Summary of Tax Effects of Each Component of Other Comprehensive Income or Loss (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Aug. 31, 2014	Aug. 31, 2013
Before-Tax
Foreign currency translation, before tax	$ (9,592)	$ (486)
Cash flow hedges, before tax	1,543	4,820
Other comprehensive income (loss), before tax	(8,049)	4,334
Tax
Foreign currency translation, tax	0	0
Cash flow hedges, tax	(582)	(1,469)
Other comprehensive income (loss), tax	(582)	(1,469)
Net-of-tax
Foreign currency translation, net-of-tax	(9,592)	(486)
Cash flow hedges, net-of-tax	961	3,351
Other comprehensive income (loss), net-of-tax	$ (8,631)	$ 2,865