Current Liabilities (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Jul. 31, 2011 Years percentage segments	Jul. 31, 2010	Mar. 22, 2007	Mar. 12, 2007
Other Current Liabilities
Reserve for product returns	$ 20	$ 20
Reserve for rebates	11	11
Current portion of license fee payable	10	10
Current portion of deferred rent	7	7
Interest payable	21	21
Executive deferred compensation plan liabilities	50	43
Other	22	22
Total other current liabilities	141	134
Current Liabilities (Textuals)
Debt instrument, face amount	1,000	1,000		1,000
Unsecured revolving credit facility			500
Incremental rate of interest if the credit facility exceeds the specified limit	0.05%
Limit of amount of credit facility for incremental interest rate	250
Maximum ratio of debt to annual earnings before interest, taxes, depreciation and amortization as per agreement	3.25
Minimum ratio of annual earnings before interest, taxes, depreciation and amortization to interest payable as per agreement	3
Letters of credit outstanding, amount	0
Minimum [Member]
Current Liabilities (Textuals)
Libor plus variable interest rate on advances under credit facilities	0.18%
Maximum [Member]
Current Liabilities (Textuals)
Libor plus variable interest rate on advances under credit facilities	0.575%
5.40 percent fixed-rate notes due 2012 [Member]
Current Liabilities (Textuals)
Debt instrument, face amount		$ 500		$ 500
Senior notes, rate				5.40%