Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Millions	Feb. 29, 2016	May. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash	$ 809	$ 615
Assets at Fair Value	5,126	5,932
Cash and Equivalents	3,044	3,852
Short-term Investments	2,062	2,072
Other Long-term Assets	20	8
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	1,027	869
Cash and Equivalents	0	225
Short-term Investments	1,027	644
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	3,270	4,440
Cash and Equivalents	2,235	3,012
Short-term Investments	1,035	1,428
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	695	684
Cash and Equivalents	695	684
Short-term Investments	0	0
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	593	976
Cash and Equivalents	50	110
Short-term Investments	543	866
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	697	914
Cash and Equivalents	205	352
Short-term Investments	492	562
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	1,285	1,866
Cash and Equivalents	1,285	1,866
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	20	8
Cash and Equivalents	0	0
Short-term Investments	0	0
Other Long-term Assets	$ 20	$ 8