Goodwill and other intangible assets - schedule of finite-lived intangible assets by major class (Details) - USD ($) $ in Millions	Aug. 31, 2024	Aug. 31, 2023
Finite-Lived Intangible Assets [Line Items]
Total gross amortizable intangible assets	$ 10,745	$ 10,767
Total accumulated amortization	3,379	2,609
Total amortizable intangible assets, net	7,367	8,158
Total indefinite-lived intangible assets	5,607	5,477
Total intangible assets, net	12,973	13,635
Trade names and trademarks
Finite-Lived Intangible Assets [Line Items]
Total indefinite-lived intangible assets	4,759	4,650
Pharmacy licenses
Finite-Lived Intangible Assets [Line Items]
Total indefinite-lived intangible assets	848	828
Customer relationships and loyalty card holders
Finite-Lived Intangible Assets [Line Items]
Total gross amortizable intangible assets	4,868	4,658
Total accumulated amortization	2,127	1,784
Primary Care Provider Network
Finite-Lived Intangible Assets [Line Items]
Total gross amortizable intangible assets	2,957	3,202
Total accumulated amortization	411	233
Trade names and trademarks
Finite-Lived Intangible Assets [Line Items]
Total gross amortizable intangible assets	2,294	2,300
Total accumulated amortization	558	401
Developed Technology
Finite-Lived Intangible Assets [Line Items]
Total gross amortizable intangible assets	469	469
Total accumulated amortization	221	143
Other Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Total gross amortizable intangible assets	156	137
Total accumulated amortization	$ 62	$ 48