Business Segment Information - Schedule of Segment Information (Details) - USD ($) $ in Millions	3 Months Ended
	Aug. 31, 2022	Aug. 31, 2021
Segment Reporting Information [Line Items]
Revenue	$ 23,242	$ 22,003
Operating income (loss)	1,191	1,398
Operating Segments [Member] | FedEx Express Segment [Member]
Segment Reporting Information [Line Items]
Revenue	11,127	10,966
Operating income (loss)	174	567
Operating Segments [Member] | FedEx Ground Segment [Member]
Segment Reporting Information [Line Items]
Revenue	8,160	7,677
Operating income (loss)	694	671
Operating Segments [Member] | FedEx Freight Segment [Member]
Segment Reporting Information [Line Items]
Revenue	2,723	2,251
Operating income (loss)	651	390
Operating Segments [Member] | FedEx Services Segment [Member]
Segment Reporting Information [Line Items]
Revenue	70	35
Corporate, Other and Eliminations [Member]
Segment Reporting Information [Line Items]
Revenue	1,162	1,074
Operating income (loss)	$ (328)	$ (230)