Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Millions	Aug. 31, 2020	May 31, 2020
Assets, Fair Value Disclosure [Abstract]
Cash	$ 542	$ 596
ASSETS AT FAIR VALUE	9,480	8,787
CASH AND EQUIVALENTS	8,148	8,348
SHORT-TERM INVESTMENTS	1,332	439
Fair Value, Inputs, Level 1 | U.S. Treasury securities
Assets, Fair Value Disclosure [Abstract]
ASSETS AT FAIR VALUE	1,695	1,204
CASH AND EQUIVALENTS	400	800
SHORT-TERM INVESTMENTS	1,295	404
Fair Value, Inputs, Level 2
Assets, Fair Value Disclosure [Abstract]
ASSETS AT FAIR VALUE	7,243	6,987
CASH AND EQUIVALENTS	7,206	6,952
SHORT-TERM INVESTMENTS	37	35
Fair Value, Inputs, Level 2 | Commercial paper and bonds
Assets, Fair Value Disclosure [Abstract]
ASSETS AT FAIR VALUE	33	32
CASH AND EQUIVALENTS	0	0
SHORT-TERM INVESTMENTS	33	32
Fair Value, Inputs, Level 2 | Money market funds
Assets, Fair Value Disclosure [Abstract]
ASSETS AT FAIR VALUE	6,340	5,973
CASH AND EQUIVALENTS	6,340	5,973
SHORT-TERM INVESTMENTS	0	0
Fair Value, Inputs, Level 2 | Time deposits
Assets, Fair Value Disclosure [Abstract]
ASSETS AT FAIR VALUE	867	981
CASH AND EQUIVALENTS	866	979
SHORT-TERM INVESTMENTS	1	2
Fair Value, Inputs, Level 2 | U.S. Agency securities
Assets, Fair Value Disclosure [Abstract]
ASSETS AT FAIR VALUE	3	1
CASH AND EQUIVALENTS	0	0
SHORT-TERM INVESTMENTS	$ 3	$ 1