Fair Value of Foreign Exchange Forward Contracts (Detail) (Derivatives Not Designated as Hedging Instruments, Foreign exchange forward contracts, Other assets, USD $) In Thousands, unless otherwise specified	Feb. 28, 2013	May 31, 2012
Derivatives Not Designated as Hedging Instruments | Foreign exchange forward contracts | Other assets
Derivatives Not Designated as Hedging Instruments
Foreign exchange forward contracts other assets	$ 71	$ 179