Current Liabilities - Other Current Liabilities (Details) - USD ($) $ in Millions	Jan. 31, 2018	Jul. 31, 2017
Other Liabilities, Current [Abstract]
Executive deferred compensation plan liabilities	$ 94	$ 83
Reserve for promotional discounts and rebates	37	19
Reserve for product returns	51	7
Current portion of license fee payable	10	10
Current portion of deferred rent	6	6
Current portion of dividend payable	6	9
Other	47	44
Total other current liabilities	$ 251	$ 178