Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Millions	Aug. 31, 2019	May 31, 2019
Assets, Fair Value Disclosure [Abstract]
Cash	$ 614	$ 853
ASSETS AT FAIR VALUE	3,644	4,663
CASH AND EQUIVALENTS	3,446	4,466
SHORT-TERM INVESTMENTS	198	197
Fair Value, Inputs, Level 1 | U.S. Treasury securities
Assets, Fair Value Disclosure [Abstract]
ASSETS AT FAIR VALUE	361	347
CASH AND EQUIVALENTS	200	200
SHORT-TERM INVESTMENTS	161	147
Fair Value, Inputs, Level 2
Assets, Fair Value Disclosure [Abstract]
ASSETS AT FAIR VALUE	2,669	3,463
CASH AND EQUIVALENTS	2,632	3,413
SHORT-TERM INVESTMENTS	37	50
Fair Value, Inputs, Level 2 | Commercial paper and bonds
Assets, Fair Value Disclosure [Abstract]
ASSETS AT FAIR VALUE	31	34
CASH AND EQUIVALENTS	0	1
SHORT-TERM INVESTMENTS	31	33
Fair Value, Inputs, Level 2 | Money market funds
Assets, Fair Value Disclosure [Abstract]
ASSETS AT FAIR VALUE	1,687	1,637
CASH AND EQUIVALENTS	1,687	1,637
SHORT-TERM INVESTMENTS	0	0
Fair Value, Inputs, Level 2 | Time deposits
Assets, Fair Value Disclosure [Abstract]
ASSETS AT FAIR VALUE	949	1,791
CASH AND EQUIVALENTS	945	1,775
SHORT-TERM INVESTMENTS	4	16
Fair Value, Inputs, Level 2 | U.S. Agency securities
Assets, Fair Value Disclosure [Abstract]
ASSETS AT FAIR VALUE	2	1
CASH AND EQUIVALENTS	0	0
SHORT-TERM INVESTMENTS	$ 2	$ 1