Income taxes - components of earnings before income tax provision (Details) - USD ($) $ in Millions	12 Months Ended
	Aug. 31, 2021	Aug. 31, 2020	Aug. 31, 2019
Income Tax Disclosure [Abstract]
U.S.	$ 61	$ 759	$ 1,898
Non–U.S.	1,934	(313)	2,461
Earnings before income tax provision	$ 1,995	$ 446	$ 4,359