Leases - Supplemental Cash Flow Information (Details) $ in Millions	9 Months Ended
	May 31, 2020 USD ($)
Cash paid for amounts included in the measurement of lease obligations
Operating cash flows from operating leases	$ 2,521
Operating cash flows from finance leases	36
Financing cash flows from finance leases	39
Total	2,596
Right-of-use assets obtained in exchange for new lease obligations:
Operating leases	1,954
Finance leases	65
Total	$ 2,019