Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) (Fair Value, Measurements, Recurring, USD $) In Millions, unless otherwise specified	Nov. 30, 2014	May 31, 2014
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Cash	$ 780	$ 780
Assets at Fair Value	4,719	5,149
Cash and Cash Equivalents	2,273	2,220
Short-term Investments	2,440	2,922
Other Long-term Assets	6	7
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	873	1,137
Cash and Cash Equivalents	25	151
Short-term Investments	848	986
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	3,060	3,225
Cash and Cash Equivalents	1,468	1,289
Short-term Investments	1,592	1,936
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	302	227
Cash and Cash Equivalents	302	227
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	788	1,027
Cash and Cash Equivalents	0	25
Short-term Investments	788	1,002
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	959
Cash and Cash Equivalents	50	25
Short-term Investments	804	934
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	1,116	1,012
Cash and Cash Equivalents	1,116	1,012
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	6	7
Cash and Cash Equivalents	0	0
Short-term Investments	0	0
Other Long-term Assets	$ 6	$ 7