Leases (Supplemental Cash Flow Information) (Details) - USD ($) $ in Millions	12 Months Ended
	Aug. 31, 2021	Aug. 31, 2020
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows for operating leases	$ 121	$ 112
Operating cash flows for finance leases	5	5
Financing activities for finance leases	39	6
Non-cash right-of-use assets obtained in exchange for new lease liabilities:
Operating leases	141	91
Finance leases	$ 190	$ 112