Condensed Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Feb. 28, 2023	Feb. 28, 2022	Feb. 28, 2023	Feb. 28, 2022
Income Statement [Abstract]
REVENUE	$ 22,169	$ 23,641	$ 68,225	$ 69,118
OPERATING EXPENSES:
Salaries and employee benefits	7,817	8,244	23,468	24,155
Purchased transportation	5,402	6,272	16,834	18,172
Rentals and landing fees	1,205	1,225	3,559	3,535
Depreciation and amortization	1,031	986	3,101	2,952
Fuel	1,350	1,201	4,765	3,355
Maintenance and repairs	789	822	2,575	2,530
Business optimization and realignment costs	123	107	197	218
Other	3,410	3,458	10,317	9,880
OPERATING EXPENSES	21,127	22,315	64,816	64,797
OPERATING INCOME	1,042	1,326	3,409	4,321
OTHER (EXPENSE) INCOME:
Interest, net	(122)	(163)	(391)	(478)
Other retirement plans income	102	211	304	380
Other, net		1	(87)	(11)
OTHER (EXPENSE) INCOME	(20)	49	(174)	(109)
INCOME BEFORE INCOME TAXES	1,022	1,375	3,235	4,212
PROVISION FOR INCOME TAXES	251	263	801	944
NET INCOME	$ 771	$ 1,112	$ 2,434	$ 3,268
EARNINGS PER COMMON SHARE:
Basic	$ 3.07	$ 4.26	$ 9.52	$ 12.36
Diluted	3.05	4.20	9.46	12.17
DIVIDENDS DECLARED PER COMMON SHARE	$ 1.15	$ 0.75	$ 4.60	$ 3.00