Cash and Cash Equivalents, Investments and Funds Held for Customers Classification on Balance Sheets (Details) (USD $) In Millions, unless otherwise specified	Jan. 31, 2014	Jul. 31, 2013	Jan. 31, 2013	Jul. 31, 2012
Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents, Amortized Cost	$ 625	$ 1,009	$ 399	$ 393
Available-for-sale Securities, Fair Value Disclosure	1,666	1,979
Cash and Cash Equivalents and Available-for-sale Securities, Amortized Cost Basis	1,642	1,951
Cash and Cash Equivalents and Available-for-sale Securities, Fair Value Disclosure	1,666	1,979
Cash and Cash Equivalents [Member]
Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents, Amortized Cost	625	1,009
Cash and Cash Equivalents, Fair Value Disclosure	625	1,009
Investments [Member]
Cash and Cash Equivalents Items [Line Items]
Available-for-sale Securities, Amortized Cost Basis	682	653
Available-for-sale Securities, Fair Value Disclosure	706	652
Funds held for customers [Member]
Cash and Cash Equivalents Items [Line Items]
Available-for-sale Securities, Amortized Cost Basis	290	235
Available-for-sale Securities, Fair Value Disclosure	290	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