Condensed Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Feb. 29, 2024	Feb. 28, 2023	Feb. 29, 2024	Feb. 28, 2023
Income Statement [Abstract]
REVENUE	$ 21,738	$ 22,169	$ 65,584	$ 68,225
OPERATING EXPENSES:
Salaries and employee benefits	7,693	7,817	23,311	23,468
Purchased transportation	5,345	5,402	15,776	16,834
Rentals and landing fees	1,145	1,205	3,434	3,559
Depreciation and amortization	1,072	1,031	3,183	3,101
Fuel	1,140	1,350	3,569	4,765
Maintenance and repairs	804	789	2,482	2,575
Business optimization and realignment costs	114	123	364	197
Other	3,182	3,410	9,461	10,317
OPERATING EXPENSES	20,495	21,127	61,580	64,816
OPERATING INCOME	1,243	1,042	4,004	3,409
OTHER (EXPENSE) INCOME:
Interest, net	(91)	(122)	(279)	(391)
Other retirement plans, net	40	102	120	304
Other, net	(9)		(37)	(87)
OTHER (EXPENSE) INCOME	(60)	(20)	(196)	(174)
INCOME BEFORE INCOME TAXES	1,183	1,022	3,808	3,235
PROVISION FOR INCOME TAXES	304	251	951	801
NET INCOME	$ 879	$ 771	$ 2,857	$ 2,434
EARNINGS PER COMMON SHARE:
Basic	$ 3.55	$ 3.07	$ 11.43	$ 9.52
Diluted	3.51	3.05	11.31	9.46
DIVIDENDS DECLARED PER COMMON SHARE	$ 1.26	$ 1.15	$ 3.78	$ 4.6