Description of Business Segments and Summary of Significant Accounting Policies - Schedule of Revenue by Service Type (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Nov. 30, 2024	Nov. 30, 2023	Nov. 30, 2024	Nov. 30, 2023
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		$ 21,967	$ 22,165	$ 43,546	$ 43,846
Operating Segments [Member] | Federal Express Segment [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		18,841	18,773	37,146	37,199
Operating Segments [Member] | Federal Express Segment [Member] | Package Revenue [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		17,027	16,907	33,503	33,484
Operating Segments [Member] | Federal Express Segment [Member] | Package Revenue [Member] | U.S. priority [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		2,563	2,605	5,154	5,278
Operating Segments [Member] | Federal Express Segment [Member] | Package Revenue [Member] | U.S. deferred [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		1,199	1,207	2,350	2,394
Operating Segments [Member] | Federal Express Segment [Member] | Package Revenue [Member] | U.S. ground [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		8,256	8,309	16,312	16,442
Operating Segments [Member] | Federal Express Segment [Member] | Package Revenue [Member] | Total U.S [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		12,018	12,121	23,816	24,114
Operating Segments [Member] | Federal Express Segment [Member] | Package Revenue [Member] | International priority [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		2,231	2,390	4,437	4,717
Operating Segments [Member] | Federal Express Segment [Member] | Package Revenue [Member] | International economy [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		1,588	1,183	2,948	2,300
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		3,819	3,573	7,385	7,017
Operating Segments [Member] | Federal Express Segment [Member] | Package Revenue [Member] | International domestic [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues	[1]	1,190	1,213	2,302	2,353
Operating Segments [Member] | Federal Express Segment [Member] | Total freight revenue [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		1,552	1,615	3,110	3,217
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		383	577	952	1,154
Operating Segments [Member] | Federal Express Segment [Member] | Total freight revenue [Member] | International priority [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		640	568	1,166	1,121
Operating Segments [Member] | Federal Express Segment [Member] | Total freight revenue [Member] | International economy [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		529	470	992	942
Operating Segments [Member] | Federal Express Segment [Member] | Other [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		262	251	533	498
Operating Segments [Member] | FedEx Freight Segment [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		2,177	2,452	4,506	4,837
Other and eliminations [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues	[2]	$ 949	$ 940	$ 1,894	$ 1,810

[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.