Fair Value Totals and Balance Sheet Classification for Derivatives Designated as Hedges (Detail) (Long-term Debt, Designated as Hedging Instrument, Euro denominated long-term debt, USD $) In Thousands, unless otherwise specified	Nov. 30, 2013	May 31, 2013
Long-term Debt | Designated as Hedging Instrument | Euro denominated long-term debt
Derivatives, Fair Value [Line Items]
Fair value liability	$ 1,242	$ 2,004