Long-Term Obligations and Commitments - Other Long-Term Obligations (Details) - USD ($) $ in Millions	Apr. 30, 2019	Jul. 31, 2018
Debt Disclosure [Abstract]
Total deferred rent	$ 48	$ 47
Long-term income tax liabilities	82	61
Total license fee payable	10	9
Total dividend payable	15	14
Other	17	15
Total long-term obligations	172	146
Less current portion (included in other current liabilities)	(27)	(27)
Long-term obligations due after one year	$ 145	$ 119