Business Segments and Disaggregated Revenue - Schedule of Segment Information (Details) - USD ($) $ in Millions		12 Months Ended
		May 31, 2022		May 31, 2021		May 31, 2020
Segment Reporting Information [Line Items]
Revenues	[1]	$ 93,512		$ 83,959		$ 69,217
Depreciation and amortization		3,970		3,793		3,615
Operating income (loss)		6,245	[2]	5,857	[3]	2,417	[4]
Segment assets	[5]	85,994		82,777		73,537
Capital expenditures		6,763		5,884		5,868
Operating Segments [Member] | FedEx Express Segment [Member]
Segment Reporting Information [Line Items]
Revenues		45,814		42,078		35,513
Depreciation and amortization		2,007		1,946		1,894
Operating income (loss)		2,922	[2]	2,810	[3]	996	[4]
Segment assets	[5]	47,604		46,356		41,252
Capital expenditures		3,637		3,503		3,560
Operating Segments [Member] | FedEx Ground Segment [Member]
Segment Reporting Information [Line Items]
Revenues		33,232		30,496		22,733
Depreciation and amortization		919		843		789
Operating income (loss)		2,642	[2]	3,193	[3]	2,014	[4]
Segment assets	[5]	32,645		29,134		24,700
Capital expenditures		2,139		1,446		1,083
Operating Segments [Member] | FedEx Freight Segment [Member]
Segment Reporting Information [Line Items]
Revenues		9,532		7,833		7,102
Depreciation and amortization		406		417		381
Operating income (loss)		1,663	[2]	1,005	[3]	580	[4]
Segment assets	[5]	8,904		7,371		6,434
Capital expenditures		319		320		539
Operating Segments [Member] | FedEx Services Segment [Member]
Segment Reporting Information [Line Items]
Revenues		253		32		22
Depreciation and amortization		513		462		413
Segment assets	[5]	8,389		8,639		7,285
Capital expenditures		565		512		527
Corporate, Other and Eliminations [Member]
Segment Reporting Information [Line Items]
Revenues		4,681		3,520		3,847
Depreciation and amortization		125		125		138
Operating income (loss)		(982)	[2]	(1,151)	[3]	(1,173)	[4]
Segment assets	[5]	(11,548)		(8,723)		(6,134)
Capital expenditures		$ 103		$ 103		$ 159

[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.

[2] Includes business realignment costs of $278 million included in the FedEx Express segment, as well as a charge of $210 million related to the pre- and post-judgment interest in connection with a FedEx Ground legal matter included in “Corporate, other, and eliminations.” Also includes TNT Express integration expenses of $132 million included in “Corporate, other, and eliminations” and the FedEx Express segment.

[3] Includes TNT Express integration expenses of $210 million included in “Corporate, other, and eliminations” and the FedEx Express segment. Also includes business realignment costs of $116 million included in the FedEx Express segment.

[4] Includes noncash goodwill and other asset impairment charges of $435 million primarily related to goodwill impairment at FedEx Office and from the decision to permanently retire certain aircraft and related engines at FedEx Express. Also includes TNT Express integration expenses of $270 million included in “Corporate, other, and eliminations” and the FedEx Express segment.

[5] Segment assets include intercompany receivables.