Cash and Cash Equivalents, Investments and Funds Held for Customers Type of issue (Details) (USD $) In Millions, unless otherwise specified																			3 Months Ended
	Jan. 31, 2013	Oct. 31, 2012	Jul. 31, 2012	Jan. 31, 2012	Oct. 31, 2011	Jul. 31, 2011	Jan. 31, 2013 Total cash and cash equivalents	Jul. 31, 2012 Total cash and cash equivalents	Jan. 31, 2013 Available-for-sale debt securities [Member]	Jul. 31, 2012 Available-for-sale debt securities [Member]	Jan. 31, 2013 Municipal bonds [Member]	Jul. 31, 2012 Municipal bonds [Member]	Jan. 31, 2013 Municipal auction rate securities [Member]	Jul. 31, 2012 Municipal auction rate securities [Member]	Jan. 31, 2013 Corporate notes [Member]	Jul. 31, 2012 Corporate notes [Member]	Jan. 31, 2013 U.S. agency securities [Member]	Jul. 31, 2012 U.S. agency securities [Member]	Jan. 31, 2013 Available-for-sale equity securities [Member]	Jul. 31, 2012 Available-for-sale equity securities [Member]	Jan. 31, 2013 Other long-term investments [Member]	Jul. 31, 2012 Other long-term investments [Member]
Cash and Cash Equivalents Items [Line Items]
Cash and Cash Equivalents, at Carrying Value	$ 399	$ 216	$ 393	$ 277	$ 333	$ 722	$ 509	$ 508
Available-for-sale Securities [Abstract]
Available-for-sale Securities, Amortized Cost Basis	486		565						486	565	206	259	33	41	142	141	105	124
Available-for-sale Equity Securities, Amortized Cost Basis																			5	5
Available-for-sale Securities, Amortized Cost Basis																					17	1
Available-for-sale Securities, Fair Value Disclosure	1,050		1,109				509	508	487	567	206	260	33	41	143	142	105	124	37	33	17	1
Total cash and cash equivalents investments and funds held for customers	1,017		1,079
Available-for-sale Securities, Gross Realized Gains																			$ 33