Cash and Cash Equivalents, Investments and Funds Held for Customers - Classified by the stated maturity date (Details) (USD $) In Millions, unless otherwise specified	Oct. 31, 2014	Jul. 31, 2014
Available-for-sale Securities, Debt Maturities
Due within one year, Amortized Cost	$ 399	$ 363
Due within one year, Fair Value	399	363
Due within two years, Amortized Cost	471	443
Due within two years, Fair Value	472	443
Due within three years, Amortized Cost	292	303
Due within three years, Fair Value	292	303
Due after three years, Amortized Cost	80	120
Due after three years, Fair Value	80	121
Total available-for-sale debt securities, Amortized Cost	1,242	1,229
Total available-for-sale debt securities, Fair Value	$ 1,243	$ 1,230