Goodwill and other intangible assets - Schedule of Finite-Lived Intangible Assets by Major Class (Details) - USD ($) $ in Millions	May 31, 2024	Aug. 31, 2023
Finite-Lived Intangible Assets [Line Items]
Gross amortizable intangible assets	$ 10,532	$ 10,767
Accumulated amortization	3,162	2,609
Total amortizable intangible assets, net	7,370	8,158
Indefinite-lived intangible assets	5,466	5,477
Total intangible assets, net	12,836	13,635
Trade names and trademarks
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	4,640	4,650
Pharmacy licenses
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	826	828
Customer relationships and loyalty card holders
Finite-Lived Intangible Assets [Line Items]
Gross amortizable intangible assets	4,688	4,658
Accumulated amortization	2,014	1,784
Provider networks
Finite-Lived Intangible Assets [Line Items]
Gross amortizable intangible assets	2,957	3,202
Accumulated amortization	362	233
Trade names and trademarks
Finite-Lived Intangible Assets [Line Items]
Gross amortizable intangible assets	2,303	2,300
Accumulated amortization	528	401
Developed technology
Finite-Lived Intangible Assets [Line Items]
Gross amortizable intangible assets	469	469
Accumulated amortization	201	143
Others
Finite-Lived Intangible Assets [Line Items]
Gross amortizable intangible assets	114	137
Accumulated amortization	$ 57	$ 48