Employee Benefit Plans - Summary of Restricted Stock and Stock Unit Activity (Details) - Restricted Stock Units - USD ($) $ / shares in Units, shares in Millions, $ in Millions	9 Months Ended	12 Months Ended
	Apr. 30, 2022	Jul. 31, 2021
Restricted Stock/ Stock Units
Beginning balance (in shares)	94	96
Granted and assumed (in shares)	37	51
Vested (in shares)	(27)	(39)
Canceled/forfeited/other (in shares)	(10)	(14)
Ending balance (in shares)	94	94
Weighted-Average Grant Date Fair Value per Share
Beginning balance (in dollars per share)	$ 42.93	$ 42.03
Granted and assumed (in dollars per share)	53.63	41.89
Vested (in dollars per share)	41.45	39.63
Canceled/forfeited/other (in dollars per share)	45.52	42.13
Ending balance (in dollars per share)	$ 47.33	$ 42.93
Aggregate Fair  Value
Vested	$ 1,560	$ 1,813