Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring - USD ($) $ in Millions	May 31, 2017	May 31, 2016
Assets, Fair Value Disclosure [Abstract]
Cash	$ 505	$ 774
Assets at Fair Value	6,189	5,467
Cash Equivalents	3,808	3,138
Short-term Investments	2,371	2,319
Other Long-term Assets	10	10
Fair Value, Inputs, Level 1 | U.S. Treasury securities
Assets, Fair Value Disclosure [Abstract]
Assets at Fair Value	1,545	1,265
Cash Equivalents	159	100
Short-term Investments	1,386	1,165
Other Long-term Assets	0	0
Fair Value, Inputs, Level 2
Assets, Fair Value Disclosure [Abstract]
Assets at Fair Value	4,129	3,418
Cash Equivalents	3,144	2,264
Short-term Investments	985	1,154
Other Long-term Assets	0	0
Fair Value, Inputs, Level 2 | Time deposits
Assets, Fair Value Disclosure [Abstract]
Assets at Fair Value	813	831
Cash Equivalents	769	827
Short-term Investments	44	4
Other Long-term Assets	0	0
Fair Value, Inputs, Level 2 | U.S. Agency securities
Assets, Fair Value Disclosure [Abstract]
Assets at Fair Value	522	679
Cash Equivalents	150	0
Short-term Investments	372	679
Other Long-term Assets	0	0
Fair Value, Inputs, Level 2 | Commercial paper and bonds
Assets, Fair Value Disclosure [Abstract]
Assets at Fair Value	820	733
Cash Equivalents	251	262
Short-term Investments	569	471
Other Long-term Assets	0	0
Fair Value, Inputs, Level 2 | Money market funds
Assets, Fair Value Disclosure [Abstract]
Assets at Fair Value	1,974	1,175
Cash Equivalents	1,974	1,175
Short-term Investments	0	0
Other Long-term Assets	0	0
Fair Value, Inputs, Level 3 | Non-marketable preferred stock
Assets, Fair Value Disclosure [Abstract]
Assets at Fair Value	10	10
Cash Equivalents	0	0
Short-term Investments	0	0
Other Long-term Assets	$ 10	$ 10