Income Taxes - Components of deferred tax assets and liabilities (Details) - USD ($) $ in Millions	Jul. 31, 2020	Jul. 31, 2019
Deferred tax assets:
Accruals and reserves not currently deductible	$ 23	$ 13
Operating lease liabilities	64
Accrued and deferred compensation	112	48
Loss and tax credit carryforwards	114	117
Intangible assets	26	0
Share-based compensation	44	47
Other, net	13	11
Total gross deferred tax assets	396	236
Valuation allowance	(132)	(107)
Total deferred tax assets	264	129
Deferred tax liabilities:
Deferred revenue	68	66
Operating lease right-of-use assets	55
Intangibles	45	71
Property and equipment	22	20
Other, net	11	8
Total deferred tax liabilities	201	165
Net deferred tax asset	63
Net deferred tax liabilities		(36)
Deferred Tax Assets, Net [Abstract]
Long-term deferred income taxes	65	1
Long-term deferred income tax liabilities	$ (2)	$ (37)