Fair Value Measurements Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Millions	May. 31, 2015	May. 31, 2014
Assets, Fair Value Disclosure [Abstract]
Cash	$ 615	$ 780
Assets at Fair Value	5,932	5,149
Cash and Cash Equivalents	3,852	2,220
Short-term Investments	2,072	2,922
Other Long-term Assets	8	7
Fair Value, Inputs, Level 1 [Member] | U.S. Treasury securities
Assets, Fair Value Disclosure [Abstract]
Assets at Fair Value	869	1,137
Cash and Cash Equivalents	225	151
Short-term Investments	644	986
Other Long-term Assets	0	0
Fair Value, Inputs, Level 2 [Member]
Assets, Fair Value Disclosure [Abstract]
Assets at Fair Value	4,440	3,225
Cash and Cash Equivalents	3,012	1,289
Short-term Investments	1,428	1,936
Other Long-term Assets	0	0
Fair Value, Inputs, Level 2 [Member] | Time deposits
Assets, Fair Value Disclosure [Abstract]
Assets at Fair Value	684	227
Cash and Cash Equivalents	684	227
Short-term Investments	0	0
Other Long-term Assets	0	0
Fair Value, Inputs, Level 2 [Member] | U.S. Agency securities
Assets, Fair Value Disclosure [Abstract]
Assets at Fair Value	976	1,027
Cash and Cash Equivalents	110	25
Short-term Investments	866	1,002
Other Long-term Assets	0	0
Fair Value, Inputs, Level 2 [Member] | Commercial paper and bonds
Assets, Fair Value Disclosure [Abstract]
Assets at Fair Value	914	959
Cash and Cash Equivalents	352	25
Short-term Investments	562	934
Other Long-term Assets	0	0
Fair Value, Inputs, Level 2 [Member] | Money market funds
Assets, Fair Value Disclosure [Abstract]
Assets at Fair Value	1,866	1,012
Cash and Cash Equivalents	1,866	1,012
Short-term Investments	0	0
Other Long-term Assets	0	0
Fair Value, Inputs, Level 3 [Member] | Non-marketable preferred stock
Assets, Fair Value Disclosure [Abstract]
Assets at Fair Value	8	7
Cash and Cash Equivalents	0	0
Short-term Investments	0	0
Other Long-term Assets	$ 8	$ 7