Income tax - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 31, 2025	Jul. 31, 2024	Jul. 31, 2023	Jul. 31, 2022
Investments, Owned, Federal Income Tax Note [Line Items]
Change in valuation allowance	$ 1	$ 47	$ 4
Unrecognized tax benefits	126	151	144	$ 140
Accrued interest	32	28	23
Interest included in income tax expense	4	5	$ 6
Decrease in unrecognized tax benefits is reasonably possible	61
Foreign earnings reinvested	800	$ 795
UNITED STATES
Investments, Owned, Federal Income Tax Note [Line Items]
Foreign gross loss carryforwards	8
U.S. state operating loss carryforwards	24
Foreign, Excluding United States
Investments, Owned, Federal Income Tax Note [Line Items]
Foreign gross loss carryforwards	$ 369