Cash and Cash Equivalents, Investments and Funds Held for Customers Classification on Balance Sheets (Details) (USD $) In Millions, unless otherwise specified	Oct. 31, 2013	Jul. 31, 2013	Oct. 31, 2012	Jul. 31, 2012
Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents, Amortized Cost	$ 417	$ 1,009	$ 216	$ 393
Available-for-sale Securities, Fair Value Disclosure	1,389	1,979
Cash and Cash Equivalents and Available-for-sale Securities, Amortized Cost Basis	1,360	1,951
Cash and Cash Equivalents and Available-for-sale Securities, Fair Value Disclosure	1,389	1,979
Cash and Cash Equivalents
Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents, Amortized Cost	417	1,009
Cash and Cash Equivalents, Fair Value Disclosure	417	1,009
Investments [Member]
Cash and Cash Equivalents Items [Line Items]
Available-for-sale Securities, Amortized Cost Basis	670	653
Available-for-sale Securities, Fair Value Disclosure	699	652
Funds held for customers [Member]
Cash and Cash Equivalents Items [Line Items]
Available-for-sale Securities, Amortized Cost Basis	228	235
Available-for-sale Securities, Fair Value Disclosure	228	235
Long-term investments [Member]
Cash and Cash Equivalents Items [Line Items]
Available-for-sale Securities, Amortized Cost Basis	45	54
Available-for-sale Securities, Fair Value Disclosure	$ 45	$ 83