General - Schedule of Revenue by Service Type (Details) - USD ($) $ in Millions		3 Months Ended
		Aug. 31, 2022	Aug. 31, 2021
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		$ 23,242	$ 22,003
Operating Segments [Member] | FedEx Express Segment [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		11,127	10,966
Operating Segments [Member] | FedEx Express Segment [Member] | U.S. overnight box [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		2,316	2,170
Operating Segments [Member] | FedEx Express Segment [Member] | U.S. overnight envelope [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		525	482
Operating Segments [Member] | FedEx Express Segment [Member] | U.S. deferred [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		1,287	1,231
Operating Segments [Member] | FedEx Express Segment [Member] | Total U.S. domestic package revenue [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		4,128	3,883
Operating Segments [Member] | FedEx Express Segment [Member] | International priority [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		2,897	2,839
Operating Segments [Member] | FedEx Express Segment [Member] | International economy [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		707	669
Operating Segments [Member] | FedEx Express Segment [Member] | Total international export package revenue [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		3,604	3,508
Operating Segments [Member] | FedEx Express Segment [Member] | International domestic [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues	[1]	974	1,114
Operating Segments [Member] | FedEx Express Segment [Member] | Total package revenue [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		8,706	8,505
Operating Segments [Member] | FedEx Express Segment [Member] | U.S. freight [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		796	775
Operating Segments [Member] | FedEx Express Segment [Member] | International priority freight [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		888	873
Operating Segments [Member] | FedEx Express Segment [Member] | International Economy Freight [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		377	414
Operating Segments [Member] | FedEx Express Segment [Member] | International Airfreight [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		41	47
Operating Segments [Member] | FedEx Express Segment [Member] | Total freight revenue [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		2,102	2,109
Operating Segments [Member] | FedEx Express Segment [Member] | Other [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		319	352
Operating Segments [Member] | FedEx Ground Segment [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		8,160	7,677
Operating Segments [Member] | FedEx Freight Segment [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		2,723	2,251
Operating Segments [Member] | FedEx Services Segment [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		70	35
Other and eliminations [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues	[2]	$ 1,162	$ 1,074

[1] International domestic revenue relates to our international intra-country operations.

[2] Includes the FedEx Office and Print Services, Inc. (“FedEx Office”), FedEx Logistics, Inc. (“FedEx Logistics”), and FedEx Dataworks (including ShopRunner, Inc.) (“FedEx Dataworks”) operating segments.