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Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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No definition available.

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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.

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

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Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount of increase (decrease) of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of impairment loss resulting from write-down of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit to fair value.

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Description of the Business and Summary of Significant Accounting Policies - Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Goodwill
Goodwill	$ 397,470	$ 745,158
Equity-Based Compensation
Compensation expense for stock options	27,100	22,800	$ 15,200
OmniSource
Goodwill
Cumulative goodwill impairment charges	341,300
Goodwill decrease due to tax benefit related to the normal amortization of the component	6,400
Metals Recycling Operations \| OmniSource
Goodwill
Goodwill	109,039	456,727
Metals Recycling Operations \| Butler Flat Roll Division, Structural and Rail Division, and Engineered Bar Division
Goodwill
Goodwill	95,000	95,000
Metals Recycling Operations \| Asset impairment charges \| OmniSource
Impairment of Goodwill and Indefinite Lived Intangible Assets
Goodwill impairment charge	341,300
Metals Recycling Operations \| Asset impairment charges \| Trade names
Impairment of Goodwill and Indefinite Lived Intangible Assets
Indefinite-lived intangible assets impairment charge	68,500
Steel Operations \| The Techs
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