Summary of Tax Effects on Each Component of OCI (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2017	Nov. 30, 2016	Nov. 30, 2017	Nov. 30, 2016
Components Of Other Comprehensive Income Loss [Line Items]
Other comprehensive income (loss), before tax	$ (1,984)	$ (5,470)	$ 16,881	$ (5,047)
Other comprehensive income (loss), tax	1,285	(395)	173	(858)
Other comprehensive income (loss)	(699)	(5,865)	17,054	(5,905)
Foreign Currency Translation
Components Of Other Comprehensive Income Loss [Line Items]
Other comprehensive income (loss), before tax	1,511	(7,517)	17,383	(8,182)
Other comprehensive income (loss)	1,511	(7,517)	17,383	(8,182)
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	(3,495)	2,047	(502)	3,135
Other comprehensive income (loss), tax	1,285	(395)	179	(858)
Other comprehensive income (loss)	$ (2,210)	$ 1,652	$ (323)	$ 2,277