Current Liabilities - Other current liabilities (Details) - USD ($) $ in Millions	Oct. 31, 2015	Jul. 31, 2015
Other Liabilities, Current [Abstract]
Reserve for product returns	$ 9	$ 12
Reserve for rebates	13	12
Current portion of license fee payable	10	10
Current portion of deferred rent	11	8
Interest payable	3	10
Amounts due for share repurchases	17	0
Executive deferred compensation plan liabilities	69	63
Other	33	35
Total other current liabilities	$ 165	$ 150