Condensed Consolidating Financial Statements (Details 3) - USD ($) $ in Millions	3 Months Ended																12 Months Ended
	May. 31, 2015		Feb. 28, 2015		Nov. 30, 2014		Aug. 31, 2014		May. 31, 2014		Feb. 28, 2014		Nov. 30, 2013		Aug. 31, 2013		May. 31, 2015	May. 31, 2014	May. 31, 2013
Condensed Financial Statements Captions [Line Items]
REVENUES	$ 12,114		$ 11,716		$ 11,939		$ 11,684		$ 11,839		$ 11,301		$ 11,403		$ 11,024		$ 47,453	$ 45,567	$ 44,287
OPERATING EXPENSES:
Salaries and employee benefits																	17,110	16,171	16,055
Purchased transportation																	8,483	8,011	7,272
Rentals and landing fees																	2,682	2,622	2,521
Depreciation and amortization																	2,611	2,587	2,386
Fuel																	3,720	4,557	4,746
Maintenance and repairs																	2,099	1,862	1,909
Business realignment, impairment and other charges																	276		660
Retirement plans mark-to-market adjustment																	2,190	15	(1,368)
Other																	6,415	5,927	5,672
OPERATING EXPENSES																	45,586	41,752	39,853
OPERATING INCOME	(1,321)	[1]	1,038	[1]	1,088	[1]	1,062	[1]	1,264	[1]	737	[1]	923	[1]	891	[1]	1,867	3,815	4,434
OTHER INCOME (EXPENSE):
Interest, net																	(221)	(142)	(61)
Other, net																	(19)	(15)	(35)
INCOME BEFORE INCOME TAXES																	1,627	3,658	4,338
PROVISION FOR INCOME TAXES																	577	1,334	1,622
NET INCOME	$ (895)	[1]	$ 628	[1]	$ 663	[1]	$ 653	[1]	$ 780	[1]	$ 437	[1]	$ 559	[1]	$ 548	[1]	1,050	2,324	2,716
COMPREHENSIVE INCOME (LOSS)																	716	2,223	2,694
Parent Company [Member]
OPERATING EXPENSES:
Salaries and employee benefits																	106	99	103
Rentals and landing fees																	5	5	5
Depreciation and amortization																	1	1	1
Maintenance and repairs																	1	1	1
Business realignment, impairment and other charges																			21
Intercompany charges, net																	(450)	(209)	(227)
Other																	337	103	96
OTHER INCOME (EXPENSE):
Equity in earnings of subsidiaries																	1,050	2,324	2,716
Interest, net																	(247)	(167)	(108)
Intercompany charges, net																	253	172	113
Other, net																	(6)	(5)	(5)
INCOME BEFORE INCOME TAXES																	1,050	2,324	2,716
NET INCOME																	1,050	2,324	2,716
COMPREHENSIVE INCOME (LOSS)																	1,053	2,248	2,644
Guarantor Subsidiaries [Member]
Condensed Financial Statements Captions [Line Items]
REVENUES																	39,420	38,088	37,073
OPERATING EXPENSES:
Salaries and employee benefits																	14,626	13,936	13,877
Purchased transportation																	5,802	5,374	4,839
Rentals and landing fees																	2,322	2,282	2,198
Depreciation and amortization																	2,370	2,379	2,200
Fuel																	3,632	4,460	4,650
Maintenance and repairs																	1,949	1,734	1,791
Business realignment, impairment and other charges																	276		639
Retirement plans mark-to-market adjustment																	2,075	13	(1,335)
Intercompany charges, net																	117	(125)	(329)
Other																	4,946	4,823	4,565
OPERATING EXPENSES																	38,115	34,876	33,095
OPERATING INCOME																	1,305	3,212	3,978
OTHER INCOME (EXPENSE):
Equity in earnings of subsidiaries																	337	412	245
Interest, net																	23	16	42
Intercompany charges, net																	(265)	(194)	(131)
Other, net																	(32)	(14)	(20)
INCOME BEFORE INCOME TAXES																	1,368	3,432	4,114
PROVISION FOR INCOME TAXES																	390	1,141	1,416
NET INCOME																	978	2,291	2,698
COMPREHENSIVE INCOME (LOSS)																	929	2,294	2,697
Non Guarantor Subsidiaries [Member]
Condensed Financial Statements Captions [Line Items]
REVENUES																	8,414	7,820	7,543
OPERATING EXPENSES:
Salaries and employee benefits																	2,378	2,136	2,075
Purchased transportation																	2,878	2,796	2,574
Rentals and landing fees																	360	340	324
Depreciation and amortization																	240	207	185
Fuel																	88	97	96
Maintenance and repairs																	149	127	117
Retirement plans mark-to-market adjustment																	115	2	(33)
Intercompany charges, net																	333	334	556
Other																	1,311	1,178	1,193
OPERATING EXPENSES																	7,852	7,217	7,087
OPERATING INCOME																	562	603	456
OTHER INCOME (EXPENSE):
Interest, net																	3	9	5
Intercompany charges, net																	12	22	18
Other, net																	19	4	(10)
INCOME BEFORE INCOME TAXES																	596	638	469
PROVISION FOR INCOME TAXES																	187	193	206
NET INCOME																	409	445	263
COMPREHENSIVE INCOME (LOSS)																	121	417	314
Consolidation Eliminations [Member]
Condensed Financial Statements Captions [Line Items]
REVENUES																	(381)	(341)	(329)
OPERATING EXPENSES:
Purchased transportation																	(197)	(159)	(141)
Rentals and landing fees																	(5)	(5)	(6)
Other																	(179)	(177)	(182)
OPERATING EXPENSES																	(381)	(341)	(329)
OTHER INCOME (EXPENSE):
Equity in earnings of subsidiaries																	(1,387)	(2,736)	(2,961)
INCOME BEFORE INCOME TAXES																	(1,387)	(2,736)	(2,961)
NET INCOME																	(1,387)	(2,736)	(2,961)
COMPREHENSIVE INCOME (LOSS)																	$ (1,387)	$ (2,736)	$ (2,961)

[1] 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. In addition, the first, second and third quarters of 2015 and all quarters of 2014 have been recast to conform to the current year presentation reflecting the retirement plans accounting changes discussed further in Note 1 and Note 13 and that were included in our June 12, 2015, Form 8-K filing with the Securities and Exchange Commission.