Cash and Cash Equivalents, Investments and Funds Held for Customers Classified by the stated maturity date (Details) (USD $) In Millions, unless otherwise specified	Apr. 30, 2014	Jul. 31, 2013
Available-for-sale Securities, Debt Maturities
Due within one year, Amortized Cost	$ 345	$ 234
Due within one year, Fair Value	346	235
Due within two years, Amortized Cost	397	245
Due within two years, Fair Value	397	245
Due within three years, Amortized Cost	360	211
Due within three years, Fair Value	360	210
Due after three years, Amortized Cost	125	170
Due after three years, Fair Value	125	170
Total available-for-sale debt securities, Amortized Cost	1,227	860
Total available-for-sale debt securiites, Fair Value	$ 1,228	$ 860