Exit and disposal activities - Restructuring Reserve Activity (Details) - Transformational Cost Management Program $ in Millions	6 Months Ended
	Feb. 28, 2021 USD ($)
Restructuring Reserve [Roll Forward]
Beginning balance	$ 199
Costs	235
Payments	(193)
Other	(17)
Currency	3
Ending balance	228
Lease obligations and other real estate costs
Restructuring Reserve [Roll Forward]
Beginning balance	19
Costs	40
Payments	(36)
Other	(6)
Currency	1
Ending balance	19
Asset impairments
Restructuring Reserve [Roll Forward]
Beginning balance	0
Costs	5
Payments	0
Other	(5)
Currency	0
Ending balance	0
Employee severance and business transition costs
Restructuring Reserve [Roll Forward]
Beginning balance	166
Costs	174
Payments	(135)
Other	(3)
Currency	3
Ending balance	206
Information technology transformation and other exit costs
Restructuring Reserve [Roll Forward]
Beginning balance	14
Costs	15
Payments	(22)
Other	(3)
Currency	(1)
Ending balance	$ 3