Fair Value - Assets Measured at Fair Value on Non-Recurring Basis (Detail) - Fair Value, Nonrecurring - USD ($)		Nov. 30, 2023	May 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure		$ 0	$ 2,693,000
Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure			2,693,000
Long Lived Assets Held and Used
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[1]		70,000
Long Lived Assets Held and Used | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[1]		70,000
Long Lived Assets Held for Sale
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[2]		2,623,000
Long Lived Assets Held for Sale | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure	[2]		$ 2,623,000

[1] Comprised of certain assets associated with a capital project at our Building Products facility in Jefferson, Ohio which were written down to their estimated salvage value of $70.

[2] Comprised of the following: (a) idled equipment at the manufacturing facility in Taylor, Michigan; and (b) the net assets of our former toll processing facility in Cleveland, Ohio.