Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	May 31, 2017	May 31, 2016	May 31, 2015
Statement Of Income And Comprehensive Income [Abstract]
NET INCOME	$ 2,997	$ 1,820	$ 1,050
OTHER COMPREHENSIVE LOSS:
Foreign currency translation adjustments, net of tax expense of $52 in 2017, tax benefit of $22 in 2016 and tax benefit of $45 in 2015	(171)	(261)	(334)
Amortization of prior service credit and other, net of tax benefit of $43 in 2017, tax benefit of $45 in 2016 and tax expense of $1 in 2015	(75)	(80)
Other comprehensive loss	(246)	(341)	(334)
COMPREHENSIVE INCOME	$ 2,751	$ 1,479	$ 716