Stockholders' Equity - Accumulated other comprehensive loss (Details) - USD ($) $ in Millions	Jul. 31, 2024	Jul. 31, 2023	Jul. 31, 2022	Jul. 31, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders’ equity	$ 18,436	$ 17,269	$ 16,441	$ 9,869
Unrealized loss on available-for-sale debt securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders’ equity	0	(7)
Foreign currency translation adjustments
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders’ equity	(54)	(48)
Total accumulated other comprehensive loss
Accumulated Other Comprehensive Income (Loss) [Line Items]
Stockholders’ equity	$ (54)	$ (55)	$ (60)	$ (24)