Schedule of Financial Assets And Liabilities Measured at Fair Value on Recurring Basis (Detail) (USD $) In Thousands, unless otherwise specified	Feb. 28, 2014		May 31, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	$ 1,839		$ 761
Liabilities	4,964		9,774
Derivative Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	1,839	[1]	761	[1]
Liabilities	4,654	[1]	9,774	[1]
Contingent consideration obligation
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	310	[2]
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	1,839		761
Liabilities	4,654		9,774
Significant Other Observable Inputs (Level 2) | Derivative Contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	1,839	[1]	761	[1]
Liabilities	4,654	[1]	9,774	[1]
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	310
Significant Unobservable Inputs (Level 3) | Contingent consideration obligation
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	$ 310	[2]

[1] The fair value of our derivative contracts is based on the present value of the expected future cash flows considering the risks involved, including non-performance risk, and using discount rates appropriate for the respective maturities. Market observable, Level 2 inputs are used to determine the present value of the expected future cash flows. Refer to "NOTE O - Derivative Instruments and Hedging Activities" for additional information regarding our use of derivative instruments.

[2] The fair value of the contingent consideration obligation is determined using a Monte Carlo simulation model based on management's projections of future EBITDA levels. The fair value measurement is based on significant inputs not observable in the market and thus represents a Level 3 measurement. At each reporting date, we will revalue the contingent consideration obligation to estimated fair value and record changes in fair value as income or expense in our consolidated statement of earnings.