Condensed Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Nov. 30, 2024	Nov. 30, 2023	Nov. 30, 2024	Nov. 30, 2023
Income Statement [Abstract]
REVENUE	$ 21,967	$ 22,165	$ 43,546	$ 43,846
OPERATING EXPENSES:
Salaries and employee benefits	7,879	7,833	15,664	15,618
Purchased transportation	5,500	5,395	10,775	10,431
Rentals and landing fees	1,168	1,138	2,329	2,289
Depreciation and amortization	1,063	1,040	2,141	2,111
Fuel	947	1,328	2,022	2,429
Maintenance and repairs	831	854	1,660	1,678
Business optimization costs	326	145	454	250
Other	3,201	3,156	6,369	6,279
OPERATING EXPENSES	20,915	20,889	41,414	41,085
OPERATING INCOME	1,052	1,276	2,132	2,761
OTHER (EXPENSE) INCOME:
Interest, net	(102)	(97)	(186)	(188)
Other retirement plans, net	50	41	99	80
Other, net	(19)	(18)	(8)	(28)
OTHER (EXPENSE) INCOME	(71)	(74)	(95)	(136)
INCOME BEFORE INCOME TAXES	981	1,202	2,037	2,625
PROVISION FOR INCOME TAXES	240	302	502	647
NET INCOME	$ 741	$ 900	$ 1,535	$ 1,978
EARNINGS PER COMMON SHARE:
Basic	$ 3.06	$ 3.59	$ 6.3	$ 7.88
Diluted	3.03	3.55	6.24	7.79
DIVIDENDS DECLARED PER COMMON SHARE	$ 1.38	$ 1.26	$ 4.14	$ 2.52