets	(3)	(6)	(6)	(12)
Corporate, Non-Segment | Other Intangible Assets
Unallocated corporate items:
Amortization of other acquired intangible assets	0	(1)	(1)	(3)
Small Business
Financial results by reportable segment
Total net revenue	632	564	1,238	1,110
Total operating income (loss) from continuing operations	241	204	481	420
Consumer Tax
Financial results by reportable segment
Total net revenue	285	275	345	332
Total operating income (loss) from continuing operations	55	63	16	35
ProConnect
Financial results by reportable segment
Total net revenue	99	84	211	194
Total operating income (loss) from continuing operations	$ 50	$ 41	$ 120	$ 113