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 Statement of Financial Accounting Standard (FAS)

-Number 159

-Paragraph 18

-Subparagraph f

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 18

-Paragraph 20

-Subparagraph a (1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: 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

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

Basis Of Presentation (Details) (USD $)	May 09, 2011 Joint Venture Transactions [Member] ArtiFlex [Member]	Mar. 01, 2011 Joint Venture Transactions [Member] ClarkDietrich [Member]	Feb. 29, 2012 Joint Venture Transactions [Member] Spartan Steel Coating, LLC [Member]	Feb. 29, 2012 Joint Venture Transactions [Member] Worthington Nitin Cylinders Limited [Member]	Feb. 29, 2012 Metal Framing [Member]	Feb. 29, 2012 Steel Processing [Member]	Feb. 29, 2012 Steel Processing [Member] Other MMI Steel Processing Assets [Member]
Basis Of Presentation [Line Items]
Percent of controlling interest by the Company			52.00%	60.00%
Percent of interest by unconsolidated affiliates	50.00%	25.00%
Carrying value of asset group					$ 10,985,000	$ 4,272,000	$ 4,450,000