Fair Value Measurements - Additional Information (Detail)			9 Months Ended
	Feb. 28, 2014 USD ($)	Feb. 28, 2014 EUR (€)	Feb. 28, 2014 Unsecured Senior Notes	Feb. 28, 2014 Fair Value, Measurements, Recurring Cross-currency swap USD ($)	May 31, 2013 Fair Value, Measurements, Recurring Cross-currency swap USD ($)	Feb. 28, 2014 Fair Value, Measurements, Recurring Foreign currency forward contract USD ($)	May 31, 2013 Fair Value, Measurements, Recurring Foreign currency forward contract USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Foreign currency contracts, fair value of liability				$ 21,099,000	$ 10,048,000		$ 4,751,000
Debt, interest rate			6.70%
Debt, due date			Nov. 01, 2015
Effective euro fixed-rate borrowing	5.31%	5.31%
Notional principal amount of cross-currency swap	150,000,000	125,000,000
Foreign currency forward contract						$ 3,816,000