Current Liabilities (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended			3 Months Ended
	Apr. 30, 2011	Jul. 31, 2010	Mar. 22, 2007	Apr. 30, 2011 Senior Notes Due 2012 [Member]
Debt Instrument [Line Items]
Current portion of long-term debt	$ 500	$ 0		$ 500
Period for contractual maturities of senior notes				within 1 year
Senior notes, rate				5.40%
Other Current Liabilities
Reserve for product returns	57	20
Reserve for rebates	48	11
Current portion of license fee payable	10	10
Current portion of deferred rent	7	7
Interest payable	7	21
Executive deferred compensation plan liabilities	54	43
Other	35	22
Total other current liabilities	218	134
Current Liabilities (Textuals)
Unsecured revolving credit facility			500
Libor plus minimum interest rate on advances under credit facilities	0.18%
Libor plus maximum interest rate on advances under credit facilities	0.575%
Limit of amount of credit facility for incremental interest rate	$ 250
Incremental rate of interest if the credit facility exceeds the specified limit	0.05%
Minimum ratio of debt to annual earnings before interest, taxes, depreciation and amortization as per agreement	1.00
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	1.00
Maximum ratio of annual earnings before interest, taxes, depreciation and amortization to interest payable as per agreement	3.00