Income Taxes - Provision for Income Taxes (Detail) - USD ($) $ in Millions	12 Months Ended
	May 31, 2018	May 31, 2017	May 31, 2016
Current:
Federal	$ 1,167	$ 398	$ 304
State	45	82	71
Foreign	533	439	568
Total	1,745	919	943
Deferred:
Federal	595	(279)	(57)
State	25	(9)	(16)
Foreign	27	15	(7)
Total	647	(273)	(80)
Income tax expense	$ 2,392	$ 646	$ 863