Leases - other supplemental information (Details) - USD ($) $ in Millions	12 Months Ended
	Aug. 31, 2023	Aug. 31, 2022	Aug. 31, 2021
Cash paid for amounts included in the measurement of lease obligations
Operating cash flows from operating leases	$ 3,579	$ 3,351	$ 3,414
Operating cash flows from finance leases	47	47	48
Financing cash flows from finance leases	52	43	42
Total	3,679	3,441	3,503
Right-of-use assets obtained in exchange for new lease obligations
Operating leases	2,323	2,078	2,765
Finance leases	30	11	0
Total	$ 2,352	$ 2,089	$ 2,765