Long-Term Obligations and Commitments (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Jul. 31, 2013	Jul. 31, 2012	Jul. 31, 2011	Jul. 31, 2010	Mar. 12, 2007
Long Term Obligations And Commitments (Textuals)
Senior notes					$ 1,000
Interest paid	33	60	60
Cash paid to license technology	14	10	15	20
Amount payable over next ten fiscal years for agreement to license technology				100
Present value of license technology agreement				89
Years lease term can be extended under lease option	10 years
Operating leases, rent expense	53	47	44
Other long-term obligations
Total deferred rent	55	53
Total license fee payable	48	54
Long-term income tax liabilities	38	41
Long-term deferred revenue	32	32
Long-term deferred income tax liabilities	6	0
Other	7	5
Total long-term obligations	186	185
Less current portion (included in other current liabilities)	(19)	(19)
Long-term obligations due after one year	167	166
Senior Notes [Member]
Long Term Obligations And Commitments (Textuals)
Interest paid	29	56	56
5.40% fixed-rate notes, due 2012 [Member]
Long Term Obligations And Commitments (Textuals)
Senior notes		500
Senior notes, rate					5.40%
5.75% fixed-rate notes, due 2017 [Member]
Long Term Obligations And Commitments (Textuals)
Senior notes	500
Senior notes, rate					5.75%
Operating Lease Expense [Member]
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Operating Leases, Future Minimum Payments Due, Current	63
Operating Leases, Future Minimum Payments, Due in Two Years	58
Operating Leases, Future Minimum Payments, Due in Three Years	47
Operating Leases, Future Minimum Payments, Due in Four Years	45
Operating Leases, Future Minimum Payments, Due in Five Years	30
Operating Leases, Future Minimum Payments, Due Thereafter	160
Operating Leases, Future Minimum Payments Due	403
Purchase Commitment [Member]
Purchase Obligation, Fiscal Year Maturity [Abstract]
Purchase Obligation, Due in Next Twelve Months	18
Purchase Obligation, Due in Second Year	18
Purchase Obligation, Due in Third Year	5
Purchase Obligation, Due in Fourth Year	1
Purchase Obligation, Due in Fifth Year	0
Purchase Obligation, Due after Fifth Year	1
Purchase Obligation	$ 43