Cash and Cash Equivalents, Investments and Funds Held for Customers Classified by the stated maturity date (Details) (USD $) In Millions, unless otherwise specified	Jan. 31, 2013	Jul. 31, 2012
Available-for-sale Securities, Debt Maturities
Due within one year, Amortized Cost	$ 191	$ 218
Due within one year, Fair Value	191	218
Due within two years, Amortized Cost	132	134
Due within two years, Fair Value	133	135
Due within three years, Amortized Cost	92	131
Due within three years, Fair Value	92	132
Due after three years, Amortized Cost	71	82
Due after three years, Fair Value	71	82
Total available-for-sale debt securiites, Amortized Cost	486	565
Total available-for-sale debt securiites, Fair Value	$ 487	$ 567