Property and Equipment (Details) (USD $) In Millions	12 Months Ended
	Jul. 31, 2011	Jul. 31, 2010	Jul. 31, 2009
Property, Plant and Equipment [Line Items]
Land	$ 2	$ 4
Capital in progress	36	59
Total property plant and equipment, gross	1,524	1,392
Less accumulated depreciation and amortization	(963)	(882)
Total property and equipment, net	561	510
Capitalized computer software, additions	99	56	52
Capitalized labor costs	35	28	17
Equipment [Member]
Property, Plant and Equipment [Line Items]
Equipment	531	475
Property, plant and equipment, estimated useful lives	3-5
Software [Member]
Property, Plant and Equipment [Line Items]
Computer software	478	359
Property, plant and equipment, estimated useful lives	3-6
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Furniture and fixtures	61	64
Property, plant and equipment, estimated useful lives	5
Leasehold Improvements [Member]
Property, Plant and Equipment [Line Items]
Leasehold improvements	229	229
Property, plant and equipment, estimated useful lives	2-16
Building [Member]
Property, Plant and Equipment [Line Items]
Buildings	$ 187	$ 202
Property, plant and equipment, estimated useful lives	5-30