Revenue and segment information - Items not Allocated (Details) - USD ($)	12 Months Ended
	Jul. 31, 2024	Jul. 31, 2023	Jul. 31, 2022
Net sales:
Total net sales	$ 29,635,000,000	$ 29,734,000,000	$ 28,566,000,000
Adjusted operating profit:
Adjusted segment operating profit	2,652,000,000	2,659,000,000	2,820,000,000
Central and other costs	(56,000,000)	(51,000,000)	(54,000,000)
Impairments and other charges	0	(125,000,000)	0
Amortization of acquired intangible assets	(144,000,000)	(133,000,000)	(114,000,000)
Interest expense, net	(179,000,000)	(184,000,000)	(111,000,000)
Other expense, net	(9,000,000)	(11,000,000)	(1,000,000)
Income before income taxes	2,464,000,000	2,464,000,000	2,708,000,000
Corporate restructurings
Adjusted operating profit:
Restructuring costs	(28,000,000)	0	(17,000,000)
United States
Net sales:
Total net sales	28,195,000,000	28,291,000,000	27,067,000,000
Adjusted operating profit:
Adjusted segment operating profit	2,820,000,000	2,892,000,000	2,893,000,000
Canada
Net sales:
Total net sales	1,440,000,000	1,443,000,000	1,499,000,000
Adjusted operating profit:
Adjusted segment operating profit	$ 60,000,000	$ 76,000,000	$ 112,000,000