Current Liabilities (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Jul. 31, 2013	Jul. 31, 2012	Feb. 17, 2012
Current Liabilities (Textuals)
Unsecured revolving credit facility			$ 500
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	3.00
Other Current Liabilities
Reserve for product returns	20	19
Reserve for rebates	15	17
Current portion of license fee payable	10	10
Current portion of deferred rent	8	8
Interest payable	10	10
Executive deferred compensation plan liabilities	64	56
Other	27	24
Total other current liabilities	$ 154	$ 144
JP Morgan Alternate Base [Member] | Minimum [Member]
Current Liabilities (Textuals)
Libor plus variable interest rate on advances under credit facilities	0.00%
JP Morgan Alternate Base [Member] | Maximum [Member]
Current Liabilities (Textuals)
Libor plus variable interest rate on advances under credit facilities	0.50%
LIBOR [Member] | Minimum [Member]
Current Liabilities (Textuals)
Libor plus variable interest rate on advances under credit facilities			0.90%
LIBOR [Member] | Maximum [Member]
Current Liabilities (Textuals)
Libor plus variable interest rate on advances under credit facilities			1.50%