Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Millions	May 31, 2019	May 31, 2018
Assets, Fair Value Disclosure [Abstract]
Cash	$ 853	$ 415
ASSETS AT FAIR VALUE	4,663	5,245
CASH AND EQUIVALENTS	4,466	4,249
SHORT-TERM INVESTMENTS	197	996
Fair Value, Inputs, Level 1 | U.S. Treasury securities
Assets, Fair Value Disclosure [Abstract]
ASSETS AT FAIR VALUE	347	1,178
CASH AND EQUIVALENTS	200	500
SHORT-TERM INVESTMENTS	147	678
Fair Value, Inputs, Level 2
Assets, Fair Value Disclosure [Abstract]
ASSETS AT FAIR VALUE	3,463	3,652
CASH AND EQUIVALENTS	3,413	3,334
SHORT-TERM INVESTMENTS	50	318
Fair Value, Inputs, Level 2 | Commercial paper and bonds
Assets, Fair Value Disclosure [Abstract]
ASSETS AT FAIR VALUE	34	451
CASH AND EQUIVALENTS	1	153
SHORT-TERM INVESTMENTS	33	298
Fair Value, Inputs, Level 2 | Money market funds
Assets, Fair Value Disclosure [Abstract]
ASSETS AT FAIR VALUE	1,637	2,174
CASH AND EQUIVALENTS	1,637	2,174
SHORT-TERM INVESTMENTS	0	0
Fair Value, Inputs, Level 2 | Time deposits
Assets, Fair Value Disclosure [Abstract]
ASSETS AT FAIR VALUE	1,791	925
CASH AND EQUIVALENTS	1,775	907
SHORT-TERM INVESTMENTS	16	18
Fair Value, Inputs, Level 2 | U.S. Agency securities
Assets, Fair Value Disclosure [Abstract]
ASSETS AT FAIR VALUE	1	102
CASH AND EQUIVALENTS	0	100
SHORT-TERM INVESTMENTS	$ 1	$ 2