Business Segments and Disaggregated Revenue - Schedule of Segment Information (Details) - USD ($) $ in Millions		12 Months Ended
		May 31, 2023		May 31, 2022		May 31, 2021
Segment Reporting Information [Line Items]
Revenues	[1]	$ 90,155		$ 93,512		$ 83,959
Depreciation and amortization		4,176		3,970		3,793
Operating income (loss)		4,912	[2]	6,245	[3]	5,857	[4]
Segment assets	[5]	87,143		85,994		82,777
Capital expenditures		6,174		6,763		5,884
Operating Segments [Member] | FedEx Express Segment [Member]
Segment Reporting Information [Line Items]
Revenues		42,743		45,814		42,078
Depreciation and amortization		2,105		2,007		1,946
Operating income (loss)		1,064	[2]	2,922	[3]	2,810	[4]
Segment assets	[5]	47,754		47,604		46,356
Capital expenditures		3,055		3,637		3,503
Operating Segments [Member] | FedEx Ground Segment [Member]
Segment Reporting Information [Line Items]
Revenues		33,507		33,232		30,496
Depreciation and amortization		1,020		919		843
Operating income (loss)		3,140	[2]	2,642	[3]	3,193	[4]
Segment assets	[5]	36,815		32,645		29,134
Capital expenditures		1,995		2,139		1,446
Operating Segments [Member] | FedEx Freight Segment [Member]
Segment Reporting Information [Line Items]
Revenues		9,632		9,532		7,833
Depreciation and amortization		387		406		417
Operating income (loss)		1,925	[2]	1,663	[3]	1,005	[4]
Segment assets	[5]	10,197		8,904		7,371
Capital expenditures		556		319		320
Operating Segments [Member] | FedEx Services Segment [Member]
Segment Reporting Information [Line Items]
Revenues		301		253		32
Depreciation and amortization		529		513		462
Segment assets	[5]	7,415		8,389		8,639
Capital expenditures		431		565		512
Corporate, Other and Eliminations [Member]
Segment Reporting Information [Line Items]
Revenues		3,972		4,681		3,520
Depreciation and amortization		135		125		125
Operating income (loss)		(1,217)	[2]	(982)	[3]	(1,151)	[4]
Segment assets	[5]	(15,038)		(11,548)		(8,723)
Capital expenditures		$ 137		$ 103		$ 103

[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 optimization costs of $262 million included in “Corporate, other, and eliminations” and business optimization and realignment costs of $11 million and $36 million, respectively, included in the FedEx Express segment. Includes noncash other asset impairment charges of $70 million primarily related to the decision to permanently retire certain aircraft and related engines at FedEx Express and goodwill and other asset impairment charges of $47 million at FedEx Dataworks related to the ShopRunner acquisition. Also includes $35 million in connection with a FedEx Ground legal matter included in “Corporate, other, and eliminations.”

[3] 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 separate 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.

[4] 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.

[5] Segment assets include intercompany receivables.