Condensed Consolidating Financial Statements (Details 3) - USD ($) $ in Millions	3 Months Ended												12 Months Ended
	May 31, 2016		Feb. 29, 2016	[1]	Nov. 30, 2015	[1]	Aug. 31, 2015	May 31, 2015		Feb. 28, 2015	Nov. 30, 2014	Aug. 31, 2014	May 31, 2016	May 31, 2015	May 31, 2014
Condensed Income Statements Captions [Line Items]
REVENUES	$ 12,979	[1]	$ 12,654		$ 12,453		$ 12,279	$ 12,114	[2]	$ 11,716	$ 11,939	$ 11,684	$ 50,365	$ 47,453	$ 45,567
OPERATING EXPENSES:
Salaries and employee benefits													18,581	17,110	16,171
Purchased transportation													9,966	8,483	8,011
Rentals and landing fees													2,854	2,682	2,622
Depreciation and amortization													2,631	2,611	2,587
Fuel													2,399	3,720	4,557
Maintenance and repairs													2,108	2,099	1,862
Impairment and other charges														276
Retirement plans mark-to-market adjustment	1,500							2,200					1,498	2,190	15
Other													7,251	6,415	5,927
OPERATING EXPENSES													47,288	45,586	41,752
OPERATING INCOME	(68)	[1]	864		1,137		1,144	(1,321)	[2]	1,038	1,088	1,062	3,077	1,867	3,815
OTHER INCOME (EXPENSE):
Interest, net													(315)	(221)	(142)
Other, net													(22)	(19)	(15)
INCOME BEFORE INCOME TAXES													2,740	1,627	3,658
PROVISION FOR INCOME TAXES													920	577	1,334
NET INCOME	$ (70)	[1]	$ 507		$ 691		$ 692	$ (895)	[2]	$ 628	$ 663	$ 653	1,820	1,050	2,324
COMPREHENSIVE INCOME (LOSS)													1,479	716	2,223
Parent Company [Member]
OPERATING EXPENSES:
Salaries and employee benefits													119	106	99
Rentals and landing fees													5	5	5
Depreciation and amortization													1	1	1
Maintenance and repairs													1	1	1
Intercompany charges, net													(645)	(450)	(209)
Other													519	337	103
OTHER INCOME (EXPENSE):
Equity in earnings of subsidiaries													1,820	1,050	2,324
Interest, net													(355)	(247)	(167)
Intercompany charges, net													369	253	172
Other, net													(14)	(6)	(5)
INCOME BEFORE INCOME TAXES													1,820	1,050	2,324
NET INCOME													1,820	1,050	2,324
COMPREHENSIVE INCOME (LOSS)													1,746	1,053	2,248
Guarantor Subsidiaries [Member]
Condensed Income Statements Captions [Line Items]
REVENUES													42,143	39,420	38,088
OPERATING EXPENSES:
Salaries and employee benefits													15,880	14,626	13,936
Purchased transportation													7,380	5,802	5,374
Rentals and landing fees													2,484	2,322	2,282
Depreciation and amortization													2,399	2,370	2,379
Fuel													2,324	3,632	4,460
Maintenance and repairs													1,954	1,949	1,734
Impairment and other charges														276
Retirement plans mark-to-market adjustment													1,414	2,075	13
Intercompany charges, net													425	117	(125)
Other													5,274	4,946	4,823
OPERATING EXPENSES													39,534	38,115	34,876
OPERATING INCOME													2,609	1,305	3,212
OTHER INCOME (EXPENSE):
Equity in earnings of subsidiaries													279	337	412
Interest, net													27	23	16
Intercompany charges, net													(354)	(265)	(194)
Other, net													(14)	(32)	(14)
INCOME BEFORE INCOME TAXES													2,547	1,368	3,432
PROVISION FOR INCOME TAXES													818	390	1,141
NET INCOME													1,729	978	2,291
COMPREHENSIVE INCOME (LOSS)													1,704	929	2,294
Non Guarantor Subsidiaries [Member]
Condensed Income Statements Captions [Line Items]
REVENUES													8,547	8,414	7,820
OPERATING EXPENSES:
Salaries and employee benefits													2,582	2,378	2,136
Purchased transportation													2,720	2,878	2,796
Rentals and landing fees													371	360	340
Depreciation and amortization													231	240	207
Fuel													75	88	97
Maintenance and repairs													153	149	127
Retirement plans mark-to-market adjustment													84	115	2
Intercompany charges, net													220	333	334
Other													1,643	1,311	1,178
OPERATING EXPENSES													8,079	7,852	7,217
OPERATING INCOME													468	562	603
OTHER INCOME (EXPENSE):
Interest, net													13	3	9
Intercompany charges, net													(15)	12	22
Other, net													6	19	4
INCOME BEFORE INCOME TAXES													472	596	638
PROVISION FOR INCOME TAXES													102	187	193
NET INCOME													370	409	445
COMPREHENSIVE INCOME (LOSS)													128	121	417
Consolidation Eliminations [Member]
Condensed Income Statements Captions [Line Items]
REVENUES													(325)	(381)	(341)
OPERATING EXPENSES:
Purchased transportation													(134)	(197)	(159)
Rentals and landing fees													(6)	(5)	(5)
Other													(185)	(179)	(177)
OPERATING EXPENSES													(325)	(381)	(341)
OTHER INCOME (EXPENSE):
Equity in earnings of subsidiaries													(2,099)	(1,387)	(2,736)
INCOME BEFORE INCOME TAXES													(2,099)	(1,387)	(2,736)
NET INCOME													(2,099)	(1,387)	(2,736)
COMPREHENSIVE INCOME (LOSS)													$ (2,099)	$ (1,387)	$ (2,736)

[1] The fourth quarter of 2016 includes a $1.5 billion retirement plans mark-to-market loss and TNT Express transaction, financing and integration planning expenses and immaterial financial results from the time of acquisition totaling $79 million. In addition, the fourth quarter of 2016 includes a $76 million favorable tax impact from an internal corporate restructuring to facilitate the integration of FedEx Express and TNT Express and $11 million of expenses related to independent contractor litigation matters at FedEx Ground. The third quarter of 2016 includes provisions related to independent contractor litigation matters at FedEx Ground for $204 million and expenses related to the settlement of a U.S. Customs and Border Protection notice of action in the amount of $69 million, as well as TNT Express transaction, financing and integration planning expenses of $25 million. The second quarter of 2016 includes provisions related to independent contractor litigation matters at FedEx Ground for $41 million and $19 million of TNT Express transaction, financing and integration planning expenses.

[2] The fourth quarter of 2015 includes a $2.2 billion retirement plans mark-to-market loss, $276 million of impairment and related charges resulting from the decision to permanently retire and adjust the retirement schedule of certain aircraft and related engines at FedEx Express and a $197 million reserve increase due to the settlement of a legal matter at FedEx Ground.