Other Expense, Net (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Feb. 29, 2020	Feb. 28, 2019	Feb. 29, 2020	Feb. 28, 2019
Other Income And Expenses [Abstract]
Royalty (income) expense, net		$ (61)	$ 88	$ (155)	$ 154
(Income) related to unconsolidated equity affiliates		(150)	(133)	(125)	(299)
Pension non-service costs		1,510	372	4,489	1,146
Loss on extinguishment of debt	[1]				3,051
Loss on divestiture	[2]	123		949
Other expense, net		$ 1,422	$ 327	$ 5,158	$ 4,052

[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.