Commitments - Additional Information (Details) $ in Millions	3 Months Ended
Aug. 31, 2017 USD ($) air-craft
Other Aircraft Commitments Disclosure [Abstract]
Boeing 767F Conditional Aircraft Commitments	4
Boeing 777F Conditional Aircraft Commitments	6
Deposit and Progress Payments \| $	$ 860

Balance of deposits and progress payments on aircraft purchases and other planned aircraft-related transactions.

No definition available.

Name:	fdx_DepositAndProgressPayments
Namespace Prefix:	fdx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant