Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands		Aug. 31, 2017	May 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets		$ 9,079	$ 8,326
Liabilities		935	1,727
Derivative Instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	[1]	9,079	8,326
Liabilities	[1]	342	1,142
Contingent consideration obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	[2]	593	585
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets		9,079	8,326
Liabilities		342	1,142
Significant Other Observable Inputs (Level 2) | Derivative Instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets	[1]	9,079	8,326
Liabilities	[1]	342	1,142
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities		593	585
Significant Unobservable Inputs (Level 3) | Contingent consideration obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	[2]	$ 593	$ 585

[1] The fair value of our derivative instruments 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 N - 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 probability weighted cash flow approach based on management's projections of future cash flows of the acquired business. The fair value measurement was based on Level 3 inputs not observable in the market.