Description of Business Segments and Summary of Significant Accounting Policies - Schedule of Revenue by Service Type (Details) - USD ($) $ in Millions		3 Months Ended
		Aug. 31, 2024	Aug. 31, 2023
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		$ 21,579	$ 21,681
Operating Segments [Member] | Federal Express Segment [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		18,305	18,426
Operating Segments [Member] | Federal Express Segment [Member] | Package Revenue [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		16,476	16,577
Operating Segments [Member] | Federal Express Segment [Member] | Package Revenue [Member] | U.S. priority [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		2,591	2,673
Operating Segments [Member] | Federal Express Segment [Member] | Package Revenue [Member] | U.S. deferred [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		1,151	1,187
Operating Segments [Member] | Federal Express Segment [Member] | Package Revenue [Member] | U.S. ground [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		8,056	8,133
Operating Segments [Member] | Federal Express Segment [Member] | Package Revenue [Member] | Total U.S [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		11,798	11,993
Operating Segments [Member] | Federal Express Segment [Member] | Package Revenue [Member] | International priority [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		2,206	2,327
Operating Segments [Member] | Federal Express Segment [Member] | Package Revenue [Member] | International economy [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		1,360	1,117
Operating Segments [Member] | Federal Express Segment [Member] | Package Revenue [Member] | Total international export package revenue [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		3,566	3,444
Operating Segments [Member] | Federal Express Segment [Member] | Package Revenue [Member] | International domestic [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues	[1]	1,112	1,140
Operating Segments [Member] | Federal Express Segment [Member] | Total freight revenue [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		1,558	1,602
Operating Segments [Member] | Federal Express Segment [Member] | Total freight revenue [Member] | Total U.S [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		569	577
Operating Segments [Member] | Federal Express Segment [Member] | Total freight revenue [Member] | International priority [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		526	553
Operating Segments [Member] | Federal Express Segment [Member] | Total freight revenue [Member] | International economy [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		463	472
Operating Segments [Member] | Federal Express Segment [Member] | Other [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		271	247
Operating Segments [Member] | FedEx Freight Segment [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		2,329	2,385
Other and eliminations [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues	[2]	$ 945	$ 870

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

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