Segment and net sales information - Disaggregation of Net Sales (Details) - USD ($) $ in Millions	12 Months Ended
	Jul. 31, 2025	Jul. 31, 2024	Jul. 31, 2023
Segment Reporting Information [Line Items]
Total net sales	$ 30,762	$ 29,635	$ 29,734
United States
Segment Reporting Information [Line Items]
Total net sales	29,269	28,195	28,291
Canada
Segment Reporting Information [Line Items]
Total net sales	1,493	1,440	1,443
Residential | United States
Segment Reporting Information [Line Items]
Total net sales	14,598	14,464	14,820
Non-residential: | United States
Segment Reporting Information [Line Items]
Total net sales	14,671	13,731	13,471
Commercial | United States
Segment Reporting Information [Line Items]
Total net sales	10,088	9,431	9,213
Civil/Infrastructure | United States
Segment Reporting Information [Line Items]
Total net sales	2,609	2,396	2,344
Industrial | United States
Segment Reporting Information [Line Items]
Total net sales	$ 1,974	$ 1,904	$ 1,914