Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Millions	Nov. 30, 2017	May 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash	$ 485	$ 505
Assets at Fair Value	6,399	6,189
Cash and Equivalents	4,304	3,808
Short-term Investments	2,085	2,371
Other Long-term Assets	10	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	1,235	1,545
Cash and Equivalents	50	159
Short-term Investments	1,185	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	4,669	4,129
Cash and Equivalents	3,769	3,144
Short-term Investments	900	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	926	813
Cash and Equivalents	892	769
Short-term Investments	34	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	172	522
Cash and Equivalents	0	150
Short-term Investments	172	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	733	820
Cash and Equivalents	39	251
Short-term Investments	694	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	2,838	1,974
Cash and Equivalents	2,838	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	10	10
Cash and Equivalents	0	0
Short-term Investments	0	0
Other Long-term Assets	$ 10	$ 10