Leases - future lease payments for operating and finance leases (Details) - USD ($) $ in Millions	Aug. 31, 2022	Aug. 31, 2021
Finance lease
2022	$ 87
2024	87
2025	86
2026	86
2027	86
Later	1,041
Total undiscounted minimum lease payments	1,471
Less: Present value discount	(536)
Lease liability	936	$ 1,010
Operating lease
2022	3,440
2024	3,342
2025	3,236
2026	3,136
2027	3,038
Later	14,140
Total undiscounted minimum lease payments	30,333
Less: Present value discount	(6,530)
Lease liability	$ 23,803	$ 24,412