Other Expense, Net (Detail) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Nov. 30, 2019	Nov. 30, 2018	Nov. 30, 2019	Nov. 30, 2018
Other Income And Expenses [Abstract]
Royalty (income) expense, net		$ (360)	$ 63	$ (94)	$ 66
(Income) loss related to unconsolidated equity affiliates		(65)	(48)	25	(166)
Pension non-service costs		1,550	346	2,979	774
Loss on extinguishment of debt	[1]		3,051		3,051
Loss on divestiture	[2]	826		826
Other expense, net		$ 1,951	$ 3,412	$ 3,736	$ 3,725

[1] In connection with the redemption of all our outstanding 2.25% convertible senior notes in November 2018, we recognized a loss of $3.1 million, due to the fair value measurement of the instrument on the date of conversion.

[2] Reflects the loss incurred upon divestiture of a contracting business located in Australia, which had reported through our PCG segment.