Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Millions	Aug. 31, 2015	May. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash	$ 746	$ 615
Assets at Fair Value	5,417	5,932
Cash and Equivalents	3,246	3,852
Short-term Investments	2,162	2,072
Other Long-term Assets	9	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	1,050	869
Cash and Equivalents	275	225
Short-term Investments	775	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	3,612	4,440
Cash and Equivalents	2,225	3,012
Short-term Investments	1,387	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	616	684
Cash and Equivalents	616	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	872	976
Cash and Equivalents	15	110
Short-term Investments	857	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	685	914
Cash and Equivalents	155	352
Short-term Investments	530	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	1,439	1,866
Cash and Equivalents	1,439	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	9	8
Cash and Equivalents	0	0
Short-term Investments	0	0
Other Long-term Assets	$ 9	$ 8