Retirement benefits (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	May 31, 2021	May 31, 2020	May 31, 2021	May 31, 2020
Components of net periodic benefit costs [Abstract]
Total net periodic pension costs (income)	$ (48)	$ (35)	$ (140)	$ (106)
Employer cash contributions to defined benefit pension plans			37
Expected employer cash contributions to defined benefit plan in current fiscal year	2		2
Selling, general and administrative expenses
Components of net periodic benefit costs [Abstract]
Service costs	2	0	4	1
Other income
Components of net periodic benefit costs [Abstract]
Interest costs	36	34	104	106
Expected returns on plan assets/other	(85)	(69)	(248)	(214)
United States
Components of net periodic benefit costs [Abstract]
Profit sharing provision expense	54	57	166	171
Foreign Plan
Components of net periodic benefit costs [Abstract]
Cost recognized in the consolidated condensed statements of earnings	$ 25	$ 26	$ 77	$ 80