Restructuring and Other Income, Net - Schedule of Progression of Liabilities Associated with Restructuring Activities, Combined with Reconciliation to Restructuring and Other Income, Net (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Feb. 28, 2019	Feb. 28, 2018	Feb. 28, 2019	Feb. 28, 2018
Restructuring Cost and Reserve [Line Items]
Beginning Balance			$ 1,116
Expense (income)			1,685
Payments			(1,800)
Adjustments			(50)
Ending Balance	$ 951		951
Net gain on sale of assets			(13,395)
Restructuring and other income, net	(11,176)	$ (3)	(11,710)	$ (7,393)
Early Retirement And Severance
Restructuring Cost and Reserve [Line Items]
Beginning Balance			1,116
Expense (income)			1,379
Payments			(1,522)
Adjustments			(58)
Ending Balance	915		915
Facility Exit And Other Costs
Restructuring Cost and Reserve [Line Items]
Beginning Balance			0
Expense (income)			306
Payments			(278)
Adjustments			8
Ending Balance	$ 36		$ 36