Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Millions	Feb. 28, 2017	May 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash	$ 610	$ 774
Assets at Fair Value	6,170	5,467
Cash and Equivalents	4,021	3,138
Short-term Investments	2,139	2,319
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	1,195	1,265
Cash and Equivalents	150	100
Short-term Investments	1,045	1,165
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	4,355	3,418
Cash and Equivalents	3,261	2,264
Short-term Investments	1,094	1,154
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	839	831
Cash and Equivalents	812	827
Short-term Investments	27	4
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	633	679
Cash and Equivalents	260	0
Short-term Investments	373	679
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	854	733
Cash and Equivalents	160	262
Short-term Investments	694	471
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	2,029	1,175
Cash and Equivalents	2,029	1,175
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