For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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-URI http://asc.fasb.org/extlink&oid=99393423&loc=d3e6404-108592

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Balance Type:	na
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Segment Data - Additional Information (Detail)	12 Months Ended
Segment Data - Additional Information (Detail)	May 31, 2021 JointVenture Segment	May 31, 2020	May 31, 2019
Segment Reporting Information [Line Items]
Number of reportable segments \| Segment	2
Number of joint ventures	9
Joint Venture Transactions
Segment Reporting Information [Line Items]
Number of joint ventures	4
Sales Revenue, Net \| Product Concentration Risk
Segment Reporting Information [Line Items]
Concentration risk percentage	37.00%	32.00%	38.00%
Pressure Cylinders \| Sales Revenue, Net \| Product Concentration Risk
Segment Reporting Information [Line Items]
Concentration risk percentage	35.00%	37.00%	32.00%
Steel Processing \| Sales Revenue, Net \| Product Concentration Risk
Segment Reporting Information [Line Items]
Concentration risk percentage	65.00%	61.00%	65.00%
Worthington Steel \| Steel Processing
Segment Reporting Information [Line Items]
Number of joint ventures	4