Leases - Schedule of Supplemental Cash Flow Information Related to Leases (Details) $ in Millions	6 Months Ended
	Nov. 30, 2019 USD ($)
Leases [Abstract]
Operating cash flows paid for operating leases	$ 1,247
Operating cash flows paid for interest portion of finance leases	2
Financing cash flows paid for principal portion of finance leases	64
Right-of-use assets obtained in exchange for new operating lease liabilities	1,049
Right-of-use assets obtained in exchange for new finance lease liabilities	$ 93