Equity method investments - Schedule of Equity Method Investments (Details) - USD ($) $ in Millions	Nov. 30, 2021	Aug. 31, 2021
Schedule of Equity Method Investments [Line Items]
Carrying value of equity method investments	$ 6,367	$ 6,987
AmerisourceBergen
Schedule of Equity Method Investments [Line Items]
Carrying value of equity method investments	$ 4,393	$ 4,407
Ownership percentage	28.30%	28.30%
Others
Schedule of Equity Method Investments [Line Items]
Carrying value of equity method investments	$ 1,974	$ 2,580
Others | Minimum
Schedule of Equity Method Investments [Line Items]
Ownership percentage	8.00%	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	$ 6,367	$ 6,987