Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Feb. 29, 2020	Feb. 28, 2019	Feb. 29, 2020	Feb. 28, 2019
Statement Of Income And Comprehensive Income [Abstract]
NET INCOME	$ 315	$ 739	$ 1,620	$ 2,509
OTHER COMPREHENSIVE INCOME (LOSS):
Foreign currency translation adjustments, net of tax benefit of $6 and $3 in 2020 and tax expense of $9 and tax benefit of $22 in 2019	(1)	103	(12)	(90)
Amortization of prior service credit, net of tax benefit of $7 and $19 in 2020 and tax benefit of $7 and $21 in 2019	(20)	(23)	(61)	(69)
Other comprehensive income (loss)	(21)	80	(73)	(159)
COMPREHENSIVE INCOME	$ 294	$ 819	$ 1,547	$ 2,350