Other (Income) Expense, Net (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Feb. 28, 2018	Feb. 28, 2017	Feb. 28, 2018	Feb. 28, 2017
Other Income And Expenses [Abstract]
Royalty expense, net	$ 148	$ 744	$ 238	$ 2,080
(Income) related to unconsolidated equity affiliates	(313)	(242)	(830)	(779)
Other (income) expense, net	$ (165)	$ 502	$ (592)	$ 1,301