Business Segments and Disaggregated Revenue - Schedule of Geographical Information (Details) - USD ($) $ in Millions		12 Months Ended
		May 31, 2024	May 31, 2023	May 31, 2022
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	[1]	$ 87,693	$ 90,155	$ 93,512
Assets Noncurrent	[1]	68,800	68,533	65,629
U.S. [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	[1]	63,531	64,890	64,941
Assets Noncurrent	[1]	56,822	56,449	53,311
International [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	[1]	24,162	25,265	28,571
Assets Noncurrent	[1]	11,978	12,084	12,318
FedEx Express Segment [Member] | International [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	[1]	22,291	23,090	25,564
FedEx Ground Segment [Member] | International [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	[1]	844	860	857
FedEx Freight Segment [Member] | International [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	[1]	266	264	235
FedEx Services Segment [Member] | International [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	[1]	1	1	1
Other international revenue [Member] | International [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenues	[1]	$ 760	$ 1,050	$ 1,914

[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.