Condensed Consolidated Statements of Changes in Common Stockholders' Investment - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Feb. 28, 2022	Feb. 28, 2021	Feb. 28, 2022	Feb. 28, 2021
Beginning Balance			$ 24,168
Net income	$ 1,112	$ 892	3,268	$ 3,363
Other comprehensive income, net of tax (expense)/benefit of ($2), ($1), $3, and ($4)	90	134	(155)	383
Ending Balance	24,526	21,981	24,526	21,981
Common Stock
Beginning Balance	32	32	32	32
Ending Balance	32	32	32	32
Additional Paid-In Capital
Beginning Balance	3,653	3,400	3,481	3,356
Employee incentive plans and other (0.3, 0.3, 1.1, and 3.7 million shares)	42	45	214	89
Purchase of treasury stock (6.1, 0.0, 8.9, and 0.0 million shares)	(9)		(9)
Ending Balance	3,686	3,445	3,686	3,445
Retained Earnings
Beginning Balance	31,307	27,208	29,817	25,216
Net income	1,112	892	3,268	3,363
Cash dividends declared ($0.75, $0.65, $3.00, and $2.60 per share)	(194)	(173)	(792)	(686)
Employee incentive plans and other (0.3, 0.3, 1.1, and 3.7 million shares)		(3)	(68)	31
Ending Balance	32,225	27,924	32,225	27,924
Accumulated Other Comprehensive Loss
Beginning Balance	(977)	(898)	(732)	(1,147)
Other comprehensive income, net of tax (expense)/benefit of ($2), ($1), $3, and ($4)	90	134	(155)	383
Ending Balance	(887)	(764)	(887)	(764)
Treasury Stock
Beginning Balance	(9,075)	(8,703)	(8,430)	(9,162)
Employee incentive plans and other (0.3, 0.3, 1.1, and 3.7 million shares)	36	47	139	506
Purchase of treasury stock (6.1, 0.0, 8.9, and 0.0 million shares)	(1,491)		(2,239)
Ending Balance	$ (10,530)	$ (8,656)	$ (10,530)	$ (8,656)