Other Expense (Income), Net (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Nov. 30, 2016	Nov. 30, 2015	Nov. 30, 2016	Nov. 30, 2015
Other Income And Expenses [Abstract]
Royalty expense, net	$ 581	$ 174	$ 1,336	$ 163
(Income) related to unconsolidated equity affiliates	(324)	(473)	(537)	(951)
Other expense (income), net	$ 257	$ (299)	$ 799	$ (788)