Exit and disposal activities - Restructuring Reserve Activity (Details) - USD ($) $ in Millions	3 Months Ended
	Nov. 30, 2024	Nov. 30, 2023
Restructuring Reserve [Roll Forward]
Costs	$ 333	$ 0
Footprint Optimization Program
Restructuring Reserve [Roll Forward]
Costs	333
Lease obligations and other real estate costs | Footprint Optimization Program
Restructuring Reserve [Roll Forward]
Costs	164
Asset impairments | Footprint Optimization Program
Restructuring Reserve [Roll Forward]
Costs	127
Employee severance and other exit costs | Footprint Optimization Program
Restructuring Reserve [Roll Forward]
Beginning balance	0
Costs	42
Payments	(13)
Other	0
Ending balance	$ 28