Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Millions	May 31, 2018	May 31, 2017
Assets, Fair Value Disclosure [Abstract]
Cash	$ 415	$ 505
Assets at Fair Value	5,256	6,189
Cash Equivalents	4,249	3,808
Short-term Investments	996	2,371
Other Long-term Assets	11	10
Fair Value, Inputs, Level 1 | U.S. Treasury securities
Assets, Fair Value Disclosure [Abstract]
Assets at Fair Value	1,178	1,545
Cash Equivalents	500	159
Short-term Investments	678	1,386
Other Long-term Assets	0	0
Fair Value, Inputs, Level 2
Assets, Fair Value Disclosure [Abstract]
Assets at Fair Value	3,652	4,129
Cash Equivalents	3,334	3,144
Short-term Investments	318	985
Other Long-term Assets	0	0
Fair Value, Inputs, Level 2 | Time deposits
Assets, Fair Value Disclosure [Abstract]
Assets at Fair Value	925	813
Cash Equivalents	907	769
Short-term Investments	18	44
Other Long-term Assets	0	0
Fair Value, Inputs, Level 2 | U.S. Agency securities
Assets, Fair Value Disclosure [Abstract]
Assets at Fair Value	102	522
Cash Equivalents	100	150
Short-term Investments	2	372
Other Long-term Assets	0	0
Fair Value, Inputs, Level 2 | Commercial paper and bonds
Assets, Fair Value Disclosure [Abstract]
Assets at Fair Value	451	820
Cash Equivalents	153	251
Short-term Investments	298	569
Other Long-term Assets	0	0
Fair Value, Inputs, Level 2 | Money market funds
Assets, Fair Value Disclosure [Abstract]
Assets at Fair Value	2,174	1,974
Cash Equivalents	2,174	1,974
Short-term Investments	0	0
Other Long-term Assets	0	0
Fair Value, Inputs, Level 3 | Non-marketable preferred stock
Assets, Fair Value Disclosure [Abstract]
Assets at Fair Value	11	10
Cash Equivalents	0	0
Short-term Investments	0	0
Other Long-term Assets	$ 11	$ 10