Segment Information (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jan. 31, 2016 USD ($)	Jan. 31, 2015 USD ($)	Jan. 31, 2016 USD ($) segment	Jan. 31, 2015 USD ($)
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	$ 923	$ 749	$ 1,636	$ 1,361
Total operating income (loss) from continuing operations	42	(89)	13	(198)
Unallocated corporate items:
Share-based compensation expense			(137)	(122)
Amortization of other acquired intangible assets	(1)	(3)	(3)	(6)
Operating Segments
Financial results by reportable segment
Total operating income (loss) from continuing operations	302	159	557	308
Corporate, Non-Segment
Financial results by reportable segment
Total operating income (loss) from continuing operations	(260)	(248)	(544)	(506)
Unallocated corporate items:
Share-based compensation expense	(65)	(56)	(132)	(113)
Other common expenses	(188)	(182)	(397)	(373)
Corporate, Non-Segment | Technology-Based Intangible Assets
Unallocated corporate items:
Amortization of other acquired intangible assets	(6)	(7)	(12)	(14)
Corporate, Non-Segment | Other Intangible Assets
Unallocated corporate items:
Amortization of other acquired intangible assets	(1)	(3)	(3)	(6)
Small Business segment
Financial results by reportable segment
Total net revenue	564	525	1,110	1,044
Total operating income (loss) from continuing operations	199	170	410	358
Consumer Tax segment
Financial results by reportable segment
Total net revenue	275	213	332	270
Total operating income (loss) from continuing operations	62	26	34	(10)
Professional Tax segment
Financial results by reportable segment
Total net revenue	84	11	194	47
Total operating income (loss) from continuing operations	$ 41	$ (37)	$ 113	$ (40)