Summary of Each Component of Other Comprehensive Income or Loss (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Aug. 31, 2013	Aug. 31, 2012
Before-Tax
Foreign currency translation, before tax	$ (486)	$ 3,908
Pension liability adjustment, before tax		(255)
Cash flow hedges, before tax	4,820	1,224
Other comprehensive income, before tax	4,334	4,877
Tax
Foreign currency translation, tax
Pension liability adjustment, tax		83
Cash flow hedges, tax	(1,469)	(240)
Other comprehensive income, tax	(1,469)	(157)
Net-of-tax
Foreign currency translation, net-of-tax	(486)	3,908
Pension liability adjustment, net-of-tax		(172)
Cash flow hedges, net-of-tax	3,351	984
Other comprehensive income, net-of-tax	$ 2,865	$ 4,720