Income taxes - provision for income taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Aug. 31, 2020	Aug. 31, 2019	Aug. 31, 2018
Current provision
Federal	$ 150	$ 201	$ 866
State	49	46	103
Non–U.S.	204	241	353
Total current provisions for income taxes	403	488	1,322
Deferred provision
Federal – tax law change	0	0	(648)
Federal – excluding tax law change	(83)	151	304
State	2	4	78
Non–U.S. – tax law change	139	0	0
Non–U.S. – excluding tax law change	(101)	(55)	(58)
Total non-current provisions for income taxes	(43)	100	(324)
Income tax provision	$ 360	$ 588	$ 998