Goodwill and Acquired Intangible Assets Intangible Assets (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Jul. 31, 2013	Jul. 31, 2012
Finite-Lived Intangible Assets [Abstract]
Cost	$ 648	$ 715
Accumulated amortization	(499)	(508)
Acquired intangible assets, net	149	207
Weighted average life in years	7 years	7 years
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2014	43
2015	39
2016	28
2017	19
2018	13
Thereafter	7
Acquired intangible assets, net	149	207
Customer Lists [Member]
Finite-Lived Intangible Assets [Abstract]
Cost	306	345
Accumulated amortization	(249)	(255)
Acquired intangible assets, net	57	90
Weighted average life in years	7 years	6 years
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Acquired intangible assets, net	57	90
Purchased Technology [Member]
Finite-Lived Intangible Assets [Abstract]
Cost	277	304
Accumulated amortization	(207)	(214)
Acquired intangible assets, net	70	90
Weighted average life in years	6 years	6 years
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Acquired intangible assets, net	70	90
Trade Names [Member]
Finite-Lived Intangible Assets [Abstract]
Cost	32	33
Accumulated amortization	(20)	(18)
Acquired intangible assets, net	12	15
Weighted average life in years	6 years	6 years
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Acquired intangible assets, net	12	15
Noncompete Agreements [Member]
Finite-Lived Intangible Assets [Abstract]
Cost	33	33
Accumulated amortization	(23)	(21)
Acquired intangible assets, net	10	12
Weighted average life in years	9 years	8 years
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Acquired intangible assets, net	$ 10	$ 12