Goodwill and other intangible assets - schedule of finite-lived intangible assets by major class (Details) - USD ($) $ in Millions	Aug. 31, 2023	Aug. 31, 2022
Finite-Lived Intangible Assets [Line Items]
Total gross amortizable intangible assets	$ 10,767	$ 7,155
Total accumulated amortization	2,609	1,953
Total amortizable intangible assets, net	8,158	5,202
Total indefinite-lived intangible assets	5,477	5,528
Total intangible assets, net	13,635	10,730
Trade names and trademarks
Finite-Lived Intangible Assets [Line Items]
Total indefinite-lived intangible assets	4,650	4,319
Pharmacy licenses
Finite-Lived Intangible Assets [Line Items]
Total indefinite-lived intangible assets	828	1,209
Customer relationships and loyalty card holders
Finite-Lived Intangible Assets [Line Items]
Total gross amortizable intangible assets	4,658	4,619
Total accumulated amortization	1,784	1,548
Primary Care Provider Network
Finite-Lived Intangible Assets [Line Items]
Total gross amortizable intangible assets	3,202	1,247
Total accumulated amortization	233	64
Trade names and trademarks
Finite-Lived Intangible Assets [Line Items]
Total gross amortizable intangible assets	2,300	760
Total accumulated amortization	401	246
Developed Technology
Finite-Lived Intangible Assets [Line Items]
Total gross amortizable intangible assets	469	436
Total accumulated amortization	143	56
Other Intangible Assets
Finite-Lived Intangible Assets [Line Items]
Total gross amortizable intangible assets	137	93
Total accumulated amortization	$ 48	$ 39