Equity method investments - Schedule of Equity Method Investments (Details) - USD ($) $ in Millions	Feb. 28, 2023	Aug. 31, 2022
Schedule of Equity Method Investments [Line Items]
Carrying value of equity method investments	$ 4,069	$ 5,495
AmerisourceBergen
Schedule of Equity Method Investments [Line Items]
Carrying value of equity method investments	$ 2,563	$ 3,916
Ownership percentage	16.70%	25.40%
Others
Schedule of Equity Method Investments [Line Items]
Carrying value of equity method investments	$ 1,506	$ 1,579
Others | Minimum
Schedule of Equity Method Investments [Line Items]
Ownership percentage	4.00%	8.00%
Others | Maximum
Schedule of Equity Method Investments [Line Items]
Ownership percentage	50.00%	50.00%
Total
Schedule of Equity Method Investments [Line Items]
Carrying value of equity method investments	$ 4,069	$ 5,495