Goodwill and Other Long-Lived Assets - Summary of Changes in Carrying Amount of Goodwill (Detail) - USD ($)		12 Months Ended
		May 31, 2022	May 31, 2021
Goodwill [Line Items]
Goodwill, Beginning Balance		$ 351,056,000	$ 321,434,000
Acquisitions and purchase accounting adjustments	[1]	60,547,000	37,876,000
Divestitures	[2]		(13,556,000)
Translation adjustments		(10,134,000)	5,302,000
Goodwill, Ending Balance		401,469,000	351,056,000
Steel Processing
Goodwill [Line Items]
Goodwill, Beginning Balance		20,218,000	19,695,000
Acquisitions and purchase accounting adjustments	[1]	60,115,000	523,000
Translation adjustments		(300,000)
Goodwill, Ending Balance		80,033,000	20,218,000
Consumer products
Goodwill [Line Items]
Goodwill, Beginning Balance	[3]	240,941,000	207,373,000
Acquisitions and purchase accounting adjustments	[1],[3]	432,000	33,568,000
Goodwill, Ending Balance	[3]	241,373,000	240,941,000
Building Products
Goodwill [Line Items]
Goodwill, Beginning Balance	[3]	72,273,000	67,120,000
Translation adjustments	[3]	(6,865,000)	5,153,000
Goodwill, Ending Balance	[3]	65,408,000	72,273,000
Sustainable Energy Solutions
Goodwill [Line Items]
Goodwill, Beginning Balance	[3]	17,624,000	13,690,000
Acquisitions and purchase accounting adjustments	[1],[3]		3,785,000
Translation adjustments	[3]	(2,969,000)	149,000
Goodwill, Ending Balance	[3]	14,655,000	17,624,000
Other
Goodwill [Line Items]
Goodwill, Beginning Balance		0	13,556,000
Divestitures	[2]		(13,556,000)
Goodwill, Ending Balance		$ 0	$ 0

[1] For additional information regarding our acquisitions, refer to “Note Q - Acquisitions”.

[2] Fiscal 2021 divestitures related to the sale of our SCI business located in Pomona, California, the sale of our cryogenic and hydrogen trailer business, including the Theodore, Alabama site, and sale of our cryo-science and microbulk storage unit business.

[3] In connection with the realignment of the our legacy Pressure Cylinders business, as discussed further in “Note P - Segment Data”, the goodwill of our legacy Pressure Cylinders business unit was allocated to the new reporting units on a relative fair value basis.