Condensed Consolidated Statements of Changes in Common Stockholders' Investment - USD ($) $ in Millions	3 Months Ended
	Aug. 31, 2021	Aug. 31, 2020
Beginning Balance	$ 24,168
Net income	1,112	$ 1,245
Other comprehensive income, net of tax (expense)/benefit	(149)	127
Ending Balance	24,321	19,462
Common Stock
Beginning Balance	32	32
Ending Balance	32	32
Additional Paid-In Capital
Beginning Balance	3,481	3,356
Employee incentive plans and other	129	19
Ending Balance	3,610	3,375
Retained Earnings
Beginning Balance	29,817	25,216
Net income	1,112	1,245
Cash dividends declared	(400)	(341)
Employee incentive plans and other	(67)	(12)
Ending Balance	30,462	26,108
Accumulated Other Comprehensive Income
Beginning Balance	(732)	(1,147)
Other comprehensive income, net of tax (expense)/benefit	(149)	127
Ending Balance	(881)	(1,020)
Treasury Stock
Beginning Balance	(8,430)	(9,162)
Purchase of treasury stock	(549)
Employee incentive plans and other	77	129
Ending Balance	$ (8,902)	$ (9,033)