v2.4.0.6
Fair Value Measurements - Additional Information (Detail) (USD $)
In Millions, unless otherwise specified
12 Months Ended
May 31, 2012
May 31, 2011
May 31, 2010
Fair Value, Measurement Inputs, Disclosure [Line Items]      
Available-for-sale securities with maturity dates within one year from purchase date $ 1,129 $ 2,253  
Available-for-sale securities with maturity dates over one year and less than five years from purchase date 311 330  
Interest income related to cash and equivalents and short-term investments $ 30 $ 30 $ 30