Exit and disposal activities - Restructuring Reserve Activity (Details) - Transformational Cost Management Program $ in Millions	6 Months Ended
	Feb. 28, 2023 USD ($)
Restructuring Reserve [Roll Forward]
Beginning balance	$ 113
Costs	267
Payments	(139)
Other	(170)
Ending balance	72
Lease obligations and other real estate costs
Restructuring Reserve [Roll Forward]
Beginning balance	10
Costs	98
Payments	(51)
Other	(57)
Ending balance	0
Asset Impairments
Restructuring Reserve [Roll Forward]
Beginning balance	0
Costs	113
Payments	0
Other	(113)
Ending balance	0
Employee severance and business transition costs
Restructuring Reserve [Roll Forward]
Beginning balance	76
Costs	31
Payments	(72)
Other	1
Ending balance	36
Information technology transformation and other exit costs
Restructuring Reserve [Roll Forward]
Beginning balance	27
Costs	25
Payments	(17)
Other	0
Ending balance	$ 36