Summary of Tax Effects on Each Component of OCI (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2016	Nov. 30, 2015	Nov. 30, 2016	Nov. 30, 2015
Components Of Other Comprehensive Income Loss [Line Items]
Other comprehensive loss, before tax	$ (5,470)	$ (13,019)	$ (5,047)	$ (9,966)
Other comprehensive loss, tax	(395)	1,282	(858)	674
Other comprehensive loss	(5,865)	(11,737)	(5,905)	(9,292)
Foreign Currency Translation
Components Of Other Comprehensive Income Loss [Line Items]
Other comprehensive loss, before tax	(7,517)	(9,214)	(8,182)	(7,391)
Other comprehensive loss	(7,517)	(9,214)	(8,182)	(7,391)
Pension Liability Adjustment
Components Of Other Comprehensive Income Loss [Line Items]
Other comprehensive loss, before tax				(8)
Other comprehensive loss				(8)
Cash Flow Hedges
Components Of Other Comprehensive Income Loss [Line Items]
Other comprehensive loss, before tax	2,047	(3,805)	3,135	(2,567)
Other comprehensive loss, tax	(395)	1,282	(858)	674
Other comprehensive loss	$ 1,652	$ (2,523)	$ 2,277	$ (1,893)