General - Schedule of Revenue by Service Type (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Nov. 30, 2022	Nov. 30, 2021	Nov. 30, 2022	Nov. 30, 2021
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		$ 22,814	$ 23,474	$ 46,056	$ 45,477
Operating Segments [Member] | FedEx Express Segment [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		10,864	11,605	21,991	22,571
Operating Segments [Member] | FedEx Express Segment [Member] | U.S. overnight box [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		2,237	2,249	4,553	4,419
Operating Segments [Member] | FedEx Express Segment [Member] | U.S. overnight envelope [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		474	474	999	956
Operating Segments [Member] | FedEx Express Segment [Member] | U.S. deferred [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		1,253	1,307	2,540	2,538
Operating Segments [Member] | FedEx Express Segment [Member] | Total U.S. domestic package revenue [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		3,964	4,030	8,092	7,913
Operating Segments [Member] | FedEx Express Segment [Member] | International priority [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		2,823	3,107	5,720	5,946
Operating Segments [Member] | FedEx Express Segment [Member] | International economy [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		711	706	1,418	1,375
Operating Segments [Member] | FedEx Express Segment [Member] | Total international export package revenue [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		3,534	3,813	7,138	7,321
Operating Segments [Member] | FedEx Express Segment [Member] | International domestic [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues	[1]	1,036	1,147	2,010	2,261
Operating Segments [Member] | FedEx Express Segment [Member] | Total package revenue [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		8,534	8,990	17,240	17,495
Operating Segments [Member] | FedEx Express Segment [Member] | U.S. freight [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		784	775	1,580	1,550
Operating Segments [Member] | FedEx Express Segment [Member] | International priority freight [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		811	994	1,699	1,867
Operating Segments [Member] | FedEx Express Segment [Member] | International Economy Freight [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		388	438	765	852
Operating Segments [Member] | FedEx Express Segment [Member] | International Airfreight [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		39	47	80	94
Operating Segments [Member] | FedEx Express Segment [Member] | Total freight revenue [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		2,022	2,254	4,124	4,363
Operating Segments [Member] | FedEx Express Segment [Member] | Other [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		308	361	627	713
Operating Segments [Member] | FedEx Ground Segment [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		8,393	8,264	16,553	15,941
Operating Segments [Member] | FedEx Freight Segment [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		2,454	2,272	5,177	4,523
Operating Segments [Member] | FedEx Services Segment [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		68	77	138	112
Other and eliminations [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues	[2]	$ 1,035	$ 1,256	$ 2,197	$ 2,330

[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, Inc. (including ShopRunner, Inc.) (“FedEx Dataworks”) operating segments.