The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

Subsequent Events - Additional Information (Detail) - Joint Venture Transactions - Worthington Specialty Processing	Mar. 01, 2016	Feb. 29, 2016
Subsequent Event [Line Items]
Percent of interest by unconsolidated affiliates		51.00%
Subsequent Event
Subsequent Event [Line Items]
Percent of interest by unconsolidated affiliates	51.00%
Subsequent Event \| United States Steel Corporation
Subsequent Event [Line Items]
Percent of interest by unconsolidated affiliates	49.00%