Condensed Consolidated Statements of Changes in Common Stockholders' Investment - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Nov. 30, 2021	Nov. 30, 2020	Nov. 30, 2021	Nov. 30, 2020
Beginning Balance			$ 24,168
Net income	$ 1,044	$ 1,226	2,156	$ 2,471
Other comprehensive income, net of tax benefit/(expense)	(96)	122	(245)	249
Ending Balance	24,940	21,039	24,940	21,039
Common Stock
Beginning Balance	32	32	32	32
Ending Balance	32	32	32	32
Additional Paid-In Capital
Beginning Balance	3,610	3,375	3,481	3,356
Employee incentive plans and other	43	25	172	44
Ending Balance	3,653	3,400	3,653	3,400
Retained Earnings
Beginning Balance	30,462	26,108	29,817	25,216
Net income	1,044	1,226	2,156	2,471
Cash dividends declared	(198)	(172)	(598)	(513)
Employee incentive plans and other	(1)	46	(68)	34
Ending Balance	31,307	27,208	31,307	27,208
Accumulated Other Comprehensive Income
Beginning Balance	(881)	(1,020)	(732)	(1,147)
Other comprehensive income, net of tax benefit/(expense)	(96)	122	(245)	249
Ending Balance	(977)	(898)	(977)	(898)
Treasury Stock
Beginning Balance	(8,902)	(9,033)	(8,430)	(9,162)
Purchase of treasury stock	(199)		(748)
Employee incentive plans and other	26	330	103	459
Ending Balance	$ (9,075)	$ (8,703)	$ (9,075)	$ (8,703)