Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Millions	Feb. 29, 2020	May 31, 2019
Assets, Fair Value Disclosure [Abstract]
Cash	$ 649	$ 853
ASSETS AT FAIR VALUE	3,182	4,663
CASH AND EQUIVALENTS	2,863	4,466
SHORT-TERM INVESTMENTS	319	197
Fair Value, Inputs, Level 1 | U.S. Treasury securities
Assets, Fair Value Disclosure [Abstract]
ASSETS AT FAIR VALUE	280	347
CASH AND EQUIVALENTS	0	200
SHORT-TERM INVESTMENTS	280	147
Fair Value, Inputs, Level 2
Assets, Fair Value Disclosure [Abstract]
ASSETS AT FAIR VALUE	2,253	3,463
CASH AND EQUIVALENTS	2,214	3,413
SHORT-TERM INVESTMENTS	39	50
Fair Value, Inputs, Level 2 | Commercial paper and bonds
Assets, Fair Value Disclosure [Abstract]
ASSETS AT FAIR VALUE	36	34
CASH AND EQUIVALENTS	1	1
SHORT-TERM INVESTMENTS	35	33
Fair Value, Inputs, Level 2 | Money market funds
Assets, Fair Value Disclosure [Abstract]
ASSETS AT FAIR VALUE	1,390	1,637
CASH AND EQUIVALENTS	1,390	1,637
SHORT-TERM INVESTMENTS	0	0
Fair Value, Inputs, Level 2 | Time deposits
Assets, Fair Value Disclosure [Abstract]
ASSETS AT FAIR VALUE	826	1,791
CASH AND EQUIVALENTS	823	1,775
SHORT-TERM INVESTMENTS	3	16
Fair Value, Inputs, Level 2 | U.S. Agency securities
Assets, Fair Value Disclosure [Abstract]
ASSETS AT FAIR VALUE	1	1
CASH AND EQUIVALENTS	0	0
SHORT-TERM INVESTMENTS	$ 1	$ 1