Current Liabilities - Other Current Liabilities (Details) - USD ($) $ in Millions	Jul. 31, 2020	Jul. 31, 2019
Other Liabilities Disclosure [Abstract]
Executive deferred compensation plan liabilities	$ 123	$ 108
Current portion of operating lease liabilities	46
Reserve for returns and credits	24	24
Reserve for promotional discounts and rebates	11	11
Current portion of dividend payable	6	7
Current portion of deferred rent		6
Interest payable	3	0
Other	84	46
Total other current liabilities	$ 297	$ 202