Summary of Tax Effects on Each Component of OCI (Detail) - USD ($) $ in Thousands	3 Months Ended
	Aug. 31, 2017	Aug. 31, 2016
Components Of Other Comprehensive Income Loss [Line Items]
Other comprehensive income (loss), before tax	$ 18,865	$ 423
Other comprehensive income (loss), tax	(1,112)	(463)
Other comprehensive income (loss)	17,753	(40)
Foreign Currency Translation
Components Of Other Comprehensive Income Loss [Line Items]
Other comprehensive income (loss), before tax	15,872	(665)
Other comprehensive income (loss)	15,872	(665)
Pension Liability Adjustment
Components Of Other Comprehensive Income Loss [Line Items]
Other comprehensive income (loss), tax	(6)
Other comprehensive income (loss)	(6)
Cash Flow Hedges
Components Of Other Comprehensive Income Loss [Line Items]
Other comprehensive income (loss), before tax	2,993	1,088
Other comprehensive income (loss), tax	(1,106)	(463)
Other comprehensive income (loss)	$ 1,887	$ 625