Employee Pension Plans - Additional Information (Detail) $ in Thousands	12 Months Ended
	May 31, 2020 USD ($) DefinedBenefitPlan	May 31, 2019 USD ($)	May 31, 2018 USD ($)
Defined Benefit Plan Disclosure [Line Items]
Estimated net loss	$ 775
Description of investment policy and strategy for the defined benefit plan	The investment policy and strategy for the defined benefit plan is: (i) long-term in nature with liquidity requirements that are anticipated to be minimal due to the projected normal retirement date of the average employee and the current average age of participants;  (ii) to earn nominal returns, net of investment fees, equal to or in excess of the defined benefit plan’s liability growth rate; and (iii) to include a diversified asset allocation of domestic and international equities and fixed income investments.
Employer contribution to defined benifit plan in fiscal 2021	$ 142
Number of planned contributions in fiscal 2021 | DefinedBenefitPlan	11
Expected employer contribution to defined benefit plan during fiscal 2021	$ 1,558
Net periodic pension costs	$ 52	$ 53	$ 141
Discount rate	3.57%	4.02%	3.94%
Austrian Pressure Cylinders
Defined Benefit Plan Disclosure [Line Items]
Accrued liability of unfunded plans included in other liabilities	$ 6,863	$ 7,009
Net periodic pension costs	$ 494	$ 925	$ 601
Assumed salary rate increase	2.75%	2.75%	2.75%
Discount rate	1.65%	1.40%	1.80%