Leases - Lease Cost (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jan. 31, 2022	Jan. 31, 2021	Jan. 31, 2022	Jan. 31, 2021
Leases [Abstract]
Operating lease cost	$ 25	$ 18	$ 46	$ 33
Variable lease cost	4	3	7	6
Sublease income	(5)	(4)	(10)	(8)
Total net lease cost	$ 24	$ 17	$ 43	$ 31