Leases - Supplemental Balance Sheet (Details) - USD ($) $ in Millions	Jul. 31, 2021	Jul. 31, 2020
Leases [Abstract]
Operating lease right-of-use assets	$ 380	$ 226
Other current liabilities	66	46
Operating lease liabilities	380	221
Total operating lease liabilities	$ 446	$ 267
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesCurrent	us-gaap:OtherLiabilitiesCurrent