Restructuring and Other Income, Net - Additional Information (Detail) $ in Thousands	9 Months Ended
	Feb. 28, 2019 USD ($) Facility
Restructuring Cost and Reserve [Line Items]
Net gain on disposal of assets	$ 13,395
Other Non-significant Restructuring Activities
Restructuring Cost and Reserve [Line Items]
Severance expense	204
Facility exit costs reduction	9
Pressure Cylinders
Restructuring Cost and Reserve [Line Items]
Severance expense	89
Net gain on disposal of assets	11,433
Pressure Cylinders | Oil & gas equipment
Restructuring Cost and Reserve [Line Items]
Net gain on disposal of assets	$ 1,962
Number of facilities sold | Facility	2
Pressure Cylinders | AMTROL
Restructuring Cost and Reserve [Line Items]
Severance expense	$ 1,086
Facility exit costs	$ 315