Condensed Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Nov. 30, 2021	Nov. 30, 2020	Nov. 30, 2021	Nov. 30, 2020
Income Statement [Abstract]
REVENUE	$ 23,474	$ 20,563	$ 45,477	$ 39,884
OPERATING EXPENSES:
Salaries and employee benefits	8,135	7,443	15,911	14,295
Purchased transportation	6,241	5,407	11,900	10,384
Rentals and landing fees	1,177	1,006	2,310	1,942
Depreciation and amortization	995	936	1,966	1,862
Fuel	1,145	625	2,154	1,190
Maintenance and repairs	839	815	1,708	1,621
Business realignment costs	44		111
Other	3,301	2,866	6,422	5,535
OPERATING EXPENSES	21,877	19,098	42,482	36,829
OPERATING INCOME	1,597	1,465	2,995	3,055
OTHER (EXPENSE) INCOME:
Interest, net	(155)	(184)	(315)	(368)
Other retirement plans (expense) income	(47)	150	169	351
Other, net	(15)	(25)	(12)	(26)
OTHER INCOME (EXPENSE)	(217)	(59)	(158)	(43)
INCOME BEFORE INCOME TAXES	1,380	1,406	2,837	3,012
PROVISION FOR INCOME TAXES	336	180	681	541
NET INCOME	$ 1,044	$ 1,226	$ 2,156	$ 2,471
EARNINGS PER COMMON SHARE:
Basic	$ 3.94	$ 4.64	$ 8.11	$ 9.40
Diluted	3.88	4.55	7.97	9.26
DIVIDENDS DECLARED PER COMMON SHARE	$ 0.75	$ 0.65	$ 2.25	$ 1.95