Condensed Consolidated Statements of Changes in Common Shareholders Investment - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Feb. 28, 2019	Feb. 28, 2018	Feb. 28, 2019	Feb. 28, 2018
Beginning Balance			$ 19,416
NET INCOME	$ 739	$ 2,074	2,509	$ 3,445
Other comprehensive income, net of tax (expense)/benefit	80	77	(159)	58
Ending Balance	19,894	18,894	19,894	18,894
Common Stock
Beginning Balance	32	32	32	32
Ending Balance	32	32	32	32
Additional Paid-In Capital
Beginning Balance	3,185	3,055	3,117	3,005
Employee incentive plans and other	24	30	92	80
Ending Balance	3,209	3,085	3,209	3,085
Retained Earnings
Beginning Balance	26,080	21,785	24,823	20,833
NET INCOME	739	2,074	2,509	3,445
Cash dividends declared	(169)	(133)	(683)	(535)
Employee incentive plans and other		(16)	1	(33)
Ending Balance	26,650	23,710	26,650	23,710
Accumulated Other Comprehensive Income
Beginning Balance	(817)	(434)	(578)	(415)
Other comprehensive income, net of tax (expense)/benefit	80	77	(159)	58
Ending Balance	(737)	(357)	(737)	(357)
Treasury Stock
Beginning Balance	(9,186)	(7,383)	(7,978)	(7,382)
Purchase of treasury stock	(93)	(288)	(1,365)	(558)
Employee incentive plans and other	19	95	83	364
Ending Balance	$ (9,260)	$ (7,576)	$ (9,260)	$ (7,576)