Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Millions	Feb. 28, 2018	May 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash	$ 620	$ 505
Assets at Fair Value	4,762	6,189
Cash and Equivalents	3,662	3,808
Short-term Investments	1,089	2,371
Other Long-term Assets	11	10
Fair Value Measurements Using Level 1 | U.S. Treasury securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets at Fair Value	865	1,545
Cash and Equivalents	150	159
Short-term Investments	715	1,386
Other Long-term Assets	0	0
Fair Value Measurements Using Level 2
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets at Fair Value	3,266	4,129
Cash and Equivalents	2,892	3,144
Short-term Investments	374	985
Other Long-term Assets	0	0
Fair Value Measurements Using Level 2 | Time deposits
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets at Fair Value	773	813
Cash and Equivalents	769	769
Short-term Investments	4	44
Other Long-term Assets	0	0
Fair Value Measurements Using Level 2 | U.S. Agency securities
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets at Fair Value	45	522
Cash and Equivalents	0	150
Short-term Investments	45	372
Other Long-term Assets	0	0
Fair Value Measurements Using Level 2 | Commercial paper and bonds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets at Fair Value	477	820
Cash and Equivalents	152	251
Short-term Investments	325	569
Other Long-term Assets	0	0
Fair Value Measurements Using Level 2 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets at Fair Value	1,971	1,974
Cash and Equivalents	1,971	1,974
Short-term Investments	0	0
Other Long-term Assets	0	0
Fair Value Measurements Using Level 3 | Non-marketable preferred stock
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Assets at Fair Value	11	10
Cash and Equivalents	0	0
Short-term Investments	0	0
Other Long-term Assets	$ 11	$ 10