Business Segment Information - Schedule of Segment Information (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Feb. 28, 2017	Feb. 29, 2016	Feb. 28, 2017	Feb. 29, 2016
Segment Reporting Information [Line Items]
Revenues	$ 14,997	$ 12,654	$ 44,591	$ 37,386
Operating Income	1,025	864	3,456	3,145
FedEx Express Segment [Member]
Segment Reporting Information [Line Items]
Revenues	6,779	6,557	20,178	19,736
Operating Income	555	595	1,815	1,762
TNT Express Segment [Member]
Segment Reporting Information [Line Items]
Revenues	1,790		5,493
Operating Income	2		58
FedEx Ground Segment [Member]
Segment Reporting Information [Line Items]
Revenues	4,688	4,408	13,397	12,288
Operating Income	515	557	1,590	1,620
FedEx Freight Segment [Member]
Segment Reporting Information [Line Items]
Revenues	1,492	1,447	4,747	4,595
Operating Income	41	56	264	289
FedEx Services Segment [Member]
Segment Reporting Information [Line Items]
Revenues	389	384	1,198	1,177
Eliminations, Corporate and Other [Member]
Segment Reporting Information [Line Items]
Revenues	(141)	(142)	(422)	(410)
Operating Income	$ (88)	$ (344)	$ (271)	$ (526)