Current Liabilities (Details) (USD $)	12 Months Ended
	Jul. 31, 2014	Jul. 31, 2013	Feb. 17, 2012
Current Liabilities (Textuals)
Unsecured revolving credit facility			$ 500,000,000
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	24,000,000	20,000,000
Reserve for rebates	23,000,000	15,000,000
Current portion of license fee payable	10,000,000	10,000,000
Current portion of deferred rent	7,000,000	8,000,000
Interest payable	10,000,000	10,000,000
Executive deferred compensation plan liabilities	63,000,000	64,000,000
Other	30,000,000	29,000,000
Total other current liabilities	$ 167,000,000	$ 156,000,000
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%