Leases - Future Lease Payments for Operating and Finance Leases (Details) - USD ($) $ in Millions	Feb. 28, 2021	Aug. 31, 2020
Finance lease
2021 (Remaining period)	$ 45
2022	89
2023	88
2024	88
2025	87
2026	87
Later	1,147
Total undiscounted minimum lease payments	1,631
Less: Present value discount	(597)
Lease liability	1,034	$ 1,044
Operating lease
2021 (Remaining period)	1,729
2022	3,378
2023	3,264
2024	3,135
2025	2,998
2026	2,862
Later	14,039
Total undiscounted minimum lease payments	31,405
Less: Present value discount	(6,911)
Operating lease liability	$ 24,494	$ 24,123