Income tax - Provision for Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 31, 2024	Jul. 31, 2023	Jul. 31, 2022
Current:
United Kingdom	$ 3	$ 0	$ (18)
Total current	604	679	568
Deferred:
United Kingdom	155	17	20
Total deferred	125	(104)	41
Provision for income taxes	729	575	609
Foreign, United States
Current:
International	552	624	528
Deferred:
International	(32)	(120)	20
Foreign, Excluding United States
Current:
International	49	55	58
Deferred:
International	$ 2	$ (1)	$ 1