Long-term Debt and Other Financing Arrangements - Additional Information (Details)		12 Months Ended
	Mar. 15, 2024 USD ($)	May 31, 2024 USD ($) AirCraft	May 31, 2023 USD ($)
Debt Instrument [Line Items]
Long-term debt weighted-average interest rate		3.50%
Long term debt, including current maturities and exclusive of finance leases fair value		$ 17,500,000,000	$ 17,500,000,000
Debt instrument, face amount		$ 19,977,000,000
Number of Boeing aircraft | AirCraft		19
Net book value of Boeing aircraft		$ 1,700,000,000
Financial covenant terms ratio	4.00%	3.50%
Financial covenant compliance ratio	3.50%	1.80%
Line of credit facility, financial covenant, minimum cash consideration for acquisition	$ 250,000,000
1.875% due in February 2034 [Member]
Debt Instrument [Line Items]
Debt instrument, face amount		$ 970,000,000
Fixed interest rate		1.875%
Debt instrument, maturity date		2034-02
Old Five-Year Credit Agreement [Member]
Debt Instrument [Line Items]
Line of credit facility maximum borrowing capacity	$ 2,000,000,000
Line of credit facility, term	5 years
New Five-Year Credit Agreement [Member]
Debt Instrument [Line Items]
Line of credit facility maximum borrowing capacity		$ 1,750,000,000
Line of credit facility, expiration date		2029-03
Letter of credit maximum sublimit amount		$ 125,000,000
New Credit Agreements [Member]
Debt Instrument [Line Items]
Line of credit outstanding		0
Commercial paper outstanding		0
Letter of credit outstanding sublimit unused amount		250,000,000
Maximum required net unrestricted cash and cash equivalents for financial covenant		$ 500,000,000
Line of credit facility, financial covenant terms	(i) net unrestricted cash and cash equivalents up to $500 million from the definition of debt and (ii) add back business optimization and restructuring expenses and pro forma cost savings and synergies associated with an acquisition to adjusted EBITDA. The aggregate amount of adjustments for business optimization and restructuring expenses and pro forma cost savings and synergies associated with an acquisition may not exceed 10% of adjusted EBITDA (calculated after giving effect to any such addback and such cap and all other permitted addbacks and adjustments) in any period. Additionally, following the consummation of an acquisition for which the aggregate cash consideration is at least $250 million, FedEx may elect to increase the ratio to 4.0 to 1.0 with respect to the last day of the fiscal quarter during which such acquisition is consummated and the last day of each of the immediately following three consecutive fiscal quarters, provided that there must be at least two consecutive fiscal quarters between such elections during which the ratio is 3.5 to 1.0.
Line of credit facility, financial covenant, maximum percentage of adjusted EBITDA		10.00%
Old Three-Year Credit Agreement [Member]
Debt Instrument [Line Items]
Line of credit facility maximum borrowing capacity	$ 1,500,000,000
Line of credit facility, term	3 years
New Three-Year Credit Agreement [Member]
Debt Instrument [Line Items]
Line of credit facility maximum borrowing capacity		$ 1,750,000,000
Line of credit facility, expiration date		2027-03
Letter of credit maximum sublimit amount		$ 125,000,000