ACQUISITIONS (Details 2) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011
KA Steel [Member]
Business Acquisition [Line Items]
Business Acquisition, Pro Forma Revenue	$ 2,462.6	$ 2,351.5
Business Acquisition, Pro Forma Net Income (Loss)	160.1	240.0
Business Acquisition, Pro Forma Earnings Per Share, Basic	$ 2.00	$ 3.00
Business Acquisition, Pro Forma Earnings Per Share, Diluted	$ 1.98	$ 2.97
SunBelt [Member]
Business Acquisition [Line Items]
Business Acquisition, Pro Forma Revenue		1,987.4
Business Acquisition, Pro Forma Net Income (Loss)		$ 140.6
Business Acquisition, Pro Forma Earnings Per Share, Basic		$ 1.76
Business Acquisition, Pro Forma Earnings Per Share, Diluted		$ 1.74

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The pro forma basic net income per share for a period as if the business combination or combinations had been completed at the beginning of a period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(2)-(3)

-URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463

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+ References

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The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

+ References

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The pro forma revenue for a period as if the business combination or combinations had been completed at the beginning of the period.

+ References

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