Cash and Cash Equivalents, Investments and Funds Held for Customers Type of issue (Details) (USD $) In Millions, unless otherwise specified																	9 Months Ended
	Apr. 30, 2014	Jul. 31, 2013	Apr. 30, 2013	Jul. 31, 2012	Apr. 30, 2014 Total cash and cash equivalents [Member]	Jul. 31, 2013 Total cash and cash equivalents [Member]	Apr. 30, 2014 Available-for-sale debt securities [Member]	Jul. 31, 2013 Available-for-sale debt securities [Member]	Apr. 30, 2014 Municipal bonds [Member]	Jul. 31, 2013 Municipal bonds [Member]	Apr. 30, 2014 Corporate notes [Member]	Jul. 31, 2013 Corporate notes [Member]	Apr. 30, 2014 U.S. agency securities [Member]	Jul. 31, 2013 U.S. agency securities [Member]	Apr. 30, 2014 Municipal auction rate securities [Member]	Jul. 31, 2013 Municipal auction rate securities [Member]	Apr. 30, 2014 Available-for-sale equity securities [Member]	Jul. 31, 2013 Available-for-sale equity securities [Member]	Apr. 30, 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	$ 1,574	$ 1,009	$ 1,412	$ 393	$ 1,672	$ 1,069
Available-for-sale Securities [Abstract]
Available-for-sale Securities, Amortized Cost Basis	1,227	860					1,227	860	663	489	445	269	98	69	21	33
Available-for-sale Equity Securities, Amortized Cost Basis																	5	5
Available-for-sale Securities, Amortized Cost Basis																			10	17
Total cash and cash equivalents investments and funds held for customers	2,914	1,951
Available-for-sale Securities, Fair Value Disclosure	2,937	1,979			1,672	1,069	1,228	860	664	489	445	269	98	69	21	33	27	33	10	17
Available-for-sale Securities, Gross Unrealized Gains																	$ 22