Description of the Business and Significant Accounting Policies (Details 2) - USD ($) $ in Thousands	9 Months Ended
Sep. 30, 2015	Dec. 31, 2014
Goodwill
Goodwill	$ 740,243	$ 745,158
Omni Source
Goodwill
Goodwill decrease due to tax benefit related to the amortization of the component	4,900
Metals Recycling Operations \| Omni Source
Goodwill
Goodwill	451,812	456,727
Metals Recycling Operations \| Butler Flat Roll Division, Structural and Rail Division, and Engineered Bar Division
Goodwill
Goodwill	95,000	95,000
Steel Operations \| The Techs Operations
Goodwill
Goodwill	142,783	142,783
Steel Operations \| Roanoke Bar Division
Goodwill
Goodwill	29,041	29,041
Steel Operations \| Columbus Flat Roll Division
Goodwill
Goodwill	19,682	19,682
Steel Fabrication Operations \| New Millennium Building Systems
Goodwill
Goodwill	$ 1,925	$ 1,925

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=35741047&loc=d3e13816-109267

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 20

-Section 45

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6388280&loc=d3e13770-109266

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