Business Segments and Disaggregated Revenue - Schedule of Revenue by Service Type (Details) - USD ($) $ in Millions		12 Months Ended
		May 31, 2023	May 31, 2022	May 31, 2021
Entity Wide Information Revenue From External Customer [Line Items]
Revenues	[1]	$ 90,155	$ 93,512	$ 83,959
Operating Segments [Member] | FedEx Express Segment [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		42,743	45,814	42,078
Operating Segments [Member] | FedEx Express Segment [Member] | U.S. overnight box [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		8,916	9,084	8,116
Operating Segments [Member] | FedEx Express Segment [Member] | U.S. overnight envelope [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		1,980	1,971	1,791
Operating Segments [Member] | FedEx Express Segment [Member] | U.S. deferred [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		5,128	5,330	4,984
Operating Segments [Member] | FedEx Express Segment [Member] | Total U.S. domestic package revenue [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		16,024	16,385	14,891
Operating Segments [Member] | FedEx Express Segment [Member] | International priority [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		10,939	12,130	10,317
Operating Segments [Member] | FedEx Express Segment [Member] | International economy [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		2,911	2,838	2,632
Operating Segments [Member] | FedEx Express Segment [Member] | Total international export package revenue [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		13,850	14,968	12,949
Operating Segments [Member] | FedEx Express Segment [Member] | International domestic [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues	[2]	4,043	4,340	4,640
Operating Segments [Member] | FedEx Express Segment [Member] | Total package revenue [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		33,917	35,693	32,480
Operating Segments [Member] | FedEx Express Segment [Member] | U.S. freight [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		2,906	3,041	3,325
Operating Segments [Member] | FedEx Express Segment [Member] | International priority freight [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		3,060	3,840	3,030
Operating Segments [Member] | FedEx Express Segment [Member] | International Economy Freight
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		1,510	1,653	1,582
Operating Segments [Member] | FedEx Express Segment [Member] | International Airfreight [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		166	177	245
Operating Segments [Member] | FedEx Express Segment [Member] | Total freight revenue [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		7,642	8,711	8,182
Operating Segments [Member] | FedEx Express Segment [Member] | Other [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues	[3]	1,184	1,410	1,416
Operating Segments [Member] | FedEx Ground Segment [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		33,507	33,232	30,496
Operating Segments [Member] | FedEx Freight Segment [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		9,632	9,532	7,833
Operating Segments [Member] | FedEx Services Segment [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues		301	253	32
Corporate, Other and Eliminations [Member]
Entity Wide Information Revenue From External Customer [Line Items]
Revenues	[4]	$ 3,972	$ 4,681	$ 3,520

[1] International revenue includes shipments that either originate in or are destined to locations outside the United States, which could include U.S. payors. Noncurrent assets include property and equipment, operating lease right-of-use assets, goodwill, and other long-term assets. Our flight equipment is registered in the U.S. and is included as U.S. assets; however, many of our aircraft operate internationally.

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

[3] Includes the operations of FedEx Cross Border beginning June 1, 2020.

[4] Includes the FedEx Office, FedEx Logistics, and FedEx Dataworks operating segments.