Description of the Business, The Separation, Agreements with Former Parent and Separation Costs, and Basis of Presentation - Additional Information (Detail) $ in Millions	3 Months Ended		6 Months Ended
	Nov. 30, 2024 USD ($) Jointventure	Nov. 30, 2023 USD ($)	Nov. 30, 2024 USD ($) Jointventure	Nov. 30, 2023 USD ($)	Feb. 29, 2024 USD ($)	Dec. 01, 2023 USD ($)
Significant Accounting Policies [Line Items]
Percentage of pro rata distribution common shares						100.00%
Cash distribution made as part of spinoff						$ 150.0
Cash and cash equivalents received as contribution of assets and liabilities					$ 3.8	$ 3.8
Separation costs	$ 0.0	$ 14.9	$ 0.0	$ 18.5
Joint Venture Transactions
Significant Accounting Policies [Line Items]
Number of operating joint ventures | Jointventure	3		3
Serviacero Worthington
Significant Accounting Policies [Line Items]
Number of unconsolidated joint ventures | Jointventure	1		1
Percent of ownership own a noncontrolling interest held in unconsolidated joint venture	50.00%		50.00%
Spartan | Joint Venture Transactions
Significant Accounting Policies [Line Items]
Percent of controlling interest by the Company	52.00%		52.00%
TWB | Joint Venture Transactions
Significant Accounting Policies [Line Items]
Percent of controlling interest by the Company	55.00%		55.00%
WSCP | Joint Venture Transactions
Significant Accounting Policies [Line Items]
Percent of controlling interest by the Company	63.00%		63.00%
WSP | Joint Venture Transactions
Significant Accounting Policies [Line Items]
Percent of controlling interest by the Company	51.00%		51.00%