Cash and Cash Equivalents, Investments and Funds Held for Customers Type of issue (Details) (USD $) In Millions, unless otherwise specified																	6 Months Ended
	Jan. 31, 2014	Jul. 31, 2013	Jan. 31, 2013	Jul. 31, 2012	Jan. 31, 2014 Total cash and cash equivalents [Member]	Jul. 31, 2013 Total cash and cash equivalents [Member]	Jan. 31, 2014 Available-for-sale debt securities [Member]	Jul. 31, 2013 Available-for-sale debt securities [Member]	Jan. 31, 2014 Municipal bonds [Member]	Jul. 31, 2013 Municipal bonds [Member]	Jan. 31, 2014 Corporate notes [Member]	Jul. 31, 2013 Corporate notes [Member]	Jan. 31, 2014 U.S. agency securities [Member]	Jul. 31, 2013 U.S. agency securities [Member]	Jan. 31, 2014 Municipal auction rate securities [Member]	Jul. 31, 2013 Municipal auction rate securities [Member]	Jan. 31, 2014 Available-for-sale equity securities [Member]	Jul. 31, 2013 Available-for-sale equity securities [Member]	Jan. 31, 2014 Other long-term investments [Member]	Jul. 31, 2013 Other long-term investments [Member]
Cash and Cash Equivalents Items [Line Items]
Cash and cash equivalents, Amortized Cost	$ 625	$ 1,009	$ 399	$ 393	$ 740	$ 1,069
Available-for-sale Securities [Abstract]
Available-for-sale Securities, Amortized Cost Basis	880	860					880	860	516	489	265	269	71	69	28	33
Available-for-sale Equity Securities, Amortized Cost Basis																	5	5
Available-for-sale Securities, Amortized Cost Basis																			17	17
Total cash and cash equivalents investments and funds held for customers	1,642	1,951
Available-for-sale Securities, Fair Value Disclosure	1,666	1,979			740	1,069	881	860	517	489	265	269	71	69	28	33	28	33	17	17
Available-for-sale Securities, Gross Umrealized Gains																	$ 23