Business Segment Information - Schedule of Segment Information (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Nov. 30, 2024	Nov. 30, 2023	Nov. 30, 2024	Nov. 30, 2023	May 31, 2024
Segment Reporting Information [Line Items]
Revenues	$ 21,967	$ 22,165	$ 43,546	$ 43,846
Operating income (loss)	1,052	1,276	2,132	2,761
Assets	85,481		85,481		$ 87,007
Operating Segments [Member] | Federal Express Segment [Member]
Segment Reporting Information [Line Items]
Revenues	18,841	18,773	37,146	37,199
Operating income (loss)	1,052	1,035	2,005	2,341
Assets	72,881		72,881		73,259
Operating Segments [Member] | FedEx Freight Segment [Member]
Segment Reporting Information [Line Items]
Revenues	2,177	2,452	4,506	4,837
Operating income (loss)	312	491	751	973
Assets	12,284		12,284		11,615
Corporate, Other and Eliminations [Member]
Segment Reporting Information [Line Items]
Revenues	949	940	1,894	1,810
Operating income (loss)	(312)	$ (250)	(624)	$ (553)
Assets	$ 316		$ 316		$ 2,133